WO2024095761A1 - Efficient brake system - Google Patents

Efficient brake system Download PDF

Info

Publication number
WO2024095761A1
WO2024095761A1 PCT/JP2023/037542 JP2023037542W WO2024095761A1 WO 2024095761 A1 WO2024095761 A1 WO 2024095761A1 JP 2023037542 W JP2023037542 W JP 2023037542W WO 2024095761 A1 WO2024095761 A1 WO 2024095761A1
Authority
WO
WIPO (PCT)
Prior art keywords
vehicle
wheels
control unit
brake
steering
Prior art date
Application number
PCT/JP2023/037542
Other languages
French (fr)
Japanese (ja)
Inventor
正義 孫
Original Assignee
ソフトバンクグループ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2022181942A external-priority patent/JP2024066362A/en
Application filed by ソフトバンクグループ株式会社 filed Critical ソフトバンクグループ株式会社
Publication of WO2024095761A1 publication Critical patent/WO2024095761A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T1/00—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles
    • B60T1/02—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles acting by retarding wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T1/00—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles
    • B60T1/12—Arrangements of braking elements, i.e. of those parts where braking effect occurs specially for vehicles acting otherwise than by retarding wheels, e.g. jet action
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T7/00—Brake-action initiating means
    • B60T7/12—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B60T8/176—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS
    • B60T8/1761—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS responsive to wheel or brake dynamics, e.g. wheel slip, wheel acceleration or rate of change of brake fluid pressure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/18—Conjoint control of vehicle sub-units of different type or different function including control of braking systems
    • B60W10/184—Conjoint control of vehicle sub-units of different type or different function including control of braking systems with wheel brakes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/20—Conjoint control of vehicle sub-units of different type or different function including control of steering systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/02—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to ambient conditions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/08—Interaction between the driver and the control system
    • B60W50/14—Means for informing the driver, warning the driver or prompting a driver intervention
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D17/00—Means on vehicles for adjusting camber, castor, or toe-in
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D9/00—Steering deflectable wheels not otherwise provided for

Definitions

  • the present invention relates to an efficient brake system.
  • Patent Document 1 describes a brake device that changes the braking force by controlling the strength of the regenerative braking force.
  • the present invention aims to provide a brake that can decelerate a vehicle more quickly and in a shorter distance.
  • An efficient brake system includes at least a pair of wheels positioned approximately symmetrically on the left and right of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, and a control unit that acquires or generates information related to the deceleration of the vehicle, and when the information is acquired or generated, the control unit controls the steering means so that the right wheel of the pair of wheels faces left and the left wheel faces right, or the right wheel faces right and the left wheel faces left, relative to the traveling direction of the vehicle.
  • One aspect of the present invention allows the vehicle to decelerate faster and over a shorter distance.
  • FIG. 1 is a diagram showing an example of a system configuration of a vehicle 1 equipped with an efficient brake system according to a first embodiment.
  • FIG. 2 is a diagram illustrating an example of the configuration of a control unit 10 according to the present embodiment.
  • FIG. 1 is a diagram illustrating an example of an efficient brake system according to an embodiment of the present invention.
  • FIG. 1 is a diagram illustrating an example of an efficient brake system according to an embodiment of the present invention.
  • 4 is a flowchart showing an example of a processing procedure of a vehicle 1 equipped with an efficient brake system.
  • FIG. 2 is a diagram comparing the efficiency brake of the present embodiment with a conventional brake.
  • FIG. 4 is a flowchart showing an example of a processing procedure of a vehicle 1 equipped with the efficient brake system according to the present embodiment.
  • 4 is a diagram illustrating an example of acceleration data when a collision accident occurs in this embodiment.
  • FIG. FIG. 11 is a diagram showing an example of a system configuration of a vehicle equipped with an efficient brake system according to a third embodiment.
  • FIG. 4 is a diagram showing an example of an operation mode of an efficiency brake.
  • FIG. 4 is a diagram showing an example of an operation mode of an efficiency brake.
  • FIG. 4 is a diagram showing an example of an operation mode of an efficiency brake.
  • 4 is a flowchart showing an example of a processing procedure of a vehicle equipped with an efficient brake system.
  • FIG. 13 is a diagram showing an example of a system configuration of a vehicle equipped with a brake system according to a fourth embodiment.
  • FIG. 11 is an explanatory diagram showing an example of a selection operation of the type of brake.
  • 4 is a flowchart showing an example of a processing procedure of a vehicle equipped with a brake system.
  • a figure showing an example of the system configuration of a vehicle 1 equipped with an efficient brake system according to the fifth embodiment. 4 is a flowchart showing an example of a processing procedure of a vehicle 1 equipped with the efficient brake system according to the present embodiment.
  • 3A to 3C are diagrams illustrating the control of the steering angle of the wheels 30 by the steering means 20 in this embodiment.
  • 3A to 3C are diagrams illustrating the control of the steering angle of the wheels 30 by the steering means 20 in this embodiment.
  • 2 is a diagram illustrating an example of the relationship between the speed of the vehicle 1 and the steering angle of the wheels 30 in this embodiment.
  • FIG. 4A to 4C are diagrams illustrating the control of the steering angle of the wheels 30 while the vehicle is traveling along a curve in this embodiment.
  • 4A to 4C are diagrams illustrating the control of the steering angle of the wheels 30 while the vehicle is traveling along a curve in this embodiment.
  • 5 is a diagram showing an example of pattern data of the steering angle of the wheels 30 in the present embodiment.
  • FIG. 1 is a diagram showing an example of a system configuration of a vehicle 1 equipped with an efficient brake system according to this embodiment.
  • the vehicle 1 shown in Fig. 1 includes a control unit 10, a steering means 20, wheels 30, a first sensor 40, and a second sensor 50.
  • the vehicle 1 may also include various configurations constituting a conventional vehicle.
  • the vehicle 1 may have an automatic driving function that assists in automatic driving of the vehicle 1 in addition to a manual driving function that allows a driver to drive the vehicle 1, and each mode may be arbitrarily selected.
  • the control unit 10 can cause the steering means 20 to control the steering angle of the wheels 30 using various information acquired from inside and outside the vehicle 1. For example, the control unit 10 instructs the steering means 20 on the steering angle of the wheels 30 based on information detected by the first sensor 40 and/or the second sensor 50. At this time, the control unit 10 may acquire information related to the deceleration of the vehicle 1 from the first sensor 40. The control unit 10 may also generate information related to the deceleration based on the information acquired from the first sensor 40 and/or the second sensor 50.
  • the steering means 20 can individually control the steering angle of each wheel 30 based on instructions received from the control unit 10.
  • the steering means 20 includes steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 30Ar, 30Al, 30Br, and 30Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 30Ar, 30Al, 30Br, and 30Bl.
  • the vehicle 1 is equipped with at least a pair of wheels 30, which are arranged approximately symmetrically on the left and right sides of the vehicle 1.
  • the vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 30A (30Ar and 30Al) and a pair of left and right rear wheels 30B (30Br and 30Bl).
  • the wheels 30 may be equipped with hub motors. Hub motors are also called in-wheel motors (IWM). By installing hub motors on all four wheels, the movement of each wheel 30 can be controlled individually, which is preferable for achieving efficient braking that changes the angle of the wheels to slow down the vehicle.
  • IWM in-wheel motors
  • the first sensor 40 detects information related to braking. For example, the first sensor 40 detects that the driver has stepped on the brake pedal and transmits the detected information to the control unit 10.
  • the second sensor 50 may be any of a variety of sensors mounted on the vehicle 1.
  • the second sensor 50 may be a speed sensor or an acceleration sensor.
  • the second sensor 50 transmits the detected information to the control unit 10.
  • FIG. 2 is a diagram showing an example of the configuration of the control unit 10 according to this embodiment.
  • the control unit 10 includes, for example, a processor 12 and a memory 14.
  • the processor 12 controls the operation of the entire vehicle 1.
  • the processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller.
  • the processor 12 functions as a control unit that controls the operation of the entire vehicle 1 by executing programs stored in the memory 14.
  • the memory 14 stores various programs and data executed by the processor 12.
  • the memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
  • volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory)
  • non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
  • the various data includes, for example, pattern data on the steering angles of each of the four wheels 30Ar, 30Al, 30Br, and 30Bl when using the efficient brake.
  • FIGS. 3 and 4 are diagrams showing an example of an efficient brake system in this embodiment.
  • Efficient braking is a method of decelerating a vehicle 1 in which at least a pair of left and right wheels can be steered individually by controlling the steering angle of the pair of left and right wheels. For example, in a vehicle 1 in which all four wheels can be steered, the steering angles of the four wheels can be controlled individually to decelerate the vehicle.
  • the steering angle of all four wheels can be freely controlled. Normally, when decelerating a vehicle, the brakes are used to reduce the rotational speed of the wheels through friction, but in this embodiment, the ability to change the steering angle of all four wheels is utilized to control the steering angle of the wheels to counteract the moment in the direction of travel.
  • the control unit 10 uses the steering means 20 to control the steering angle of the pair of front wheels 30A and the pair of rear wheels 30B so that they each form a "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle of the right wheel 30Ar of the pair of front wheels 30A to face left and the left wheel 30Al to face right. The control unit 10 also uses the steering means 20 to control the steering angle of the right wheel 30Br of the pair of rear wheels 30B to face left and the left wheel 30Bl to face right.
  • the control unit 10 uses the steering means 20 to control the steering angle so that the pair of front wheels 30A and the pair of rear wheels 30B form an inverted "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle so that, of the pair of front wheels 30A, the right wheel 30Ar faces right and the left wheel 30Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that, of the pair of rear wheels 30B, the right wheel 30Br faces right and the left wheel 30Bl faces left.
  • the pair of left and right wheels 30A, 30B are turned inward to narrow the side in the direction of travel, or turned outward to widen the side in the direction of travel, thereby increasing the frictional force between the contact surface of the wheels 30 and the ground, thereby achieving deceleration.
  • the steering angle of the wheels 30 it is possible to adjust the coefficient of friction between the wheels 30 and the ground, and thereby adjust the frictional force.
  • the control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 30A form a "V" shape and the rear wheels 30B form an inverted “V” shape.
  • the control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 30A form an inverted "V” shape and the rear wheels 30B form an inverted "V” shape.
  • the control unit 10 may control the steering means 20 so that the angle between the traveling direction of the vehicle 1 and the steering angle of the right wheel 30Ar or 30Br of the pair of wheels 30A or 30B is approximately the same as the angle between the traveling direction of the vehicle 1 and the steering angle of the left wheel 30Al or 30Bl.
  • the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 30Ar or 30Br and the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 30Al or 30Bl are approximately the same. This makes the frictional forces acting on the left and right wheels approximately the same, which is expected to stabilize steering during deceleration.
  • the control unit 10 may also set the steering angle of each wheel 30 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 50. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 30 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
  • the control unit 10 may control the steering means 20 so that the steering angle of each pair of wheels 30A or 30B relative to the traveling direction of the vehicle 1 increases as the speed of the vehicle 1 decreases.
  • control unit 10 may control the steering means 20 so as not to change the steering angle of each wheel 30 even if it detects or generates information related to deceleration.
  • a conventional brake mechanism when traveling at high speed, a conventional brake mechanism is used for deceleration, but when traveling at a low speed below a predetermined threshold, such as 30 km/h, an efficient brake may be activated. Also, the lower the speed, the greater the angle of the wheels relative to the direction of travel may be, thereby increasing the frictional force at lower speeds. This makes it possible to achieve both stable driving and efficient deceleration.
  • control unit 10 may control the steering means 20 so that the steering angle of each of the pair of wheels 30A or 30B is increased relative to the traveling direction of the vehicle 1. This is expected to reduce the risk of multiple rear-end collisions by activating an efficient brake in the event of an accident such as a rear-end collision, and stopping the vehicle 1 in a short distance.
  • FIG. 5 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
  • the control unit 10 determines whether information related to deceleration has been acquired or generated while the vehicle 1 is traveling (step S101). For example, the control unit 10 may determine whether information related to deceleration of the vehicle 1 has been acquired from the first sensor 40. The control unit 10 may also determine whether information related to deceleration has been generated based on information acquired from the first sensor 40 and/or the second sensor 50.
  • step S101: No If the control unit 10 has not acquired or generated information regarding deceleration (step S101: No), the vehicle continues traveling.
  • control unit 10 If the control unit 10 has acquired or generated information related to deceleration (step S101: Yes), it activates the efficiency brake. For example, it uses the steering means 20 to set and control the steering angle of each wheel 30 so that the steering angle is as shown in FIG. 3 or FIG. 4 (step S102).
  • the control unit 10 activates the efficiency brake (S102) while the vehicle 1 is not stopped and information regarding deceleration is being acquired or generated (step S103: No).
  • control unit 10 releases the operation of the efficiency brake and controls the steering means 20 to return the steering angle of the wheels 30 to the original direction and to the same direction as the traveling direction (step S104).
  • FIG. 6 is a diagram comparing the efficient brake of this embodiment with a conventional brake.
  • FIG. 6(A) is a diagram showing the brake mechanism of a conventional two-wheel drive vehicle (front-wheel drive vehicle).
  • a two-wheel drive vehicle front-wheel drive vehicle
  • FIG. 6(B) is a diagram showing a conventional brake mechanism for a four-wheel drive vehicle.
  • a four-wheel drive vehicle has a mechanism for decelerating all four drive wheels.
  • a hub motor can brake all four wheels.
  • a four-wheel drive vehicle can obtain twice the deceleration power of a two-wheel drive vehicle, so it can stop the vehicle 1 in approximately half the distance compared to a two-wheel drive vehicle.
  • FIG. 6(C) shows the efficient brake of this embodiment.
  • the efficient brake also decelerates the vehicle by tilting the tires in a V-shape. This provides four times the deceleration power of a two-wheel drive vehicle, meaning that the vehicle 1 can be stopped in approximately one-quarter the distance compared to a two-wheel drive vehicle.
  • the vehicle can be decelerated more quickly and over a shorter distance.
  • Second Embodiment There is a need to stop the vehicle in a particularly short distance when it is necessary to prevent an accident, such as when avoiding a collision or rear-end collision, or when an erroneous operation has been performed.
  • An object of the present invention is to provide a brake system that prevents accidents from occurring.
  • An efficient brake system according to one embodiment of the present invention comprises at least a pair of wheels positioned approximately symmetrically on the left and right sides of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a sensor for detecting the acceleration of the vehicle, and a control unit for controlling the steering means to change the steering angle of each wheel relative to the direction of travel of the vehicle when the acceleration of the vehicle satisfies a first condition.
  • the present invention provides a brake system that can prevent accidents from occurring.
  • FIG. 7 is a diagram showing an example of the system configuration of a vehicle 1 equipped with the efficient brake system according to this embodiment.
  • the vehicle 1 shown in FIG. 7 includes a control unit 10, a steering means 20, wheels 30, a first sensor 40, a second sensor 50, and a braking means 60.
  • the vehicle 1 may also include various configurations that constitute a conventional vehicle.
  • the vehicle 1 may also have an automatic driving function that assists in automatic driving of the vehicle 1, and each driving mode may be freely selected.
  • the control unit 10 can cause the steering means 20 to control the steering angle of the wheels 30 using various information acquired from inside and outside the vehicle 1.
  • the steering angle is the angle of the wheels 30 relative to the traveling direction of the vehicle 1.
  • the control unit 10 instructs the steering means 20 on the steering angle of the wheels 30 based on information detected by the first sensor 40 and/or the second sensor 50.
  • the control unit 10 can acquire information on the deceleration of the vehicle 1 due to braking from the first sensor 40.
  • the control unit 10 can also acquire information on the speed or acceleration of the vehicle 1 from the second sensor 50.
  • the steering means 20 can individually control the steering angle of each wheel 30 based on instructions received from the control unit 10.
  • the steering means 20 includes steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 30Ar, 30Al, 30Br, and 30Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 30Ar, 30Al, 30Br, and 30Bl.
  • the vehicle 1 has at least a pair of wheels 30, which are arranged approximately symmetrically on the left and right sides of the vehicle 1.
  • the vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 30A (30Ar and 30Al) and a pair of left and right rear wheels 30B (30Br and 30Bl).
  • Each wheel 30 may be equipped with a hub motor, which is an electric motor mounted inside the hub. Note that even if the motor itself is not mounted inside the hub, a motor (in-wheel motor (IWM)) in which the driving force of the electric motor is transmitted directly to the wheel may be installed.
  • IWM in-wheel motor
  • the first sensor 40 detects information related to braking by the braking means 60. For example, the first sensor 40 detects that the braking means 60 has applied the brakes to the wheels 30 due to the driver's brake operation or automatic driving control, and transmits the detected information to the control unit 10.
  • the second sensor 50 may be any of a variety of sensors mounted on the vehicle 1.
  • the second sensor 50 may be a speed sensor or an acceleration sensor.
  • the second sensor 50 transmits the detected information to the control unit 10.
  • the braking means 60 can brake each of the wheels 30 based on instructions received from the control unit 10.
  • the braking means 60 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 30Ar, 30Al, 30Br, and 30Bl, and brake actuators (not shown) connected to the wheel cylinders.
  • the brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary magnitude and supplies it to the wheel cylinders to brake each of the wheels 30Ar, 30Al, 30Br, and 30Bl.
  • the control unit 10 detects that the driver has stepped on the brake pedal, it may issue an instruction to the braking means 60 to brake the wheels 30, or may issue an instruction to the braking means 60 to brake the wheels 30 by automatic driving control.
  • the configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2, and therefore is not shown in the figure.
  • the control unit 10 includes, for example, a processor 12 and a memory 14 .
  • the processor 12 controls the operation of the entire vehicle 1.
  • the processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller.
  • the processor 12 functions as a control unit that controls the operation of the entire vehicle 1 by executing programs stored in the memory 14.
  • the memory 14 stores various programs and data executed by the processor 12.
  • the memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or a flash memory.
  • the various data include, for example, pattern data of the steering angles of each of the four wheels 30Ar, 30Al, 30Br, and 30Bl when using the efficiency brake, and condition data for activating the efficiency brake (for example, a vehicle speed threshold value, etc.).
  • the memory 14 stores information on characteristic signals (e.g., pulse signals) that may be included in the acceleration data of the vehicle 1 acquired via the second sensor 50 in the event of an accident, such as sudden acceleration, sudden braking, or sudden steering.
  • characteristic signals e.g., pulse signals
  • FIG. 8 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
  • the control unit 10 acquires information on changes in the speed and acceleration of the vehicle 1 from the second sensor 50 while the vehicle 1 is traveling (step S101).
  • the control unit 10 determines whether the acceleration data includes a signal indicating an accident sign, such as sudden acceleration, sudden braking, or sudden steering (whether the first condition is satisfied) (step S102).
  • the control unit 10 makes the determination by comparing the acceleration data with the characteristics of the acceleration data that indicate an accident sign stored in the memory 14.
  • the control unit 10 may also make the determination by determining whether the absolute value of the acceleration of the vehicle 1 exceeds a predetermined threshold.
  • the determination may also be made using a machine learning model that has learned the characteristics of the acceleration data that indicate an accident sign.
  • step S102 If it is determined that the acceleration data includes a signal indicating an accident (step S102: YES), the control unit 10 outputs an instruction to the steering means 20 to control the steering angle of the wheels 30 (step S103).
  • the vehicle 1 can individually control the steering angles of all four wheels 30Ar, 30Al, 30Br, and 30Bl by the corresponding steering means 20Ar, 20Al, 20Br, and 20Bl.
  • the braking means 20 decelerates by braking the rotation of the wheels 30, but the steering means 20 decelerates by changing the steering angle of each of the four wheels to cancel out the moment in the traveling direction.
  • the control unit 10 may use the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form a "V" shape when viewed from above the vehicle 1. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 30Ar faces left and the left wheel 30Al faces right. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 30Br faces left and the left wheel 30Bl faces right.
  • control unit 10 may use the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form an inverted V shape when viewed from above the vehicle 1. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 30Ar faces right and the left wheel 30Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 30Br faces right and the left wheel 30Bl faces left.
  • the steering angle may be set so that the front wheels 30Ar, 30Al form a "V" shape and the rear wheels 30Br, 30Bl form an inverted “V” shape, or the steering angle may be set so that the front wheels 30Ar, 30Al form an inverted "V” shape and the rear wheels 30Br, 30Bl form an "V” shape.
  • the control unit 10 may control the steering means 20 so that the steering angle of the wheels 30 corresponds to the acceleration of the vehicle 1. Specifically, the greater the angle of the wheels 30 relative to the direction of travel (i.e., the narrower the side in the direction of travel in the case of a "V" shape, and the wider the side in the direction of travel in the case of an inverted “V” shape), the greater the frictional force with the ground, and the greater the deceleration effect.
  • the control unit 10 can shorten the time until deceleration by controlling the angle of the wheels 30 relative to the traveling direction to be larger as the acceleration of the vehicle 1 is greater. This is expected to prevent the occurrence of multiple rear-end collisions by stopping the vehicle 1 in a short distance in the event of an accident such as a rear-end collision.
  • the control unit 10 may also derive the steering angle using acceleration data that indicates signs of an accident stored in the memory 14. In this way, accidents can be prevented or suppressed by detecting signs of an accident using acceleration data and responding accordingly. Furthermore, when an accident occurs (when the occurrence of an accident is detected by acceleration data), the vehicle 1 can be immediately stopped to prevent or suppress the accident from expanding or becoming a chain reaction.
  • the control unit 10 may also control the steering means 20 so that the steering angles of the right-side wheels 30Ar, 30Br and the left-side wheels 30Al, 30Bl are substantially the same.
  • the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Ar or 30Br and the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Al or 30Bl are substantially the same. This makes the frictional forces acting on the left and right wheels substantially the same, which is expected to result in stable steering during deceleration.
  • control unit 10 when the control unit 10 determines that a spin has occurred based on the characteristics of the acceleration data, it may set the orientation of each wheel 30 so that it faces inward or outward at a predetermined angle relative to the direction of rotation of the spin. In other words, by setting the orientation of each wheel 30 so that it is tilted by ⁇ (a predetermined angle) in a direction perpendicular to the center of gravity of the vehicle, a frictional force against the rotation may be generated to prevent the spin.
  • FIG. 9 is a diagram illustrating an example of an acceleration waveform (G) and a spin waveform (S) when a collision accident occurs while a vehicle is traveling. Note that this diagram is quoted from an accident analysis report by Data Tech Institute of Fundamental Theories Co., Ltd. (http://re-www.datatec.jp/product/report/kaiseki_2.html).
  • the acceleration waveform G in the section indicated by (A) in the diagram indicates that the brakes were applied to avoid the collision.
  • the acceleration waveform G in section (B) indicates that a collision (side collision) occurred.
  • the spin waveform C indicates that a spin occurred due to a side collision.
  • the acceleration waveform G in section (D) indicates that another collision occurred.
  • the control unit 10 may use acceleration waveforms and spin waveforms such as those shown in FIG. 9 to control the wheels 30 in response to the event that has occurred. For example, when an acceleration waveform caused by braking such as that shown in section (A) is detected, the steering means 20 can be controlled to immediately stop the vehicle 1, thereby avoiding a collision. Also, when a spin waveform such as that shown in section (C) is detected, the wheels 30 can be controlled to face inward or outward from the direction of the spin rotation, thereby avoiding a collision caused by a spin.
  • the control unit 10 controls the steering angle of the wheels 30 until the vehicle 1 stops (step S104).
  • step S104 the control unit 10 ends control of the steering means 20 (step S105).
  • the control unit 10 may set the steering angle of each wheel 30 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 50. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 30 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
  • the control unit 10 when the speed or acceleration of the vehicle 1 while the vehicle 1 is traveling meets a predetermined condition that indicates an accident, such as sudden acceleration or deceleration, the control unit 10 outputs an instruction to the steering means 20 to change the steering angle of the wheels 30, canceling the moment in the traveling direction and stopping the vehicle 1 as quickly as possible. This makes it possible to prevent accidents such as collisions and rear-end collisions.
  • ABS anti-lock brake system
  • the present invention aims to provide a brake system that can sufficiently shorten the braking distance required to bring the vehicle to a complete stop.
  • the efficient brake system comprises at least a pair of wheels positioned approximately symmetrically on the left and right sides of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a braking means for generating a braking force on the pair of wheels, and a control unit for controlling the steering means and the braking means, and when the control unit determines that one of the wheels is prone to locking during braking, it controls the braking means so that the braking force on the pair of wheels is reduced, and controls the steering means so that the pair of wheels form an approximately V-shape when viewed from above the vehicle.
  • the present invention makes it possible to sufficiently shorten the braking distance required to stop the vehicle.
  • FIG. 10 is a diagram showing an example of the system configuration of a vehicle 1 equipped with an efficient brake system according to this embodiment.
  • the efficient brake system not only controls the brake pressure when any of the wheels tend to lock during braking, but also changes the angle of each wheel to efficiently decelerate the vehicle, thereby preventing the wheels from locking and making it possible to sufficiently shorten the braking distance required to stop the vehicle.
  • the above braking method using the efficient brake system will be referred to as "efficient braking.”
  • the vehicle 1 shown in FIG. 10 includes a control unit 10, a steering means 20, a braking means 30, wheels 40, a first sensor 50, a second sensor 60, and a notification means 70.
  • the vehicle 1 may also include various components constituting a conventional vehicle.
  • the vehicle 1 may also have an automatic driving function that assists in the automatic driving of the vehicle 1, and each driving function may be selectable at will.
  • the control unit 10 performs control related to the efficient brake using various information acquired from inside and outside the vehicle 1. For example, the control unit 10 instructs the steering means 20 on the steering angle of the wheels 40 and instructs the braking means 30 on the braking force of the wheels 40 based on information detected by the first sensor 50 and/or the second sensor 60. At this time, the control unit 10 may obtain information regarding the brakes of the vehicle 1 from the first sensor 50 and information regarding the wheel speed from the second sensor 60 .
  • the steering means 20 can individually control the steering angle of each wheel 40 based on instructions received from the control unit 10.
  • the steering means 20 may be configured to include steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 40Ar, 40Al, 40Br, and 40Bl of the vehicle 1, and each of the steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 40Ar, 40Al, 40Br, and 40Bl.
  • the braking means 30 can brake each of the wheels 40 based on instructions received from the control unit 10.
  • the braking means 30 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 40Ar, 40Al, 40Br, and 40Bl, and brake actuators (not shown) connected to the wheel cylinders.
  • the brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary level and supplies it to the wheel cylinder, thereby braking each of the wheels 40Ar, 40Al, 40Br, and 40Bl.
  • Vehicle 1 has at least one pair of wheels, which are arranged approximately symmetrically on the left and right sides of vehicle 1.
  • vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 40A (40Ar and 40Al) and a pair of left and right rear wheels 40B (40Br and 40Bl).
  • the wheels 40 may be equipped with hub motors.
  • Hub motors are also called in-wheel motors (IWM).
  • IWM in-wheel motors
  • the first sensor 50 detects information related to braking. For example, when the driver operates the brake pedal, the first sensor 50 transmits information indicating the amount of brake pedal operation (i.e., the stroke amount) to the control unit 10.
  • the second sensor 60 may be any of a variety of sensors mounted on the vehicle 1.
  • the second sensor 60 may be configured with a speed sensor, an acceleration sensor, or a wheel speed sensor provided on each of the wheels 40Ar, 40Al, 40Br, and 40Bl.
  • the second sensor 60 transmits information such as the speed, acceleration, and wheel speed of the vehicle 1 that are successively detected to the control unit 10.
  • the notification means 70 issues a specified warning to the driver when the efficient brake is activated.
  • the notification means 70 may be a buzzer or a lamp provided on the instrument panel (not shown). Note that if the vehicle 1 is provided with multiple notification means, these notification means may be activated simultaneously.
  • the configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2 above, and is therefore not shown.
  • the control unit 10 includes, for example, a processor 12 and a memory 14.
  • the processor 12 controls the efficient braking of the vehicle 1.
  • the processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller.
  • the processor 12 functions as a control unit by executing a program stored in the memory 14.
  • the memory 14 stores various programs and data executed by the processor 12.
  • the memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
  • volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory)
  • non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
  • the various data include, for example, steering angle pattern data for each of the four wheels 40Ar, 40Al, 40Br, and 40Bl when using the efficiency brake, and condition data for activating the efficiency brake (for example, vehicle speed and wheel speed thresholds, etc.).
  • 11 to 13 are diagrams showing an example of an operation mode of the efficiency brake in this embodiment.
  • this embodiment it is possible to freely control the steering angles of all four wheels, so efficient braking is achieved by controlling the braking pressure and controlling the steering angles of the wheels to cancel out the moment in the direction of travel.
  • the control unit 10 controls the brake means 30 to control the brake pressure in order to reduce the braking force of the wheels. Furthermore, the control unit 10 controls the steering angle of the pair of front wheels 40A and the pair of rear wheels 40B using the steering means 20 so that they are each shaped like the letter "V" when viewed from above the vehicle, as shown in FIG. 11. That is, the control unit 10 controls the steering angle of the pair of front wheels 40A using the steering means 20 so that the right wheel 40Ar faces left and the left wheel 40Al faces right.
  • the control unit 10 also controls the steering angle of the pair of rear wheels 40B using the steering means 20 so that the right wheel 40Br faces left and the left wheel 40Bl faces right. It should be noted that detection of whether any of the wheels is locking can be achieved, for example, by comparing the wheel speeds detected by wheel speed sensors provided on each wheel 40.
  • FIG. 11 illustrates an example of controlling the steering angle using the steering means 20 so that the pair of front wheels 40A and the pair of rear wheels 40B form a "V" shape when viewed from above the vehicle, but as shown in FIG. 12, for example, the steering angle may be controlled so that the pair of front wheels 40A and the pair of rear wheels 40B form an inverted "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 40Ar of the pair of front wheels 40A faces right and the left wheel 40Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 40Br of the pair of rear wheels 40B faces right and the left wheel 40Bl faces left.
  • control unit 10 may alternate at a predetermined timing between a first steering mode in which the steering angle of the pair of left and right wheels 40A, 40B is controlled so that they form a "V" shape when viewed from above the vehicle, as shown in FIG. 13, and a second steering mode in which the steering angle of the pair of left and right wheels 40A, 40B is controlled so that they form an inverted "V" shape when viewed from above the vehicle.
  • the control unit 10 may derive the timing of switching the steering mode based on various information obtained from the first sensor 50 and the second sensor 60, so that the wheels 40 can be prevented from locking and the maximum braking force can be secured to shorten the braking distance.
  • the brake pressure is not simply controlled, but the pair of left and right wheels 40A, 40B are turned inward to narrow the side in the direction of travel, or turned outward to widen the side in the direction of travel, thereby increasing the frictional force at the contact surface between the wheels 40 and the ground.
  • the control unit 10 can adjust the frictional force between the wheels 40 and the ground by adjusting the steering angle of the wheels 40.
  • the control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 40A form a "V" shape and the rear wheels 40B form an inverted “V” shape.
  • the control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 40A form an inverted "V” shape and the rear wheels 40B form an inverted "V” shape.
  • the control unit 10 may control the steering means 20 so that the angle between the traveling direction of the vehicle 1 and the steering angle of the right wheel 40Ar or 40Br of the pair of wheels 40A or 40B is approximately the same as the angle between the traveling direction of the vehicle 1 and the steering angle of the left wheel 40Al or 40Bl.
  • the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Ar or 40Br and the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Al or 40Bl are approximately the same. This makes the frictional forces acting on the left and right wheels approximately the same, which is expected to stabilize steering during deceleration.
  • the control unit 10 may also set the steering angle of each wheel 40 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 60. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 40 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
  • the control unit 10 may also control the steering means 20 so that the steering angle of each of the pair of wheels 40A or 40B relative to the traveling direction of the vehicle 1 increases as the speed of the vehicle 1 decreases.
  • FIG. 14 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
  • the control unit 10 determines (detects) whether any of the wheels 40 are in a state of locking by comparing the wheel speeds detected by the wheel speed sensors provided on each wheel 40 (step S101).
  • control unit 10 determines that none of the wheels 40 are in a state of locking (step S101: NO), it continues normal operation without activating the efficiency brake.
  • control unit 10 determines that any of the wheels 40 are tending to lock (step S101: YES), it activates the efficiency brake. Specifically, the control unit 10 instructs the brake means 30 to control the brake pressure in order to prevent the wheels 40 from locking (step S102). It also instructs the steering means 20 to control the steering angle of the wheels 40 in the manner shown in any of Figures 11 to 13 (step S103). Furthermore, the control unit 10 issues a predetermined alarm from the notification means 70 to inform the driver that the efficiency brake is being activated (step S104).
  • the control unit 10 activates the efficiency brake (steps S102 ⁇ S103 ⁇ S104) until the vehicle 1 stops (step S105: NO).
  • control unit 10 detects that the vehicle 1 has stopped (step S105: YES), it ends the issuance of the specified alarm, stops the operation of all brakes including the efficiency brakes (step S106), and performs control to return the steering angle of the wheels 40 to the same direction as the traveling direction (step S107), and then ends the processing.
  • controlling the wheel angle rather than simply controlling the brake pressure makes it possible to prevent the wheel from locking and sufficiently shorten the braking distance required to stop the vehicle.
  • An automatic braking device that detects the distance and relative speed between the vehicle and an obstacle ahead, and automatically applies the brakes to suddenly brake the vehicle if the detection result indicates that the vehicle is abnormally close to the obstacle ahead.
  • the above-mentioned automatic braking system is effective in preventing the vehicle from getting too close to an obstacle ahead, but there is a problem in that if the automatic braking system suddenly brakes when there is a vehicle behind, the vehicle behind may not be able to brake in time and may collide with the vehicle behind.
  • the present invention aims to provide a brake system that can perform optimal brake control according to the circumstances surrounding the vehicle.
  • a brake system includes at least a pair of wheels positioned approximately symmetrically on the left and right of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a braking means for generating a braking force on the pair of wheels, a first acquisition unit for acquiring brake operation information related to the brake operation of the vehicle, a second acquisition unit for acquiring ambient environment information related to the ambient environment of the vehicle, and a control unit for controlling the steering means and the braking means, and the control unit selects, based on the brake operation information and the ambient environment information, either a normal brake that controls the braking means to brake the vehicle, or an efficient brake that controls the steering means together with the braking means to brake the vehicle.
  • the present invention makes it possible to perform optimal brake control according to the circumstances surrounding the vehicle.
  • FIG. 15 is a diagram showing an example of the system configuration of a vehicle 1 equipped with a brake system according to this embodiment.
  • the brake system according to this embodiment is capable of operating two types of brakes: a "normal brake” that controls the brake pressure to brake the vehicle, and an “efficient brake” that not only controls the brake pressure but also changes the angle of each wheel to efficiently decelerate and brake the vehicle.
  • the vehicle 1 shown in FIG. 1 includes a control unit 10, a steering means 20, a brake means 30, wheels 40, a first sensor 50, a second sensor 60, and a notification means 70.
  • the vehicle 1 may also include various configurations that configure a conventional vehicle.
  • the vehicle 1 may have an automatic driving function that assists in automatic driving of the vehicle 1, and each driving function may be selected arbitrarily.
  • the control unit 10 performs various controls related to the brakes using various information acquired from inside and outside the vehicle 1. For example, the control unit 10 selects the type of brakes (specifically, normal brakes or efficient brakes) based on the information detected by the first sensor 50 and the second sensor 60, and instructs the steering means 20 on the steering angle of the wheels 40 and instructs the braking means 30 on the braking force of the wheels 40 according to the selected type of brakes.
  • the type of brakes specifically, normal brakes or efficient brakes
  • the steering means 20 can individually control the steering angle of each wheel 40 based on instructions received from the control unit 10.
  • the steering means 20 may be configured to include steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 40Ar, 40Al, 40Br, and 40Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 40Ar, 40Al, 40Br, and 40Bl.
  • the braking means 30 can brake each of the wheels 40 based on instructions received from the control unit 10.
  • the braking means 30 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 40Ar, 40Al, 40Br, and 40Bl, and brake actuators (not shown) connected to the wheel cylinders.
  • the brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary level and supplies it to the wheel cylinder, thereby braking each of the wheels 40Ar, 40Al, 40Br, and 40Bl.
  • Vehicle 1 has at least a pair of wheels (tires), which are arranged approximately symmetrically on the left and right sides of vehicle 1.
  • vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 40A (40Ar and 40Al) and a pair of left and right rear wheels 40B (40Br and 40Bl).
  • the wheels 40 may be equipped with hub motors.
  • Hub motors are also called in-wheel motors (IWM).
  • IWM in-wheel motors
  • the first sensor 50 detects brake operation information related to brake operation.
  • the first sensor 50 is composed of, for example, a brake pedal sensor. When the driver operates the brake pedal, the first sensor 50 transmits brake operation information indicating the amount of brake pedal operation (i.e., the stroke amount) to the control unit (first acquisition unit) 10.
  • the second sensor 60 detects information related to the surrounding environment of the vehicle (in this embodiment, rear vehicle information indicating the distance to the rear vehicle, relative speed, etc.).
  • the second sensor 60 is composed of, for example, a LIDAR (Light Detection And Ranging) sensor, an ultrasonic sonar, and a stereo camera. When the second sensor 60 detects rear vehicle information, it transmits it to the control unit (second acquisition unit) 10.
  • LIDAR Light Detection And Ranging
  • vehicle 1 is equipped with various sensors, including a speed sensor, an accelerator pedal sensor, a shift position sensor, and an acceleration sensor.
  • sensors including a speed sensor, an accelerator pedal sensor, a shift position sensor, and an acceleration sensor.
  • the notification means 70 notifies the outside (such as the driver) of the brake operation status.
  • the notification means 70 is composed of, for example, a buzzer, a lamp or a brake lamp provided on the instrument panel (not shown).
  • the notification means 70 may notify the driver of the presence or absence of the brake operation, the type of brake being operated, etc., by, for example, the color of the lamp, the lighting pattern, a text message, etc.
  • a specific lamp on the instrument panel is displayed as lit in yellow
  • a specific lamp on the instrument panel is displayed as flashing in blue. In this way, by notifying in different ways depending on the type of brake being operated, the driver can accurately grasp the brake being operated.
  • the combination of notification means to be used may be changed depending on the type of brake being operated. Also, the brake operation status may be notified to the rear vehicle, etc. by changing the display mode of the brake lamp depending on the type of brake being operated.
  • the configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2 above, and is therefore not shown.
  • the control unit 10 includes, for example, a processor 12 and a memory 14.
  • the processor 12 controls the brakes of the vehicle 1.
  • the processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller.
  • the processor 12 functions as a control unit by executing a program stored in the memory 14.
  • the memory 14 stores various programs and data executed by the processor 12.
  • the memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
  • volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory)
  • non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
  • the various data include, for example, steering angle patterns that indicate the steering angles of each of the four wheels 40Ar, 40Al, 40Br, and 40Bl when the efficiency brake is activated.
  • the control unit 10 when the control unit 10 selects the efficient brake as the applied brake based on the brake operation information and rear vehicle information, it first controls the brake means 30 to control the brake pressure. Furthermore, the control unit 10 uses the steering means 20 to control the steering angle so that the pair of front wheels 40A and the pair of rear wheels 40B form a "V" shape when viewed from above the vehicle, for example as shown in FIG. 11 above. In other words, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 40Ar of the pair of front wheels 40A faces left and the left wheel 40Al faces right. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 40Br of the pair of rear wheels 40B faces left and the left wheel 40Bl faces right.
  • the steering means 20 is used to control the steering angle so that the pair of front wheels 40A and the pair of rear wheels 40B form a "V" shape when viewed from above the vehicle, but as shown in FIG. 12, the steering angle may be controlled so that the pair of front wheels 40A and the pair of rear wheels 40B form an inverted "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 40Ar of the pair of front wheels 40A faces right and the left wheel 40Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 40Br of the pair of rear wheels 40B faces right and the left wheel 40Bl faces left.
  • the control unit 10 can adjust the frictional force between the wheels 40 and the ground by adjusting the steering angle of the wheels 40.
  • control unit 10 selects the type of brake to be applied so that a rear-end collision from a vehicle behind can also be avoided.
  • control unit 10 selects whether to apply normal brakes or efficient brakes based on the brake operation information obtained from the first sensor 50 and the rear vehicle information obtained from the second sensor 60.
  • control unit 10 determines that there is no risk of being rear-ended by a vehicle behind even if the efficient brake is applied because a sufficient inter-vehicle distance is secured, the control unit 10 selects the efficient brake.
  • control unit 10 determines that there is a high possibility of being rear-ended by a vehicle behind if the efficient brake is applied because a sufficient inter-vehicle distance is not secured, the control unit 10 selects the normal brake. In this way, in this embodiment, it is possible to reliably prevent rear-end collisions from vehicles behind by selecting the type of brake to be applied according to the situation surrounding the vehicle.
  • the criteria for selecting the type of brake can be set or changed as desired, taking into account the probability of a collision accident occurring.
  • the probability of a collision accident occurring can be derived from the inter-vehicle distance and relative speed based on past collision accident cases, and if the derived probability of a collision accident occurring is less than a threshold value, the efficient brake can be selected, whereas if it exceeds the threshold value, the normal brake can be selected.
  • FIG. 17 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with a brake system.
  • the control unit 10 determines whether or not brake operation information has been acquired from the first sensor 50 while the vehicle 1 is traveling (step S101).
  • step S101 NO
  • step S101 YES
  • step S102 rear vehicle information from the second sensor 60
  • the control unit 10 selects the type of brake to be applied based on the brake operation information and rear vehicle information obtained from each sensor (step S103).
  • control unit 10 instructs the brake means 30 to control the brake pressure (step S104).
  • control unit 10 selects the efficient brake, it instructs the brake means 30 to control the brake pressure and instructs the steering means 20 to control the steering angle of the wheels 40 in the manner shown in Figure 11 or Figure 12 (step S105).
  • control unit 10 notifies the driver of the brake operation status (whether the brakes are operating, the type of brakes that are operating, etc.) using the lamps of the notification means 70 (step S106).
  • the control unit 10 continues selecting the type of brake and applying the selected brake until the vehicle 1 stops (step S107: NO).
  • step S107 when the control unit 10 detects that the vehicle 1 has stopped (step S107: YES), it ends the notification of the brake operation status, stops the brake operation (step S108), and ends the process.
  • the brake system according to this embodiment makes it possible to perform optimal brake control according to the circumstances surrounding the vehicle.
  • the type of brake to be applied is selected on the assumption that a vehicle behind is present, but the present invention is not limited to this.
  • the type of brake to be applied may be selected depending on the road surface condition on which the vehicle is traveling.
  • the second sensor 60 in the modified example detects road surface-related information relating to the road surface condition.
  • the second sensor 60 is composed of, for example, a surface temperature sensor, a temperature and humidity sensor, an image camera, etc.
  • road surface-related information indicating the road surface condition for example, unevenness of the road surface, dryness, semi-humidity, wetness, slush, snow accumulation, packed snow, freezing, humidity, air temperature, road surface temperature, etc.
  • the control unit 10 selects whether to apply normal brakes or efficient brakes based on the brake operation information obtained from the first sensor 50 and the road surface-related information obtained from the second sensor 60.
  • control unit 10 selects efficient braking to shorten the braking distance as much as possible, but when the road surface is dry, it selects normal braking. This makes it possible to perform safe and optimal brake control according to the road surface conditions, etc.
  • the second sensor 60 may detect the tire wear state (such as the amount of wear) in addition to the road surface condition.
  • the control unit 10 can select the optimal brake by taking into account not only the road surface condition but also the tire wear state.
  • the optimal brake may be selected by using various information related to the surrounding environment of the vehicle detected by the second sensor 60.
  • control unit 10 may use the steering means 20 to set the steering angle so that the front wheels 40A form a "V" shape and the rear wheels 40B form an inverted “V” shape.
  • control unit 10 may use the steering means 20 to set the steering angle so that the front wheels 40A form an inverted "V” shape and the rear wheels 40B form an inverted "V” shape.
  • the control unit 10 may control the steering means 20 so that the angle between the traveling direction of the vehicle 1 and the steering angle of the right wheel 40Ar or 40Br of the pair of wheels 40A or 40B is approximately the same as the angle between the traveling direction of the vehicle 1 and the steering angle of the left wheel 40Al or 40Bl.
  • the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Ar or 40Br and the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Al or 40Bl are approximately the same. This makes the frictional forces acting on the left and right wheels approximately the same, which is expected to stabilize steering during deceleration.
  • the control unit 10 may also set the steering angle of each wheel 40 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 60. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 40 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
  • the control unit 10 may also control the steering means 20 so that the steering angle of each of the pair of wheels 40A or 40B relative to the traveling direction of the vehicle 1 increases as the speed of the vehicle 1 decreases.
  • the present invention aims to provide an efficient brake system that can appropriately decelerate a vehicle when it changes direction.
  • the efficient brake system comprises at least a pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a sensor that detects changes in the vehicle's traveling direction, and a control unit that controls the steering means so that the steering angle of each wheel becomes an angle that is set according to the change in the traveling direction.
  • the present invention provides an efficient brake system that can appropriately decelerate a vehicle when it changes direction.
  • FIG. 18 is a diagram showing an example of the system configuration of a vehicle 1 equipped with the efficient brake system according to this embodiment.
  • the vehicle 1 shown in FIG. 1 includes a control unit 10, a steering means 20, wheels 30, a first sensor 40, a second sensor 50, and a braking means 60.
  • the vehicle 1 may also include various configurations that constitute a conventional vehicle.
  • the vehicle 1 may also have an automatic driving function that assists in automatic driving of the vehicle 1, and each driving mode may be freely selected.
  • the control unit 10 can cause the steering means 20 to control the steering angle of the wheels 30 using various information acquired from inside and outside the vehicle 1.
  • the steering angle is the angle of the wheels 30 with respect to the traveling direction of the vehicle 1.
  • the control unit 10 instructs the steering means 20 on the steering angle of the wheels 30 based on information detected by the first sensor 40 and/or the second sensor 50.
  • the control unit 10 can acquire information on the deceleration of the vehicle 1 due to braking from the first sensor 40.
  • the control unit 10 can also acquire information on the speed, acceleration, angular velocity, or angular acceleration of the vehicle 1 from the second sensor 50.
  • position information of the vehicle 1 may be acquired from the second sensor 50.
  • the steering means 20 can individually control the steering angle of each wheel 30 based on instructions received from the control unit 10.
  • the steering means 20 includes steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 30Ar, 30Al, 30Br, and 30Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 30Ar, 30Al, 30Br, and 30Bl.
  • the vehicle 1 has at least a pair of wheels 30, which are arranged approximately symmetrically on the left and right sides of the vehicle 1.
  • the vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 30A (30Ar and 30Al) and a pair of left and right rear wheels 30B (30Br and 30Bl).
  • Each wheel 30 may be equipped with a hub motor, which is an electric motor mounted inside the hub. Note that even if the motor itself is not mounted inside the hub, a motor (in-wheel motor (IWM)) in which the driving force of the electric motor is transmitted directly to the wheel may be installed.
  • IWM in-wheel motor
  • the first sensor 40 detects information related to braking by the braking means 60. For example, the first sensor 40 detects that the braking means 60 has applied the brakes to the wheels 30 due to the driver's brake operation or automatic driving control, and transmits the detected information to the control unit 10.
  • the second sensor 50 may be any of various sensors mounted on the vehicle 1.
  • the second sensor 50 may be a speed sensor, an acceleration sensor, a gyro sensor, or a wheel speed sensor that measures the number of rotations of the wheels 30, a steering angle sensor that measures the angle of the steering wheel, a yaw rate sensor that detects the speed at which the vehicle 1 turns, a GPS sensor, or the like.
  • the second sensor 50 transmits the detected information to the control unit 10.
  • the braking means 60 can brake each of the wheels 30 based on instructions received from the control unit 10.
  • the braking means 60 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 30Ar, 30Al, 30Br, and 30Bl, and brake actuators (not shown) connected to the wheel cylinders.
  • the brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary magnitude and supplies it to the wheel cylinders to brake each of the wheels 30Ar, 30Al, 30Br, and 30Bl.
  • the control unit 10 detects that the driver has stepped on the brake pedal, it may issue an instruction to the braking means 60 to brake the wheels 30, or may issue an instruction to the braking means 60 to brake the wheels 30 by automatic driving control.
  • the configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2, and therefore is not shown in the figure.
  • the control unit 10 includes, for example, a processor 12 and a memory 14 .
  • the processor 12 controls the operation of the entire vehicle 1.
  • the processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller.
  • the processor 12 functions as a control unit that controls the operation of the entire vehicle 1 by executing programs stored in the memory 14.
  • the memory 14 stores various programs and data executed by the processor 12.
  • the memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or a flash memory.
  • the various data include, for example, pattern data of the steering angles of each of the four wheels 30Ar, 30Al, 30Br, and 30Bl when using the efficiency brake, and condition data for activating the efficiency brake (for example, a vehicle speed threshold value, etc.).
  • FIG. 19 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
  • the control unit 10 acquires information regarding the traveling direction of the vehicle 1 while the vehicle 1 is traveling (step S101). Furthermore, the control unit 10 determines whether the traveling direction of the vehicle 1 has changed based on the acquired information (step S102). The control unit 10 can determine whether the traveling direction has changed based on, for example, a change in angular velocity detected by a gyro sensor. The control unit 10 may also acquire position information of the vehicle 1 from a GPS sensor and acquire information on the change in the traveling direction from information on the road on which the vehicle 1 is traveling. Note that, in this embodiment, an example is shown in which the efficiency brake is activated when a change in the traveling direction of the vehicle 1 is detected, but this is not intended to be limiting. For example, the efficiency brake may be activated when a change in the traveling direction of the vehicle 1 is detected and the speed of the vehicle exceeds a set reference speed (for example, xx km/h).
  • a set reference speed for example, xx km/h
  • step S102 If the control unit 10 does not detect a change in the traveling direction of the vehicle 1 (step S102: NO), the control unit 10 proceeds to step S103, performs normal driving control, and returns to step S101. On the other hand, if the control unit 10 detects a change in the traveling direction of the vehicle 1 (step S102: YES), it outputs an instruction to the steering means 20 to control the steering angle of the wheels 30 (step S104) and activates the efficiency brake.
  • FIGS. 20 and 21 are diagrams for explaining the control of the steering angle of the wheels 30 by the steering means 20.
  • the vehicle 1 can individually control the steering angles of all four wheels 30Ar, 30Al, 30Br, and 30Bl by the corresponding steering means 20Ar, 20Al, 20Br, and 20Bl.
  • the braking means 20 decelerates by braking the rotation of the wheels 30, but the steering means 20 decelerates by changing the steering angle of each of the four wheels to cancel out the moment in the traveling direction.
  • the control unit 10 uses the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form a "V" shape when viewed from above the vehicle 1. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 30Ar faces left and the left wheel 30Al faces right. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 30Br faces left and the left wheel 30Bl faces right. In this way, by using the steering means 20 to turn the pair of left and right wheels 30A, 30B inward to narrow the traveling direction side, the frictional force between the contact surface of the wheels 30 and the ground is increased, achieving deceleration. Conversely, the control unit 10 may use the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form an inverted V shape when viewed from above the vehicle 1 (see FIG. 21).
  • the control unit 10 also controls the steering means 20 so that the steering angle of the wheels 30 is an angle that corresponds to the change in the traveling direction of the vehicle 1.
  • the greater the steering angle ⁇ of the wheels 30 relative to the traveling direction i.e., the narrower the traveling direction side in the case of a "V" shape, and the wider the traveling direction side in the case of an inverted "V" shape
  • the steering angle ⁇ of the wheels may be controlled according to the magnitude of the curve to change the degree of deceleration of the vehicle 1. For example, as shown in FIG.
  • the steering angle ⁇ of the wheels 30 may be set large to increase the degree of deceleration, while as shown in FIG. 24, when the curvature C of the curve is small, the steering angle ⁇ of the wheels 30 may be set small to reduce the degree of deceleration.
  • the present invention is not limited to such settings.
  • the control unit 10 controls the steering angle ⁇ of the wheels 30 relative to the traveling direction to be larger as the speed of the vehicle 1 is slower.
  • the steering angle ⁇ of the wheels 30 relative to the traveling direction may be controlled to be larger as the speed of the vehicle 1 is faster.
  • the relationship between the speed of the vehicle 1 and the steering angle ⁇ of the wheels 30 is not limited to this, and can be set so as to enable efficient and stable braking of the vehicle 1.
  • the control unit 10 may derive an appropriate steering angle using pattern data stored in the memory 14 that indicates the relationship between the amount of change in the traveling direction of the vehicle 1, the speed of the vehicle 1, and the steering angle of the wheels 30.
  • FIG. 25 is a diagram showing an example of pattern data of the steering angle of the wheels 30 that is appropriate for efficiently stopping the vehicle 1.
  • the control unit 10 uses the first pattern data D1 to set the steering angle ⁇ 2 of the wheels 30Ar, 30Br located on the outside (i.e., the right side) to be greater than the steering angle ⁇ 1 of the wheels 30Al, 30Bl located on the inside (i.e., the left side).
  • the control unit 10 uses the second pattern data D2 to set the steering angle ⁇ 1 of the inner wheels 30Ar, 30Br to remain unchanged (“KEEP"), while changing the steering angle ⁇ 2 of the outer wheels 30Al, 30Bl ("CHANGE").
  • the control unit 10 may control the steering means 20 so that the steering angle of the outer wheels 30Ar, 30Br and the steering angle of the inner wheels 30Al, 30Bl are substantially the same.
  • the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Ar or 30Br and the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Al or 30Bl are substantially the same. This makes the frictional forces acting on the left and right wheels substantially the same, and is expected to stabilize steering during deceleration.
  • the control unit 10 determines whether the information regarding the vehicle 1 stopping or deceleration has been released (step S105). If the information regarding the vehicle 1 stopping or deceleration has not been released (step S105: NO), the control unit 10 returns to step S104 and controls the steering angle of the wheels 30. On the other hand, if the vehicle 1 has stopped or the information regarding deceleration has been released (step S105: YES), the control unit 10 stops the operation of the efficiency brake by controlling the steering means 20 so that the steering angle of the wheels 30 is in the same direction as the traveling direction (step S106), and ends the process.
  • control unit 10 may set the steering angle of each wheel 30 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on the information detected by the second sensor 50. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 30 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
  • control unit 10 when the control unit 10 detects a change in the traveling direction, for example when the vehicle 1 approaches a curve, it outputs an instruction to the steering means 20 to change the steering angle of the wheels 30 to an angle corresponding to the change in the traveling direction of the vehicle 1, and controls the vehicle to decelerate by canceling the moment in the traveling direction.
  • This makes it possible to efficiently decelerate the vehicle 1 in accordance with the change in the traveling direction, while avoiding slipping due to sudden deceleration.

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Automation & Control Theory (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mathematical Physics (AREA)
  • Human Computer Interaction (AREA)
  • Regulating Braking Force (AREA)

Abstract

This efficient brake system comprises: at least a pair of wheels positioned substantially symmetrically on the left and right of a vehicle; a steering means capable of individually controlling a steering angle of each of the pair of wheels; and a control unit which acquires or generates information relating to deceleration of the vehicle, and which, when the information has been acquired or generated, controls the steering means such that, relative to a direction of progress of the vehicle, the right-side wheel of the pair of wheels faces left and the left-side wheel faces right, or the right-side wheel faces right and the left-side wheel faces left.

Description

効率ブレーキシステムEfficient Brake System 関連出願の相互参照CROSS-REFERENCE TO RELATED APPLICATIONS
　本出願は、２０２２年１０月３１日に出願された日本特許出願番号２０２２－１７４９９４号、２０２２年１１月１４日に出願された日本特許出願番号２０２２－１８１９４２号、２０２２年１１月２１日に出願された日本特許出願番号２０２２－１８５６８７号、２０２２年１２月１４日に出願された日本特許出願番号２０２２－１９９５４８号及び２０２３年２月９日に出願された日本特許出願番号２０２３－０１８７１２号に基づくもので、ここにその記載内容を援用する。 This application is based on Japanese Patent Application No. 2022-174994 filed on October 31, 2022, Japanese Patent Application No. 2022-181942 filed on November 14, 2022, Japanese Patent Application No. 2022-185687 filed on November 21, 2022, Japanese Patent Application No. 2022-199548 filed on December 14, 2022, and Japanese Patent Application No. 2023-018712 filed on February 9, 2023, the contents of which are incorporated herein by reference.
　本発明は、効率ブレーキシステムに関する。 The present invention relates to an efficient brake system.
　従来、２輪駆動車や４輪駆動車では、駆動輪のタイヤの回転を減速して車両を停車、減速させる。例えば、特許文献１には、回生ブレーキ力の強さを制御することで、ブレーキ力を変更させるブレーキ装置について記載されている。
　［先行技術文献］
　［特許文献］
　［特許文献１］特開２０２０－１４５８７４号公報 Conventionally, in two-wheel drive vehicles and four-wheel drive vehicles, the rotation of the tires of the drive wheels is decelerated to stop or decelerate the vehicle. For example, Patent Document 1 describes a brake device that changes the braking force by controlling the strength of the regenerative braking force.
[Prior Art Literature]
[Patent Documents]
[Patent Document 1] JP 2020-145874 A
　２輪駆動車において、前輪駆動車における後輪、後輪駆動車における前輪は、単に駆動輪についてくるのみであり、制動の対象ではない。そのため、タイヤの回転速度が落ちても、タイヤは進行方向へ進む力が働いており、減速のパワーが弱い。 In two-wheel drive vehicles, the rear wheels in a front-wheel drive vehicle, and the front wheels in a rear-wheel drive vehicle, simply follow the driving wheels and are not subject to braking. Therefore, even if the rotational speed of the tires slows down, the tires are still acting with a force moving in the direction of travel, so the deceleration power is weak.
　そこで、本発明は、車両の減速をより早く、より短い距離で行うことのできるブレーキを提供することを目的とする。 The present invention aims to provide a brake that can decelerate a vehicle more quickly and in a shorter distance.
　本発明の一態様に係る効率ブレーキシステムは、車両の左右に略対称に位置する少なくとも一対の車輪と、一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、車両の減速に関する情報を取得又は生成する制御部であって、情報を取得又は生成したとき、車両の進行方向に対して、一対の車輪のうち右側の車輪を左向きかつ左側の車輪を右向き、又は、右側の車輪を右向きかつ左側の車輪を左向きとなるように、操舵手段を制御する、制御部と、を備える。 An efficient brake system according to one aspect of the present invention includes at least a pair of wheels positioned approximately symmetrically on the left and right of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, and a control unit that acquires or generates information related to the deceleration of the vehicle, and when the information is acquired or generated, the control unit controls the steering means so that the right wheel of the pair of wheels faces left and the left wheel faces right, or the right wheel faces right and the left wheel faces left, relative to the traveling direction of the vehicle.
　本発明の一態様によれば、車両の減速をより早く、より短い距離で行うことができる。 One aspect of the present invention allows the vehicle to decelerate faster and over a shorter distance.
第１実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。1 is a diagram showing an example of a system configuration of a vehicle 1 equipped with an efficient brake system according to a first embodiment. 本実施形態に係る制御部１０の構成の一例を示す図である。FIG. 2 is a diagram illustrating an example of the configuration of a control unit 10 according to the present embodiment. 本実施形態における効率ブレーキシステムの一例を示す図である。FIG. 1 is a diagram illustrating an example of an efficient brake system according to an embodiment of the present invention. 本実施形態における効率ブレーキシステムの一例を示す図である。FIG. 1 is a diagram illustrating an example of an efficient brake system according to an embodiment of the present invention. 効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。4 is a flowchart showing an example of a processing procedure of a vehicle 1 equipped with an efficient brake system. 本実施形態の効率ブレーキと従来のブレーキとを比較した図である。FIG. 2 is a diagram comparing the efficiency brake of the present embodiment with a conventional brake. 第２実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。A figure showing an example of a system configuration of a vehicle 1 equipped with an efficient brake system according to a second embodiment. 本実施形態に係る効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。4 is a flowchart showing an example of a processing procedure of a vehicle 1 equipped with the efficient brake system according to the present embodiment. 本実施形態における衝突事故が発生した際の加速度データを例示する図である。4 is a diagram illustrating an example of acceleration data when a collision accident occurs in this embodiment. FIG. 第３実施形態に係る効率ブレーキシステムを搭載する車両のシステム構成の一例を示す図である。FIG. 11 is a diagram showing an example of a system configuration of a vehicle equipped with an efficient brake system according to a third embodiment. 効率ブレーキの作動態様の一例を示す図である。FIG. 4 is a diagram showing an example of an operation mode of an efficiency brake. 効率ブレーキの作動態様の一例を示す図である。FIG. 4 is a diagram showing an example of an operation mode of an efficiency brake. 効率ブレーキの作動態様の一例を示す図である。FIG. 4 is a diagram showing an example of an operation mode of an efficiency brake. 効率ブレーキシステムを搭載した車両の処理手順の一例を示すフローチャートである。4 is a flowchart showing an example of a processing procedure of a vehicle equipped with an efficient brake system. 第４実施形態に係るブレーキシステムを搭載する車両のシステム構成の一例を示す図である。FIG. 13 is a diagram showing an example of a system configuration of a vehicle equipped with a brake system according to a fourth embodiment. ブレーキの種類の選択動作の一例を示す説明図である。FIG. 11 is an explanatory diagram showing an example of a selection operation of the type of brake. ブレーキシステムを搭載した車両の処理手順の一例を示すフローチャートである。4 is a flowchart showing an example of a processing procedure of a vehicle equipped with a brake system. 第５実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。A figure showing an example of the system configuration of a vehicle 1 equipped with an efficient brake system according to the fifth embodiment. 本実施形態に係る効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。4 is a flowchart showing an example of a processing procedure of a vehicle 1 equipped with the efficient brake system according to the present embodiment. 本実施形態における操舵手段２０による車輪３０の操舵角の制御を説明する図である。3A to 3C are diagrams illustrating the control of the steering angle of the wheels 30 by the steering means 20 in this embodiment. 本実施形態における操舵手段２０による車輪３０の操舵角の制御を説明する図である。3A to 3C are diagrams illustrating the control of the steering angle of the wheels 30 by the steering means 20 in this embodiment. 本実施形態における車両１の速度と車輪３０の操舵角との関係を例示する図である。2 is a diagram illustrating an example of the relationship between the speed of the vehicle 1 and the steering angle of the wheels 30 in this embodiment. FIG. 本実施形態におけるカーブ走行中の車輪３０の操舵角の制御を説明する図である。4A to 4C are diagrams illustrating the control of the steering angle of the wheels 30 while the vehicle is traveling along a curve in this embodiment. 本実施形態におけるカーブ走行中の車輪３０の操舵角の制御を説明する図である。4A to 4C are diagrams illustrating the control of the steering angle of the wheels 30 while the vehicle is traveling along a curve in this embodiment. 本実施形態における車輪３０の操舵角のパターンデータの例を示す図である。5 is a diagram showing an example of pattern data of the steering angle of the wheels 30 in the present embodiment. FIG.
　添付図面を参照して、本発明の実施形態について説明する。なお、各図において、同一の符号を付したものは、同一又は同様の構成を有する。 An embodiment of the present invention will be described with reference to the attached drawings. In each drawing, the same reference numerals denote the same or similar configurations.
（１）第１実施形態
　図１は、本実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。図１に示す車両１は、制御部１０と、操舵手段２０と、車輪３０と、第１センサ４０と、第２センサ５０とを備える。また、図示省略するが、従来の車両を構成する種々の構成を備えてもよい。車両１は、運転者が車両１を運転する手動運転機能の他に、車両１の自動運転を支援する自動運転機能を有し、各モードを任意に選択できることとしてもよい。 (1) First embodiment Fig. 1 is a diagram showing an example of a system configuration of a vehicle 1 equipped with an efficient brake system according to this embodiment. The vehicle 1 shown in Fig. 1 includes a control unit 10, a steering means 20, wheels 30, a first sensor 40, and a second sensor 50. Although not shown, the vehicle 1 may also include various configurations constituting a conventional vehicle. The vehicle 1 may have an automatic driving function that assists in automatic driving of the vehicle 1 in addition to a manual driving function that allows a driver to drive the vehicle 1, and each mode may be arbitrarily selected.
　制御部１０は、車両１の内外から取得した種々の情報を用いて、操舵手段２０に車輪３０の操舵角を制御させることができる。例えば、制御部１０は、第１センサ４０及び／又は第２センサ５０が検知した情報に基づいて、操舵手段２０に対して、車輪３０の操舵角を指示する。このとき、制御部１０は、第１センサ４０から車両１の減速に関する情報を取得してよい。また、制御部１０は、第１センサ４０及び／又は第２センサ５０から取得した情報に基づいて減速に関する情報を生成してよい。 The control unit 10 can cause the steering means 20 to control the steering angle of the wheels 30 using various information acquired from inside and outside the vehicle 1. For example, the control unit 10 instructs the steering means 20 on the steering angle of the wheels 30 based on information detected by the first sensor 40 and/or the second sensor 50. At this time, the control unit 10 may acquire information related to the deceleration of the vehicle 1 from the first sensor 40. The control unit 10 may also generate information related to the deceleration based on the information acquired from the first sensor 40 and/or the second sensor 50.
　操舵手段２０は、制御部１０から受け取った指示に基づいて、車輪３０それぞれの操舵角を個別に制御することができる。本実施形態において、操舵手段２０としては、車両１が備える４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌそれぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌを備え、各操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌが各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌの操舵角を個別に設定し、制御できるように構成されてよい。 The steering means 20 can individually control the steering angle of each wheel 30 based on instructions received from the control unit 10. In this embodiment, the steering means 20 includes steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 30Ar, 30Al, 30Br, and 30Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 30Ar, 30Al, 30Br, and 30Bl.
　車輪３０として、車両１は、少なくとも一対の車輪を備え、車両１の左右に略対称に配置される。本実施形態において、車両１は４輪で構成され、左右一対の前輪３０Ａ（３０Ａｒと３０Ａｌ）と、左右一対の後輪３０Ｂ（３０Ｂｒと３０Ｂｌ）とを有する。 The vehicle 1 is equipped with at least a pair of wheels 30, which are arranged approximately symmetrically on the left and right sides of the vehicle 1. In this embodiment, the vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 30A (30Ar and 30Al) and a pair of left and right rear wheels 30B (30Br and 30Bl).
　車輪３０にはハブモーター（HUB motor）が搭載されてもよい。ハブモーターは、インホイールモーター（ＩＷＭ：In Wheel Motor）と呼ばれることもある。４輪全てにハブモーターが搭載されることで、車輪３０それぞれの動きを個別に制御することができるようになるため、車輪の角度を変えて減速する効率ブレーキを実現させる上で好ましい。 The wheels 30 may be equipped with hub motors. Hub motors are also called in-wheel motors (IWM). By installing hub motors on all four wheels, the movement of each wheel 30 can be controlled individually, which is preferable for achieving efficient braking that changes the angle of the wheels to slow down the vehicle.
　第１センサ４０は、ブレーキに関する情報を検知する。例えば、第１センサ４０は、運転者がブレーキペダルを踏んだことを検知し、検知した情報を制御部１０に送信する。 The first sensor 40 detects information related to braking. For example, the first sensor 40 detects that the driver has stepped on the brake pedal and transmits the detected information to the control unit 10.
　第２センサ５０は、車両１に搭載される種々のセンサであってよい。例えば、第２センサ５０は、速度センサ又は加速度センサであってよい。第２センサ５０は検知した情報を制御部１０に送信する。 The second sensor 50 may be any of a variety of sensors mounted on the vehicle 1. For example, the second sensor 50 may be a speed sensor or an acceleration sensor. The second sensor 50 transmits the detected information to the control unit 10.
　図２は、本実施形態に係る制御部１０の構成の一例を示す図である。制御部１０は、例えば、プロセッサ１２とメモリ１４とを含む。 FIG. 2 is a diagram showing an example of the configuration of the control unit 10 according to this embodiment. The control unit 10 includes, for example, a processor 12 and a memory 14.
　プロセッサ１２は、車両１全体の動作を制御する。プロセッサ１２として、例えば、ＣＰＵ（Central Processing Unit）、ＭＰＵ（Micro Processing Unit）、ＦＰＧＡ（Field Programmable Gate Array）又はマイコン（マイクロコントローラ）等を用いることができる。プロセッサ１２は、メモリ１４に記憶されたプログラムを実行することで、車両１全体の動作を制御する制御部として機能する。 The processor 12 controls the operation of the entire vehicle 1. The processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller. The processor 12 functions as a control unit that controls the operation of the entire vehicle 1 by executing programs stored in the memory 14.
　メモリ１４は、プロセッサ１２により実行される各種プログラムや各種データを記憶する。メモリ１４には、例えば、ＲＯＭ（Read Only Memory）やＲＡＭ（Random Access Memory）等の揮発性記憶装置、及びＨＤＤ（Hard Disk Drive）やフラッシュメモリ等の不揮発性記憶装置が含まれ得る。 The memory 14 stores various programs and data executed by the processor 12. The memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
　各種データとして、例えば、効率ブレーキを用いる際の、４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌそれぞれの操舵角度のパターンデータを含む。 The various data includes, for example, pattern data on the steering angles of each of the four wheels 30Ar, 30Al, 30Br, and 30Bl when using the efficient brake.
　図３及び図４は、本実施形態における効率ブレーキシステムの一例を示す図である。効率ブレーキは、少なくとも左右一対の車輪のそれぞれを個別に操舵可能な車両１において、左右一対の車輪の操舵角を制御することにより減速する方法である。例えば、４輪の全てで操舵可能な車両１において、４輪の操舵角をそれぞれ個別に制御して減速してよい。 FIGS. 3 and 4 are diagrams showing an example of an efficient brake system in this embodiment. Efficient braking is a method of decelerating a vehicle 1 in which at least a pair of left and right wheels can be steered individually by controlling the steering angle of the pair of left and right wheels. For example, in a vehicle 1 in which all four wheels can be steered, the steering angles of the four wheels can be controlled individually to decelerate the vehicle.
　車輪３０にハブモーターが搭載されると、４輪全ての操舵角をそれぞれ自由自在に制御することができる。通常車両を減速する際はブレーキで車輪の回転速度を摩擦によって弱めるが、本実施形態においては、４輪全ての操舵角を変更できることを利用し、進行方向に向かうモーメントを打ち消すような車輪の操舵角制御を行う。 When hub motors are installed on the wheels 30, the steering angle of all four wheels can be freely controlled. Normally, when decelerating a vehicle, the brakes are used to reduce the rotational speed of the wheels through friction, but in this embodiment, the ability to change the steering angle of all four wheels is utilized to control the steering angle of the wheels to counteract the moment in the direction of travel.
　例えば、図３に示すとおり、４輪の全てで操舵可能な車両１において、制御部１０は操舵手段２０を用いて、一対の前輪３０Ａ及び一対の後輪３０Ｂを、車両上面から見て、それぞれ「ハ」の字になるよう操舵角を制御する。すなわち、制御部１０は操舵手段２０を用いて、一対の前輪３０Ａのうち、右側の車輪３０Ａｒを左向きかつ左側の車輪３０Ａｌを右向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、一対の後輪３０Ｂのうち、右側の車輪３０Ｂｒを左向きかつ左側の車輪３０Ｂｌを右向きとなるよう操舵角を制御する。 For example, as shown in FIG. 3, in a vehicle 1 in which all four wheels can be steered, the control unit 10 uses the steering means 20 to control the steering angle of the pair of front wheels 30A and the pair of rear wheels 30B so that they each form a "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle of the right wheel 30Ar of the pair of front wheels 30A to face left and the left wheel 30Al to face right. The control unit 10 also uses the steering means 20 to control the steering angle of the right wheel 30Br of the pair of rear wheels 30B to face left and the left wheel 30Bl to face right.
　また、図４に示すとおり、４輪の全てで操舵可能な車両１において、制御部１０は操舵手段２０を用いて、車両上面から見て、一対の前輪３０Ａ及び一対の後輪３０Ｂを、車両上面から見て、それぞれ逆「ハ」の字になるよう操舵角を制御する。すなわち、制御部１０は操舵手段２０を用いて、一対の前輪３０Ａのうち、右側の車輪３０Ａｒを右向きかつ左側の車輪３０Ａｌを左向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、一対の後輪３０Ｂのうち、右側の車輪３０Ｂｒを右向きかつ左側の車輪３０Ｂｌを左向きとなるよう操舵角を制御する。 Also, as shown in FIG. 4, in a vehicle 1 in which all four wheels can be steered, the control unit 10 uses the steering means 20 to control the steering angle so that the pair of front wheels 30A and the pair of rear wheels 30B form an inverted "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle so that, of the pair of front wheels 30A, the right wheel 30Ar faces right and the left wheel 30Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that, of the pair of rear wheels 30B, the right wheel 30Br faces right and the left wheel 30Bl faces left.
　このように、本実施形態の効率ブレーキシステムにおいては、左右一対の車輪３０Ａ，３０Ｂを内側に向けて進行方向側を狭くしたり、外側に向けて進行方向側を広くしたりすることで、車輪３０と地面の接触面の摩擦力を増大させ、減速を実現させる。このとき、車輪３０の操舵角を調整することで、車輪３０と地面の間の摩擦係数を調整し、摩擦力を調整することが可能となる。 In this way, in the efficient brake system of this embodiment, the pair of left and right wheels 30A, 30B are turned inward to narrow the side in the direction of travel, or turned outward to widen the side in the direction of travel, thereby increasing the frictional force between the contact surface of the wheels 30 and the ground, thereby achieving deceleration. At this time, by adjusting the steering angle of the wheels 30, it is possible to adjust the coefficient of friction between the wheels 30 and the ground, and thereby adjust the frictional force.
　また、制御部１０は操舵手段２０を用いて、前輪３０Ａを「ハ」の字、後輪３０Ｂを逆「ハ」の字となるように操舵角を設定してもよい。また、制御部１０は操舵手段２０を用いて、前輪３０Ａを逆「ハ」の字、後輪３０Ｂを「ハ」の字となるように操舵角を設定してもよい。 The control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 30A form a "V" shape and the rear wheels 30B form an inverted "V" shape. The control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 30A form an inverted "V" shape and the rear wheels 30B form an inverted "V" shape.
　制御部１０は、一対の車輪３０Ａ又は３０Ｂのうち、車両１の進行方向と右側の車輪３０Ａｒ又は３０Ｂｒの操舵角との間の角度と、車両１の進行方向と左側の車輪３０Ａｌ又は３０Ｂｌの操舵角との間の角度とが、略同一となるように操舵手段２０を制御してよい。すなわち、車両１の進行方向と車輪３０Ａｒ又は３０Ｂｒの回転面とによって形成される角度と、車両１の進行方向と車輪３０Ａｌ又は３０Ｂｌの回転面とによって形成される角度とが、略同一となるように操舵手段２０を制御してよい。これにより、左右の車輪に働く摩擦力が略同一となり、減速時の操舵が安定することが期待できる。 The control unit 10 may control the steering means 20 so that the angle between the traveling direction of the vehicle 1 and the steering angle of the right wheel 30Ar or 30Br of the pair of wheels 30A or 30B is approximately the same as the angle between the traveling direction of the vehicle 1 and the steering angle of the left wheel 30Al or 30Bl. In other words, the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 30Ar or 30Br and the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 30Al or 30Bl are approximately the same. This makes the frictional forces acting on the left and right wheels approximately the same, which is expected to stabilize steering during deceleration.
　また、制御部１０は、車両１の速度及び／又は加速度に応じて、車輪３０それぞれの操舵角を設定してもよい。例えば、制御部１０は、第２センサ５０が検知した情報に基づいて速度及び／又は加速度を取得する。そして、車両１の速度及び／又は加速度に適した操舵角を導出し、導出された操舵角になるよう操舵手段２０を制御する。このとき、メモリ１４に記憶された、速度及び／又は加速度と車輪３０それぞれの操舵角とのパターンデータを用いて、操舵角を導出してよい。これにより、車両１の速度及び／又は加速度に応じて、効率良く減速することが可能となる。 The control unit 10 may also set the steering angle of each wheel 30 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 50. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 30 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
　制御部１０は、車両１の速度が小さいほど、車両１の進行方向に対して一対の車輪３０Ａ又は３０Ｂそれぞれの操舵角が大きくなるように操舵手段２０を制御してよい。 The control unit 10 may control the steering means 20 so that the steering angle of each pair of wheels 30A or 30B relative to the traveling direction of the vehicle 1 increases as the speed of the vehicle 1 decreases.
　また、制御部１０は、車両１の速度が所定の閾値よりも大きいとき、減速に関する情報を検知又は生成しても、車輪３０それぞれの操舵角を変化させないように操舵手段２０を制御してよい、 In addition, when the speed of the vehicle 1 is greater than a predetermined threshold, the control unit 10 may control the steering means 20 so as not to change the steering angle of each wheel 30 even if it detects or generates information related to deceleration.
　このように、車両１が高速に走行しているとき、減速は従来のブレーキ機構を用いるものとし、例えば毎時３０ｋｍなど、所定の閾値以下の速度で低速に走行しているときに、効率ブレーキを作動させてもよい。また、低速になればなるほど、進行方向に対する車輪の角度を大きくすることにより、低速時ほど摩擦力が大きく働かせてもよい。これにより、走行の安定性と、効率的な減速とを両立させることができる。 In this way, when the vehicle 1 is traveling at high speed, a conventional brake mechanism is used for deceleration, but when traveling at a low speed below a predetermined threshold, such as 30 km/h, an efficient brake may be activated. Also, the lower the speed, the greater the angle of the wheels relative to the direction of travel may be, thereby increasing the frictional force at lower speeds. This makes it possible to achieve both stable driving and efficient deceleration.
　また、制御部１０は、車両１の加速度が所定の閾値よりも大きいとき、車両１の進行方向に対して一対の車輪３０Ａ又は３０Ｂそれぞれの操舵角が大きくなるように操舵手段２０を制御してよい。これにより、例えば追突などの事故の際に効率ブレーキを作動させて、短い距離で車両１を停止させることで、多重の追突事故が発生するおそれを減らすことが期待できる。 In addition, when the acceleration of the vehicle 1 is greater than a predetermined threshold, the control unit 10 may control the steering means 20 so that the steering angle of each of the pair of wheels 30A or 30B is increased relative to the traveling direction of the vehicle 1. This is expected to reduce the risk of multiple rear-end collisions by activating an efficient brake in the event of an accident such as a rear-end collision, and stopping the vehicle 1 in a short distance.
　図５は、効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。 FIG. 5 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
　制御部１０は、車両１の走行中に、減速に関する情報を取得又は生成したか判断する（ステップＳ１０１）。例えば、制御部１０は、第１センサ４０から車両１の減速に関する情報を取得したか否か判断してよい。また、制御部１０は、第１センサ４０及び／又は第２センサ５０から取得した情報に基づいて減速に関する情報を生成したか否か判断してよい。 The control unit 10 determines whether information related to deceleration has been acquired or generated while the vehicle 1 is traveling (step S101). For example, the control unit 10 may determine whether information related to deceleration of the vehicle 1 has been acquired from the first sensor 40. The control unit 10 may also determine whether information related to deceleration has been generated based on information acquired from the first sensor 40 and/or the second sensor 50.
　制御部１０は、減速に関する情報を取得又は生成していなければ（ステップＳ１０１：Ｎｏ）、そのまま走行を続ける。 If the control unit 10 has not acquired or generated information regarding deceleration (step S101: No), the vehicle continues traveling.
　制御部１０は、減速に関する情報を取得又は生成していれば（ステップＳ１０１：Ｙｅｓ）、効率ブレーキを作動させる。例えば、操舵手段２０を用いて、図３または図４に図示したような操舵角になるよう、車輪３０それぞれの操舵角を設定、制御する（ステップＳ１０２）。 If the control unit 10 has acquired or generated information related to deceleration (step S101: Yes), it activates the efficiency brake. For example, it uses the steering means 20 to set and control the steering angle of each wheel 30 so that the steering angle is as shown in FIG. 3 or FIG. 4 (step S102).
　制御部１０は、車両１が停止しておらず、かつ、減速に関する情報が取得されている間又は減速に関する情報が生成されている間は（ステップＳ１０３：Ｎｏ）、効率ブレーキを作動させる（Ｓ１０２）。 The control unit 10 activates the efficiency brake (S102) while the vehicle 1 is not stopped and information regarding deceleration is being acquired or generated (step S103: No).
　制御部１０は、減速に関する情報が解除されたとき（すなわち、減速に関する情報が取得されなくなったとき、若しくは、減速に関する情報が生成されなくなったとき）、又は、車両１が停止したとき（ステップＳ１０３：Ｙｅｓ）、効率ブレーキの作動を解除し、車輪３０の操舵角を元に戻して、進行方向と同じ方向にするよう操舵手段２０を制御する（ステップＳ１０４）。 When the information regarding deceleration is released (i.e., when information regarding deceleration is no longer acquired or when information regarding deceleration is no longer generated) or when the vehicle 1 stops (step S103: Yes), the control unit 10 releases the operation of the efficiency brake and controls the steering means 20 to return the steering angle of the wheels 30 to the original direction and to the same direction as the traveling direction (step S104).
　図６は、本実施形態の効率ブレーキと従来のブレーキとを比較した図である。図６（Ａ）は、従来の２輪駆動車（前輪駆動車）のブレーキ機構を示す図である。２輪駆動車（前輪駆動車）は、駆動輪である２輪（前輪）のみを減速させる機構である。 FIG. 6 is a diagram comparing the efficient brake of this embodiment with a conventional brake. FIG. 6(A) is a diagram showing the brake mechanism of a conventional two-wheel drive vehicle (front-wheel drive vehicle). A two-wheel drive vehicle (front-wheel drive vehicle) has a mechanism that decelerates only the two driving wheels (front wheels).
　図６（Ｂ）は、従来の４輪駆動車のブレーキ機構を示す図である。４輪駆動車は、駆動輪である全輪（４輪）を減速させる機構である。例えば、ハブモーターは４輪全てにブレーキが可能である。４輪駆動車は、２輪駆動車の２倍の減速パワーを得られるため、２輪駆動車と比べると、およそ２分の１の距離で車両１を停止させることができる。 FIG. 6(B) is a diagram showing a conventional brake mechanism for a four-wheel drive vehicle. A four-wheel drive vehicle has a mechanism for decelerating all four drive wheels. For example, a hub motor can brake all four wheels. A four-wheel drive vehicle can obtain twice the deceleration power of a two-wheel drive vehicle, so it can stop the vehicle 1 in approximately half the distance compared to a two-wheel drive vehicle.
　図６（Ｃ）は、本実施形態の効率ブレーキを示す図である。効率ブレーキは、通常のブレーキ機構に加え、更にタイヤの角度を「ハ」の字にして減速させる。そのため、２輪駆動車の４倍の減速パワーを得られるため、２輪駆動車と比べると、およそ４分の１の距離で車両１を停止させることがきる。 FIG. 6(C) shows the efficient brake of this embodiment. In addition to the normal brake mechanism, the efficient brake also decelerates the vehicle by tilting the tires in a V-shape. This provides four times the deceleration power of a two-wheel drive vehicle, meaning that the vehicle 1 can be stopped in approximately one-quarter the distance compared to a two-wheel drive vehicle.
　以上説明したとおり、車輪の角度を変えて減速する効率ブレーキを用いることで、車両の減速をより早く、より短い距離で行うことができる。 As explained above, by using efficient brakes that change the angle of the wheels to slow down, the vehicle can be decelerated more quickly and over a shorter distance.
（２）第２実施形態
　車両を特に短い距離で停止させることが求められるのは、衝突や追突を避ける場合や誤った操作を行ってしまった場合など、事故を防止する必要がある時である。 (2) Second Embodiment There is a need to stop the vehicle in a particularly short distance when it is necessary to prevent an accident, such as when avoiding a collision or rear-end collision, or when an erroneous operation has been performed.
　そこで本発明は、事故の発生を防止するブレーキシステムを提供することを目的とする。
　本発明の一態様に係る効率ブレーキシステムは、車両の左右に略対称に位置する少なくとも一対の車輪と、前記一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、前記車両の加速度を検知するセンサと、前記車両の加速度が第１の条件を満たした場合に、前記操舵手段を制御して、前記車両の進行方向に対する各々の車輪の操舵角を変化させる制御部を備えたものである。 SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a brake system that prevents accidents from occurring.
An efficient brake system according to one embodiment of the present invention comprises at least a pair of wheels positioned approximately symmetrically on the left and right sides of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a sensor for detecting the acceleration of the vehicle, and a control unit for controlling the steering means to change the steering angle of each wheel relative to the direction of travel of the vehicle when the acceleration of the vehicle satisfies a first condition.
　本発明によれば、事故の発生を防止することが可能なブレーキシステムを提供することができる。 The present invention provides a brake system that can prevent accidents from occurring.
　図７は、本実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。図７に示す車両１は、制御部１０と、操舵手段２０と、車輪３０と、第１センサ４０と、第２センサ５０と、ブレーキ手段６０を備える。また、図示を省略するが、従来の車両を構成する種々の構成を備えてもよい。車両１は、運転者が車両１を運転する手動運転機能の他に、車両１の自動運転を支援する自動運転機能を有し、各運転モードを任意に選択できるようにしてもよい。 FIG. 7 is a diagram showing an example of the system configuration of a vehicle 1 equipped with the efficient brake system according to this embodiment. The vehicle 1 shown in FIG. 7 includes a control unit 10, a steering means 20, wheels 30, a first sensor 40, a second sensor 50, and a braking means 60. Although not shown, the vehicle 1 may also include various configurations that constitute a conventional vehicle. In addition to a manual driving function that allows the driver to drive the vehicle 1, the vehicle 1 may also have an automatic driving function that assists in automatic driving of the vehicle 1, and each driving mode may be freely selected.
　制御部１０は、車両１の内外から取得した種々の情報を用いて、操舵手段２０に車輪３０の操舵角を制御させることができる。ここで操舵角とは、車両１の進行方向に対する車輪３０の角度である。例えば、制御部１０は、第１センサ４０及び／又は第２センサ５０が検知した情報に基づいて、操舵手段２０に対して、車輪３０の操舵角を指示する。このとき、制御部１０は、第１センサ４０からブレーキによる車両１の減速に関する情報を取得することができる。また、制御部１０は、第２センサ５０から車両１の速度または加速度に関する情報を取得することができる。 The control unit 10 can cause the steering means 20 to control the steering angle of the wheels 30 using various information acquired from inside and outside the vehicle 1. Here, the steering angle is the angle of the wheels 30 relative to the traveling direction of the vehicle 1. For example, the control unit 10 instructs the steering means 20 on the steering angle of the wheels 30 based on information detected by the first sensor 40 and/or the second sensor 50. At this time, the control unit 10 can acquire information on the deceleration of the vehicle 1 due to braking from the first sensor 40. The control unit 10 can also acquire information on the speed or acceleration of the vehicle 1 from the second sensor 50.
　操舵手段２０は、制御部１０から受け取った指示に基づいて、車輪３０それぞれの操舵角を個別に制御することができる。本実施形態において、操舵手段２０としては、車両１が備える４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌそれぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌを備え、各操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌが各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌの操舵角を個別に設定し、制御できるように構成されてよい。 The steering means 20 can individually control the steering angle of each wheel 30 based on instructions received from the control unit 10. In this embodiment, the steering means 20 includes steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 30Ar, 30Al, 30Br, and 30Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 30Ar, 30Al, 30Br, and 30Bl.
　車両１は、少なくとも一対の車輪３０を備え、車両１の左右に略対称に配置される。本実施形態において、車両１は４輪で構成され、左右一対の前輪３０Ａ（３０Ａｒと３０Ａｌ）と、左右一対の後輪３０Ｂ（３０Ｂｒと３０Ｂｌ）とを有する。 The vehicle 1 has at least a pair of wheels 30, which are arranged approximately symmetrically on the left and right sides of the vehicle 1. In this embodiment, the vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 30A (30Ar and 30Al) and a pair of left and right rear wheels 30B (30Br and 30Bl).
　各車輪３０にはハブの内部に実装される電気モーターであるハブモーター（HUB motor）が搭載されてもよい。なお、モーター自体がハブの内部に実装されていなくても、電気モーターの駆動力が直接ホイールへ伝わるモーター（インホイールモーター（ＩＷＭ：In Wheel Motor））が搭載されてもよい。４輪全てにハブモーターが搭載されることで、車輪３０それぞれの動きを個別に制御することができるようになるため、車輪の角度を変えて減速する効率ブレーキを実現させる上で好ましい。 Each wheel 30 may be equipped with a hub motor, which is an electric motor mounted inside the hub. Note that even if the motor itself is not mounted inside the hub, a motor (in-wheel motor (IWM)) in which the driving force of the electric motor is transmitted directly to the wheel may be installed. By installing hub motors on all four wheels, it becomes possible to individually control the movement of each wheel 30, which is preferable for realizing efficient braking that changes the angle of the wheels to decelerate.
　第１センサ４０は、ブレーキ手段６０によるブレーキに関する情報を検知する。例えば、第１センサ４０は、運転者によるブレーキ操作や自動運転制御により、ブレーキ手段６０による車輪３０の制動が発動したことを検知し、検知した情報を制御部１０に送信する。 The first sensor 40 detects information related to braking by the braking means 60. For example, the first sensor 40 detects that the braking means 60 has applied the brakes to the wheels 30 due to the driver's brake operation or automatic driving control, and transmits the detected information to the control unit 10.
　第２センサ５０は、車両１に搭載される種々のセンサであってよい。例えば、第２センサ５０は、速度センサ又は加速度センサであってよい。第２センサ５０は検知した情報を制御部１０に送信する。 The second sensor 50 may be any of a variety of sensors mounted on the vehicle 1. For example, the second sensor 50 may be a speed sensor or an acceleration sensor. The second sensor 50 transmits the detected information to the control unit 10.
　ブレーキ手段６０は、制御部１０から受け取った指示に基づいて、車輪３０それぞれを制動することができる。ブレーキ手段６０は、例えば各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌにそれぞれ設けられたホイールシリンダ（図示略）や、ホイールシリンダに接続されたブレーキアクチュエータ（図示略）などを備える構成であってもよい。ブレーキアクチュエータは、モーターで駆動される液圧ポンプ等で発生したブレーキ圧を、任意の大きさに制御してホイールシリンダに供給することで、各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌを制動する。制御部１０は、運転者がブレーキペダルを踏んだことを検知した場合に、ブレーキ手段６０に対し車輪３０の制動を行うように指示を出してもよいし、自動運転制御により、ブレーキ手段６０に対して車輪３０の制動を行うように指示を出してもよい。 The braking means 60 can brake each of the wheels 30 based on instructions received from the control unit 10. The braking means 60 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 30Ar, 30Al, 30Br, and 30Bl, and brake actuators (not shown) connected to the wheel cylinders. The brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary magnitude and supplies it to the wheel cylinders to brake each of the wheels 30Ar, 30Al, 30Br, and 30Bl. When the control unit 10 detects that the driver has stepped on the brake pedal, it may issue an instruction to the braking means 60 to brake the wheels 30, or may issue an instruction to the braking means 60 to brake the wheels 30 by automatic driving control.
　本実施形態に係る制御部１０の構成は、前掲図２と同様であるため、図示を省略する。
　制御部１０は、例えば、プロセッサ１２とメモリ１４とを含む。 The configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2, and therefore is not shown in the figure.
The control unit 10 includes, for example, a processor 12 and a memory 14 .
　プロセッサ１２は、車両１全体の動作を制御する。プロセッサ１２として、例えば、ＣＰＵ（Central Processing Unit）、ＭＰＵ（Micro Processing Unit）、ＦＰＧＡ（Field Programmable Gate Array）又はマイコン（マイクロコントローラ）等を用いることができる。プロセッサ１２は、メモリ１４に記憶されたプログラムを実行することで、車両１全体の動作を制御する制御部として機能する。 The processor 12 controls the operation of the entire vehicle 1. The processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller. The processor 12 functions as a control unit that controls the operation of the entire vehicle 1 by executing programs stored in the memory 14.
　メモリ１４は、プロセッサ１２により実行される各種プログラムや各種データを記憶する。メモリ１４には、例えば、ＲＯＭ（Read Only Memory）やＲＡＭ（Random Access Memory）等の揮発性記憶装置、及びＨＤＤ（Hard Disk Drive）やフラッシュメモリ等の不揮発性記憶装置が含まれ得る。各種データは、例えば、効率ブレーキを用いる際の、４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌそれぞれの操舵角度のパターンデータや、効率ブレーキを作動させる条件データ（例えば、車両速度の閾値等）を含む。 The memory 14 stores various programs and data executed by the processor 12. The memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or a flash memory. The various data include, for example, pattern data of the steering angles of each of the four wheels 30Ar, 30Al, 30Br, and 30Bl when using the efficiency brake, and condition data for activating the efficiency brake (for example, a vehicle speed threshold value, etc.).
　また、メモリ１４には、急加速、急ブレーキ、急ハンドルなど、事故が発生した場合に第２センサ５０を介して取得される車両１の加速度のデータに含まれ得る特徴的な信号（パルス信号等）の情報が記憶されている。 In addition, the memory 14 stores information on characteristic signals (e.g., pulse signals) that may be included in the acceleration data of the vehicle 1 acquired via the second sensor 50 in the event of an accident, such as sudden acceleration, sudden braking, or sudden steering.
　図８は、効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。 FIG. 8 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
　制御部１０は、車両１の走行中、第２センサ５０から車両１の速度や加速度の変化に関する情報を取得する（ステップＳ１０１）。制御部１０は、加速度のデータに、急加速や急ブレーキ、急ハンドルなどの事故の兆候を示す信号が含まれるか否か（第１の条件を満たすか否か）を判定する（ステップＳ１０２）。例えば、制御部１０は、メモリ１４に記憶されている事故の兆候を示す加速度データの特徴と比較することにより、判定を行う。また、制御部１０は、車両１の加速度の絶対値が所定の閾値を超えたか否かを判断することにより判定を行ってもよい。また、事故の兆候を示す加速度データの特徴を学習した機械学習モデルを用いて判定を行うようにしてもよい。 The control unit 10 acquires information on changes in the speed and acceleration of the vehicle 1 from the second sensor 50 while the vehicle 1 is traveling (step S101). The control unit 10 determines whether the acceleration data includes a signal indicating an accident sign, such as sudden acceleration, sudden braking, or sudden steering (whether the first condition is satisfied) (step S102). For example, the control unit 10 makes the determination by comparing the acceleration data with the characteristics of the acceleration data that indicate an accident sign stored in the memory 14. The control unit 10 may also make the determination by determining whether the absolute value of the acceleration of the vehicle 1 exceeds a predetermined threshold. The determination may also be made using a machine learning model that has learned the characteristics of the acceleration data that indicate an accident sign.
　加速度データに事故の兆候を示す信号が含まれると判定された場合には（ステップＳ１０２：ＹＥＳ）、制御部１０は、操舵手段２０に指示を出力して車輪３０の操舵角の制御を実施する（ステップＳ１０３）。 If it is determined that the acceleration data includes a signal indicating an accident (step S102: YES), the control unit 10 outputs an instruction to the steering means 20 to control the steering angle of the wheels 30 (step S103).
　操舵手段２０による車輪３０の操舵角の制御を前掲図３及び前掲図４を使って説明する。図３，４に示す例では、車両１は４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌ全ての操舵角を、それぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌによって個別に制御することができる。ブレーキ手段２０による減速は、車輪３０の回転を制動することで行うが、操舵手段２０は、４輪それぞれの操舵角を変化させることで、進行方向に向かうモーメントを打ち消して減速する。 The control of the steering angle of the wheels 30 by the steering means 20 will be explained using Figures 3 and 4 above. In the example shown in Figures 3 and 4, the vehicle 1 can individually control the steering angles of all four wheels 30Ar, 30Al, 30Br, and 30Bl by the corresponding steering means 20Ar, 20Al, 20Br, and 20Bl. The braking means 20 decelerates by braking the rotation of the wheels 30, but the steering means 20 decelerates by changing the steering angle of each of the four wheels to cancel out the moment in the traveling direction.
　例えば、図３に示すように、制御部１０は操舵手段２０を用いて、前輪３０Ａｒ、３０Ａｌ及び後輪３０Ｂｒ、３０Ｂｌが、車両１の上面から見て、それぞれ「ハ」の字になるように操舵角を制御するようにしてよい。すなわち、制御部１０は操舵手段２０を用いて、右側の車輪３０Ａｒが左向きかつ左側の車輪３０Ａｌが右向きとなるように操舵角を制御する。また、制御部１０は操舵手段２０を用いて、右側の車輪３０Ｂｒが左向きかつ左側の車輪３０Ｂｌが右向きとなるよう操舵角を制御する。 For example, as shown in FIG. 3, the control unit 10 may use the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form a "V" shape when viewed from above the vehicle 1. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 30Ar faces left and the left wheel 30Al faces right. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 30Br faces left and the left wheel 30Bl faces right.
　また、図４に示すように、制御部１０は操舵手段２０を用いて、前輪３０Ａｒ、３０Ａｌ及び後輪３０Ｂｒ、３０Ｂｌが、車両１の上面から見て、それぞれ逆「ハ」の字になるよう操舵角を制御するようにしてもよい。すなわち、制御部１０は操舵手段２０を用いて、右側の車輪３０Ａｒが右向きかつ左側の車輪３０Ａｌが左向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、右側の車輪３０Ｂｒが右向きかつ左側の車輪３０Ｂｌが左向きとなるように操舵角を制御する。 Also, as shown in FIG. 4, the control unit 10 may use the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form an inverted V shape when viewed from above the vehicle 1. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 30Ar faces right and the left wheel 30Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 30Br faces right and the left wheel 30Bl faces left.
　このように、操舵手段２０を用いて左右一対の車輪３０Ａ，３０Ｂを内側に向けて進行方向側を狭くしたり、外側に向けて進行方向側を広くしたりすることで、車輪３０と地面の接触面の摩擦力を増大させ、減速を実現させる。なお、前輪３０Ａｒ、３０Ａｌを「ハ」の字、後輪３０Ｂｒ、３０Ｂｌを逆「ハ」の字となるように操舵角を設定してもよいし、前輪３０Ａｒ、３０Ａｌを逆「ハ」の字、後輪３０Ｂｒ、３０Ｂｌを「ハ」の字となるように操舵角を設定してもよい。 In this way, by using the steering means 20 to turn the pair of left and right wheels 30A, 30B inward to narrow the side in the direction of travel, or outward to widen the side in the direction of travel, the frictional force between the contact surface of the wheels 30 and the ground is increased, realizing deceleration. The steering angle may be set so that the front wheels 30Ar, 30Al form a "V" shape and the rear wheels 30Br, 30Bl form an inverted "V" shape, or the steering angle may be set so that the front wheels 30Ar, 30Al form an inverted "V" shape and the rear wheels 30Br, 30Bl form an "V" shape.
　制御部１０は、車輪３０の操舵角が車両１の加速度に応じた角度となるように操舵手段２０を制御してもよい。具体的には、進行方向に対する車輪３０の角度が大きくなるほど（すなわち、「ハ」の字の場合は進行方向側が狭くなるほど、逆「ハ」の字の場合は進行方向側が広くなるほど）地面に対する摩擦力は増大し、減速の効果は高くなる。 The control unit 10 may control the steering means 20 so that the steering angle of the wheels 30 corresponds to the acceleration of the vehicle 1. Specifically, the greater the angle of the wheels 30 relative to the direction of travel (i.e., the narrower the side in the direction of travel in the case of a "V" shape, and the wider the side in the direction of travel in the case of an inverted "V" shape), the greater the frictional force with the ground, and the greater the deceleration effect.
　制御部１０は、車両１の加速度が大きいほど進行方向に対する車輪３０の角度が大きくなるように制御することにより、減速までの時間を短縮させることができる。これにより、例えば追突などの事故の際に、短い距離で車両１を停止させることで、多重の追突事故の発生を防止することが期待できる。なお、制御部１０は、メモリ１４に記憶された、事故の兆候を示す加速度データを用いて操舵角を導出するようにしてもよい。このように、加速度データで事故の兆候を検知して対応することで、事故の発生を防止・抑止することができる。さらに、事故発生時（加速度データで事故の発生が検知された時）には、即座に車両１を停止させることで、事故の拡大や連鎖を防止・抑止することができる。 The control unit 10 can shorten the time until deceleration by controlling the angle of the wheels 30 relative to the traveling direction to be larger as the acceleration of the vehicle 1 is greater. This is expected to prevent the occurrence of multiple rear-end collisions by stopping the vehicle 1 in a short distance in the event of an accident such as a rear-end collision. The control unit 10 may also derive the steering angle using acceleration data that indicates signs of an accident stored in the memory 14. In this way, accidents can be prevented or suppressed by detecting signs of an accident using acceleration data and responding accordingly. Furthermore, when an accident occurs (when the occurrence of an accident is detected by acceleration data), the vehicle 1 can be immediately stopped to prevent or suppress the accident from expanding or becoming a chain reaction.
　また、制御部１０は、右側の車輪３０Ａｒ、３０Ｂｒの操舵角と、左側の車輪３０Ａｌ、３０Ｂｌの操舵角が、略同一となるように操舵手段２０を制御してよい。すなわち、車両１の進行方向と車輪３０Ａｒ又は３０Ｂｒの回転面とによって形成される角度と、車両１の進行方向と車輪３０Ａｌ又は３０Ｂｌの回転面とによって形成される角度とが、略同一となるように操舵手段２０を制御してよい。これにより、左右の車輪に働く摩擦力が略同一となり、減速時の操舵が安定することが期待できる。 The control unit 10 may also control the steering means 20 so that the steering angles of the right-side wheels 30Ar, 30Br and the left-side wheels 30Al, 30Bl are substantially the same. In other words, the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Ar or 30Br and the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Al or 30Bl are substantially the same. This makes the frictional forces acting on the left and right wheels substantially the same, which is expected to result in stable steering during deceleration.
　また、制御部１０は、加速度データの特徴からスピンが発生したと判断された場合には、各車輪３０の向きがスピンの回転方向に対して所定の角度だけ内側または外側を向くように設定してもよい。すなわち、各車輪３０の向きを、車両の重心に対して直交する方向±α（所定角度）だけ傾けるように設定することで、回転に対する摩擦力を生じさせてスピンを抑止させるようにしてもよい。 In addition, when the control unit 10 determines that a spin has occurred based on the characteristics of the acceleration data, it may set the orientation of each wheel 30 so that it faces inward or outward at a predetermined angle relative to the direction of rotation of the spin. In other words, by setting the orientation of each wheel 30 so that it is tilted by ±α (a predetermined angle) in a direction perpendicular to the center of gravity of the vehicle, a frictional force against the rotation may be generated to prevent the spin.
　図９は、車両の走行中に衝突事故が発生した際の加速度の波形（Ｇ）とスピン波形（Ｓ）を例示する図である。なお、同図は、株式会社データ・テック基礎理論研究所の事故解析レポート（http://re-www.datatec.jp/product/report/kaiseki_2.html）から引用したものである。図中（Ａ）で示す区間の加速度波形Ｇは、衝突を回避するためにブレーキ操作が行われたことを示している。また、区間（Ｂ）の加速度波形Ｇは衝突（側面衝突）が発生したことを示している。また、区間（Ｃ）では、スピン波形Ｃによって、側面衝突によりスピンが発生したことが示されている。さらに、区間（Ｄ）の加速度波形Ｇは再度衝突が発生したことを示している。 Figure 9 is a diagram illustrating an example of an acceleration waveform (G) and a spin waveform (S) when a collision accident occurs while a vehicle is traveling. Note that this diagram is quoted from an accident analysis report by Data Tech Institute of Fundamental Theories Co., Ltd. (http://re-www.datatec.jp/product/report/kaiseki_2.html). The acceleration waveform G in the section indicated by (A) in the diagram indicates that the brakes were applied to avoid the collision. The acceleration waveform G in section (B) indicates that a collision (side collision) occurred. In section (C), the spin waveform C indicates that a spin occurred due to a side collision. Furthermore, the acceleration waveform G in section (D) indicates that another collision occurred.
　制御部１０は、図９に示すような加速度波形やスピン波形を利用して、発生した事象に応じた車輪３０の制御を行うようにしてもよい。例えば、区間（Ａ）に示すようなブレーキ操作による加速度波形を検知したら、即座に車両１を停止させるように操舵手段２０を制御することにより、衝突の発生を回避することができる。また、区間（Ｃ）のようなスピン波形を検知したら、車輪３０がスピンの回転方向よりも内側または外側を向くように制御することにより、スピンによる衝突を回避することができる。 The control unit 10 may use acceleration waveforms and spin waveforms such as those shown in FIG. 9 to control the wheels 30 in response to the event that has occurred. For example, when an acceleration waveform caused by braking such as that shown in section (A) is detected, the steering means 20 can be controlled to immediately stop the vehicle 1, thereby avoiding a collision. Also, when a spin waveform such as that shown in section (C) is detected, the wheels 30 can be controlled to face inward or outward from the direction of the spin rotation, thereby avoiding a collision caused by a spin.
　制御部１０は、車両１が停止するまで（ステップＳ１０４）車輪３０の操舵角の制御を実施する。制御部１０は、車両１が停止したら（ステップＳ１０４：ＹＥＳ）、操舵手段２０の制御を終了する（ステップＳ１０５）。 The control unit 10 controls the steering angle of the wheels 30 until the vehicle 1 stops (step S104). When the vehicle 1 stops (step S104: YES), the control unit 10 ends control of the steering means 20 (step S105).
　なお、制御部１０は、車両１の速度及び／又は加速度に応じて、車輪３０それぞれの操舵角を設定してもよい。例えば、制御部１０は、第２センサ５０が検知した情報に基づいて速度及び／又は加速度を取得する。そして、車両１の速度及び／又は加速度に適した操舵角を導出し、導出された操舵角になるよう操舵手段２０を制御する。このとき、メモリ１４に記憶された、速度及び／又は加速度と車輪３０それぞれの操舵角とのパターンデータを用いて操舵角を導出するようにしてもよい。これにより、車両１の速度及び／又は加速度に応じて、効率良く減速することが可能となる。 The control unit 10 may set the steering angle of each wheel 30 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 50. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 30 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
　以上のように、本実施形態によれば、制御部１０は、車両１の走行中に車両１の速度や加速度が、急な加速や減速など、事故の兆候を示す所定の条件を満たした場合に、操舵手段２０に指示を出力して車輪３０の操舵角を変化させ、進行方向に向かうモーメントを打ち消して車両１ができるだけ早く停止するようにした。これにより、衝突や追突などの事故の発生を防止することができる。 As described above, according to this embodiment, when the speed or acceleration of the vehicle 1 while the vehicle 1 is traveling meets a predetermined condition that indicates an accident, such as sudden acceleration or deceleration, the control unit 10 outputs an instruction to the steering means 20 to change the steering angle of the wheels 30, canceling the moment in the traveling direction and stopping the vehicle 1 as quickly as possible. This makes it possible to prevent accidents such as collisions and rear-end collisions.
（３）第３実施形態
　制動中のいずれかの車輪がロック傾向になったときに、その車輪の制動力を低減させることで車輪がロックするのを抑制し、停止までの制動距離の短縮を図るＡＢＳ（アンチロック・ブレーキ・システム）が知られている。
　通常、制動中のいずれかの車輪がロック傾向になると、ＡＢＳを作動させてブレーキ圧を制御（減圧、加圧を繰り返すなど）しているが、このブレーキ圧の制御のみでは、停止までの制動距離を十分に短縮することができない場合があった。 (3) Third embodiment An ABS (anti-lock brake system) is known that, when one of the wheels tends to lock during braking, reduces the braking force on that wheel to prevent the wheel from locking and shortens the braking distance required to stop the vehicle.
Normally, if one of the wheels begins to lock during braking, the ABS is activated to control the brake pressure (by repeatedly reducing and increasing the pressure, etc.), but there are cases where this brake pressure control alone is not enough to sufficiently shorten the braking distance required to stop the vehicle.
　そこで、本発明は、停止までの制動距離を十分に短縮することが可能なブレーキシステムを提供することを目的とする。 The present invention aims to provide a brake system that can sufficiently shorten the braking distance required to bring the vehicle to a complete stop.
　本発明の一態様に係る効率ブレーキシステムは、車両の左右に略対称に位置する少なくとも一対の車輪と、一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、一対の車輪に制動力を発生させるブレーキ手段と、操舵手段及びブレーキ手段を制御する制御部とを備え、制御部は、制動中のいずれかの車輪がロック傾向にあると判定した場合に、一対の車輪に対する制動力が低減されるようにブレーキ手段を制御するとともに、一対の車輪を車両上面から見て略ハの字になるように操舵手段を制御することを要旨とする。 The efficient brake system according to one aspect of the present invention comprises at least a pair of wheels positioned approximately symmetrically on the left and right sides of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a braking means for generating a braking force on the pair of wheels, and a control unit for controlling the steering means and the braking means, and when the control unit determines that one of the wheels is prone to locking during braking, it controls the braking means so that the braking force on the pair of wheels is reduced, and controls the steering means so that the pair of wheels form an approximately V-shape when viewed from above the vehicle.
　本発明によれば、停止までの制動距離を十分に短縮することが可能となる。 The present invention makes it possible to sufficiently shorten the braking distance required to stop the vehicle.
　図１０は、本実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。効率ブレーキシステムは、従来のＡＢＳの問題点を解消するべく、制動中のいずれかの車輪がロック傾向になったときに、ブレーキ圧を制御するだけでなく、各車輪の角度を変えて効率的に減速することで、車輪のロックを抑制するとともに、停止までの制動距離を十分に短縮することを可能とする。なお、以下の説明では、効率ブレーキシステムを用いた上記ブレーキ方法を、「効率ブレーキ」と呼ぶ。 FIG. 10 is a diagram showing an example of the system configuration of a vehicle 1 equipped with an efficient brake system according to this embodiment. In order to solve the problems of conventional ABS, the efficient brake system not only controls the brake pressure when any of the wheels tend to lock during braking, but also changes the angle of each wheel to efficiently decelerate the vehicle, thereby preventing the wheels from locking and making it possible to sufficiently shorten the braking distance required to stop the vehicle. In the following explanation, the above braking method using the efficient brake system will be referred to as "efficient braking."
　図１０に示す車両１は、制御部１０と、操舵手段２０と、ブレーキ手段３０と、車輪４０と、第１センサ５０と、第２センサ６０と、報知手段７０とを備える。また、図示を省略するが、従来の車両を構成する種々の構成を備えてもよい。車両１は、運転者が車両１を運転する手動運転機能の他に、車両１の自動運転を支援する自動運転機能を有し、各運転機能を任意に選択できることとしてもよい。 The vehicle 1 shown in FIG. 10 includes a control unit 10, a steering means 20, a braking means 30, wheels 40, a first sensor 50, a second sensor 60, and a notification means 70. Although not shown, the vehicle 1 may also include various components constituting a conventional vehicle. In addition to a manual driving function in which the driver drives the vehicle 1, the vehicle 1 may also have an automatic driving function that assists in the automatic driving of the vehicle 1, and each driving function may be selectable at will.
　制御部１０は、車両１の内外から取得した種々の情報を用いて、効率ブレーキに関する制御を行う。例えば、制御部１０は、第１センサ５０及び／又は第２センサ６０が検知した情報に基づいて、操舵手段２０に車輪４０の操舵角を指示したり、ブレーキ手段３０に車輪４０の制動力を指示したりする。
　このとき、制御部１０は、第１センサ５０から車両１のブレーキに関する情報を取得するとともに、第２センサ６０から車輪速度に関する情報を取得してよい。 The control unit 10 performs control related to the efficient brake using various information acquired from inside and outside the vehicle 1. For example, the control unit 10 instructs the steering means 20 on the steering angle of the wheels 40 and instructs the braking means 30 on the braking force of the wheels 40 based on information detected by the first sensor 50 and/or the second sensor 60.
At this time, the control unit 10 may obtain information regarding the brakes of the vehicle 1 from the first sensor 50 and information regarding the wheel speed from the second sensor 60 .
　操舵手段２０は、制御部１０から受け取った指示に基づいて、車輪４０それぞれの操舵角を個別に制御することができる。操舵手段２０としては、車両１が備える４つの車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌそれぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌを備え、各操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌが各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌの操舵角を個別に設定し、制御できるように構成されてもよい。 The steering means 20 can individually control the steering angle of each wheel 40 based on instructions received from the control unit 10. The steering means 20 may be configured to include steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 40Ar, 40Al, 40Br, and 40Bl of the vehicle 1, and each of the steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 40Ar, 40Al, 40Br, and 40Bl.
　ブレーキ手段３０は、制御部１０から受け取った指示に基づいて、車輪４０それぞれを制動することができる。ブレーキ手段３０は、例えば各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌにそれぞれ設けられたホイールシリンダ（図示略）や、ホイールシリンダに接続されたブレーキアクチュエータ（図示略）などを備える構成であってもよい。ブレーキアクチュエータは、モータで駆動される液圧ポンプ等で発生したブレーキ圧を、任意の大きさに制御してホイールシリンダに供給することで、各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌを制動する。 The braking means 30 can brake each of the wheels 40 based on instructions received from the control unit 10. The braking means 30 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 40Ar, 40Al, 40Br, and 40Bl, and brake actuators (not shown) connected to the wheel cylinders. The brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary level and supplies it to the wheel cylinder, thereby braking each of the wheels 40Ar, 40Al, 40Br, and 40Bl.
　車両１は、少なくとも一対の車輪を備え、車輪は車両１の左右に略対称に配置される。本実施形態において、車両１は４輪で構成され、左右一対の前輪４０Ａ（４０Ａｒと４０Ａｌ）と、左右一対の後輪４０Ｂ（４０Ｂｒと４０Ｂｌ）とを有する。 Vehicle 1 has at least one pair of wheels, which are arranged approximately symmetrically on the left and right sides of vehicle 1. In this embodiment, vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 40A (40Ar and 40Al) and a pair of left and right rear wheels 40B (40Br and 40Bl).
　車輪４０にはハブモーター（HUB motor）が搭載されてもよい。ハブモーターは、インホイールモーター（ＩＷＭ：In Wheel Motor）と呼ばれることもある。４輪全てにハブモーターが搭載されることで、車輪４０それぞれの動きを個別に制御することができるようになるため、車輪の角度を変えて減速する効率ブレーキを実現させる上で好ましい。 The wheels 40 may be equipped with hub motors. Hub motors are also called in-wheel motors (IWM). By installing hub motors on all four wheels, it becomes possible to control the movement of each wheel 40 individually, which is preferable for achieving efficient braking that changes the angle of the wheels to slow down the vehicle.
　第１センサ５０は、ブレーキに関する情報を検知する。例えば、第１センサ５０は、運転者によってブレーキペダルが操作されると、ブレーキペダルの操作量（すなわち、ストローク量）などをあらわす情報を制御部１０に送信する。 The first sensor 50 detects information related to braking. For example, when the driver operates the brake pedal, the first sensor 50 transmits information indicating the amount of brake pedal operation (i.e., the stroke amount) to the control unit 10.
　第２センサ６０は、車両１に搭載される種々のセンサであってよい。例えば、第２センサ６０は、速度センサ、加速度センサのほか、各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌにそれぞれ設けられた車輪速センサなどによって構成されてもよい。第２センサ６０は、逐次検出される車両１の速度、加速度、車輪速度などの情報を制御部１０に送信する。 The second sensor 60 may be any of a variety of sensors mounted on the vehicle 1. For example, the second sensor 60 may be configured with a speed sensor, an acceleration sensor, or a wheel speed sensor provided on each of the wheels 40Ar, 40Al, 40Br, and 40Bl. The second sensor 60 transmits information such as the speed, acceleration, and wheel speed of the vehicle 1 that are successively detected to the control unit 10.
　報知手段７０は、効率ブレーキが作動している場合に所定の警報を運転者に報知する。例えば、報知手段７０は、ブザーやインストルメントパネル（図示略）に設けられたランプであってもよい。なお、車両１に複数の報知手段を設けた場合には、これらの報知手段を同時に作動させるようにしてもよい。 The notification means 70 issues a specified warning to the driver when the efficient brake is activated. For example, the notification means 70 may be a buzzer or a lamp provided on the instrument panel (not shown). Note that if the vehicle 1 is provided with multiple notification means, these notification means may be activated simultaneously.
　本実施形態に係る制御部１０の構成は、前掲図２と同様であるため、図示を省略する。　制御部１０は、例えば、プロセッサ１２とメモリ１４とを含む。 The configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2 above, and is therefore not shown. The control unit 10 includes, for example, a processor 12 and a memory 14.
　プロセッサ１２は、車両１の効率ブレーキに関する制御を行う。プロセッサ１２として、例えば、ＣＰＵ（Central Processing Unit）、ＭＰＵ（Micro Processing Unit）、ＦＰＧＡ（Field Programmable Gate Array）又はマイコン（マイクロコントローラ）等を用いることができる。プロセッサ１２は、メモリ１４に記憶されたプログラムを実行することで、制御部として機能する。 The processor 12 controls the efficient braking of the vehicle 1. The processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller. The processor 12 functions as a control unit by executing a program stored in the memory 14.
　メモリ１４は、プロセッサ１２により実行される各種プログラムや各種データを記憶する。メモリ１４には、例えば、ＲＯＭ（Read Only Memory）やＲＡＭ（Random Access Memory）等の揮発性記憶装置、及びＨＤＤ（Hard Disk Drive）やフラッシュメモリ等の不揮発性記憶装置が含まれ得る。 The memory 14 stores various programs and data executed by the processor 12. The memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
　各種データとして、例えば、効率ブレーキを用いる際の、４つの車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌそれぞれの操舵角のパターンデータや、効率ブレーキを作動させる条件データ（例えば、車両の速度や車輪速度の閾値など）を含む。 The various data include, for example, steering angle pattern data for each of the four wheels 40Ar, 40Al, 40Br, and 40Bl when using the efficiency brake, and condition data for activating the efficiency brake (for example, vehicle speed and wheel speed thresholds, etc.).
　図１１～図１３は、本実施形態における効率ブレーキの作動態様の一例を示す図である。
　本実施形態においては、４輪全ての操舵角をそれぞれ自由自在に制御することが可能となっているため、ブレーキ圧を制御するとともに、進行方向に向かうモーメントを打ち消すように車輪の操舵角を制御することで、効率ブレーキを実現する。 11 to 13 are diagrams showing an example of an operation mode of the efficiency brake in this embodiment.
In this embodiment, it is possible to freely control the steering angles of all four wheels, so efficient braking is achieved by controlling the braking pressure and controlling the steering angles of the wheels to cancel out the moment in the direction of travel.
　４輪の全てで操舵可能な車両１において、例えば制動中のいずれかの車輪がロック傾向に入ったことを検出すると、制御部１０は、車輪の制動力を低減するべく、ブレーキ手段３０を制御してブレーキ圧を制御する。さらに、制御部１０は、例えば図１１に示すように、操舵手段２０を用いて、一対の前輪４０Ａ及び一対の後輪４０Ｂを、車両上面から見て、それぞれ「ハ」の字になるよう操舵角を制御する。すなわち、制御部１０は操舵手段２０を用いて、一対の前輪４０Ａのうち、右側の車輪４０Ａｒを左向きかつ左側の車輪４０Ａｌを右向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、一対の後輪４０Ｂのうち、右側の車輪４０Ｂｒを左向きかつ左側の車輪４０Ｂｌを右向きとなるよう操舵角を制御する。なお、いずれかの車輪がロック傾向に入ったか否かの検出は、例えば各車輪４０に設けた車輪速センサで検出した車輪速度を比較等することで実現できる。 In a vehicle 1 in which all four wheels can be steered, when it is detected that one of the wheels is locking during braking, the control unit 10 controls the brake means 30 to control the brake pressure in order to reduce the braking force of the wheels. Furthermore, the control unit 10 controls the steering angle of the pair of front wheels 40A and the pair of rear wheels 40B using the steering means 20 so that they are each shaped like the letter "V" when viewed from above the vehicle, as shown in FIG. 11. That is, the control unit 10 controls the steering angle of the pair of front wheels 40A using the steering means 20 so that the right wheel 40Ar faces left and the left wheel 40Al faces right. The control unit 10 also controls the steering angle of the pair of rear wheels 40B using the steering means 20 so that the right wheel 40Br faces left and the left wheel 40Bl faces right. It should be noted that detection of whether any of the wheels is locking can be achieved, for example, by comparing the wheel speeds detected by wheel speed sensors provided on each wheel 40.
　図１１では、操舵手段２０を用いて、一対の前輪４０Ａ及び一対の後輪４０Ｂを、車両上面から見て、それぞれ「ハ」の字になるよう操舵角を制御する態様を例示したが、例えば図１２に示すように、一対の前輪４０Ａ及び一対の後輪４０Ｂを、車両上面から見て、それぞれ逆「ハ」の字になるよう操舵角を制御してもよい。すなわち、制御部１０は操舵手段２０を用いて、一対の前輪４０Ａのうち、右側の車輪４０Ａｒを右向きかつ左側の車輪４０Ａｌを左向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、一対の後輪４０Ｂのうち、右側の車輪４０Ｂｒを右向きかつ左側の車輪４０Ｂｌを左向きとなるよう操舵角を制御する。 FIG. 11 illustrates an example of controlling the steering angle using the steering means 20 so that the pair of front wheels 40A and the pair of rear wheels 40B form a "V" shape when viewed from above the vehicle, but as shown in FIG. 12, for example, the steering angle may be controlled so that the pair of front wheels 40A and the pair of rear wheels 40B form an inverted "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 40Ar of the pair of front wheels 40A faces right and the left wheel 40Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 40Br of the pair of rear wheels 40B faces right and the left wheel 40Bl faces left.
　さらに別の態様として、制御部１０は、例えば図１３に示すように、左右一対の車輪４０Ａ，４０Ｂを、車両上面から見て、それぞれ「ハ」の字になるよう操舵角を制御する第１操舵モードと、左右一対の車輪４０Ａ，４０Ｂを、車両上面から見て、それぞれ逆「ハ」の字になるよう操舵角を制御する第２操舵モードとを、所定のタイミングで交互に切り換えるようにしてもよい。このとき、制御部１０は、第１センサ５０及び第２センサ６０から得られる様々な情報に基づいて、車輪４０のロックを回避でき、かつ、最大限の制動力を確保して制動距離を短縮できるような操舵モードの切り換えタイミングを導出すればよい。 As yet another aspect, the control unit 10 may alternate at a predetermined timing between a first steering mode in which the steering angle of the pair of left and right wheels 40A, 40B is controlled so that they form a "V" shape when viewed from above the vehicle, as shown in FIG. 13, and a second steering mode in which the steering angle of the pair of left and right wheels 40A, 40B is controlled so that they form an inverted "V" shape when viewed from above the vehicle. In this case, the control unit 10 may derive the timing of switching the steering mode based on various information obtained from the first sensor 50 and the second sensor 60, so that the wheels 40 can be prevented from locking and the maximum braking force can be secured to shorten the braking distance.
　このように、本実施形態の効率ブレーキシステムにおいては、制動中のいずれかの車輪４０がロック傾向に入ったことを検出すると、単にブレーキ圧を制御するだけでなく、左右一対の車輪４０Ａ，４０Ｂを内側に向けて進行方向側を狭くしたり、外側に向けて進行方向側を広くしたりすることで、車輪４０と地面の接触面の摩擦力を増大させる。これにより、車輪４０のロックを抑制するとともに、停止までの制動距離を十分に短縮することが可能となる。このとき、制御部１０は、車輪４０の操舵角を調整することで、車輪４０と地面の間の摩擦力を調整することができる。 In this way, in the efficient brake system of this embodiment, when it is detected that one of the wheels 40 is beginning to lock during braking, the brake pressure is not simply controlled, but the pair of left and right wheels 40A, 40B are turned inward to narrow the side in the direction of travel, or turned outward to widen the side in the direction of travel, thereby increasing the frictional force at the contact surface between the wheels 40 and the ground. This makes it possible to prevent the wheels 40 from locking and to sufficiently shorten the braking distance required to stop the vehicle. At this time, the control unit 10 can adjust the frictional force between the wheels 40 and the ground by adjusting the steering angle of the wheels 40.
　また、制御部１０は操舵手段２０を用いて、前輪４０Ａを「ハ」の字、後輪４０Ｂを逆「ハ」の字となるように操舵角を設定してもよい。また、制御部１０は操舵手段２０を用いて、前輪４０Ａを逆「ハ」の字、後輪４０Ｂを「ハ」の字となるように操舵角を設定してもよい。 The control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 40A form a "V" shape and the rear wheels 40B form an inverted "V" shape. The control unit 10 may also use the steering means 20 to set the steering angle so that the front wheels 40A form an inverted "V" shape and the rear wheels 40B form an inverted "V" shape.
　制御部１０は、一対の車輪４０Ａ又は４０Ｂのうち、車両１の進行方向と右側の車輪４０Ａｒ又は４０Ｂｒの操舵角との間の角度と、車両１の進行方向と左側の車輪４０Ａｌ又は４０Ｂｌの操舵角との間の角度とが、略同一となるように操舵手段２０を制御してよい。すなわち、車両１の進行方向と車輪４０Ａｒ又は４０Ｂｒの回転面とによって形成される角度と、車両１の進行方向と車輪４０Ａｌ又は４０Ｂｌの回転面とによって形成される角度とが、略同一となるように操舵手段２０を制御してよい。これにより、左右の車輪に働く摩擦力が略同一となり、減速時の操舵が安定することが期待できる。 The control unit 10 may control the steering means 20 so that the angle between the traveling direction of the vehicle 1 and the steering angle of the right wheel 40Ar or 40Br of the pair of wheels 40A or 40B is approximately the same as the angle between the traveling direction of the vehicle 1 and the steering angle of the left wheel 40Al or 40Bl. In other words, the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Ar or 40Br and the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Al or 40Bl are approximately the same. This makes the frictional forces acting on the left and right wheels approximately the same, which is expected to stabilize steering during deceleration.
　また、制御部１０は、車両１の速度及び／又は加速度に応じて、車輪４０それぞれの操舵角を設定してもよい。例えば、制御部１０は、第２センサ６０が検知した情報に基づいて速度及び／又は加速度を取得する。そして、車両１の速度及び／又は加速度に適した操舵角を導出し、導出された操舵角になるよう操舵手段２０を制御する。このとき、メモリ１４に記憶された、速度及び／又は加速度と車輪４０それぞれの操舵角とのパターンデータを用いて、操舵角を導出してよい。これにより、車両１の速度及び／又は加速度に応じて、効率良く減速することが可能となる。 The control unit 10 may also set the steering angle of each wheel 40 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 60. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 40 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
　また、制御部１０は、車両１の速度が小さいほど、車両１の進行方向に対して一対の車輪４０Ａ又は４０Ｂそれぞれの操舵角が大きくなるように操舵手段２０を制御してよい。 The control unit 10 may also control the steering means 20 so that the steering angle of each of the pair of wheels 40A or 40B relative to the traveling direction of the vehicle 1 increases as the speed of the vehicle 1 decreases.
　図１４は、効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。 FIG. 14 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
　制御部１０は、各車輪４０に設けた車輪速センサで検出した車輪速を比較することで、いずれかの車輪４０がロック傾向に入ったか否かを判断（検出）する（ステップＳ１０１）。 The control unit 10 determines (detects) whether any of the wheels 40 are in a state of locking by comparing the wheel speeds detected by the wheel speed sensors provided on each wheel 40 (step S101).
　制御部１０は、いずれの車輪４０もロック傾向に入っていないと判断した場合には（ステップＳ１０１：ＮＯ）、効率ブレーキを作動させることなく、通常運転を続ける。 If the control unit 10 determines that none of the wheels 40 are in a state of locking (step S101: NO), it continues normal operation without activating the efficiency brake.
　一方、制御部１０は、いずれかの車輪４０がロック傾向に入っていると判断すると（ステップＳ１０１：ＹＥＳ）、効率ブレーキを作動させる。具体的には、制御部１０は、車輪４０のロックを抑制するために、ブレーキ手段３０に対して、ブレーキ圧の制御を指示するとともに（ステップＳ１０２）。操舵手段２０に対して、図１１～図１３のいずれかに示した態様で、車輪４０の操舵角を制御するように指示する（ステップＳ１０３）。さらに、制御部１０は、効率ブレーキが作動していることを運転者に知らせるために、所定の警報を報知手段７０から報知する（ステップＳ１０４）。 On the other hand, if the control unit 10 determines that any of the wheels 40 are tending to lock (step S101: YES), it activates the efficiency brake. Specifically, the control unit 10 instructs the brake means 30 to control the brake pressure in order to prevent the wheels 40 from locking (step S102). It also instructs the steering means 20 to control the steering angle of the wheels 40 in the manner shown in any of Figures 11 to 13 (step S103). Furthermore, the control unit 10 issues a predetermined alarm from the notification means 70 to inform the driver that the efficiency brake is being activated (step S104).
　制御部１０は、車両１が停止するまでの間は（ステップＳ１０５：ＮＯ）、効率ブレーキを作動させる（ステップＳ１０２→Ｓ１０３→Ｓ１０４）。 The control unit 10 activates the efficiency brake (steps S102 → S103 → S104) until the vehicle 1 stops (step S105: NO).
　その後、制御部１０は、車両１が停止したことを検知すると（ステップＳ１０５：ＹＥＳ）、所定の警報の報知を終了し、効率ブレーキを含むすべてのブレーキの作動を停止し（ステップＳ１０６）、車輪４０の操舵角を進行方向と同じ方向に戻す制御を行った後（ステップＳ１０７）、処理を終了する。 After that, when the control unit 10 detects that the vehicle 1 has stopped (step S105: YES), it ends the issuance of the specified alarm, stops the operation of all brakes including the efficiency brakes (step S106), and performs control to return the steering angle of the wheels 40 to the same direction as the traveling direction (step S107), and then ends the processing.
　以上説明したとおり、制動中のいずれかの車輪がロック傾向に入った場合には、単にブレーキ圧を制御するだけでなく、車輪の角度を制御することで、車輪のロックを抑制するとともに、停止までの制動距離を十分に短縮することが可能となる。 As explained above, if one of the wheels begins to lock during braking, controlling the wheel angle rather than simply controlling the brake pressure makes it possible to prevent the wheel from locking and sufficiently shorten the braking distance required to stop the vehicle.
（４）第４実施形態
　自車両と前方の障害物との間の距離及び相対速度を検出し、その検出結果から前方の障害物に対して異常接近した場合に、自動的にブレーキを作動させて自車両を急制動する自動制動装置が知られている。 (4) Fourth embodiment An automatic braking device is known that detects the distance and relative speed between the vehicle and an obstacle ahead, and automatically applies the brakes to suddenly brake the vehicle if the detection result indicates that the vehicle is abnormally close to the obstacle ahead.
　上記自動制動装置においては、自車両と前方の障害物の距離が近すぎないようにするには効果的であるが、後方車両が存在する場合に自動制動装置が急ブレーキをかけると、後方車両が急制動に間に合わずに追突するおそれがある、という問題があった。 The above-mentioned automatic braking system is effective in preventing the vehicle from getting too close to an obstacle ahead, but there is a problem in that if the automatic braking system suddenly brakes when there is a vehicle behind, the vehicle behind may not be able to brake in time and may collide with the vehicle behind.
　そこで、本発明は、自車両を取り巻く状況に応じて最適なブレーキ制御を行うことが可能なブレーキシステムを提供することを目的とする。 The present invention aims to provide a brake system that can perform optimal brake control according to the circumstances surrounding the vehicle.
　本発明の一態様に係るブレーキシステムは、車両の左右に略対称に位置する少なくとも一対の車輪と、一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、一対の車輪に制動力を発生させるブレーキ手段と、車両のブレーキ操作に関するブレーキ操作情報を取得する第１取得部と、車両の周囲環境に関する周囲環境情報を取得する第２取得部と、操舵手段及びブレーキ手段を制御する制御部と、を備え、制御部は、ブレーキ操作情報及び周囲環境情報に基づき、ブレーキ手段を制御して車両を制動する通常ブレーキと、ブレーキ手段とともに操舵手段を制御して車両を制動する効率ブレーキのいずれかを選択する、ブレーキシステム。 A brake system according to one embodiment of the present invention includes at least a pair of wheels positioned approximately symmetrically on the left and right of a vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a braking means for generating a braking force on the pair of wheels, a first acquisition unit for acquiring brake operation information related to the brake operation of the vehicle, a second acquisition unit for acquiring ambient environment information related to the ambient environment of the vehicle, and a control unit for controlling the steering means and the braking means, and the control unit selects, based on the brake operation information and the ambient environment information, either a normal brake that controls the braking means to brake the vehicle, or an efficient brake that controls the steering means together with the braking means to brake the vehicle.
　本発明によれば、自車両を取り巻く状況に応じて最適なブレーキ制御を行うことが可能となる。 The present invention makes it possible to perform optimal brake control according to the circumstances surrounding the vehicle.
　図１５は、本実施形態に係るブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。本実施形態に係るブレーキシステムは、ブレーキ圧を制御して車両を制動する「通常ブレーキ」と、ブレーキ圧を制御するだけでなく、各車輪の角度を変えて効率的に減速して車両を制動する「効率ブレーキ」の２種類のブレーキを作動することが可能となっている。図１に示す車両１は、制御部１０と、操舵手段２０と、ブレーキ手段３０と、車輪４０と、第１センサ５０と、第２センサ６０と、報知手段７０を備える。また、図示省略するが、従来の車両を構成する種々の構成を備えてもよい。車両１は、運転者が車両１を運転する手動運転機能の他に、車両１の自動運転を支援する自動運転機能を有し、各運転機能を任意に選択できることとしてもよい。 FIG. 15 is a diagram showing an example of the system configuration of a vehicle 1 equipped with a brake system according to this embodiment. The brake system according to this embodiment is capable of operating two types of brakes: a "normal brake" that controls the brake pressure to brake the vehicle, and an "efficient brake" that not only controls the brake pressure but also changes the angle of each wheel to efficiently decelerate and brake the vehicle. The vehicle 1 shown in FIG. 1 includes a control unit 10, a steering means 20, a brake means 30, wheels 40, a first sensor 50, a second sensor 60, and a notification means 70. Although not shown, the vehicle 1 may also include various configurations that configure a conventional vehicle. In addition to a manual driving function that allows the driver to drive the vehicle 1, the vehicle 1 may have an automatic driving function that assists in automatic driving of the vehicle 1, and each driving function may be selected arbitrarily.
　制御部１０は、車両１の内外から取得した種々の情報を用いて、ブレーキに関する様々な制御を行う。例えば、制御部１０は、第１センサ５０及び第２センサ６０が検知した情報に基づいて、ブレーキの種類（具体的には、通常ブレーキまたは効率ブレーキ）を選択し、選択したブレーキの種類に応じて操舵手段２０に車輪４０の操舵角を指示したり、ブレーキ手段３０に車輪４０の制動力を指示したりする。 The control unit 10 performs various controls related to the brakes using various information acquired from inside and outside the vehicle 1. For example, the control unit 10 selects the type of brakes (specifically, normal brakes or efficient brakes) based on the information detected by the first sensor 50 and the second sensor 60, and instructs the steering means 20 on the steering angle of the wheels 40 and instructs the braking means 30 on the braking force of the wheels 40 according to the selected type of brakes.
　操舵手段２０は、制御部１０から受け取った指示に基づいて、車輪４０それぞれの操舵角を個別に制御することができる。操舵手段２０としては、車両１が備える４つの車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌそれぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌを備え、各操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌが各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌの操舵角を個別に設定し、制御できるように構成されてもよい。 The steering means 20 can individually control the steering angle of each wheel 40 based on instructions received from the control unit 10. The steering means 20 may be configured to include steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 40Ar, 40Al, 40Br, and 40Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 40Ar, 40Al, 40Br, and 40Bl.
　ブレーキ手段３０は、制御部１０から受け取った指示に基づいて、車輪４０それぞれを制動することができる。ブレーキ手段３０は、例えば各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌにそれぞれ設けられたホイールシリンダ（図示略）や、ホイールシリンダに接続されたブレーキアクチュエータ（図示略）などを備える構成であってもよい。ブレーキアクチュエータは、モーターで駆動される液圧ポンプ等で発生したブレーキ圧を、任意の大きさに制御してホイールシリンダに供給することで、各車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌを制動する。 The braking means 30 can brake each of the wheels 40 based on instructions received from the control unit 10. The braking means 30 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 40Ar, 40Al, 40Br, and 40Bl, and brake actuators (not shown) connected to the wheel cylinders. The brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary level and supplies it to the wheel cylinder, thereby braking each of the wheels 40Ar, 40Al, 40Br, and 40Bl.
　車両１は、少なくとも一対の車輪（タイヤ）を備え、車輪は車両１の左右に略対称に配置される。本実施形態において、車両１は４輪で構成され、左右一対の前輪４０Ａ（４０Ａｒと４０Ａｌ）と、左右一対の後輪４０Ｂ（４０Ｂｒと４０Ｂｌ）とを有する。 Vehicle 1 has at least a pair of wheels (tires), which are arranged approximately symmetrically on the left and right sides of vehicle 1. In this embodiment, vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 40A (40Ar and 40Al) and a pair of left and right rear wheels 40B (40Br and 40Bl).
　車輪４０にはハブモーター（HUB motor）が搭載されてもよい。ハブモーターは、インホイールモーター（ＩＷＭ：In Wheel Motor）と呼ばれることもある。４輪全てにハブモーターが搭載されることで、車輪４０それぞれの動きを個別に制御することができるようになるため、車輪の角度を変えて減速する効率ブレーキを実現させる上で好ましい。 The wheels 40 may be equipped with hub motors. Hub motors are also called in-wheel motors (IWM). By installing hub motors on all four wheels, it becomes possible to control the movement of each wheel 40 individually, which is preferable for achieving efficient braking that changes the angle of the wheels to slow down the vehicle.
　第１センサ５０は、ブレーキ操作に関するブレーキ操作情報を検知する。第１センサ５０は、例えばブレーキペダルセンサなどによって構成されている。第１センサ５０は、運転者によってブレーキペダルが操作されると、ブレーキペダルの操作量（すなわち、ストローク量）などをあらわすブレーキ操作情報を制御部（第１取得部）１０に送信する。 The first sensor 50 detects brake operation information related to brake operation. The first sensor 50 is composed of, for example, a brake pedal sensor. When the driver operates the brake pedal, the first sensor 50 transmits brake operation information indicating the amount of brake pedal operation (i.e., the stroke amount) to the control unit (first acquisition unit) 10.
　第２センサ６０は、自車両の周囲環境に関わる情報（本実施形態では、後方車両との車間距離、相対速度などをあらわす後方車両情報）を検知する。第２センサ６０は、例えばＬＩＤＡＲ（Light Detection And Ranging）センサ、超音波ソナー、及びステレオカメラなどによって構成される。第２センサ６０は、後方車両情報を検出すると、制御部（第２取得部）１０に送信する。 The second sensor 60 detects information related to the surrounding environment of the vehicle (in this embodiment, rear vehicle information indicating the distance to the rear vehicle, relative speed, etc.). The second sensor 60 is composed of, for example, a LIDAR (Light Detection And Ranging) sensor, an ultrasonic sonar, and a stereo camera. When the second sensor 60 detects rear vehicle information, it transmits it to the control unit (second acquisition unit) 10.
　その他にも、車両１には、速度センサ、アクセルペダルセンサ、シフトポジションセンサ、加速度センサをはじめとする様々なセンサが搭載されている。 In addition, vehicle 1 is equipped with various sensors, including a speed sensor, an accelerator pedal sensor, a shift position sensor, and an acceleration sensor.
　報知手段７０は、ブレーキの作動状況を外部（運転者など）に報知する。報知手段７０は、例えばブザーやインストルメントパネル（図示略）に設けられたランプやブレーキランプなどによって構成されている。報知手段７０は、制御部１０によってブレーキが作動されると、例えばランプの色、点灯パターン、文字メッセージなどによって、ブレーキの作動の有無や、作動中のブレーキの種類などを運転者に報知してもよい。一例として、通常ブレーキが作動中である場合には、インストルメントパネルの所定のランプを黄色で点灯表示する一方、効率ブレーキが作動中である場合には、インストルメントパネルの所定のランプを青色で点滅表示する。このように、作動中のブレーキの種類に応じて異なる態様で報知することで、運転者は作動中のブレーキを正確に把握することができる。なお、車両１に複数の報知手段７０が設けられている場合には、作動中のブレーキの種類に応じて、利用する報知手段の組み合わせを変えてもよい。また、作動中のブレーキの種類に応じてブレーキランプの表示態様を変えることで、後方車両などにブレーキの作動状況を知らせてもよい。 The notification means 70 notifies the outside (such as the driver) of the brake operation status. The notification means 70 is composed of, for example, a buzzer, a lamp or a brake lamp provided on the instrument panel (not shown). When the brake is operated by the control unit 10, the notification means 70 may notify the driver of the presence or absence of the brake operation, the type of brake being operated, etc., by, for example, the color of the lamp, the lighting pattern, a text message, etc. As an example, when the normal brake is operated, a specific lamp on the instrument panel is displayed as lit in yellow, while when the efficient brake is operated, a specific lamp on the instrument panel is displayed as flashing in blue. In this way, by notifying in different ways depending on the type of brake being operated, the driver can accurately grasp the brake being operated. Note that, when the vehicle 1 is provided with multiple notification means 70, the combination of notification means to be used may be changed depending on the type of brake being operated. Also, the brake operation status may be notified to the rear vehicle, etc. by changing the display mode of the brake lamp depending on the type of brake being operated.
　本実施形態に係る制御部１０の構成は、前掲図２と同様であるため、図示を省略する。　制御部１０は、例えば、プロセッサ１２とメモリ１４とを含む。 The configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2 above, and is therefore not shown. The control unit 10 includes, for example, a processor 12 and a memory 14.
　プロセッサ１２は、車両１のブレーキに関する制御を行う。プロセッサ１２として、例えば、ＣＰＵ（Central Processing Unit）、ＭＰＵ（Micro Processing Unit）、ＦＰＧＡ（Field Programmable Gate Array）又はマイコン（マイクロコントローラ）等を用いることができる。プロセッサ１２は、メモリ１４に記憶されたプログラムを実行することで、制御部として機能する。 The processor 12 controls the brakes of the vehicle 1. The processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller. The processor 12 functions as a control unit by executing a program stored in the memory 14.
　メモリ１４は、プロセッサ１２により実行される各種プログラムや各種データを記憶する。メモリ１４には、例えば、ＲＯＭ（Read Only Memory）やＲＡＭ（Random Access Memory）等の揮発性記憶装置、及びＨＤＤ（Hard Disk Drive）やフラッシュメモリ等の不揮発性記憶装置が含まれ得る。 The memory 14 stores various programs and data executed by the processor 12. The memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or flash memory.
　各種データとして、例えば効率ブレーキを作動させる際の、４つの車輪４０Ａｒ、４０Ａｌ、４０Ｂｒ、４０Ｂｌそれぞれの操舵角をあらわす操舵角パターンを含む。 The various data include, for example, steering angle patterns that indicate the steering angles of each of the four wheels 40Ar, 40Al, 40Br, and 40Bl when the efficiency brake is activated.
＜効率ブレーキの特徴＞
　本実施形態における効率ブレーキの作動態様の一例を、前掲図１１及び前掲図１２を利用して説明する。
　本実施形態においては、４輪全ての操舵角をそれぞれ自由自在に制御することが可能となっているため、ブレーキ圧を制御するとともに、進行方向に向かうモーメントを打ち消すように車輪の操舵角を制御することで、効率ブレーキを実現する。 <Features of efficient brakes>
An example of the operation of the efficiency brake in this embodiment will be described with reference to FIGS. 11 and 12. FIG.
In this embodiment, it is possible to freely control the steering angles of all four wheels, so efficient braking is achieved by controlling the braking pressure and controlling the steering angles of the wheels to cancel out the moment in the direction of travel.
　４輪の全てで操舵可能な車両１において、制御部１０は、ブレーキ操作情報、後方車両情報に基づき、作動ブレーキとして効率ブレーキを選択すると、まず、ブレーキ手段３０を制御してブレーキ圧を制御する。さらに、制御部１０は、例えば前掲図１１に示すように、操舵手段２０を用いて、一対の前輪４０Ａ及び一対の後輪４０Ｂを、車両上面から見て、それぞれ「ハ」の字になるよう操舵角を制御する。すなわち、制御部１０は操舵手段２０を用いて、一対の前輪４０Ａのうち、右側の車輪４０Ａｒを左向きかつ左側の車輪４０Ａｌを右向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、一対の後輪４０Ｂのうち、右側の車輪４０Ｂｒを左向きかつ左側の車輪４０Ｂｌを右向きとなるよう操舵角を制御する。 In a vehicle 1 that can be steered with all four wheels, when the control unit 10 selects the efficient brake as the applied brake based on the brake operation information and rear vehicle information, it first controls the brake means 30 to control the brake pressure. Furthermore, the control unit 10 uses the steering means 20 to control the steering angle so that the pair of front wheels 40A and the pair of rear wheels 40B form a "V" shape when viewed from above the vehicle, for example as shown in FIG. 11 above. In other words, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 40Ar of the pair of front wheels 40A faces left and the left wheel 40Al faces right. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 40Br of the pair of rear wheels 40B faces left and the left wheel 40Bl faces right.
　前掲図１１では、操舵手段２０を用いて、一対の前輪４０Ａ及び一対の後輪４０Ｂを、車両上面から見て、それぞれ「ハ」の字になるよう操舵角を制御する態様を例示したが、例えば前掲図１２に示すように、一対の前輪４０Ａ及び一対の後輪４０Ｂを、車両上面から見て、それぞれ逆「ハ」の字になるよう操舵角を制御してもよい。すなわち、制御部１０は操舵手段２０を用いて、一対の前輪４０Ａのうち、右側の車輪４０Ａｒを右向きかつ左側の車輪４０Ａｌを左向きとなるよう操舵角を制御する。また、制御部１０は操舵手段２０を用いて、一対の後輪４０Ｂのうち、右側の車輪４０Ｂｒを右向きかつ左側の車輪４０Ｂｌを左向きとなるよう操舵角を制御する。 In FIG. 11, the steering means 20 is used to control the steering angle so that the pair of front wheels 40A and the pair of rear wheels 40B form a "V" shape when viewed from above the vehicle, but as shown in FIG. 12, the steering angle may be controlled so that the pair of front wheels 40A and the pair of rear wheels 40B form an inverted "V" shape when viewed from above the vehicle. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 40Ar of the pair of front wheels 40A faces right and the left wheel 40Al faces left. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 40Br of the pair of rear wheels 40B faces right and the left wheel 40Bl faces left.
　このように、効率ブレーキを作動させた場合には、単にブレーキ圧を制御するだけでなく、左右一対の車輪４０Ａ，４０Ｂを内側に向けて進行方向側を狭くしたり、外側に向けて進行方向側を広くしたりすることで、車輪４０と地面の接触面の摩擦力を増大させる。これにより、停止までの制動距離を十分に短くすることが可能となる。このとき、制御部１０は、車輪４０の操舵角を調整することで、車輪４０と地面の間の摩擦力を調整することができる。 In this way, when the efficiency brake is activated, the brake pressure is not simply controlled, but the pair of left and right wheels 40A, 40B are turned inward to narrow the side in the direction of travel, or turned outward to widen the side in the direction of travel, thereby increasing the frictional force between the contact surface of the wheels 40 and the ground. This makes it possible to sufficiently shorten the braking distance required to stop the vehicle. At this time, the control unit 10 can adjust the frictional force between the wheels 40 and the ground by adjusting the steering angle of the wheels 40.
＜ブレーキの種類の選択＞
　上述したように、制動距離を短縮するという観点では、効率ブレーキを選択することが望ましいが、自車両を取り巻く状況によっては、効率ブレーキではなく通常ブレーキを選択することが望ましい場合がある。 <Selecting the brake type>
As described above, from the viewpoint of shortening the braking distance, it is desirable to select efficient braking. However, depending on the circumstances surrounding the vehicle, it may be desirable to select normal braking rather than efficient braking.
　例えば、図１６に示すように、後方車両が猛スピードで迫ってくる状況下で、効率ブレーキを作動させると、自車両は短い制動距離で停止することができるものの、後方車両はブレーキが間に合わず、後方車両から追突されるおそれがある。 For example, as shown in Figure 16, if efficient braking is applied when a vehicle behind is approaching at high speed, the vehicle can stop in a short braking distance, but the vehicle behind may not be able to brake in time and may be rear-ended by the vehicle behind.
　このような問題を未然に解消するために、本実施形態では、制御部１０は、後方車両からの追突も回避できるように、作動するブレーキの種類を選択する。 To prevent such problems from occurring, in this embodiment, the control unit 10 selects the type of brake to be applied so that a rear-end collision from a vehicle behind can also be avoided.
　具体的には、制御部１０は、第１センサ５０から取得されるブレーキ操作情報、第２センサ６０から取得される後方車両情報に基づき、通常ブレーキを作動するか、効率ブレーキを作動するかを選択する。 Specifically, the control unit 10 selects whether to apply normal brakes or efficient brakes based on the brake operation information obtained from the first sensor 50 and the rear vehicle information obtained from the second sensor 60.
　例えば、制御部１０は、十分な車間距離等が確保されているために、効率ブレーキを作動しても後方車両から追突される可能性はないと判断すると、効率ブレーキを選択する。 For example, if the control unit 10 determines that there is no risk of being rear-ended by a vehicle behind even if the efficient brake is applied because a sufficient inter-vehicle distance is secured, the control unit 10 selects the efficient brake.
　一方、制御部１０は、十分な車間距離等が確保されていないために、効率ブレーキを作動した場合には後方車両から追突される可能性が高いと判断すると、通常ブレーキを選択する。このように、本実施形態では、自車両を取り巻く状況に応じて、作動するブレーキの種類を選択することで、後方車両からの追突を確実に防ぐことが可能となる。なお、ブレーキの種類の選択基準については、衝突事故の発生確率などを勘案して任意に設定・変更可能である。例えば、衝突事故の過去事例等に基づいて、車間距離及び相対速度から衝突事故の発生確率を導出し、導出した衝突事故の発生確率が閾値未満である場合には、効率ブレーキを選択する一方、閾値を超えた場合には、通常ブレーキを選択してもよい。 On the other hand, if the control unit 10 determines that there is a high possibility of being rear-ended by a vehicle behind if the efficient brake is applied because a sufficient inter-vehicle distance is not secured, the control unit 10 selects the normal brake. In this way, in this embodiment, it is possible to reliably prevent rear-end collisions from vehicles behind by selecting the type of brake to be applied according to the situation surrounding the vehicle. The criteria for selecting the type of brake can be set or changed as desired, taking into account the probability of a collision accident occurring. For example, the probability of a collision accident occurring can be derived from the inter-vehicle distance and relative speed based on past collision accident cases, and if the derived probability of a collision accident occurring is less than a threshold value, the efficient brake can be selected, whereas if it exceeds the threshold value, the normal brake can be selected.
　図１７は、ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。 FIG. 17 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with a brake system.
　制御部１０は、車両１の走行中に、第１センサ５０からブレーキ操作情報を取得したか否かを判断する（ステップＳ１０１）。 The control unit 10 determines whether or not brake operation information has been acquired from the first sensor 50 while the vehicle 1 is traveling (step S101).
　制御部１０は、ブレーキ操作情報を取得していない場合には（ステップＳ１０１：ＮＯ）、そのまま走行を続ける一方、ブレーキ操作情報を取得している場合には（ステップＳ１０１：ＹＥＳ）、第２センサ６０から後方車両情報を取得する（ステップＳ１０２）。 If the control unit 10 has not acquired brake operation information (step S101: NO), it continues driving as is, whereas if the control unit 10 has acquired brake operation information (step S101: YES), it acquires rear vehicle information from the second sensor 60 (step S102).
　制御部１０は、各センサから取得したブレーキ操作情報及び後方車両情報に基づき、作動するブレーキの種類を選択する（ステップＳ１０３）。 The control unit 10 selects the type of brake to be applied based on the brake operation information and rear vehicle information obtained from each sensor (step S103).
　制御部１０は、通常ブレーキを選択した場合には、ブレーキ手段３０に対して、ブレーキ圧の制御を指示する（ステップＳ１０４）。 If normal braking is selected, the control unit 10 instructs the brake means 30 to control the brake pressure (step S104).
　制御部１０は、効率ブレーキを選択した場合には、ブレーキ手段３０に対して、ブレーキ圧の制御を指示するとともに、操舵手段２０に対して、前掲図１１または前掲図１２に示す態様で車輪４０の操舵角を制御するように指示する（ステップＳ１０５）。 When the control unit 10 selects the efficient brake, it instructs the brake means 30 to control the brake pressure and instructs the steering means 20 to control the steering angle of the wheels 40 in the manner shown in Figure 11 or Figure 12 (step S105).
　そして、制御部１０は、報知手段７０のランプなどを利用して、ブレーキの作動状況（ブレーキの作動の有無、作動中のブレーキの種類など）を運転者に報知する（ステップＳ１０６）。 Then, the control unit 10 notifies the driver of the brake operation status (whether the brakes are operating, the type of brakes that are operating, etc.) using the lamps of the notification means 70 (step S106).
　制御部１０は、車両１が停止するまでの間は（ステップＳ１０７：ＮＯ）、ブレーキの種類の選択及び選択したブレーキの作動を継続する。 The control unit 10 continues selecting the type of brake and applying the selected brake until the vehicle 1 stops (step S107: NO).
　その後、制御部１０は、車両１が停止したことを検知すると（ステップＳ１０７：ＹＥＳ）、ブレーキの作動状況の報知を終了するとともに、ブレーキの作動を停止し（ステップＳ１０８）、処理を終了する。 After that, when the control unit 10 detects that the vehicle 1 has stopped (step S107: YES), it ends the notification of the brake operation status, stops the brake operation (step S108), and ends the process.
　以上説明したように、本実施形態に係るブレーキシステムによれば、自車両を取り巻く状況に応じて最適なブレーキ制御を行うことが可能となる。 As described above, the brake system according to this embodiment makes it possible to perform optimal brake control according to the circumstances surrounding the vehicle.
＜変形例＞
　上述した本実施形態では、後方車両の存在を前提に作動するブレーキの種類を選択したが、これに限る趣旨ではない。例えば、自車両が走行する路面状態などに応じて、作動するブレーキの種類を選択してもよい。 <Modification>
In the above-described embodiment, the type of brake to be applied is selected on the assumption that a vehicle behind is present, but the present invention is not limited to this. For example, the type of brake to be applied may be selected depending on the road surface condition on which the vehicle is traveling.
　変形例に係る第２センサ６０は、路面状態に関する路面関連情報を検知する。第２センサ６０は、例えば表面温度センサ、温湿度センサ、画像カメラなどによって構成されている。第２センサ６０は、路面状態（例えば、路面の凹凸、乾燥、半湿、湿潤、シャーベット、積雪、圧雪、凍結、湿度、気温、路面温度など）をあらわす路面関連情報を検知すると、制御部１０に送信する。 The second sensor 60 in the modified example detects road surface-related information relating to the road surface condition. The second sensor 60 is composed of, for example, a surface temperature sensor, a temperature and humidity sensor, an image camera, etc. When the second sensor 60 detects road surface-related information indicating the road surface condition (for example, unevenness of the road surface, dryness, semi-humidity, wetness, slush, snow accumulation, packed snow, freezing, humidity, air temperature, road surface temperature, etc.), it transmits the information to the control unit 10.
　制御部１０は、第１センサ５０から取得されるブレーキ操作情報、第２センサ６０から取得される路面関連情報に基づき、通常ブレーキを作動するか、効率ブレーキを作動するかを選択する。 The control unit 10 selects whether to apply normal brakes or efficient brakes based on the brake operation information obtained from the first sensor 50 and the road surface-related information obtained from the second sensor 60.
　例えば、制御部１０は、路面温度が０度以下であって路面が凍結などしている場合には、制動距離を可能な限り短くするために、効率ブレーキを選択する一方、路面が乾燥している場合には、通常ブレーキを選択する。これにより、路面状態などに応じて安全かつ最適なブレーキ制御を行うことが可能となる。 For example, when the road surface temperature is below 0 degrees and the road surface is frozen, the control unit 10 selects efficient braking to shorten the braking distance as much as possible, but when the road surface is dry, it selects normal braking. This makes it possible to perform safe and optimal brake control according to the road surface conditions, etc.
　なお、第２センサ６０は、路面状態に加えて、タイヤの摩耗状態（摩耗量など）を検知してもよい。この場合、制御部１０は、路面状態だけでなく、タイヤの摩耗状態を考慮に入れて最適なブレーキを選択することができる。もちろん、これに限らず、第２センサ６０によって検出される自車両の周囲環境に関わる様々な情報を利用して最適なブレーキを選択してもよい。 The second sensor 60 may detect the tire wear state (such as the amount of wear) in addition to the road surface condition. In this case, the control unit 10 can select the optimal brake by taking into account not only the road surface condition but also the tire wear state. Of course, this is not limited to the above, and the optimal brake may be selected by using various information related to the surrounding environment of the vehicle detected by the second sensor 60.
　また、操舵角の制御に関して、制御部１０は操舵手段２０を用いて、前輪４０Ａを「ハ」の字、後輪４０Ｂを逆「ハ」の字となるように操舵角を設定してもよい。また、制御部１０は操舵手段２０を用いて、前輪４０Ａを逆「ハ」の字、後輪４０Ｂを「ハ」の字となるように操舵角を設定してもよい。 Furthermore, with regard to steering angle control, the control unit 10 may use the steering means 20 to set the steering angle so that the front wheels 40A form a "V" shape and the rear wheels 40B form an inverted "V" shape.Furthermore, the control unit 10 may use the steering means 20 to set the steering angle so that the front wheels 40A form an inverted "V" shape and the rear wheels 40B form an inverted "V" shape.
　制御部１０は、一対の車輪４０Ａ又は４０Ｂのうち、車両１の進行方向と右側の車輪４０Ａｒ又は４０Ｂｒの操舵角との間の角度と、車両１の進行方向と左側の車輪４０Ａｌ又は４０Ｂｌの操舵角との間の角度とが、略同一となるように操舵手段２０を制御してよい。すなわち、車両１の進行方向と車輪４０Ａｒ又は４０Ｂｒの回転面とによって形成される角度と、車両１の進行方向と車輪４０Ａｌ又は４０Ｂｌの回転面とによって形成される角度とが、略同一となるように操舵手段２０を制御してよい。これにより、左右の車輪に働く摩擦力が略同一となり、減速時の操舵が安定することが期待できる。 The control unit 10 may control the steering means 20 so that the angle between the traveling direction of the vehicle 1 and the steering angle of the right wheel 40Ar or 40Br of the pair of wheels 40A or 40B is approximately the same as the angle between the traveling direction of the vehicle 1 and the steering angle of the left wheel 40Al or 40Bl. In other words, the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Ar or 40Br and the angle formed by the traveling direction of the vehicle 1 and the rotation plane of the wheel 40Al or 40Bl are approximately the same. This makes the frictional forces acting on the left and right wheels approximately the same, which is expected to stabilize steering during deceleration.
　また、制御部１０は、車両１の速度及び／又は加速度に応じて、車輪４０それぞれの操舵角を設定してもよい。例えば、制御部１０は、第２センサ６０が検知した情報に基づいて速度及び／又は加速度を取得する。そして、車両１の速度及び／又は加速度に適した操舵角を導出し、導出された操舵角になるよう操舵手段２０を制御する。このとき、メモリ１４に記憶された、速度及び／又は加速度と車輪４０それぞれの操舵角とのパターンデータを用いて、操舵角を導出してよい。これにより、車両１の速度及び／又は加速度に応じて、効率良く減速することが可能となる。 The control unit 10 may also set the steering angle of each wheel 40 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on information detected by the second sensor 60. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 40 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
　また、制御部１０は、車両１の速度が小さいほど、車両１の進行方向に対して一対の車輪４０Ａ又は４０Ｂそれぞれの操舵角が大きくなるように操舵手段２０を制御してよい。 The control unit 10 may also control the steering means 20 so that the steering angle of each of the pair of wheels 40A or 40B relative to the traveling direction of the vehicle 1 increases as the speed of the vehicle 1 decreases.
（５）第５実施形態
　従来、２輪駆動車や４輪駆動車では、駆動輪のタイヤの回転を減速して車両を停車、減速させる。
　ところで、車両が進行方向を変える場合（例えば、カーブを曲がる場合など）には、進行方向の変化の度合いなどに応じて適切に減速する必要がある。特に、大きなカーブに差し掛かるなどして車両の進行方向が大きく変わる場合に急激な減速をすると、スリップなどが発生する場合もあり危険である。 (5) Fifth Embodiment Conventionally, in two-wheel drive vehicles and four-wheel drive vehicles, the rotation of the tires of the drive wheels is decelerated to stop or decelerate the vehicle.
Incidentally, when a vehicle changes direction (for example, when turning a curve), it is necessary to decelerate appropriately depending on the degree of change in direction. In particular, when the vehicle changes direction significantly, for example, when approaching a large curve, sudden deceleration can cause slippage, which is dangerous.
　そこで本発明は、車両が進行方向を変える場合に適切に減速することが可能な効率ブレーキシステムを提供することを目的とする。 The present invention aims to provide an efficient brake system that can appropriately decelerate a vehicle when it changes direction.
　本発明の一態様に係る効率ブレーキシステムは、車両の左右に略対称に位置する少なくとも一対の車輪と、一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、車両の進行方向の変化を検知するセンサと、各々の車輪の操舵角が、進行方向の変化に応じて設定される角度になるように、操舵手段を制御する制御部を備えることを要旨とする。 The efficient brake system according to one aspect of the present invention comprises at least a pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle, a steering means capable of individually controlling the steering angle of each of the pair of wheels, a sensor that detects changes in the vehicle's traveling direction, and a control unit that controls the steering means so that the steering angle of each wheel becomes an angle that is set according to the change in the traveling direction.
　本発明によれば、車両が進行方向を変える場合に適切に減速することが可能な効率ブレーキシステムを提供することができる。 The present invention provides an efficient brake system that can appropriately decelerate a vehicle when it changes direction.
　図１８は、本実施形態に係る効率ブレーキシステムを搭載する車両１のシステム構成の一例を示す図である。図１に示す車両１は、制御部１０と、操舵手段２０と、車輪３０と、第１センサ４０と、第２センサ５０と、ブレーキ手段６０を備える。また、図示を省略するが、従来の車両を構成する種々の構成を備えてもよい。車両１は、運転者が車両１を運転する手動運転機能の他に、車両１の自動運転を支援する自動運転機能を有し、各運転モードを任意に選択できるようにしてもよい。 FIG. 18 is a diagram showing an example of the system configuration of a vehicle 1 equipped with the efficient brake system according to this embodiment. The vehicle 1 shown in FIG. 1 includes a control unit 10, a steering means 20, wheels 30, a first sensor 40, a second sensor 50, and a braking means 60. Although not shown, the vehicle 1 may also include various configurations that constitute a conventional vehicle. In addition to a manual driving function that allows the driver to drive the vehicle 1, the vehicle 1 may also have an automatic driving function that assists in automatic driving of the vehicle 1, and each driving mode may be freely selected.
　制御部１０は、車両１の内外から取得した種々の情報を用いて、操舵手段２０に車輪３０の操舵角を制御させることができる。ここで操舵角とは、車両１の進行方向に対する車輪３０の角度である。例えば、制御部１０は、第１センサ４０及び／又は第２センサ５０が検知した情報に基づいて、操舵手段２０に対して、車輪３０の操舵角を指示する。このとき、制御部１０は、第１センサ４０からブレーキによる車両１の減速に関する情報を取得することができる。また、制御部１０は、第２センサ５０から車両１の速度、加速度、角速度、または角加速度に関する情報を取得することができる。また、第２センサ５０から車両１の位置情報が取得できてもよい。 The control unit 10 can cause the steering means 20 to control the steering angle of the wheels 30 using various information acquired from inside and outside the vehicle 1. Here, the steering angle is the angle of the wheels 30 with respect to the traveling direction of the vehicle 1. For example, the control unit 10 instructs the steering means 20 on the steering angle of the wheels 30 based on information detected by the first sensor 40 and/or the second sensor 50. At this time, the control unit 10 can acquire information on the deceleration of the vehicle 1 due to braking from the first sensor 40. The control unit 10 can also acquire information on the speed, acceleration, angular velocity, or angular acceleration of the vehicle 1 from the second sensor 50. Furthermore, position information of the vehicle 1 may be acquired from the second sensor 50.
　操舵手段２０は、制御部１０から受け取った指示に基づいて、車輪３０それぞれの操舵角を個別に制御することができる。本実施形態において、操舵手段２０としては、車両１が備える４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌそれぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌを備え、各操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌが各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌの操舵角を個別に設定し、制御できるように構成されてよい。 The steering means 20 can individually control the steering angle of each wheel 30 based on instructions received from the control unit 10. In this embodiment, the steering means 20 includes steering means 20Ar, 20Al, 20Br, and 20Bl corresponding to each of the four wheels 30Ar, 30Al, 30Br, and 30Bl of the vehicle 1, and each steering means 20Ar, 20Al, 20Br, and 20Bl may be configured to individually set and control the steering angle of each wheel 30Ar, 30Al, 30Br, and 30Bl.
　車両１は、少なくとも一対の車輪３０を備え、車両１の左右に略対称に配置される。本実施形態において、車両１は４輪で構成され、左右一対の前輪３０Ａ（３０Ａｒと３０Ａｌ）と、左右一対の後輪３０Ｂ（３０Ｂｒと３０Ｂｌ）とを有する。 The vehicle 1 has at least a pair of wheels 30, which are arranged approximately symmetrically on the left and right sides of the vehicle 1. In this embodiment, the vehicle 1 is configured with four wheels, and has a pair of left and right front wheels 30A (30Ar and 30Al) and a pair of left and right rear wheels 30B (30Br and 30Bl).
　各車輪３０にはハブの内部に実装される電気モーターであるハブモーター（HUB motor）が搭載されてもよい。なお、モーター自体がハブの内部に実装されていなくても、電気モーターの駆動力が直接ホイールへ伝わるモーター（インホイールモーター（ＩＷＭ：In Wheel Motor））が搭載されてもよい。４輪全てにハブモーターが搭載されることで、車輪３０それぞれの動きを個別に制御することができるようになるため、車輪の角度を変えて減速する効率ブレーキを実現させる上で好ましい。 Each wheel 30 may be equipped with a hub motor, which is an electric motor mounted inside the hub. Note that even if the motor itself is not mounted inside the hub, a motor (in-wheel motor (IWM)) in which the driving force of the electric motor is transmitted directly to the wheel may be installed. By installing hub motors on all four wheels, it becomes possible to individually control the movement of each wheel 30, which is preferable for realizing efficient braking that changes the angle of the wheels to decelerate.
　第１センサ４０は、ブレーキ手段６０によるブレーキに関する情報を検知する。例えば、第１センサ４０は、運転者によるブレーキ操作や自動運転制御により、ブレーキ手段６０による車輪３０の制動が発動したことを検知し、検知した情報を制御部１０に送信する。 The first sensor 40 detects information related to braking by the braking means 60. For example, the first sensor 40 detects that the braking means 60 has applied the brakes to the wheels 30 due to the driver's brake operation or automatic driving control, and transmits the detected information to the control unit 10.
　第２センサ５０は、車両１に搭載される種々のセンサであってよい。例えば、第２センサ５０は、速度センサ、加速度センサ、ジャイロセンサなどのほか、車輪３０の回転数を測定する車輪速センサ、ステアリングホイールの角度を計測する舵角センサ、車両１が回転する速度を検出するヨーレートセンサ、ＧＰＳセンサなどであってもよい。第２センサ５０は検知した情報を制御部１０に送信する。 The second sensor 50 may be any of various sensors mounted on the vehicle 1. For example, the second sensor 50 may be a speed sensor, an acceleration sensor, a gyro sensor, or a wheel speed sensor that measures the number of rotations of the wheels 30, a steering angle sensor that measures the angle of the steering wheel, a yaw rate sensor that detects the speed at which the vehicle 1 turns, a GPS sensor, or the like. The second sensor 50 transmits the detected information to the control unit 10.
　ブレーキ手段６０は、制御部１０から受け取った指示に基づいて、車輪３０それぞれを制動することができる。ブレーキ手段６０は、例えば各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌにそれぞれ設けられたホイールシリンダ（図示略）や、ホイールシリンダに接続されたブレーキアクチュエータ（図示略）などを備える構成であってもよい。ブレーキアクチュエータは、モーターで駆動される液圧ポンプ等で発生したブレーキ圧を、任意の大きさに制御してホイールシリンダに供給することで、各車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌを制動する。制御部１０は、運転者がブレーキペダルを踏んだことを検知した場合に、ブレーキ手段６０に対し車輪３０の制動を行うように指示を出してもよいし、自動運転制御により、ブレーキ手段６０に対して車輪３０の制動を行うように指示を出してもよい。 The braking means 60 can brake each of the wheels 30 based on instructions received from the control unit 10. The braking means 60 may be configured to include, for example, wheel cylinders (not shown) provided on each of the wheels 30Ar, 30Al, 30Br, and 30Bl, and brake actuators (not shown) connected to the wheel cylinders. The brake actuator controls the brake pressure generated by a hydraulic pump driven by a motor to an arbitrary magnitude and supplies it to the wheel cylinders to brake each of the wheels 30Ar, 30Al, 30Br, and 30Bl. When the control unit 10 detects that the driver has stepped on the brake pedal, it may issue an instruction to the braking means 60 to brake the wheels 30, or may issue an instruction to the braking means 60 to brake the wheels 30 by automatic driving control.
　本実施形態に係る制御部１０の構成は、前掲図２と同様であるため、図示を省略する。
　制御部１０は、例えば、プロセッサ１２とメモリ１４とを含む。 The configuration of the control unit 10 according to this embodiment is the same as that shown in FIG. 2, and therefore is not shown in the figure.
The control unit 10 includes, for example, a processor 12 and a memory 14 .
　プロセッサ１２は、車両１全体の動作を制御する。プロセッサ１２として、例えば、ＣＰＵ（Central Processing Unit）、ＭＰＵ（Micro Processing Unit）、ＦＰＧＡ（Field Programmable Gate Array）又はマイコン（マイクロコントローラ）等を用いることができる。プロセッサ１２は、メモリ１４に記憶されたプログラムを実行することで、車両１全体の動作を制御する制御部として機能する。 The processor 12 controls the operation of the entire vehicle 1. The processor 12 may be, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), or a microcontroller. The processor 12 functions as a control unit that controls the operation of the entire vehicle 1 by executing programs stored in the memory 14.
　メモリ１４は、プロセッサ１２により実行される各種プログラムや各種データを記憶する。メモリ１４には、例えば、ＲＯＭ（Read Only Memory）やＲＡＭ（Random Access Memory）等の揮発性記憶装置、及びＨＤＤ（Hard Disk Drive）やフラッシュメモリ等の不揮発性記憶装置が含まれ得る。各種データは、例えば、効率ブレーキを用いる際の、４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌそれぞれの操舵角度のパターンデータや、効率ブレーキを作動させる条件データ（例えば、車両速度の閾値等）を含む。 The memory 14 stores various programs and data executed by the processor 12. The memory 14 may include, for example, volatile storage devices such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and non-volatile storage devices such as a HDD (Hard Disk Drive) or a flash memory. The various data include, for example, pattern data of the steering angles of each of the four wheels 30Ar, 30Al, 30Br, and 30Bl when using the efficiency brake, and condition data for activating the efficiency brake (for example, a vehicle speed threshold value, etc.).
　図１９は、効率ブレーキシステムを搭載した車両１の処理手順の一例を示すフローチャートである。 FIG. 19 is a flowchart showing an example of a processing procedure for a vehicle 1 equipped with an efficient brake system.
　制御部１０は、車両１の走行中、車両１の進行方向に関する情報を取得する（ステップＳ１０１）。さらに、制御部１０は、取得した情報に基づいて、車両１の進行方向が変化しているか否かを判定する（ステップＳ１０２）。制御部１０は、例えば、ジャイロセンサによって検出される角速度の変化に基づいて進行方向の変化の有無を判定することができる。また、制御部１０は、ＧＰＳセンサから車両１の位置情報を取得し、車両１が走行している道路の情報から進行方向の変化の情報を取得してもよい。なお、本実施形態では、車両１の進行方向の変化が検知された場合に、効率ブレーキを作動させる態様を例示するが、これに限る趣旨ではない。例えば、車両１の進行方向の変化が検出され、かつ、車両の速度が設定基準速度（例えば、〇×ｋｍ／ｈ）を超えた場合に、効率ブレーキを作動させてもよい。 The control unit 10 acquires information regarding the traveling direction of the vehicle 1 while the vehicle 1 is traveling (step S101). Furthermore, the control unit 10 determines whether the traveling direction of the vehicle 1 has changed based on the acquired information (step S102). The control unit 10 can determine whether the traveling direction has changed based on, for example, a change in angular velocity detected by a gyro sensor. The control unit 10 may also acquire position information of the vehicle 1 from a GPS sensor and acquire information on the change in the traveling direction from information on the road on which the vehicle 1 is traveling. Note that, in this embodiment, an example is shown in which the efficiency brake is activated when a change in the traveling direction of the vehicle 1 is detected, but this is not intended to be limiting. For example, the efficiency brake may be activated when a change in the traveling direction of the vehicle 1 is detected and the speed of the vehicle exceeds a set reference speed (for example, xx km/h).
　制御部１０は、車両１の進行方向の変化が検出されていない場合には（ステップＳ１０２：ＮＯ）、ステップＳ１０３に進み、通常の運転制御を行い、ステップＳ１０１に戻る。一方、制御部１０は、車両１の進行方向の変化が検出されると（ステップＳ１０２：ＹＥＳ）、操舵手段２０に指示を出力して車輪３０の操舵角を制御し（ステップＳ１０４）、効率ブレーキを作動する。 If the control unit 10 does not detect a change in the traveling direction of the vehicle 1 (step S102: NO), the control unit 10 proceeds to step S103, performs normal driving control, and returns to step S101. On the other hand, if the control unit 10 detects a change in the traveling direction of the vehicle 1 (step S102: YES), it outputs an instruction to the steering means 20 to control the steering angle of the wheels 30 (step S104) and activates the efficiency brake.
　図２０及び図２１は、操舵手段２０による車輪３０の操舵角の制御を説明する図である。図２０及び図２１に示す例では、車両１は４つの車輪３０Ａｒ、３０Ａｌ、３０Ｂｒ、３０Ｂｌ全ての操舵角を、それぞれに対応する操舵手段２０Ａｒ、２０Ａｌ、２０Ｂｒ、２０Ｂｌによって個別に制御することができる。ブレーキ手段２０による減速は、車輪３０の回転を制動することで行うが、操舵手段２０は、４輪それぞれの操舵角を変化させることで、進行方向に向かうモーメントを打ち消して減速する。 FIGS. 20 and 21 are diagrams for explaining the control of the steering angle of the wheels 30 by the steering means 20. In the example shown in FIG. 20 and FIG. 21, the vehicle 1 can individually control the steering angles of all four wheels 30Ar, 30Al, 30Br, and 30Bl by the corresponding steering means 20Ar, 20Al, 20Br, and 20Bl. The braking means 20 decelerates by braking the rotation of the wheels 30, but the steering means 20 decelerates by changing the steering angle of each of the four wheels to cancel out the moment in the traveling direction.
　図２０に示す例では、制御部１０は操舵手段２０を用いて、前輪３０Ａｒ、３０Ａｌ及び後輪３０Ｂｒ、３０Ｂｌが、車両１の上面から見て、それぞれ「ハ」の字になるように操舵角を制御する。すなわち、制御部１０は操舵手段２０を用いて、右側の車輪３０Ａｒが左向きかつ左側の車輪３０Ａｌが右向きとなるように操舵角を制御する。また、制御部１０は操舵手段２０を用いて、右側の車輪３０Ｂｒが左向きかつ左側の車輪３０Ｂｌが右向きとなるよう操舵角を制御する。このように、操舵手段２０を用いて左右一対の車輪３０Ａ，３０Ｂを内側に向けて進行方向側を狭くすることで、車輪３０と地面の接触面の摩擦力を増大させ、減速を実現させる。これとは逆に、制御部１０は操舵手段２０を用いて、前輪３０Ａｒ、３０Ａｌ及び後輪３０Ｂｒ、３０Ｂｌが、車両１の上面から見て、それぞれ逆「ハ」の字になるように操舵角を制御してもよい（図２１参照）。 In the example shown in Figure 20, the control unit 10 uses the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form a "V" shape when viewed from above the vehicle 1. That is, the control unit 10 uses the steering means 20 to control the steering angle so that the right wheel 30Ar faces left and the left wheel 30Al faces right. The control unit 10 also uses the steering means 20 to control the steering angle so that the right wheel 30Br faces left and the left wheel 30Bl faces right. In this way, by using the steering means 20 to turn the pair of left and right wheels 30A, 30B inward to narrow the traveling direction side, the frictional force between the contact surface of the wheels 30 and the ground is increased, achieving deceleration. Conversely, the control unit 10 may use the steering means 20 to control the steering angle so that the front wheels 30Ar, 30Al and the rear wheels 30Br, 30Bl form an inverted V shape when viewed from above the vehicle 1 (see FIG. 21).
　また、制御部１０は、車輪３０の操舵角が車両１の進行方向の変化に応じた角度となるように操舵手段２０を制御する。図２２に示すように、進行方向に対する車輪３０の操舵角αが大きければ大きいほど（すなわち、「ハ」の字の場合は進行方向側が狭くなるほど、逆「ハ」の字の場合は進行方向側が広くなるほど）地面に対する摩擦力は増大し、減速の効果は高くなる。このため、例えば車両１がカーブに差し掛かるなどして進行方向が変化した場合には、カーブの大きさに応じて車輪の操舵角αを制御し、車両１の減速の度合いを変化させてもよい。例えば、図２３に示すように、カーブの曲率（曲がり具合）Ｃが大きい場合には、減速の度合いを高めるために車輪３０の操舵角αを大きく設定する一方、図２４に示すように、カーブの曲率Ｃが小さい場合には、減速の度合いを緩めるために車輪３０の操舵角αを小さく設定してもよい。 The control unit 10 also controls the steering means 20 so that the steering angle of the wheels 30 is an angle that corresponds to the change in the traveling direction of the vehicle 1. As shown in FIG. 22, the greater the steering angle α of the wheels 30 relative to the traveling direction (i.e., the narrower the traveling direction side in the case of a "V" shape, and the wider the traveling direction side in the case of an inverted "V" shape), the greater the frictional force with the ground and the greater the deceleration effect. For this reason, for example, when the traveling direction changes because the vehicle 1 approaches a curve, the steering angle α of the wheels may be controlled according to the magnitude of the curve to change the degree of deceleration of the vehicle 1. For example, as shown in FIG. 23, when the curvature (degree of curvature) C of the curve is large, the steering angle α of the wheels 30 may be set large to increase the degree of deceleration, while as shown in FIG. 24, when the curvature C of the curve is small, the steering angle α of the wheels 30 may be set small to reduce the degree of deceleration.
　もっとも、このような設定に限る趣旨ではなく、例えば減速までの時間の短縮化と走行の安定性の確保の両立を図りたい場合には、制御部１０は、車両１の速度が小さいほど進行方向に対する車輪３０の操舵角αが大きくなるように制御する。もちろん、より短い距離で車両１の走行速度を落としたい場合には、車両１の速度が大きいほど進行方向に対する車輪３０の操舵角αが大きくなるように制御してもよい。車両１の速度と車輪３０の操舵角αの関係はこれらに限られず、効率的で安定した車両１の制動が行えるように設定することができる。このとき、制御部１０は、メモリ１４に記憶された、車両１の進行方向の変化量と、車両１の速度と、車輪３０の操舵角との関係をあらわすパターンデータを用いて、適切な操舵角を導出するようにしてもよい。 However, the present invention is not limited to such settings. For example, when it is desired to shorten the time until deceleration while ensuring driving stability, the control unit 10 controls the steering angle α of the wheels 30 relative to the traveling direction to be larger as the speed of the vehicle 1 is slower. Of course, when it is desired to reduce the traveling speed of the vehicle 1 over a shorter distance, the steering angle α of the wheels 30 relative to the traveling direction may be controlled to be larger as the speed of the vehicle 1 is faster. The relationship between the speed of the vehicle 1 and the steering angle α of the wheels 30 is not limited to this, and can be set so as to enable efficient and stable braking of the vehicle 1. In this case, the control unit 10 may derive an appropriate steering angle using pattern data stored in the memory 14 that indicates the relationship between the amount of change in the traveling direction of the vehicle 1, the speed of the vehicle 1, and the steering angle of the wheels 30.
　図２５は、効率的に車両１を停止させるのに適切な車輪３０の操舵角のパターンデータの例を示す図である。
　制御部１０は、車両の進行方向の変化量δが第１基準変化量δｓｔ１を超えており、かつ、車両１の速度Ｖが第１基速度Ｖｓｔ１を超えている場合には、第１パターンデータＤ１を利用して、外側（すなわち右側）に位置する車輪３０Ａｒ、３０Ｂｒの操舵角α２が、内側（すなわち左側）に位置する車輪３０Ａｌ、３０Ｂｌの操舵角α１よりも大きくなるように設定する。
　一方、制御部１０は、車両の進行方向の変化量δが第１基準変化量δｓｔ１を超えているものの、車両１の速度Ｖが第１基速度Ｖｓｔ１を超えていない場合には、第２パターンデータＤ２を利用して、内側に位置する車輪３０Ａｒ、３０Ｂｒの操舵角α１を変えずに（「ＫＥＥＰ」）、外側に位置する車輪３０Ａｌ、３０Ｂｌの操舵角α２を変える（「ＣＨＡＮＧＥ」）ように設定する。 FIG. 25 is a diagram showing an example of pattern data of the steering angle of the wheels 30 that is appropriate for efficiently stopping the vehicle 1. In FIG.
When the change δ in the vehicle's direction of travel exceeds the first reference change δst1 and the speed V of the vehicle 1 exceeds the first reference speed Vst1, the control unit 10 uses the first pattern data D1 to set the steering angle α2 of the wheels 30Ar, 30Br located on the outside (i.e., the right side) to be greater than the steering angle α1 of the wheels 30Al, 30Bl located on the inside (i.e., the left side).
On the other hand, when the change δ in the vehicle's direction of travel exceeds the first reference change δst1 but the speed V of the vehicle 1 does not exceed the first reference speed Vst1, the control unit 10 uses the second pattern data D2 to set the steering angle α1 of the inner wheels 30Ar, 30Br to remain unchanged ("KEEP"), while changing the steering angle α2 of the outer wheels 30Al, 30Bl ("CHANGE").
　上述したパターンデータは、あくまで例示にすぎず、その他の態様で車両３０の操舵角を制御してもよい。例えば、制御部１０は、外側の車輪３０Ａｒ、３０Ｂｒの操舵角と、内側の車輪３０Ａｌ、３０Ｂｌの操舵角が、略同一となるように操舵手段２０を制御してもよい。すなわち、車両１の進行方向と車輪３０Ａｒ又は３０Ｂｒの回転面とによって形成される角度と、車両１の進行方向と車輪３０Ａｌ又は３０Ｂｌの回転面とによって形成される角度とが、略同一となるように操舵手段２０を制御してよい。これにより、左右の車輪に働く摩擦力が略同一となり、減速時の操舵が安定することが期待できる。 The above-mentioned pattern data is merely an example, and the steering angle of the vehicle 30 may be controlled in other ways. For example, the control unit 10 may control the steering means 20 so that the steering angle of the outer wheels 30Ar, 30Br and the steering angle of the inner wheels 30Al, 30Bl are substantially the same. In other words, the steering means 20 may be controlled so that the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Ar or 30Br and the angle formed by the traveling direction of the vehicle 1 and the rotational plane of the wheel 30Al or 30Bl are substantially the same. This makes the frictional forces acting on the left and right wheels substantially the same, and is expected to stabilize steering during deceleration.
　このようにして車輪３０の操舵角を制御すると、制御部１０は、車両１が停止または減速に関する情報が解除されたか否かを判定する（ステップＳ１０５）。制御部１０は、車両１が停止または減速に関する情報が解除されていない場合には（ステップＳ１０５：ＮＯ）、ステップＳ１０４に戻り、車輪３０の操舵角の制御を実施する。一方、制御部１０は、車両１が停止、または、減速に関する情報が解除されると（ステップＳ１０５：ＹＥＳ）、車輪３０の操舵角が進行方向と同じ方向になるように操舵手段２０を制御することで効率ブレーキの作動を停止し（ステップＳ１０６）、処理を終了する。 After controlling the steering angle of the wheels 30 in this manner, the control unit 10 determines whether the information regarding the vehicle 1 stopping or deceleration has been released (step S105). If the information regarding the vehicle 1 stopping or deceleration has not been released (step S105: NO), the control unit 10 returns to step S104 and controls the steering angle of the wheels 30. On the other hand, if the vehicle 1 has stopped or the information regarding deceleration has been released (step S105: YES), the control unit 10 stops the operation of the efficiency brake by controlling the steering means 20 so that the steering angle of the wheels 30 is in the same direction as the traveling direction (step S106), and ends the process.
　なお、制御部１０は、車両１の速度及び／又は加速度に応じて、車輪３０それぞれの操舵角を設定してもよいのはもちろんである。例えば、制御部１０は、第２センサ５０が検知した情報に基づいて速度及び／又は加速度を取得する。そして、車両１の速度及び／又は加速度に適した操舵角を導出し、導出された操舵角になるよう操舵手段２０を制御する。このとき、メモリ１４に記憶された、速度及び／又は加速度と車輪３０それぞれの操舵角とのパターンデータを用いて操舵角を導出するようにしてもよい。これにより、車両１の速度及び／又は加速度に応じて、効率良く減速することが可能となる。 Of course, the control unit 10 may set the steering angle of each wheel 30 according to the speed and/or acceleration of the vehicle 1. For example, the control unit 10 obtains the speed and/or acceleration based on the information detected by the second sensor 50. Then, the control unit 10 derives a steering angle suitable for the speed and/or acceleration of the vehicle 1, and controls the steering means 20 to achieve the derived steering angle. At this time, the steering angle may be derived using pattern data of the speed and/or acceleration and the steering angle of each wheel 30 stored in the memory 14. This makes it possible to efficiently decelerate according to the speed and/or acceleration of the vehicle 1.
　以上のように、本実施形態によれば、制御部１０は、車両１がカーブに差し掛かるなどして進行方向の変化を検知すると、操舵手段２０に指示を出力して車輪３０の操舵角を車両１の進行方向の変化に応じた角度に変化させ、進行方向に向かうモーメントを打ち消して減速するように制御する。これにより、車両１の進行方向の変化に合わせて効率よく減速させながら、急激な減速によるスリップなどを回避することができる。 As described above, according to this embodiment, when the control unit 10 detects a change in the traveling direction, for example when the vehicle 1 approaches a curve, it outputs an instruction to the steering means 20 to change the steering angle of the wheels 30 to an angle corresponding to the change in the traveling direction of the vehicle 1, and controls the vehicle to decelerate by canceling the moment in the traveling direction. This makes it possible to efficiently decelerate the vehicle 1 in accordance with the change in the traveling direction, while avoiding slipping due to sudden deceleration.
　なお、車両１がカーブを走行している間は、カーブに対して外側に位置する車輪３０の操舵角のみをカーブに応じて変化させるように制御してもよい。これにより、カーブ走行中により影響が大きい車輪３０の操舵角を制御し、効率的に減速することができる。 Note that while the vehicle 1 is traveling around a curve, only the steering angle of the wheels 30 located on the outside of the curve may be controlled to change in accordance with the curve. This allows the steering angle of the wheels 30, which have a greater impact when traveling around a curve, to be controlled, allowing efficient deceleration.
　なお、本発明は、前述した各実施形態及び変形例に限定されるものではなく、本発明の要旨を逸脱しない範囲内において、他の様々な形で実施することができる。したがって、上記実施形態はあらゆる点で単なる例示にすぎず、限定的に解釈されるものではない。例えば、前述した各処理ステップは処理内容に矛盾を生じない範囲で任意に順番を変更し、又は並列に実行することができる。 The present invention is not limited to the above-described embodiments and modifications, and can be implemented in various other forms without departing from the spirit of the present invention. Therefore, the above-described embodiments are merely examples in all respects and should not be interpreted in a restrictive manner. For example, the above-described processing steps can be arbitrarily changed in order or executed in parallel as long as no inconsistencies arise in the processing content.
１　車両
１０　制御部
１２　プロセッサ
１４　メモリ
２０　操舵手段
３０　車輪
４０　第１センサ
５０　第２センサ
  Reference Signs List 1 Vehicle 10 Control unit 12 Processor 14 Memory 20 Steering means 30 Wheels 40 First sensor 50 Second sensor

Claims (26)

  1. 　車両の左右に略対称に位置する少なくとも一対の車輪と、
    　前記一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、
    　前記車両の減速に関する情報を取得又は生成する制御部であって、前記情報を取得又は生成したとき、前記車両の進行方向に対して、前記一対の車輪のうち右側の車輪を左向きかつ左側の車輪を右向き、又は、右側の車輪を右向きかつ左側の車輪を左向きとなるように、前記操舵手段を制御する、制御部と、
    を備える効率ブレーキシステム。     At least one pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle;
    a steering means capable of individually controlling the steering angle of each of the pair of wheels;
    a control unit that acquires or generates information related to deceleration of the vehicle, and when the information is acquired or generated, controls the steering means so that the right wheel of the pair of wheels faces left and the left wheel faces right, or the right wheel faces right and the left wheel faces left, relative to a traveling direction of the vehicle;
    Efficient braking system.
  2. 　前記制御部は、前記車両の進行方向と前記右側の車輪の操舵角との間の角度と、前記車両の進行方向と前記左側の車輪の操舵角との間の角度とが、略同一となるように前記操舵手段を制御する、
    請求項１記載の効率ブレーキシステム。     the control unit controls the steering means so that an angle between a traveling direction of the vehicle and a steering angle of the right-side wheels and an angle between a traveling direction of the vehicle and a steering angle of the left-side wheels are substantially equal to each other.
    2. The efficient braking system of claim 1.
  3. 　前記制御部は、前記一対の車輪それぞれが、前記車両の速度又は加速度のうち少なくともいずれかに基づいて導出された操舵角になるように前記操舵手段を制御する、
    請求項１記載の効率ブレーキシステム。     The control unit controls the steering means so that each of the pair of wheels has a steering angle derived based on at least one of a speed or an acceleration of the vehicle.
    2. The efficient braking system of claim 1.
  4. 　前記制御部は、前記車両の速度が小さいほど、前記車両の進行方向に対して前記一対の車輪それぞれの操舵角が大きくなるように前記操舵手段を制御する、
    請求項３記載の効率ブレーキシステム。     the control unit controls the steering means so that the steering angle of each of the pair of wheels with respect to the traveling direction of the vehicle increases as the speed of the vehicle decreases.
    4. The efficient braking system of claim 3.
  5. 　前記制御部は、前記車両の速度が所定の閾値よりも大きいとき、前記減速に関する情報を検知又は生成しても、前記一対の車輪それぞれの操舵角を変化させない、
    請求項３記載の効率ブレーキシステム。     When the speed of the vehicle is greater than a predetermined threshold, the control unit does not change the steering angle of each of the pair of wheels even if the control unit detects or generates information regarding the deceleration.
    4. The efficient braking system of claim 3.
  6. 　前記制御部は、前記車両の加速度が所定の閾値よりも大きいとき、前記車両の進行方向に対して前記一対の車輪それぞれの操舵角が大きくなるように前記操舵手段を制御する、
    請求項３記載の効率ブレーキシステム。     The control unit controls the steering means so that, when the acceleration of the vehicle is greater than a predetermined threshold, the steering angle of each of the pair of wheels is increased with respect to the traveling direction of the vehicle.
    4. The efficient braking system of claim 3.
  7. 　車両の左右に略対称に位置する少なくとも一対の車輪と、
    　前記一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、
    　前記車両の加速度を検知するセンサと、
    　前記車両の加速度が第１の条件を満たした場合に、前記操舵手段を制御して、前記車両の進行方向に対する各々の車輪の操舵角を変化させる制御部を備えた、効率ブレーキシステム。     At least one pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle;
    a steering means capable of individually controlling the steering angle of each of the pair of wheels;
    A sensor for detecting an acceleration of the vehicle;
    An efficient brake system comprising a control unit that controls the steering means to change the steering angle of each wheel relative to the traveling direction of the vehicle when the acceleration of the vehicle satisfies a first condition.
  8. 　前記第１の条件は、前記車両の急加速、急ブレーキ、および急ハンドルの少なくとも１つが発生したことを示す信号が検知されることである、請求項７に記載の効率ブレーキシステム。 The efficient brake system of claim 7, wherein the first condition is that a signal indicating that at least one of sudden acceleration, sudden braking, and sudden steering of the vehicle has occurred is detected.
  9. 　前記制御部は、
    　前記車両の進行方向に対する各々の車輪の操舵角が、前記加速度に応じた角度になるように前記操舵手段を制御する、請求項７に記載の効率ブレーキシステム。     The control unit is
    8. An efficient brake system according to claim 7, wherein said steering means is controlled so that the steering angle of each wheel relative to the traveling direction of said vehicle becomes an angle according to said acceleration.
  10. 　前記制御部は、
    　前記車両の進行方向に対して、前記一対の車輪のうち、右側の車輪を左向きかつ左側の車輪を右向き、又は、右側の車輪を右向きかつ左側の車輪を左向きとなるように、前記操舵手段を制御する、請求項７に記載の効率ブレーキシステム。     The control unit is
    8. The efficient brake system according to claim 7, wherein the steering means is controlled so that, of the pair of wheels, the right wheel faces left and the left wheel faces right, or the right wheel faces right and the left wheel faces left, relative to the traveling direction of the vehicle.
  11. 　車両の左右に略対称に位置する少なくとも一対の車輪と、
    　前記一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、
    　前記一対の車輪に制動力を発生させるブレーキ手段と、
    　前記操舵手段及び前記ブレーキ手段を制御する制御部と、を備え、
    　前記制御部は、
    　制動中のいずれかの車輪がロック傾向にあると判定した場合に、前記一対の車輪に対する制動力が低減されるように前記ブレーキ手段を制御するとともに、前記一対の車輪を車両上面から見て略ハの字になるように前記操舵手段を制御する、効率ブレーキシステム。     At least one pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle;
    a steering means capable of individually controlling the steering angle of each of the pair of wheels;
    a brake means for generating a braking force on the pair of wheels;
    a control unit for controlling the steering means and the braking means,
    The control unit is
    An efficient brake system which, when it is determined that one of the wheels is prone to locking during braking, controls the brake means so as to reduce the braking force on the pair of wheels, and controls the steering means so that the pair of wheels form an approximately V-shape when viewed from above the vehicle.
  12. 　前記制御部は、
    　制動中のいずれかの車輪がロック傾向にあると判定した場合に、前記一対の車輪に対する制動力が低減されるように前記ブレーキ手段を制御するとともに、前記一対の車輪を車両上面から見て略逆ハの字になるように前記操舵手段を制御する、請求項１１に記載の効率ブレーキシステム。     The control unit is
    12. The efficient brake system according to claim 11, wherein when it is determined that one of the wheels is prone to locking during braking, the brake means is controlled so as to reduce the braking force on the pair of wheels, and the steering means is controlled so as to cause the pair of wheels to form an approximately inverted V shape when viewed from above the vehicle.
  13. 　前記制御部は、
    　制動中のいずれかの車輪がロック傾向にあると判定した場合に、前記一対の車輪に対する制動力が低減されるように前記ブレーキ手段を制御するとともに、前記一対の車輪を車両上面から見て略ハの字になるように前記操舵手段を制御する第１操舵モードと、前記一対の車輪を車両上面から見て略逆ハの字になるように前記操舵手段を制御する第２操舵モードとを交互に切り換えて、前記操舵手段を制御する、請求項１１に記載の効率ブレーキシステム。     The control unit is
    12. The efficient brake system according to claim 11, wherein, when it is determined that one of the wheels is prone to locking during braking, the brake means is controlled so as to reduce the braking force on the pair of wheels, and the steering means is controlled by alternately switching between a first steering mode in which the steering means is controlled so as to cause the pair of wheels to form an approximately V-shape when viewed from above the vehicle, and a second steering mode in which the steering means is controlled so as to cause the pair of wheels to form an approximately inverted V-shape when viewed from above the vehicle.
  14. 　前記一対の車輪のそれぞれの車輪速度を検出する車輪速センサをさらに備え、
    　前記制御部は、
    　検出される車輪速度に基づき、制動中のいずれかの車輪がロック傾向にあるか否かを判定する、請求項１１から１３のいずれか一項に記載の効率ブレーキシステム。     a wheel speed sensor for detecting a wheel speed of each of the pair of wheels;
    The control unit is
    14. The efficient brake system according to claim 11, further comprising a step of determining whether any of the wheels being braked is prone to locking based on the detected wheel speed.
  15. 　前記制御部は、
    　前記車両の速度が小さいほど、前記車両の進行方向に対して前記一対の車輪それぞれの操舵角が大きくなるように前記操舵手段を制御する、請求項１１から１３のいずれか一項に記載の効率ブレーキシステム。     The control unit is
    14. The efficient brake system according to claim 11, wherein the steering means is controlled so that the steering angle of each of the pair of wheels with respect to the traveling direction of the vehicle increases as the speed of the vehicle decreases.
  16. 　前記制御部によって前記操舵手段及び前記ブレーキ手段の制御が行われているときに、運転者に所定の警報を発する報知手段をさらに備える、請求項１１から１３のいずれか一項に記載の効率ブレーキシステム。 The efficient brake system according to any one of claims 11 to 13, further comprising a notification means for issuing a predetermined alarm to the driver when the steering means and the braking means are being controlled by the control unit.
  17. 　車両の左右に略対称に位置する少なくとも一対の車輪と、
    　前記一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、
    　前記一対の車輪に制動力を発生させるブレーキ手段と、
    　前記車両のブレーキ操作に関するブレーキ操作情報を取得する第１取得部と、
    　前記車両の周囲環境に関する周囲環境情報を取得する第２取得部と、
    　前記操舵手段及び前記ブレーキ手段を制御する制御部と、を備え、
    　前記制御部は、
    　前記ブレーキ操作情報及び前記周囲環境情報に基づき、前記ブレーキ手段を制御して車両を制動する通常ブレーキと、前記ブレーキ手段とともに前記操舵手段を制御して車両を制動する効率ブレーキのいずれかを選択する、ブレーキシステム。     At least one pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle;
    a steering means capable of individually controlling the steering angle of each of the pair of wheels;
    a brake means for generating a braking force on the pair of wheels;
    A first acquisition unit that acquires brake operation information related to a brake operation of the vehicle;
    A second acquisition unit that acquires surrounding environment information related to a surrounding environment of the vehicle;
    a control unit for controlling the steering means and the braking means,
    The control unit is
    A brake system that selects, based on the brake operation information and the surrounding environment information, either a normal brake that controls the brake means to brake the vehicle, or an efficiency brake that controls the brake means and the steering means to brake the vehicle.
  18. 　前記周囲環境情報には、後方車両との車間距離及び相対速度をあらわす後方車両情報が含まれ、
    　前記制御部は、
    　前記ブレーキ操作情報及び前記後方車両情報に基づき、前記通常ブレーキと前記効率ブレーキのいずれかを選択する、請求項１７に記載のブレーキシステム。     The surrounding environment information includes rear vehicle information indicating a distance and a relative speed between the rear vehicle and the vehicle;
    The control unit is
    The brake system according to claim 17, wherein either the normal brake or the efficiency brake is selected based on the brake operation information and the rear vehicle information.
  19. 　前記周囲環境情報には、路面状態に関する路面関連情報が含まれ、
    　前記制御部は、
    　前記ブレーキ操作情報及び前記路面関連情報に基づき、前記通常ブレーキと前記効率ブレーキのいずれかを選択する、請求項１７に記載のブレーキシステム。     The surrounding environment information includes road surface-related information regarding a road surface condition,
    The control unit is
    The brake system according to claim 17, further comprising: a brake control unit that selects between the normal brake and the efficiency brake based on the brake operation information and the road surface-related information.
  20. 　前記制御部は、
    　前記効率ブレーキを選択した場合には、前記一対の車輪に対する制動力が低減されるように前記ブレーキ手段を制御するとともに、前記一対の車輪を車両上面から見て略ハの字になるように前記操舵手段を制御する、請求項１７から１９のいずれか一項に記載のブレーキシステム。     The control unit is
    20. The brake system according to claim 17, wherein when the efficiency brake is selected, the brake means is controlled so that the braking force on the pair of wheels is reduced, and the steering means is controlled so that the pair of wheels are arranged in an approximately V-shape when viewed from above the vehicle.
  21. 　ブレーキの作動状況を外部に報知する報知手段をさらに備える、請求項１７から１９のいずれか一項に記載のブレーキシステム。 The brake system according to any one of claims 17 to 19, further comprising a notification means for notifying the outside of the operating status of the brakes.
  22. 　前記報知手段は、作動中のブレーキの種類に応じて異なる態様で報知する、請求項２１に記載のブレーキシステム。 The brake system according to claim 21, wherein the notification means notifies in different ways depending on the type of brake being applied.
  23. 　車両の左右に略対称に位置する少なくとも一対の車輪と、
    　前記一対の車輪それぞれの操舵角を個別に制御することのできる操舵手段と、
    　前記車両の進行方向の変化を検知するセンサと、
    　各々の車輪の操舵角が、前記進行方向の変化に応じて設定される角度になるように、前記操舵手段を制御する制御部を備えた、効率ブレーキシステム。     At least one pair of wheels positioned approximately symmetrically on the left and right sides of the vehicle;
    a steering means capable of individually controlling the steering angle of each of the pair of wheels;
    A sensor for detecting a change in the traveling direction of the vehicle;
    An efficient brake system comprising a control unit that controls the steering means so that the steering angle of each wheel becomes an angle that is set in response to the change in the traveling direction.
  24. 　前記センサは、さらに前記車両の進行方向の速度を検知し、
    　前記制御部は、前記車両の速度が基準速度を超えた場合に、各々の車輪の操舵角が、前記進行方向の変化に応じて設定される角度になるように、前記操舵手段を制御する、請求項２３に記載の効率ブレーキシステム。     The sensor further detects a speed of the vehicle in a traveling direction,
    24. The efficient brake system according to claim 23, wherein the control unit controls the steering means so that, when the speed of the vehicle exceeds a reference speed, the steering angle of each wheel becomes an angle that is set in accordance with the change in the traveling direction.
  25. 　前記制御部は、前記操舵手段を制御する際に、外側に位置する車輪の操舵角が、内側に位置する車輪の操舵角よりも大きくなるように設定する、請求項２４に記載の効率ブレーキシステム。 The efficient brake system of claim 24, wherein the control unit, when controlling the steering means, sets the steering angle of the outer wheels to be greater than the steering angle of the inner wheels.
  26. 　前記制御部は、前記操舵手段を制御する際に、内側に位置する車輪の操舵角を変えずに、外側に位置する車輪の操舵角を変えるように設定する、請求項２４に記載の効率ブレーキシステム。
          25. The efficient brake system according to claim 24, wherein the control unit, when controlling the steering means, sets the steering angle of the wheels positioned on the outside to be changed without changing the steering angle of the wheels positioned on the inside.
PCT/JP2023/037542 2022-10-31 2023-10-17 Efficient brake system WO2024095761A1 (en)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
JP2022174994 2022-10-31
JP2022-174994 2022-10-31
JP2022-181942 2022-11-14
JP2022181942A JP2024066362A (en) 2022-10-31 2022-11-14 Efficient Brake System
JP2022-185687 2022-11-21
JP2022185687A JP2024066369A (en) 2022-10-31 2022-11-21 Brake system
JP2022-199548 2022-12-14
JP2022199548A JP2024066374A (en) 2022-10-31 2022-12-14 Efficient Brake System
JP2023018712A JP2024066389A (en) 2022-10-31 2023-02-09 Efficient Brake System
JP2023-018712 2023-02-09

Publications (1)

Publication Number Publication Date
WO2024095761A1 true WO2024095761A1 (en) 2024-05-10

Family

ID=90930351

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/037542 WO2024095761A1 (en) 2022-10-31 2023-10-17 Efficient brake system

Country Status (1)

Country Link
WO (1) WO2024095761A1 (en)

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01145247A (en) * 1987-11-30 1989-06-07 Honda Motor Co Ltd Lamp device for air spoiler
JPH037669A (en) * 1989-06-02 1991-01-14 Sumitomo Electric Ind Ltd Skid control system
JPH0558320A (en) * 1991-08-29 1993-03-09 Mazda Motor Corp Vehicle rear wheel steering device
JPH0776235A (en) * 1993-07-16 1995-03-20 Toyota Motor Corp Lamp controller for vehicle
JPH09142203A (en) * 1995-11-17 1997-06-03 Aisin Seiki Co Ltd Rear-end collision alarm device for automobile
JP2005350011A (en) * 2004-06-14 2005-12-22 Fuji Heavy Ind Ltd Steering device for vehicle and steering method for vehicle
WO2006114977A1 (en) * 2005-04-20 2006-11-02 Equos Research Co., Ltd. Control device, ground speed measurement device, and vehicle
JP2007145253A (en) * 2005-11-29 2007-06-14 Equos Research Co Ltd Controller and vehicle
JP2007161166A (en) * 2005-12-15 2007-06-28 Equos Research Co Ltd Vehicle
JP2013220664A (en) * 2012-04-12 2013-10-28 Jtekt Corp Rear wheel steering device
JP2019171907A (en) * 2018-03-27 2019-10-10 Ntn株式会社 Steering system and vehicle comprising the same
JP2019171905A (en) * 2018-03-27 2019-10-10 Ntn株式会社 Steering system and vehicle comprising the same
JP2020145874A (en) * 2019-03-07 2020-09-10 三菱自動車工業株式会社 Regeneration brake device of electric vehicle
JP2022122068A (en) * 2021-02-09 2022-08-22 株式会社ジェイテクト Steering angle control device

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01145247A (en) * 1987-11-30 1989-06-07 Honda Motor Co Ltd Lamp device for air spoiler
JPH037669A (en) * 1989-06-02 1991-01-14 Sumitomo Electric Ind Ltd Skid control system
JPH0558320A (en) * 1991-08-29 1993-03-09 Mazda Motor Corp Vehicle rear wheel steering device
JPH0776235A (en) * 1993-07-16 1995-03-20 Toyota Motor Corp Lamp controller for vehicle
JPH09142203A (en) * 1995-11-17 1997-06-03 Aisin Seiki Co Ltd Rear-end collision alarm device for automobile
JP2005350011A (en) * 2004-06-14 2005-12-22 Fuji Heavy Ind Ltd Steering device for vehicle and steering method for vehicle
WO2006114977A1 (en) * 2005-04-20 2006-11-02 Equos Research Co., Ltd. Control device, ground speed measurement device, and vehicle
JP2007145253A (en) * 2005-11-29 2007-06-14 Equos Research Co Ltd Controller and vehicle
JP2007161166A (en) * 2005-12-15 2007-06-28 Equos Research Co Ltd Vehicle
JP2013220664A (en) * 2012-04-12 2013-10-28 Jtekt Corp Rear wheel steering device
JP2019171907A (en) * 2018-03-27 2019-10-10 Ntn株式会社 Steering system and vehicle comprising the same
JP2019171905A (en) * 2018-03-27 2019-10-10 Ntn株式会社 Steering system and vehicle comprising the same
JP2020145874A (en) * 2019-03-07 2020-09-10 三菱自動車工業株式会社 Regeneration brake device of electric vehicle
JP2022122068A (en) * 2021-02-09 2022-08-22 株式会社ジェイテクト Steering angle control device

Similar Documents

Publication Publication Date Title
KR101081777B1 (en) Method and device for reducing damage caused by an accident
JP4507976B2 (en) Vehicle travel control device
JP4705087B2 (en) Method and apparatus for automatically operating vehicle deceleration
JP3927265B2 (en) Automatic braking control device for vehicle
JP3025261B2 (en) Method and apparatus for generating operation signal of stop lamp for automobile
US20090134987A1 (en) Motor Vehicle Having a Rear-end Impact Warning Device
CN100545015C (en) Vehicle brake control apparatus
US8095277B2 (en) Method for determining a direction of travel in a motor vehicle
KR102175663B1 (en) Method for regulating driving stability
JP6533231B2 (en) Vehicle speed control system and vehicle speed control method
JP2005035535A (en) Low speed collision avoidance system for vehicle
JP2008519725A (en) Method for controlling vehicle equipped with collision avoidance system and apparatus for carrying out this method
WO2007023667A1 (en) Automatic brake control device
WO2019197864A1 (en) Collision prevention method and system for vehicle
US9393959B2 (en) Method and control unit for operating a dynamics control system of a vehicle as well as a control system for dynamics control of a vehicle using surroundings sensor data
WO2011121700A1 (en) Vehicle control device
JP2010173523A (en) Drive control device for front engine-front drive vehicle
JP2009035245A (en) Vehicle operation supporting device
WO2024095761A1 (en) Efficient brake system
CN102556044A (en) Method and system for quickly deflating and smoothly braking vehicle
US20060220908A1 (en) Method and device for supporting the driver of a vehicle during an emergency braking
JP7259217B2 (en) Control device for four-wheel drive vehicle
JP2006306270A (en) Collision control device for vehicle
JP2024066374A (en) Efficient Brake System
JP4023340B2 (en) Vehicle collision prevention device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23885523

Country of ref document: EP

Kind code of ref document: A1