CN114954646A

CN114954646A - Vehicle steering system and steering method

Info

Publication number: CN114954646A
Application number: CN202210682319.1A
Authority: CN
Inventors: 施国标; 郭琮; 王帅; 刘廷阳; 乔鹏飞; 宋铭昊
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2022-06-16
Filing date: 2022-06-16
Publication date: 2022-08-30
Anticipated expiration: 2042-06-16
Also published as: CN114954646B

Abstract

A vehicle steering system and a steering method, the steering system comprising: the front wheel steering device, the rear wheel steering device, turn to domain controller and vehicle controller, vehicle controller is used for turning to domain controller output zero radius and turning to the instruction or four-wheel steering instruction, when output zero radius turns to the instruction, turn to the rotary motion that two front wheel rotation transmission subassemblies and two rear wheel rotation transmission subassemblies of domain controller steerable all output different turns to, when output four-wheel steering instruction, turn to the rotary motion that two front wheel rotation transmission subassemblies all output the same and turn to in the domain controller, control two rear wheel rotation transmission subassemblies all output the same rotary motion that turns to. The vehicle steering system can realize multi-mode and multi-functional steering functions such as a zero-radius steering mode or a four-wheel steering mode and the like so as to improve the driving safety of the vehicle.

Description

Vehicle steering system and steering method

Technical Field

The invention relates to the technical field of vehicle driving control, in particular to a vehicle steering system and a steering method.

Background

In consideration of the multifunctional and high-safety steering requirements of the future unmanned technology, the steering system needs to meet the active steering angle control under the technologies of auxiliary driving and intelligent driving. The probability that the electric failure of the vehicle adopting the motor as a power source for steering can not realize steering is higher than the probability that the conventional mechanical steering fails. The response speed, steering flexibility, stability in the direction at high speed, and other properties of the steering system are difficult to further improve on the basis of conventional front wheel steering, and therefore, four-wheel steering applications are emerging. Four-wheel steering a set of rear wheel steering system is arranged on a rear axle of the automobile, and the relationship of the rotation angles of the front wheel and the rear wheel is controlled in a certain proportion, so that the front wheel and the rear wheel of the automobile are steered simultaneously. In order to maximize the steering flexibility, attention is paid to zero-radius steering, and since the independent steering technology can achieve individual wheel steering, a zero-radius steering function can be achieved. Generally, the technique of independent steering is to configure a steering motor for each wheel of a vehicle so that the wheels are driven independently with respect to each other to realize an independent steering function.

However, considering that the safety and control accuracy of independent steering are great when the automobile runs at high speed, the independent steering technology is only suitable for vehicles in low-speed parks. In order to realize the reliability of independent steering and synchronous steering of the left wheel and the right wheel at high speed, the clutch and the transmission engagement device can be adopted to realize separation and synchronization under different modes, so that the independent steering can be switched into integral steering, but the structure is too complex.

Disclosure of Invention

The invention mainly solves the technical problem of providing a vehicle steering system and a steering method, which can realize a multi-mode and multi-functional steering system and a steering method such as a zero-radius steering mode or a four-wheel steering mode.

According to a first aspect of the present application, there is provided a vehicle steering system comprising:

a front wheel steering apparatus comprising: the front wheel connecting and disconnecting component, the two front wheel transverse moving pieces and the two front wheel independent steering mechanisms are arranged on the front wheel connecting and disconnecting component; the two front wheel transverse moving pieces are respectively connected with the two front wheel bodies and can move along the transverse direction to drive the front wheel bodies to turn; the front wheel connecting and disconnecting assembly is used for connecting the two front wheel transverse moving pieces, and the two front wheel transverse moving pieces move in the same direction along the transverse direction, or the two front wheel transverse moving pieces are disconnected and can move in the same direction or different directions along the transverse direction; the independent steering mechanism of front wheel includes: the front wheel steering motor is connected with the front wheel rotating transmission assembly, and the front wheel rotating transmission assembly is connected with the front wheel transverse moving piece; the front wheel steering motor is used for driving the front wheel rotating transmission assembly to output rotary motion, and the front wheel transverse moving piece is used for converting the rotary motion output by the front wheel rotating transmission assembly into transverse movement along the transverse direction;

rear wheel steering apparatus, comprising: the rear wheel connecting and disconnecting assembly, the two rear wheel transverse moving pieces and the two rear wheel independent steering mechanisms are arranged on the rear wheel connecting and disconnecting assembly; the two rear wheel transverse moving pieces are respectively connected with the two rear wheel bodies and can move along the transverse direction to drive the rear wheel bodies to steer; the rear wheel connecting and disconnecting assembly is used for connecting the two rear wheel transverse moving pieces, and the two rear wheel transverse moving pieces move in the same direction along the transverse direction, or the two rear wheel transverse moving pieces are disconnected and can move in the same direction or different directions along the transverse direction; the independent steering mechanism of rear wheel includes: the rear wheel steering motor is connected with the rear wheel rotating transmission assembly, and the rear wheel rotating transmission assembly is connected with the rear wheel transverse moving piece; the rear wheel steering motor is used for driving the rear wheel rotating transmission assembly to output rotary motion, and the rear wheel transverse moving piece is used for converting the rotary motion output by the rear wheel rotating transmission assembly into transverse movement along the transverse direction;

the steering domain controller is connected with the front wheel steering motor, the rear wheel steering motor, the front wheel connection and disconnection assembly and the rear wheel connection and disconnection assembly;

the vehicle controller is connected with the steering domain controller and is used for outputting a zero-radius steering instruction or a four-wheel steering instruction to the steering domain controller;

when the vehicle controller outputs a zero-radius steering instruction, the steering domain controller controls the front wheel connection and disconnection assembly to disconnect the two front wheel transverse moving pieces, the two front wheel steering motors respectively drive the two front wheel rotation transmission assemblies to output rotary motions in different steering directions so as to drive the two front wheel bodies to steer in different directions through the two front wheel transverse moving pieces, the rear wheel connection and disconnection assembly is controlled to disconnect the two rear wheel transverse moving pieces, and the two rear wheel steering motors respectively drive the two rear wheel rotation transmission assemblies to output rotary motions in different steering directions so as to drive the two rear wheel bodies to steer in different directions through the two rear wheel transverse moving pieces; the two front wheel bodies and the two rear wheel bodies are turned to be tangent to the same circumference;

when the vehicle controller outputs a four-wheel steering instruction, the steering domain controller controls the front wheel connecting and disconnecting assembly to connect the two front wheel transverse moving pieces, the two front wheel steering motors respectively drive the two front wheel rotating transmission assemblies to output rotating motion in the same steering direction so as to drive the two front wheel bodies to steer in the same direction through the two front wheel transverse moving pieces, the rear wheel connecting and disconnecting assembly is controlled to connect the two rear wheel transverse moving pieces, and the two rear wheel steering motors respectively drive the two rear wheel rotating transmission assemblies to output rotating motion in the same steering direction so as to drive the two rear wheel bodies to steer in the same direction through the two rear wheel transverse moving pieces; the steering direction of the front wheel body is the same as or different from the steering direction of the rear wheel body.

In one embodiment of the present invention, the substrate is,

when the vehicle controller outputs a four-wheel steering command when the vehicle is in a first running speed interval, the direction in which the front-wheel steering motor drives the front-wheel cross-member to move in the same direction in the transverse direction through the front-wheel rotation transmission assembly is opposite to the direction in which the rear-wheel steering motor drives the rear-wheel cross-member to move in the same direction in the transverse direction through the rear-wheel rotation transmission assembly;

when the vehicle controller outputs a four-wheel steering command when the vehicle is in a second running speed interval, the direction in which the front-wheel steering motor drives the front-wheel cross-sliding member to move in the same direction in the transverse direction through the front-wheel rotation transmission assembly is the same as the direction in which the rear-wheel steering motor drives the rear-wheel cross-sliding member to move in the transverse direction through the rear-wheel rotation transmission assembly;

the first travel speed interval is smaller than the second travel speed interval.

In one embodiment of the present invention, the substrate is,

the independent steering mechanism of front wheel still includes: the front wheel torque and corner sensor is connected with an electronic control unit of the front wheel steering motor and used for acquiring the torque and the corner output by the front wheel rotation transmission assembly;

the independent steering mechanism of rear wheel still includes: the rear wheel torque and corner sensor is connected with an electronic control unit of the rear wheel steering motor and used for acquiring the torque and the corner output by the rear wheel rotation transmission assembly;

under the power-assisted steering function, when a vehicle controller outputs a zero-radius steering instruction to a steering domain controller, a front wheel torque and corner sensor collects a first front wheel torque and a first front wheel corner of a front wheel rotating transmission assembly connected with a steering wheel and outputs the first front wheel torque and the first front wheel corner to an electronic control unit of a corresponding front wheel steering motor, the steering domain controller controls another front wheel steering motor to drive another front wheel rotating transmission assembly corresponding to the front wheel steering motor to output a torque and a corner opposite to the first front wheel torque and the first front wheel corner, and two rear wheel steering motors respectively drive two rear wheel rotating transmission assemblies to output rotating motions with different steering directions so as to enable the two front wheel bodies and the two rear wheel bodies to steer to be tangent to the same circumference; when a vehicle controller outputs a four-wheel steering instruction to a steering domain controller, a front wheel torque and corner sensor acquires a second front wheel torque and a second front wheel corner of a front wheel steering transmission assembly connected with a steering wheel and outputs the second front wheel torque and the second front wheel corner to an electronic control unit of a corresponding front wheel steering motor, and the steering domain controller controls another front wheel steering motor to drive another front wheel steering transmission assembly corresponding to the other front wheel steering motor to output a torque and a corner which are the same as the second front wheel torque and the second front wheel corner; the steering domain controller outputs a first expected rear wheel steering angle through the second front wheel torque and the second front wheel steering angle, and controls the two rear wheel steering motors to respectively drive the two rear wheel rotating transmission assemblies to output rotary motions which are the same as the second front wheel torque and the second front wheel steering angle according to the first expected rear wheel steering angle so as to enable the steering angle of the rear wheel body to be the first expected rear wheel steering angle;

under the active steering function, when a vehicle controller outputs a zero-radius steering instruction to a steering domain controller, the steering domain controller controls two front wheel steering motors to respectively drive two front wheel rotating transmission assemblies to output rotating motions in different steering directions so as to drive two front wheel bodies to steer in different directions through two front wheel transverse moving pieces, controls two rear wheel steering motors to respectively drive two rear wheel rotating transmission assemblies to output rotating motions in different steering directions so as to drive two rear wheel bodies to steer in different directions through two rear wheel transverse moving pieces, and enables the two front wheel bodies and the two rear wheel bodies to steer to be tangent to the same circumference; when the vehicle controller outputs a four-wheel steering instruction to the steering domain controller, the front wheel torque and corner sensor collects the current torque and corner of the front wheel steering transmission assembly and outputs the current torque and corner to the electronic control unit of the corresponding front wheel steering motor, and the steering domain controller controls the front wheel steering motor to drive the front wheel steering transmission assembly to output the torque and corner of the difference according to the difference between the current torque and corner and the expected torque and corner; and the steering domain controller controls the two rear wheel steering motors to respectively drive the two rear wheel rotating transmission assemblies to output rotary motions with the same steering and torque according to the second expected rear wheel steering angle, so that the steering angle of the rear wheel body is the second expected rear wheel steering angle.

In one embodiment of the method, the first and second containers are,

the steering domain controller is also used for judging whether a front wheel independent steering mechanism fails or not through an electronic control unit of the front wheel steering motor, if one front wheel independent steering mechanism fails, the vehicle controller is also used for outputting a front wheel redundancy reconstruction instruction to the steering domain controller, and the steering domain controller increases the output power of the other front wheel steering motor according to the front wheel redundancy reconstruction instruction; or, the steering domain controller is configured to determine whether a rear wheel independent steering mechanism fails through an electronic control unit of the rear wheel steering motor, and if a rear wheel independent steering mechanism fails, the vehicle controller is further configured to output a rear wheel redundancy reconfiguration instruction to the steering domain controller, and the steering domain controller increases the output power of another rear wheel steering motor according to the rear wheel redundancy reconfiguration instruction.

In one embodiment of the present invention, the substrate is,

the independent steering mechanism of front wheel still includes: the front wheel motor position sensor is connected with an electronic control unit of the front wheel steering motor and used for acquiring the position of a rotor in the front wheel steering motor so as to control the phase change of the front wheel steering motor;

the independent steering mechanism of rear wheel still includes: the rear wheel motor position sensor is connected with an electronic control unit of the rear wheel steering motor and used for acquiring the position of a rotor in the rear wheel steering motor so as to control the phase change of the rear wheel steering motor.

In one embodiment of the present invention, the substrate is,

the independent steering mechanism of front wheel still includes: a front wheel current sensor connected to an electronic control unit of the front wheel steering motor, for detecting a current of the front wheel steering motor;

the independent steering mechanism of rear wheel still includes: and the rear wheel current sensor is connected with the electronic control unit of the rear wheel steering motor and is used for detecting the current of the rear wheel steering motor.

According to a second aspect of the present application, there is provided a vehicle steering method comprising the steps of:

the vehicle controller can output a zero-radius steering command or a four-wheel steering command to the steering domain controller;

when a vehicle controller outputs a zero-radius steering instruction, a steering domain controller controls a front wheel connection and disconnection assembly to disconnect two front wheel transverse moving pieces, two front wheel steering motors respectively drive two front wheel rotation transmission assemblies to output rotary motions in different steering directions so as to drive two front wheel bodies to steer in different directions through the two front wheel transverse moving pieces, a rear wheel connection and disconnection assembly is controlled to disconnect two rear wheel transverse moving pieces, and two rear wheel steering motors respectively drive two rear wheel rotation transmission assemblies to output rotary motions in different steering directions so as to drive the two rear wheel bodies to steer in different directions through the two rear wheel transverse moving pieces; the two front wheel bodies and the two rear wheel bodies are turned to be tangent to the same circumference;

when a vehicle controller outputs a four-wheel steering instruction, the steering domain controller controls the front wheel connecting and disconnecting assembly to connect the two front wheel transverse moving pieces, the two front wheel steering motors respectively drive the two front wheel rotating transmission assemblies to output rotating motion in the same steering direction so as to drive the two front wheel bodies to steer in the same direction through the two front wheel transverse moving pieces, the rear wheel connecting and disconnecting assembly is controlled to connect the two rear wheel transverse moving pieces, and the two rear wheel steering motors respectively drive the two rear wheel rotating transmission assemblies to output rotating motion in the same steering direction so as to drive the two rear wheel bodies to steer in the same direction through the two rear wheel transverse moving pieces; the steering direction of the front wheel body is the same as or different from the steering direction of the rear wheel body.

In one embodiment of the present invention, the substrate is,

under the power-assisted steering function, when a vehicle controller outputs a zero-radius steering instruction to a steering domain controller, a front wheel torque and corner sensor acquires a first front wheel torque and a first front wheel corner of a front wheel steering transmission assembly connected with a steering wheel and outputs the first front wheel torque and the first front wheel corner to an electronic control unit of a corresponding front wheel steering motor, the steering domain controller controls another front wheel steering motor to drive another front wheel steering transmission assembly corresponding to the other front wheel steering motor to output a torque and a corner opposite to the first front wheel torque and the first front wheel corner, and two rear wheel steering motors respectively drive two rear wheel steering transmission assemblies to output rotary motions with different steering directions so as to enable the two front wheel bodies and the two rear wheel bodies to steer to be tangent to the same circumference; when a vehicle controller outputs a four-wheel steering instruction to a steering domain controller, a front wheel torque and corner sensor acquires a second front wheel torque and a second front wheel corner of a front wheel steering transmission assembly connected with a steering wheel and outputs the second front wheel torque and the second front wheel corner to an electronic control unit of a corresponding front wheel steering motor, and the steering domain controller controls another front wheel steering motor to drive another front wheel steering transmission assembly corresponding to the other front wheel steering motor to output a torque and a corner which are the same as the second front wheel torque and the second front wheel corner; the steering domain controller outputs a first expected rear wheel steering angle through the second front wheel torque and the second front wheel steering angle, and controls the two rear wheel steering motors to respectively drive the two rear wheel rotating transmission assemblies to output rotary motions which are the same as the second front wheel torque and the second front wheel steering angle according to the first expected rear wheel steering angle so as to enable the steering angle of the rear wheel body to be the first expected rear wheel steering angle;

In one embodiment, the steering domain controller can also judge whether the independent front wheel steering mechanism fails through an electronic control unit of the front wheel steering motor, if one independent front wheel steering mechanism fails, the vehicle controller is further configured to output a front wheel redundancy reconfiguration instruction to the steering domain controller, and the steering domain controller increases the output power of the other front wheel steering motor according to the front wheel redundancy reconfiguration instruction; or the steering domain controller is used for judging whether the rear wheel independent steering mechanism fails through an electronic control unit of the rear wheel steering motor, if one rear wheel independent steering mechanism fails, the vehicle controller is also used for outputting a rear wheel redundancy reconstruction instruction to the steering domain controller, and the steering domain controller increases the output power of the other rear wheel steering motor according to the rear wheel redundancy reconstruction instruction.

According to the steering system and the steering method of the embodiment, a multi-mode and multi-functional steering function such as a zero-radius steering mode or a four-wheel steering mode can be realized, a power-assisted steering function or an active steering function can be realized in both the zero-radius steering mode and the four-wheel steering mode, the steering domain controller judges whether the front-wheel independent steering mechanism fails through the electronic control unit of the front-wheel steering motor, judges whether the rear-wheel independent steering mechanism fails through the electronic control unit of the rear-wheel steering motor, and can output a front-wheel redundancy reconfiguration command when the front-wheel independent steering mechanism fails and output a rear-wheel redundancy reconfiguration command when the rear-wheel independent steering mechanism fails, so that a high-redundancy steering function is realized, and the vehicle running safety is improved.

Drawings

FIG. 1 is a block diagram of a vehicle steering system provided herein;

FIG. 2 is a schematic structural diagram of a front wheel steering apparatus in a vehicle steering system provided by the present application;

FIG. 3 is a schematic view of a vehicle steering system provided herein in a zero radius steering mode;

FIG. 4 is a first schematic view of a vehicle steering system provided herein in a four-wheel steering mode;

FIG. 5 is a second schematic view of the vehicle steer system provided herein in a four wheel steer mode;

FIG. 6 is a block flow diagram of a vehicle steering method provided herein.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous specific details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

The first embodiment,

Referring to fig. 1 to 5, the vehicle steering system provided in the present embodiment includes: a front wheel steering device 10, a rear wheel steering device 20, a steering field controller 30, and a vehicle controller 40.

The front wheel steering device 10 includes: a front wheel connection disconnection assembly 11, two front wheel cross-members 12, and two front wheel independent steering mechanisms. The vehicle 100 has two front wheel bodies 101, and two wheels located at the front side of the vehicle 100 in the length direction of the vehicle 100 are the front wheel bodies 101, and in this embodiment, the two front wheel bodies 101 are driven to rotate by an in-wheel motor so as to drive the vehicle 100 to run. The two front-wheel lateral-movement members 12 are provided for connection with the two front-wheel bodies 101, respectively, and both the front-wheel lateral-movement members 12 are movable in a lateral direction that is the same as the width direction of the vehicle 100. The two front-wheel lateral-movement pieces 12 moving in the lateral direction can turn the front-wheel body 101.

The front wheel connection disconnection assembly 11 serves to connect the two front-wheel lateral-movement members 12 so that the two front-wheel lateral-movement members 12 move in the same direction in the lateral direction, or the front wheel connection disconnection assembly 11 serves to disconnect the two front-wheel lateral-movement members 12 so that the two front-wheel lateral-movement members 12 move in the same direction or in different directions in the lateral direction. Specifically, the two front wheel lateral moving members 12 move in the same direction along the transverse direction, and can simultaneously drive the two front wheel bodies 101 to turn left or turn right, and the two front wheel lateral moving members 12 move in different directions along the transverse direction, and can respectively drive the two front wheel bodies 101 to turn left or turn right. More specifically, taking fig. 1 as an example, both the front-wheel lateral-moving members 12 move leftward in the lateral direction, and both the front-wheel bodies 101 turn leftward; the two front wheel transverse moving pieces 12 move rightwards along the transverse direction, and the two front wheel bodies 101 turn rightwards; the two front-wheel lateral-movement members 12 are respectively moved leftward or rightward in the lateral direction, and the two front-wheel bodies 101 are respectively steered leftward or rightward.

Two front wheel sideslip pieces 12 are connected respectively to two independent steering mechanism of front wheel, and each independent steering mechanism of front wheel all includes: a front wheel steering motor 13 and a front wheel rotation transmission assembly 14, wherein the front wheel steering motor 13 is connected with the front wheel rotation transmission assembly 14, and the front wheel rotation transmission assembly 14 is connected with the front wheel transverse moving member 12. The front-wheel steering motor 13 is used for driving the front-wheel rotation transmission assembly 14 to output a rotary motion, and the front-wheel lateral moving member 12 is used for converting the rotary motion output by the front-wheel rotation transmission assembly 14 into a lateral movement in the lateral direction, so that the movement of the front-wheel lateral moving member 12 in the lateral direction is powered by the front-wheel steering motor 13. The front-wheel steering motor 13 has an electronic control unit 15.

The rear wheel steering device 20 includes: a rear wheel connection disconnection assembly 21, two rear wheel cross-members 22, and two rear wheel independent steering mechanisms. The vehicle 100 further has two rear wheel bodies 102, and the two vehicles located behind the vehicle 100 in the length direction of the vehicle 100 are the rear wheel bodies 102, in this embodiment, the two rear wheel bodies 102 can also be driven to rotate by the in-wheel motor, so as to drive the vehicle 100 to run. The two rear-wheel lateral-movement members 22 are provided for connection with the two rear-wheel bodies 102, respectively, and both the rear-wheel lateral-movement members 22 are movable in a lateral direction that is also the same as the width direction of the vehicle 100. The two rear-wheel lateral-movement members 22 that move in the lateral direction can turn the rear-wheel body 102.

The rear wheel connection disconnection assembly 21 serves to connect the two rear wheel lateral-movement members 22 so that the two rear wheel lateral-movement members 22 move in the same direction in the lateral direction, or the rear wheel connection disconnection assembly 21 serves to disconnect the two rear wheel lateral-movement members 22 so that the two rear wheel lateral-movement members 22 move in the same direction or in different directions in the lateral direction. Specifically, the two rear-wheel lateral moving members 22 move in the same direction along the transverse direction, and can simultaneously drive the two rear-wheel bodies 102 to turn left or turn right, and the two rear-wheel lateral moving members 22 move in different directions along the transverse direction, and can respectively drive the two rear-wheel bodies 102 to turn left or turn right. More specifically, taking fig. 1 as an example, both rear-wheel lateral-moving members 22 move leftward in the lateral direction, and both rear-wheel bodies 102 turn leftward; the two rear-wheel lateral-moving members 22 both move rightward in the lateral direction, and the two rear-wheel bodies 102 both turn rightward; the two rear-wheel lateral-movement members 22 are respectively moved leftward or rightward in the lateral direction, and the two rear-wheel bodies 102 are respectively turned leftward or rightward.

Two rear wheel sideslip pieces 22 are connected respectively to two independent steering mechanism of rear wheel, and each independent steering mechanism of rear wheel all includes: a rear wheel steering motor 23 and a rear wheel turning transmission assembly 24, the rear wheel steering motor 23 is connected with the rear wheel turning transmission assembly 24, and the rear wheel turning transmission assembly 24 is connected with the rear wheel lateral moving member 22. The rear-wheel steering motor 23 is used for driving the rear-wheel turning transmission assembly 24 to output a rotary motion, and the rear-wheel lateral moving member 22 is used for converting the rotary motion output by the rear-wheel turning transmission assembly 24 into a lateral movement in the lateral direction, so that the lateral movement of the rear-wheel lateral moving member 22 in the lateral direction is powered by the rear-wheel steering motor 23. The rear-wheel steering motor 23 has an electronic control unit 25.

The steering field controller 30 is connected to the electronic control units 15 of the two front-wheel steering motors 13, the electronic control units 25 of the two rear-wheel steering motors 23, the front-wheel connection disconnection assembly 11, and the rear-wheel connection disconnection assembly 21.

In an embodiment, the vehicle steering system provided by the present embodiment may further include: and the temperature sensor is used for detecting the working temperature of the steering domain controller 30, and when the working temperature is higher than the preset rated working temperature, the steering domain controller can be cooled by arranging a corresponding cooling mechanism such as a fan.

The vehicle controller 40 is connected to the steering domain controller 30, and the vehicle controller 40 is configured to output a zero-radius steering command or a four-wheel steering command to the steering domain controller 30.

When the vehicle controller 40 outputs a zero-radius steering command to the steering domain controller 30, the steering domain controller 30 controls the front wheel connecting and disconnecting assembly 11 to disconnect the two front wheel transverse moving members 12, the steering domain controller 30 controls the two front wheel steering motors 13 through the electronic control unit 15 of the front wheel steering motors 13 to respectively drive the two front wheel rotating transmission assemblies 14 to output rotating motions in different steering directions, so as to drive the two front wheel transverse moving members 12 to transversely move in different steering directions, the two front wheel main bodies 101 are driven to transversely move in different steering directions through the two front wheel transverse moving members 12, the steering domain controller 30 controls the rear wheel connecting and disconnecting assembly 21 to disconnect the two rear wheel transverse moving members 22, the steering domain controller 30 controls the two rear wheel steering motors 23 through the electronic control unit 25 of the rear wheel steering motor 23 to respectively drive the two rear wheel rotating transmission assemblies 24 to output rotating motions in different steering directions, the two rear-wheel lateral-moving members 22 can be driven to laterally move in different directions, so that the two rear-wheel bodies 102 can be driven to turn in different directions by the two rear-wheel lateral-moving members 22. In the present embodiment, the two front wheel bodies 101 and the two rear wheel bodies 102 are turned to be tangent to the same circumference. The vehicle controller 40 controls the hub motor of each front wheel body 101 to drive the front wheel body 101 to rotate, and controls the hub motor of the rear wheel body 102 to drive the rear wheel body 102 to rotate, so that the rear wheel rotates along the circumference, and the zero-radius steering function, namely pivot steering, is realized to meet the special steering requirement.

When the vehicle controller 40 outputs a four-wheel steering command to the steering domain controller 30, the steering domain controller 30 controls the front wheel connecting and disconnecting assembly 11 to connect the two front wheel traverse members 12, the steering domain controller 30 controls the two front wheel steering motors 13 through the electronic control unit 15 of the front wheel steering motors 13 to respectively drive the two front wheel rotating transmission assemblies 14 to output rotating motions with the same steering direction, and further can drive the two rear wheel traverse members 22 to move transversely in the same direction, so as to drive the two front wheel bodies 101 to steer in the same direction through the two front wheel traverse members 12, the steering domain controller 30 controls the rear wheel connecting and disconnecting assembly 21 to connect the two rear wheel traverse members 22, the steering domain controller 30 controls the two rear wheel steering motors 23 through the electronic control unit 25 of the rear wheel steering motors 23 to respectively drive the two rear wheel rotating transmission assemblies 24 to output rotating motions with the same steering direction, thereby driving the two rear-wheel lateral-moving members 22 to move laterally in the same direction, so that the two rear-wheel bodies 102 are driven to turn in the same direction by the two rear-wheel lateral-moving members 22. In this embodiment, the direction in which the front wheel body 101 turns is the same as or different from the direction in which the rear wheel body 102 turns, under the same condition, both the front wheel body 101 and the rear wheel body 102 turn left or right, and under the different condition, the front wheel body 101 turns left and the rear wheel body 102 turns right, or the front wheel body 101 turns right and the rear wheel body 102 turns left, so as to meet the requirement of high-speed driving.

When the vehicle controller 40 outputs a four-wheel steering command while the vehicle 100 is in the first running speed zone, the direction in which the front-wheel steering motor 13 drives the front-wheel lateral-movement member 12 to move in the lateral direction in the same direction through the front-wheel rotation transmission assembly 14 is opposite to the direction in which the rear-wheel steering motor 23 drives the rear-wheel lateral-movement member 22 to move in the lateral direction in the same direction through the rear-wheel rotation transmission assembly 24. That is, when the vehicle 100 is in the first traveling speed section, the steering directions of the two front wheel bodies 101 are opposite to the steering directions of the two rear wheel bodies 102. When the vehicle controller 40 outputs a four-wheel steering command while the vehicle 100 is in the second travel speed zone, the direction in which the front-wheel steering motor 13 drives the front-wheel lateral-movement member 12 to move in the lateral direction in the same direction through the front-wheel rotation transmission assembly 14 is the same as the direction in which the rear-wheel steering motor 23 drives the rear-wheel lateral-movement member 22 to move in the lateral direction through the rear-wheel rotation transmission assembly 24. That is, when the vehicle 100 is in the second travel speed zone, the steering directions of the two front wheel bodies 101 are the same as the steering directions of the two rear wheel bodies 102.

In the present embodiment, the first travel speed interval is smaller than the second travel speed interval. It is understood that the first travel speed section is a low speed travel state at the vehicle 100, and the second travel speed section is a high speed travel state at the vehicle 100.

In this embodiment, the independent steering mechanism of front wheel still includes: and the front wheel torque and corner sensor is connected with an electronic control unit 15 of the front wheel steering motor 13 and is used for acquiring the torque and the corner output by the front wheel rotating transmission assembly 14. The independent steering mechanism of rear wheel still includes: and a rear wheel torque and rotation angle sensor connected with the electronic control unit 25 of the rear wheel steering motor 23 and used for acquiring the torque and rotation angle output by the rear wheel rotation transmission assembly 24.

The vehicle 100 also has a steering wheel 103, the steering wheel 103 being connected to the front wheel rotation transmission assembly 14 in one of the front wheel steering mechanisms. In the power steering function, that is, when the vehicle 100 is in a manual driving mode, when the vehicle controller 40 outputs a zero-radius steering command to the steering domain controller 30, the front wheel torque and rotation angle sensor collects a first front wheel torque and a first front wheel rotation angle of the front wheel rotation transmission assembly 14 connected to the steering wheel 103 and outputs the first front wheel torque and the first front wheel rotation angle to the electronic control unit 15 of the corresponding front wheel steering motor 13, the steering domain controller 30 controls the other front wheel steering motor 13 to drive the other front wheel rotation transmission assembly 14 corresponding to the front wheel steering motor 13 to output a torque and a rotation angle opposite to the first front wheel torque and the first front wheel rotation angle, and the two rear wheel steering motors 23 respectively drive the two rear wheel rotation transmission assemblies 24 to output different steering rotation motions, so that the two front wheel bodies 101 and the two rear wheel bodies 102 are steered to be tangent to the same circumference. When the vehicle controller 40 outputs a four-wheel steering command to the steering field controller 30, the front wheel torque and steering angle sensor collects a second front wheel torque and a second front wheel steering angle of the front wheel rotation transmission assembly 14 connected with the steering wheel and outputs the second front wheel torque and the second front wheel steering angle to the electronic control unit 15 of the corresponding front wheel steering motor 13, and the steering field controller 30 controls the other front wheel steering motor 13 to drive the other front wheel rotation transmission assembly 14 corresponding to the other front wheel steering motor to output the same torque and steering angle as the second front wheel torque and the second front wheel steering angle, so as to control the two front wheel bodies 101 to steer in the same direction. The steering domain controller 30 outputs a first desired rear wheel steering angle through the second front wheel torque and the second front wheel steering angle, and the steering domain controller 30 controls the two rear wheel steering motors 23 to respectively drive the two rear wheel rotating transmission assemblies 24 to output the same rotary motion as the second front wheel torque and the second front wheel steering angle according to the first desired rear wheel steering angle, so that the steering angle of the rear wheel body 102 is the first desired rear wheel steering angle.

Under the active steering function, when the vehicle controller 40 outputs a zero-radius steering instruction to the steering domain controller 30, the steering domain controller 30 controls the two front wheel steering motors 13 to respectively drive the two front wheel rotating transmission assemblies 14 to output different-steering rotating motions so as to drive the two front wheel bodies 101 to steer in different directions through the two front wheel transverse moving members 12, and the steering domain controller 30 controls the two rear wheel steering motors 23 to respectively drive the two rear wheel rotating transmission assemblies 24 to output different-steering rotating motions so as to drive the two rear wheel bodies 102 to steer in different directions through the two rear wheel transverse moving members 22, and enables the two front wheel bodies 101 and the two rear wheel bodies 102 to steer to be tangent to the same circumference. When the vehicle controller 40 outputs a four-wheel steering command to the steering field controller 30, the front wheel torque and steering angle sensor collects the current torque and steering angle of the front wheel steering transmission assembly 14 and outputs the current torque and steering angle to the electronic control unit 15 of the corresponding front wheel steering motor 13, and the steering field controller 30 controls the front wheel steering motor 13 to drive the front wheel steering transmission assembly 14 to output the torque and steering angle of the difference according to the difference between the current torque and steering angle and the expected torque and steering angle, so that the steering of the two front wheel bodies 101 is compensated. Steering domain controller 30 outputs a second desired rear wheel steering angle according to the desired torque and steering angle, and steering domain controller 30 controls two rear wheel steering motors 23 to respectively drive two rear wheel turning transmission assemblies 24 to output rotary motions of the same steering and torque according to the second desired rear wheel steering angle, so that the steering angle of rear wheel body 102 is the second desired rear wheel steering angle.

In an embodiment, the steering domain controller 30 is further configured to determine whether the front wheel independent steering mechanism fails through the electronic control unit 15 of the front wheel steering motor 13, if a front wheel independent steering mechanism fails, the vehicle controller 40 is further configured to output a front wheel redundancy reconfiguration command to the steering domain controller 30, and the steering domain controller 30 increases the output power of another front wheel steering motor according to the front wheel redundancy reconfiguration command, so that the other front wheel steering motor drives the two front wheel bodies to steer, thereby implementing the desired front wheel steering function. Or, the steering domain controller 30 is configured to determine whether the rear wheel independent steering mechanism fails through the electronic control unit 25 of the rear wheel steering motor 23, if a rear wheel independent steering mechanism fails, the vehicle controller 40 is further configured to output a rear wheel redundancy reconfiguration instruction to the steering domain controller 30, and the steering domain controller 30 increases the output power of another rear wheel steering motor according to the rear wheel redundancy reconfiguration instruction, so that the another rear wheel steering motor drives the two front wheel bodies to steer, thereby implementing an expected rear wheel steering function.

In this embodiment, when the steering domain controller 30 determines that both of the two front-wheel independent steering mechanisms and the two rear-wheel independent steering mechanisms are failed and steering at zero radius occurs, the vehicle stops.

The steering field controller 30 determines whether or not the front wheel steering mechanism is malfunctioning by the electronic control unit 15 of the front wheel steering motor 13 to connect the two front-wheel lateral-movement members 12 at the time of the malfunction, and determines whether or not the rear wheel steering mechanism is malfunctioning by the electronic control unit 25 of the rear wheel steering motor 23 to connect the two rear-wheel lateral-movement members 22 at the time of the malfunction, thereby improving the safety of the steering system of the vehicle.

In one embodiment, the front wheel independent steering mechanism further comprises: the front wheel motor position sensor is connected with the electronic control unit 15 of the front wheel steering motor 13 and used for collecting the position of a rotor in the front wheel steering motor 13 so as to control the phase change of the front wheel steering motor 13 and further control the two front wheel transverse moving pieces 12 to respectively and independently work. The independent steering mechanism of rear wheel still includes: and the rear wheel motor position sensor is connected with the electronic control unit 25 of the rear wheel steering motor 23 and is used for acquiring the position of a rotor in the rear wheel steering motor 23 so as to control the phase change of the rear wheel steering motor 23 and further control the two transverse moving pieces 22 to respectively and independently work.

In one embodiment, the front wheel independent steering mechanism further comprises: a front wheel current sensor connected to the electronic control unit 15 of the front wheel steering motor 13 for detecting the current of the front wheel steering motor 13 to control the output torque of the front wheel steering motor 13, that is, to control the rotation speed of the front wheel body 101. The independent steering mechanism of rear wheel still includes: a rear wheel current sensor connected to the electronic control unit 25 of the rear wheel steering motor 23 for detecting the current of the rear wheel steering motor 23 to control the output torque of the rear wheel steering motor 23, that is, the rotation speed of the rear wheel body 102.

In the present embodiment, the front wheel connection and disconnection assembly 11 and the rear wheel connection and disconnection assembly 21 are both electromagnetic latch pin assemblies, and as shown in fig. 1, the front wheel connection and disconnection assembly 11 includes: the electromagnetic module 111 is mounted on one front wheel transverse moving piece 12, the elastic resetting piece 112 is mounted on the electromagnetic module 111, the latch 113 is mounted on the elastic resetting piece 112, a lock hole is formed in the other front wheel transverse moving piece 12, when the lock hole is aligned with the position of the latch 113, the latch 113 moves into the lock hole through the elastic resetting piece 112 in a power-off state of the electromagnetic module 111 to connect the two front wheel transverse moving pieces 12, and the electromagnetic module 111 generates electromagnetic suction force on the latch 113 in a power-on state to enable the latch 113 to overcome the elastic force of the elastic resetting piece 112, so that the latch 113 moves out of the lock hole to disconnect the two front wheel transverse moving pieces 12.

In this embodiment, the two front wheel traversing members 12 and the two rear wheel traversing members 22 are identical in structure and are both rack gears, and correspondingly, the front wheel rotating transmission assembly 14 and the rear wheel rotating transmission assembly 24 are both gear assemblies.

Example II,

Referring to fig. 6, the present embodiment provides a vehicle steering method including the steps of:

the ignition of the vehicle is powered on for starting,

vehicle controller 40 may output a zero radius steering command or a four wheel steering command to steering domain controller 30.

When the vehicle controller 40 outputs a zero-radius steering instruction to the steering domain controller 30, the steering domain controller 30 controls the front wheel connection and disconnection assembly 11 to disconnect the two front wheel transverse moving members 12, the steering domain controller 30 controls the two front wheel steering motors 13 to respectively drive the two front wheel rotation transmission assemblies 14 to output rotation motions with different steering directions through the electronic control unit 15 of the front wheel steering motors 13, further the two front wheel transverse moving members 12 can be driven to transversely move in different directions, so that the two front wheel bodies 101 can be driven to transversely move in different steering directions through the two front wheel transverse moving members 12, the steering domain controller 30 controls the rear wheel connection and disconnection assembly 21 to disconnect the two rear wheel transverse moving members 22, the steering domain controller 30 controls the two rear wheel steering motors 23 to respectively drive the two rear wheel rotation transmission assemblies 24 to output rotation motions with different steering directions through the electronic control unit 25 of the rear wheel steering motor 23, thereby driving the two rear-wheel lateral moving members 22 to laterally move in different directions, so as to drive the two rear-wheel bodies 102 to turn in different directions through the two rear-wheel lateral moving members 22. In the present embodiment, the two front wheel bodies 101 and the two rear wheel bodies 102 are turned to be tangent to the same circumference. The vehicle controller 40 controls the hub motor of each front wheel body 101 to drive the front wheel body 101 to rotate, and controls the hub motor of the rear wheel body 102 to drive the rear wheel body 102 to rotate, so that the rear wheel rotates along the circumference, and the zero-radius steering function, namely pivot steering, is realized to meet the special steering requirement.

In the power steering function, that is, when the vehicle 100 is in a manual driving mode, when the vehicle controller 40 outputs a zero-radius steering command to the steering domain controller 30, the front wheel torque and rotation angle sensor collects a first front wheel torque and a first front wheel rotation angle of the front wheel rotation transmission assembly 14 connected to the steering wheel 103 and outputs the first front wheel torque and the first front wheel rotation angle to the electronic control unit 15 of the corresponding front wheel steering motor 13, the steering domain controller 30 controls the other front wheel steering motor 13 to drive the other front wheel rotation transmission assembly 14 corresponding to the front wheel steering motor 13 to output a torque and a rotation angle opposite to the first front wheel torque and the first front wheel rotation angle, and the two rear wheel steering motors 23 respectively drive the two rear wheel rotation transmission assemblies 24 to output different steering rotation motions, so that the two front wheel bodies 101 and the two rear wheel bodies 102 are steered to be tangent to the same circumference. When the vehicle controller 40 outputs a four-wheel steering command to the steering field controller 30, the front wheel torque and steering angle sensor collects a second front wheel torque and a second front wheel steering angle of the front wheel rotation transmission assembly 14 connected with the steering wheel and outputs the second front wheel torque and the second front wheel steering angle to the electronic control unit 15 of the corresponding front wheel steering motor 13, and the steering field controller 30 controls the other front wheel steering motor 13 to drive the other front wheel rotation transmission assembly 14 corresponding to the other front wheel steering motor to output the same torque and steering angle as the second front wheel torque and the second front wheel steering angle, so as to control the two front wheel bodies 101 to steer in the same direction. The steering domain controller 30 outputs a first desired rear wheel steering angle through the second front wheel torque and the second front wheel steering angle, and the steering domain controller 30 controls the two rear wheel steering motors 23 to respectively drive the two rear wheel rotating transmission assemblies 24 to output the same rotary motion as the second front wheel torque and the second front wheel steering angle according to the first desired rear wheel steering angle, so that the steering angle of the rear wheel body 102 is the first desired rear wheel steering angle.

In this embodiment, the steering domain controller 30 is further configured to determine whether the independent front wheel steering mechanism fails through the electronic control unit 15 of the front wheel steering motor 13, if one of the independent front wheel steering mechanisms fails, the vehicle controller 40 is further configured to output a front wheel redundancy reconfiguration instruction to the steering domain controller 30, and the steering domain controller 30 increases the output power of another front wheel steering motor according to the front wheel redundancy reconfiguration instruction, so that the other front wheel steering motor drives two front wheel bodies to steer, thereby implementing a desired front wheel steering function. Or, the steering domain controller 30 is configured to determine whether the rear wheel independent steering mechanism fails through the electronic control unit 25 of the rear wheel steering motor 23, if a rear wheel independent steering mechanism fails, the vehicle controller 40 is further configured to output a rear wheel redundancy reconfiguration instruction to the steering domain controller 30, and the steering domain controller 30 increases the output power of another rear wheel steering motor according to the rear wheel redundancy reconfiguration instruction, so that the another rear wheel steering motor drives the two front wheel bodies to steer, thereby implementing an expected rear wheel steering function.

In this embodiment, when the steering domain controller 30 determines that both the two front-wheel independent steering mechanisms and the two rear-wheel independent steering mechanisms are failed and perform zero-radius steering, the vehicle stops.

In summary, the vehicle steering system and the steering method provided by the present application can implement a multi-mode and multi-functional steering function such as a zero-radius steering mode or a four-wheel steering mode, and can implement a power steering function or an active steering function in both the zero-radius steering mode and the four-wheel steering mode, the steering domain controller determines whether the front wheel independent steering mechanism fails through the electronic control unit of the front wheel steering motor, determines whether the rear wheel independent steering mechanism fails through the electronic control unit of the rear wheel steering motor, and can output a front wheel redundancy reconfiguration command when the front wheel independent steering mechanism fails, and can output a rear wheel redundancy reconfiguration command when the rear wheel independent steering mechanism fails, thereby implementing a high redundancy steering function, and improving the driving safety of the vehicle.

The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.

Claims

1. A vehicle steering system, comprising:

front wheel steering apparatus comprising: the front wheel connecting and disconnecting assembly, the two front wheel transverse moving pieces and the two front wheel independent steering mechanisms are arranged on the front wheel connecting and disconnecting assembly; the two front wheel transverse moving pieces are respectively connected with the two front wheel bodies and can move along the transverse direction to drive the front wheel bodies to turn; the front wheel connecting and disconnecting assembly is used for connecting the two front wheel transverse moving pieces, and the two front wheel transverse moving pieces move in the same direction along the transverse direction, or the two front wheel transverse moving pieces are disconnected and can move in the same direction or different directions along the transverse direction; the independent steering mechanism of front wheel includes: the front wheel steering motor is connected with the front wheel rotating transmission assembly, and the front wheel rotating transmission assembly is connected with the front wheel transverse moving piece; the front wheel steering motor is used for driving the front wheel rotating transmission assembly to output rotary motion, and the front wheel transverse moving piece is used for converting the rotary motion output by the front wheel rotating transmission assembly into transverse movement along the transverse direction;

2. The vehicle steering system according to claim 1,

3. The vehicle steering system according to claim 1,

4. The vehicle steering system according to claim 1, wherein the steering domain controller is further configured to determine whether a front wheel independent steering mechanism fails through an electronic control unit of the front wheel steering motor, and if a front wheel independent steering mechanism fails, the vehicle controller is further configured to output a front wheel redundancy reconfiguration command to the steering domain controller, and the steering domain controller increases the output power of another front wheel steering motor according to the front wheel redundancy reconfiguration command; or, the steering domain controller is configured to determine whether a rear wheel independent steering mechanism fails through an electronic control unit of the rear wheel steering motor, and if a rear wheel independent steering mechanism fails, the vehicle controller is further configured to output a rear wheel redundancy reconfiguration instruction to the steering domain controller, and the steering domain controller increases the output power of another rear wheel steering motor according to the rear wheel redundancy reconfiguration instruction.

5. The vehicle steering system according to claim 1,

6. The vehicle steering system according to claim 1,

7. A vehicle steering method, characterized by comprising the steps of:

the vehicle controller can output a zero-radius steering instruction or a four-wheel steering instruction to the steering domain controller;

8. The vehicle steering method according to claim 7,

9. The wheel turning method according to claim 7,

10. The vehicle steering control method according to claim 7, wherein the steering domain controller determines whether a front wheel independent steering mechanism fails through an electronic control unit of the front wheel steering motor, and if a front wheel independent steering mechanism fails, the vehicle controller is further configured to output a front wheel redundancy reconfiguration command to the steering domain controller, and the steering domain controller increases the output power of another front wheel steering motor according to the front wheel redundancy reconfiguration command; or the steering domain controller judges whether the rear wheel independent steering mechanism fails through an electronic control unit of the rear wheel steering motor, if one rear wheel independent steering mechanism fails, the vehicle controller is further used for outputting a rear wheel redundancy reconstruction instruction to the steering domain controller, and the steering domain controller increases the output power of the other rear wheel steering motor according to the rear wheel redundancy reconstruction instruction.