CN209739155U - electronic round of system of electronic round of line control four-wheel initiative steering - Google Patents
electronic round of system of electronic round of line control four-wheel initiative steering Download PDFInfo
- Publication number
- CN209739155U CN209739155U CN201920101375.5U CN201920101375U CN209739155U CN 209739155 U CN209739155 U CN 209739155U CN 201920101375 U CN201920101375 U CN 201920101375U CN 209739155 U CN209739155 U CN 209739155U
- Authority
- CN
- China
- Prior art keywords
- wheel
- steering
- motor
- rear wheel
- vehicle
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 claims abstract description 25
- 238000011217 control strategy Methods 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000005389 magnetism Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Landscapes
- Steering Control In Accordance With Driving Conditions (AREA)
Abstract
the utility model discloses a line control four-wheel active steering electric wheel system, this system includes the steering wheel, steering wheel corner sensor, two steering motors, two motor control units, motor fault detection device, two rack and pinion steering gear, two tie rods, four wheels and in-wheel motor, yaw velocity sensor, speed sensor, laser radar, vehicle-mounted camera and whole car control unit, in the course of going, whole car electronic control unit gathers steering wheel corner, yaw velocity, speed, laser radar signal and vehicle-mounted camera signal in real time, calculate the output torque of front and back wheel corner and four in-wheel motor and transmit these signals to each motor controller through the controller of design, motor controller sends current signal to the motor and accomplishes the steering operation; the utility model discloses can effectively solve the fault-tolerant problem of drive-by-wire four-wheel steering system, improve the security that the vehicle travel.
Description
Technical Field
the utility model relates to a vehicle active control field, especially a drive-by-wire four-wheel active steering electric wheel system.
background
The steering system is one of four major systems of an automobile chassis, and the driving safety and the operation stability of the automobile are greatly influenced. The development process of the steering system is the mechanical steering system at first, but the steering system has a complex structure and a fixed transmission ratio, and is not beneficial to realizing the light weight design of an automobile and the safe and stable driving of a driver. The steer-by-wire system cancels the mechanical connection between a steering wheel and a steering wheel, adopts a sensor to acquire the steering intention of a driver and then sends the steering intention to a steering actuator to complete steering. Compared with the traditional mechanical steering system, the steer-by-wire system has the advantages of rapidness, flexibility in steering, reduction of vehicle weight, space saving and the like.
meanwhile, with the development of automobile technology, the active safety of automobiles is increasingly emphasized. Four-wheel steering of an automobile is one of important methods for improving the active safety of the automobile. The four-wheel steering system of drive-by-wire, front wheel and rear wheel all adopt the drive-by-wire to turn to the motor and drive the wheel rotation, compare in front wheel steering system, four-wheel steering system's advantage is that front and back wheel all can independently rotate, has reduced the barycenter side declination when turning to, has improved the flexibility when the car turns to at a low speed and the stability when turning to at a high speed, has improved the operating stability and the security of traveling of car.
however, the greatest disadvantage of the steer-by-wire system is its poor reliability compared to the conventional mechanical steering system, and the steering system has a possibility of steering runaway, which is extremely dangerous for a car running on a road.
existing fault-tolerant control for steer-by-wire is mostly focused on fault tolerance for steer-by-wire systems. For example, a dual-motor redundant steer-by-wire system solves the problem of fault tolerance of the steer-by-wire system by a motor backup method, and after one motor fails, the other motor can steer, but the manufacturing cost is increased, and the system is more complicated because more space is occupied. And the emergency reaction of the driver and the path tracking problem after the fault occurs are not considered in the fault-tolerant control, so that the driver can be caused to react excessively, and the vehicle deviates from the target path.
SUMMERY OF THE UTILITY MODEL
In view of the above problem, the utility model provides a line control four-wheel active steering electric wheel system and turn to fault-tolerant control method thereof. The method aims to fully utilize the advantage of redundancy of a steering actuator of the steer-by-wire four-wheel steering electric wheel system and combine a path tracking control technology, so that the target that the steer-by-wire system can still normally track the path according to the intention of a driver after a fault occurs is achieved, the psychological burden and the operation burden of the driver after the fault occurs are reduced, and the safety and the stability of vehicle driving are improved. In addition, compared with the traditional dual-motor redundant steer-by-wire system, the system reduces the weight and the production cost of the vehicle and provides a foundation for the application of the intelligent driving auxiliary system.
In order to achieve the above object, the utility model provides a following technical scheme realizes:
A steer-by-wire four-wheel active steering electric wheel system includes: the device comprises a vehicle body, a steering wheel 9, a steering wheel angle sensor 10, a rear wheel steering motor 4, a front wheel steering motor 14, a rear wheel steering motor controller 5, a front wheel steering motor controller 13, a rear wheel motor fault detection device 2, a front wheel motor fault detection device 16, a rear rack and pinion steering gear 3, a front rack and pinion steering gear 15, a rear wheel steering tie rod 6, a front wheel steering tie rod 12, a first hub motor 1, a second hub motor 7, a third hub motor 11, a fourth hub motor 17, a yaw rate sensor 19, a mass center yaw angle sensor 20, a vehicle speed sensor 21, a laser radar 22, a vehicle-mounted camera 23, a whole vehicle electronic control unit 8(ECU) and a CAN bus 18, wherein the steering wheel 9, the steering wheel angle sensor 10, the rear wheel steering motor 4, the front wheel steering motor 14, the rear wheel steering motor;
the rear wheel steering motor 4 is positioned on a rear axle of the vehicle and is respectively connected with a rear rack and pinion steering gear 3, a rear wheel steering motor controller 5 and a rear wheel motor fault detection device 2, the rear rack and pinion steering gear 3 is positioned on a rear wheel steering tie rod 6, a first hub motor 1 and a second hub motor 7 are respectively arranged at two ends of the rear wheel steering tie rod 6, and the first hub motor 1 and the second hub motor 7 are both connected with corresponding wheels; the rear wheel steering motor 4 drives the rear rack and pinion steering gear 3 to move, and further drives the rear steering tie rod 6 to drive the first hub motor 1 and the second hub motor 7, so that corresponding wheels are driven to rotate, and steering of the wheels is realized;
The front wheel steering motor 14 is positioned on a front shaft of the vehicle and is respectively connected with a front gear rack type steering gear 15, a front wheel steering motor controller 13 and a front wheel motor fault detection device 16, the front gear rack type steering gear 15 is positioned on a front wheel steering transverse pull rod 12, a third hub motor 11 and a fourth hub motor 17 are respectively arranged at two ends of the front wheel steering transverse pull rod 12, and the third hub motor 11 and the fourth hub motor 17 are both connected with corresponding wheels; the front wheel steering motor 14 drives the front gear rack type steering gear 15 to move, and then drives the front steering tie rod 12 to drive the third hub motor 11 and the fourth hub motor 17 and drive corresponding wheels, so as to realize the steering of the vehicle;
the steering wheel 9 is positioned in the vehicle body, and the steering wheel angle sensor 10 is connected with the steering wheel 9 through a steering column of the steering wheel to acquire a steering wheel angle signal;
The front wheel motor fault detection device 16 is connected with the CAN bus 18 and is used for detecting the fault of the front wheel steering motor 14 and sending a fault signal to the CAN bus 18 through the CAN transceiver; the rear wheel motor fault detection device 2 is connected with the CAN bus 18 and used for detecting the fault of the rear wheel steering motor 4 and sending a fault signal to the CAN bus 18 through the CAN transceiver;
the yaw rate sensor 19, the mass center slip angle sensor 20, the vehicle speed sensor 21, the laser radar 22 and the vehicle-mounted camera 23 are all arranged on the vehicle body and are respectively used for acquiring a vehicle yaw rate signal, a mass center slip angle signal, a vehicle speed signal, a road obstacle condition signal and a lane condition signal; the yaw angular velocity sensor 19, the centroid sideslip angle sensor 20, the vehicle speed sensor 21, the laser radar 22 and the vehicle-mounted camera 23 are respectively connected with the CAN bus 18, and send received signals to the CAN bus 18 through the CAN transceiver;
the rear wheel steering motor controller 5 and the front wheel steering motor controller 13 are respectively connected with the CAN bus 18 and receive signals transmitted by the CAN bus 18;
The whole vehicle electronic control unit 8 is connected with a CAN bus 18 through a CAN transceiver and receives signals obtained by the CAN bus 18 through a yaw rate sensor 19, a centroid yaw angle sensor 20, a vehicle speed sensor 21, a laser radar 22 and a vehicle-mounted camera 23; the whole vehicle electronic control unit 8 is also connected with a steering wheel corner sensor 10 and acquires a steering wheel corner signal; the whole vehicle electronic control unit 8 calculates the rotation angles of the front and rear wheels and the driving moments of the four wheels through a built-in controller according to a steering wheel rotation angle signal transmitted by a steering wheel rotation angle sensor 10 and sends the rotation angles and the driving moments to a CAN bus 18;
The rear wheel steering motor controller 5, the front wheel steering motor controller 13, the first in-wheel motor 1, the second in-wheel motor 7, the third in-wheel motor 11 and the fourth in-wheel motor 17 are respectively provided with CAN transceivers, the rear wheel steering motor controller 5, the front wheel steering motor controller 13, the first in-wheel motor 1, the second in-wheel motor 7, the third in-wheel motor 11 and the fourth in-wheel motor 17 are respectively connected with a CAN bus 18 through the respective CAN transceivers, and the target turning angle and the target torque of the steering motor sent by the whole vehicle electronic control unit 8 through the CAN bus 18 are received.
the rear wheel steering motor controller 5 generates corresponding current according to a rotation angle signal obtained from the CAN bus 18 to control the rear wheel steering motor 4 to work, and the first in-wheel motor 1 and the second in-wheel motor 7 generate corresponding current according to a torque signal obtained from the CAN bus 18 to control the in-wheel motors and corresponding wheels to work.
the front wheel steering motor controller 13 generates corresponding currents according to the rotation angle signals obtained from the CAN bus 18 to control the front wheel steering motor 14 to work, and the in-wheel motor controllers of the third in-wheel motor 11 and the fourth in-wheel motor 17 generate corresponding currents according to the torque signals obtained from the CAN bus 18 to control the in-wheel motors and corresponding wheels to work.
The whole vehicle electronic control unit 8 is an ECU module and comprises a path planning module, a driver module, a stability control module and a fault-tolerant control module which are connected in sequence.
in the present invention, the term "front wheel" refers to a wheel corresponding to the third hub motor and the fourth hub motor; the term "rear wheel" refers to a wheel corresponding to the first in-wheel motor and the second in-wheel motor.
further, the utility model provides an among the drive-by-wire four-wheel active steering electric wheel system, rear wheel steer motor 4 and front wheel steer motor 14 are permanent magnetism brushless DC motor.
The utility model discloses still provide the fault-tolerant control method that turns to of above-mentioned drive-by-wire four-wheel initiative steering electric wheel system simultaneously: in the whole vehicle electronic control unit 18, a stability control module and a fault-tolerant control module are switched by a controller according to a signal sent to the whole vehicle electronic control unit 18 by the motor fault detection device 16; when the front wheel steering motor 14 is not in fault, the motor fault detection device 16 sends a low level to the whole vehicle electronic control unit 18, and the control unit operates a stability control module to implement a stability control strategy; when the front wheel steering motor 14 fails, the motor failure detection device 16 sends a high level to the entire vehicle electronic control unit 18, and the control unit operates the fault-tolerant control module to implement a fault-tolerant control strategy.
the stability control strategy comprises the following steps:
Step 1), the driver rotates the steering wheel, the whole vehicle electronic control unit 18 obtains a steering wheel corner δ sw through a steering wheel corner sensor, and obtains an ideal yaw rate w and an ideal centroid yaw angle β through the formula (1):
in the formulas (1) - (3), Gw is a set variable transmission ratio coefficient, vx is a vehicle speed, L is a vehicle wheel base, Ks is a yaw rate gain coefficient (generally taking a value of 15-20), K is a stability factor, m is a whole vehicle mass, and K1 and K2 are the front and rear wheel side deflection stiffness of the vehicle respectively;
Step 2), the stability control module calculates yaw velocity deviation wd and centroid side slip angle deviation beta d
the ideal yaw rate w and the ideal centroid slip angle β are differentiated from the actual yaw rate w and the centroid slip angle β measured by the sensors by:
w is the actual yaw velocity measured by the sensor, beta is the centroid slip angle actually measured by the sensor, wd is the yaw velocity deviation, and beta is the centroid slip angle deviation;
substituting the formula (4) into a structural singular value mu control algorithm formula (5) and substituting into a stability control module to calculate a front wheel corner delta f and a rear wheel corner delta r;
the fault-tolerant control strategy comprises the following steps:
step 1:
1.1 if the front wheel steering motor fails
the fault-tolerant control module calculates a rear wheel corner delta r according to the set transmission ratio ir between the rear wheel and the steering wheel;
Wherein δ sw represents a steering wheel angle; δ r represents a rear wheel turning angle; the if value ranges from-15 to-20;
1.2 if the rear wheel steering motor fails
the fault-tolerant control module calculates a rear wheel corner delta f according to the set transmission ratio if between the front wheel and the steering wheel:
Wherein δ sw represents a steering wheel angle; δ f represents a rear wheel turning angle. The if value ranges from 15 to 20;
Step 2:
a path planning module in the whole vehicle electronic control unit 18 receives the laser radar signal and the vehicle-mounted camera signal, generates an expected path Y according to a built-in path planning algorithm and sends the expected path signal to a fault-tolerant control module;
the path planning algorithm is a conventional algorithm in the field, such as a path planning algorithm disclosed in a document of' ann lin fang, chen tao, germany et al.
And step 3:
The driver module in the vehicle electronic control unit 18 is based on the difference between the expected path Y and the actual path Y:
ΔY＝Y-Y (8)
obtaining an expected steering angle delta fd of a driver to a steering wheel according to a built-in single-point preview driver model algorithm (9) and sending the expected steering angle delta fd to a fault-tolerant control module;
where δ fd is the desired driver steering angle to the steering wheel, Gh is the steering proportionality coefficient, and τ L is the differential time; τ d1 is the operation delay time; τ d2 is the driver reaction delay time;
and 4, step 4:
the whole vehicle electronic control unit 18 transmits signals of the vehicle yaw angular velocity w and the vehicle speed v measured by a yaw angular velocity sensor and a vehicle speed sensor to a fault-tolerant control module;
and 5:
The fault-tolerant control module obtains target driving torques T1, T2, T3 and T4 of four in-wheel motors of the vehicle according to the steering angle delta sw of the steering wheel by the driver, the expected path Y, the expected steering angle delta fd of the steering wheel by the driver and the actual state of the vehicle;
Step 6:
the vehicle electronic control unit 18 sends the front and rear wheel steering angle signals δ f or δ r, T1, T2, T3 and T4 calculated according to the steps 1-6 to the front wheel steering motor controller or the rear wheel steering motor controller and the four wheel hub motor controllers respectively from the vehicle electronic control unit 18, and the motor controllers generate corresponding currents to drive the corresponding motors to rotate, so that the vehicle can run.
Compared with the prior art, the utility model discloses following beneficial effect has:
1. the utility model discloses a drive-by-wire four-wheel active steering electric wheel system can realize the active steering of front and rear wheel and the independent drive of four-wheel. The steering system fault detection device is arranged, so that the steering system fault can be detected in real time. And the laser radar and the vehicle-mounted camera are assembled, so that path identification and planning can be realized. The system has simple structure, easy operation, low cost and easy realization.
2. the utility model discloses set up two steering controller: the device comprises a stability control module and a fault-tolerant control module. The stability control under the normal working condition and the fault-tolerant control under the fault working condition can be realized. Meanwhile, the system can realize path identification and planning, can still normally track the target of the path according to the intention of the driver after the fault occurs, reduces the psychological burden and the operation burden of the driver after the fault occurs, and improves the safety and the stability of vehicle driving.
Drawings
FIG. 1 is a block diagram of a steer-by-wire electric wheel system provided by the present invention;
FIG. 2 is a schematic diagram of a fault tolerance control strategy;
fig. 3 is a schematic diagram of a fault tolerance control strategy.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings:
In the following embodiments, the entire vehicle electronic control unit 18 (i.e., ECU) is a vehicle ECU manufactured by BOSCH corporation and having a model number of EDC 17CP 14/5/P680.
example 1
as shown in fig. 1, the present invention designs a four-wheel active steering electric wheel system based on the existing steer-by-wire system. Two steering controllers, namely a stability control module and a fault-tolerant control module, are arranged in the central controller. The stability control module works under the normal working condition, the front wheel steering angle and the rear wheel steering angle are calculated by the central controller according to signals of a steering wheel steering angle, a yaw angle speed sensor, a mass center yaw angle sensor and a vehicle speed sensor and are sent to the front wheel steering motor controller and the rear wheel steering motor controller, and then the front wheel steering motor controller and the rear wheel steering motor controller generate corresponding currents to control the corresponding motors to rotate. The fault-tolerant control module works under the fault working condition, according to fault information obtained from the steering motor fault detection device, the central controller selects the corresponding fault-tolerant control module, combines a steering wheel corner, a yaw rate, a mass center slip angle, a vehicle speed, a laser radar and a vehicle-mounted camera signal to calculate the front wheel corner and the rear wheel corner and driving moments of four hub motors and correspondingly sends the driving moments to the front wheel steering motor controller and the rear wheel steering motor controller and the hub motor controller, and then the front wheel steering motor controller and the rear wheel steering motor controller correspondingly generate corresponding currents to control the motors to rotate.
specifically, the present embodiment provides a four-wheel steering-by-wire electric wheel system including: the device comprises a steering wheel 9, a steering wheel angle sensor 10, a rear wheel steering motor 4, a front wheel steering motor 14, a rear wheel steering motor controller 5, a front wheel steering motor controller 13, a rear wheel motor fault detection device 2, a front wheel motor fault detection device 16, a rear rack and pinion steering gear 3, a front rack and pinion steering gear 15, a rear wheel steering tie rod 6, a front wheel steering tie rod 12, a first hub motor 1, a second hub motor 7, a third hub motor 11, a fourth hub motor 17, a yaw angle speed sensor 19, a mass center side deviation angle sensor 20, a vehicle speed sensor 21, a laser radar 22, an on-vehicle camera 23, a whole vehicle electronic control unit 8(ECU) and a CAN bus 18;
The rear wheel steering motor 4 is positioned on a rear axle of the vehicle and is respectively connected with a rear rack and pinion steering gear 3, a rear wheel steering motor controller 5 and a rear wheel motor fault detection device 2, the rear rack and pinion steering gear 3 is positioned on a rear wheel steering tie rod 6, a first hub motor 1 and a second hub motor 7 are respectively arranged at two ends of the rear wheel steering tie rod 6, and the first hub motor 1 and the second hub motor 7 are both connected with corresponding wheels; the rear wheel steering motor 4 drives the rear rack and pinion steering gear 3 to move, and further drives the rear steering tie rod 6 to drive the first hub motor 1 and the second hub motor 7, so that corresponding wheels are driven to rotate, and steering of the wheels is realized;
The front wheel steering motor 14 is positioned on a front shaft of the vehicle and is respectively connected with a front gear rack type steering gear 15, a front wheel steering motor controller 13 and a front wheel motor fault detection device 16, the front gear rack type steering gear 15 is positioned on a front wheel steering transverse pull rod 12, a third hub motor 11 and a fourth hub motor 17 are respectively arranged at two ends of the front wheel steering transverse pull rod 12, and the third hub motor 11 and the fourth hub motor 17 are both connected with corresponding wheels; the front wheel steering motor 14 drives the front gear rack type steering gear 15 to move, and then drives the front steering tie rod 12 to drive the third hub motor 11 and the fourth hub motor 17 and drive corresponding wheels, so as to realize the steering of the vehicle;
the steering wheel 9 is positioned in the vehicle body, and the steering wheel angle sensor 10 is connected with the steering wheel 9 through a steering column of the steering wheel to acquire a steering wheel angle signal;
the front wheel motor fault detection device 16 is connected with the CAN bus 18 and is used for detecting the fault of the front wheel steering motor 14 and sending a fault signal to the CAN bus 18 through the CAN transceiver; the rear wheel motor fault detection device 2 is connected with the CAN bus 18 and used for detecting the fault of the rear wheel steering motor 4 and sending a fault signal to the CAN bus 18 through the CAN transceiver;
the yaw rate sensor 19, the mass center slip angle sensor 20, the vehicle speed sensor 21, the laser radar 22 and the vehicle-mounted camera 23 are all arranged on the vehicle body and are respectively used for acquiring a vehicle yaw rate signal, a mass center slip angle signal, a vehicle speed signal, a road obstacle condition signal and a lane condition signal; the yaw angular velocity sensor 19, the centroid sideslip angle sensor 20, the vehicle speed sensor 21, the laser radar 22 and the vehicle-mounted camera 23 are respectively connected with the CAN bus 18, and send received signals to the CAN bus 18 through the CAN transceiver;
the rear wheel steering motor controller 5 and the front wheel steering motor controller 13 are respectively connected with the CAN bus 18 and receive signals transmitted by the CAN bus 18;
the whole vehicle electronic control unit 8 is connected with a CAN bus 18 through a CAN transceiver and receives signals obtained by the CAN bus 18 through a yaw rate sensor 19, a centroid yaw angle sensor 20, a vehicle speed sensor 21, a laser radar 22 and a vehicle-mounted camera 23; the whole vehicle electronic control unit 8 is also connected with a steering wheel corner sensor 10 and acquires a steering wheel corner signal; the whole vehicle electronic control unit 8 calculates the rotation angles of the front and rear wheels and the driving moments of the four wheels through a built-in controller according to a steering wheel rotation angle signal transmitted by a steering wheel rotation angle sensor 10 and sends the rotation angles and the driving moments to a CAN bus 18;
the rear wheel steering motor controller 5, the front wheel steering motor controller 13, the first in-wheel motor 1, the second in-wheel motor 7, the third in-wheel motor 11 and the fourth in-wheel motor 17 are respectively provided with CAN transceivers, the rear wheel steering motor controller 5, the front wheel steering motor controller 13, the first in-wheel motor 1, the second in-wheel motor 7, the third in-wheel motor 11 and the fourth in-wheel motor 17 are respectively connected with a CAN bus 18 through the respective CAN transceivers, and the target turning angle and the target torque of the steering motor sent by the whole vehicle electronic control unit 8 through the CAN bus 18 are received.
The rear wheel steering motor controller 5 generates corresponding current according to a rotation angle signal obtained from the CAN bus 18 to control the rear wheel steering motor 4 to work, and the first in-wheel motor 1 and the second in-wheel motor 7 generate corresponding current according to a torque signal obtained from the CAN bus 18 to control the in-wheel motors and corresponding wheels to work.
The front wheel steering motor controller 13 generates corresponding currents according to the rotation angle signals obtained from the CAN bus 18 to control the front wheel steering motor 14 to work, and the in-wheel motor controllers of the third in-wheel motor 11 and the fourth in-wheel motor 17 generate corresponding currents according to the torque signals obtained from the CAN bus 18 to control the in-wheel motors and corresponding wheels to work.
the whole vehicle electronic control unit 8 is an ECU module and comprises a path planning module, a driver module, a stability control module and a fault-tolerant control module which are connected in sequence.
In the present embodiment, the rear-wheel steering motor 4 and the front-wheel steering motor 14 are both permanent magnet brushless dc motors.
the embodiment also provides a steering fault-tolerant control method of the wire-controlled four-wheel active steering electric wheel system, which comprises the following steps:
The whole vehicle electronic control unit 18 is internally provided with two controllers, a stability control module and a fault-tolerant control module, and the two controllers are switched according to signals sent to the whole vehicle electronic control unit 18 by the motor fault detection device 16; when the front wheel steering motor 14 is not in fault, the motor fault detection device 16 sends a low level to the whole vehicle electronic control unit 18, and the control unit operates a stability control module to implement a stability control strategy; when the front wheel steering motor 14 fails, the motor failure detection device 16 sends a high level to the entire vehicle electronic control unit 18, and the control unit operates the fault-tolerant control module to implement a fault-tolerant control strategy.
as shown in fig. 2, the stability control strategy comprises the following steps:
Step 1), the driver rotates the steering wheel, the whole vehicle electronic control unit 18 obtains a steering wheel corner δ sw through a steering wheel corner sensor, and obtains an ideal yaw rate w and an ideal centroid yaw angle β through the formula (1):
In the formulas (1) - (3), Gw is a set variable transmission ratio coefficient, vx is a vehicle speed, L is a vehicle wheel base, Ks is a yaw rate gain coefficient (generally taking a value of 15-20), K is a stability factor, m is a whole vehicle mass, and K1 and K2 are the front and rear wheel side deflection stiffness of the vehicle respectively;
Step 2), the stability control module calculates yaw velocity deviation wd and centroid sideslip angle deviation β d:
the ideal yaw rate w and the ideal centroid slip angle β are differentiated from the actual yaw rate w and the centroid slip angle β measured by the sensors by:
w is the actual yaw rate measured by the sensor, beta is the centroid slip angle actually measured by the sensor, wd is the yaw rate deviation, and beta is the centroid slip angle deviation.
Substituting the formula (4) into a stability control module obtained by a structure singular value mu control algorithm (5) to calculate a front wheel corner delta f and a rear wheel corner delta r;
as shown in fig. 3, the fault-tolerant control strategy comprises the following steps:
Step 1:
1.1 if the front wheel steering motor fails
the fault-tolerant control module calculates a rear wheel corner delta r according to the set transmission ratio ir between the rear wheel and the steering wheel;
wherein δ sw represents a steering wheel angle; δ r represents a rear wheel turning angle; the if value ranges from-15 to-20;
1.2 if the rear wheel steering motor fails
the fault-tolerant control module calculates a rear wheel corner delta f according to the set transmission ratio if between the front wheel and the steering wheel:
Wherein δ sw represents a steering wheel angle; δ f represents a rear wheel turning angle. The if value ranges from 15 to 20;
step 2:
A path planning module in the whole vehicle electronic control unit 18 receives the laser radar signal and the vehicle-mounted camera signal, generates an expected path Y according to a built-in path planning algorithm and sends the expected path signal to a fault-tolerant control module;
the path planning algorithm used in the embodiment is disclosed in a document 'Arlinfang, Chentao, Islands, et al. an intelligent vehicle path planning simulation based on an artificial potential field algorithm [ J ]. automobile engineering, 2017.';
and step 3:
the driver module in the vehicle electronic control unit 18 is based on the difference between the expected path Y and the actual path Y:
ΔY＝Y*-Y(8)
obtaining an expected steering angle delta fd of a driver to a steering wheel according to a built-in single-point preview driver model algorithm (9) and sending the expected steering angle delta fd to a fault-tolerant control module K;
in the equation (9), δ fd is a desired driver's steering angle to the steering wheel, Gh is a steering proportionality coefficient, and τ L is a differential time; τ d1 is the operation delay time; τ d2 is the driver reaction delay time;
and 4, step 4:
Signals of the vehicle yaw rate w and the vehicle speed v measured by the yaw rate sensor and the vehicle speed sensor are transmitted to the fault-tolerant control module;
and 5:
the fault-tolerant control module obtains target driving torques T1, T2, T3 and T4 of four in-wheel motors of the vehicle according to the steering angle delta sw of the steering wheel by the driver, the expected path Y, the expected steering angle delta fd of the steering wheel by the driver and the actual state of the vehicle;
step 6:
the vehicle electronic control unit 18 sends the front and rear wheel steering angle signals δ f or δ r, T1, T2, T3 and T4 calculated according to the steps 1-6 to the front wheel steering motor controller or the rear wheel steering motor controller and the four wheel hub motor controllers respectively from the vehicle electronic control unit 18, and the motor controllers generate corresponding currents to drive the corresponding motors to rotate, so that the vehicle can run.
Claims (2)
1. The utility model provides an electronic round of system of drive-by-wire four-wheel active steering, includes the automobile body, its characterized in that, electronic round of system of drive-by-wire four-wheel active steering includes: the steering wheel, the rear wheel steering motor, the front wheel rear wheel steering motor, the whole vehicle electronic control unit and the CAN bus are arranged in the vehicle body;
The steering wheel is connected with a steering wheel corner sensor;
the rear wheel steering motor is respectively connected with the rear rack and pinion steering gear, the rear wheel steering motor controller and the rear wheel motor fault detection device; the rear gear rack type steering gear is positioned on a rear wheel steering tie rod, and a first hub motor and a second hub motor are respectively arranged at two ends of the rear wheel steering tie rod; the first hub motor and the second hub motor are respectively connected with corresponding wheels;
the front wheel steering motor is respectively connected with a front gear rack type steering gear, a front wheel steering motor controller and a front wheel motor fault detection device; the front gear rack type steering gear is positioned on a front wheel steering transverse pull rod, a third hub motor and a fourth hub motor are respectively arranged at two ends of the front wheel steering transverse pull rod, and the third hub motor and the fourth hub motor are respectively connected with corresponding wheels;
The whole vehicle electronic control unit comprises a path planning module, a driver module, a stability control module and a fault-tolerant control module;
the front wheel motor fault detection device, the rear wheel motor fault detection device and the whole vehicle electronic control unit are respectively connected with the CAN bus;
the vehicle body is also provided with a yaw angular velocity sensor, a mass center side slip angle sensor, a vehicle speed sensor, a laser radar and a vehicle-mounted camera which are respectively connected with the CAN bus;
the rear wheel steering motor controller, the front wheel steering motor controller, the first in-wheel motor, the second in-wheel motor, the third in-wheel motor and the fourth in-wheel motor are respectively provided with a CAN transceiver, and the rear wheel steering motor controller, the front wheel steering motor controller, the first in-wheel motor, the second in-wheel motor, the third in-wheel motor and the fourth in-wheel motor are respectively connected with a CAN bus through the respective CAN transceivers.
2. The four-wheel steer-by-wire active electric wheel system of claim 1, wherein said rear wheel steering motor and said front wheel steering motor are both permanent magnet brushless dc motors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920101375.5U CN209739155U (en) | 2019-01-22 | 2019-01-22 | electronic round of system of electronic round of line control four-wheel initiative steering |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920101375.5U CN209739155U (en) | 2019-01-22 | 2019-01-22 | electronic round of system of electronic round of line control four-wheel initiative steering |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209739155U true CN209739155U (en) | 2019-12-06 |
Family
ID=68706596
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920101375.5U Active CN209739155U (en) | 2019-01-22 | 2019-01-22 | electronic round of system of electronic round of line control four-wheel initiative steering |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209739155U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111301515A (en) * | 2019-12-10 | 2020-06-19 | 东风越野车有限公司 | Control method of rear wheel linear control electro-hydraulic steering system |
| CN112140868A (en) * | 2020-10-13 | 2020-12-29 | 武汉鲸鱼座机器人技术有限公司 | Chassis architecture meeting automatic driving redundancy requirement and control method |
-
2019
- 2019-01-22 CN CN201920101375.5U patent/CN209739155U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111301515A (en) * | 2019-12-10 | 2020-06-19 | 东风越野车有限公司 | Control method of rear wheel linear control electro-hydraulic steering system |
| CN112140868A (en) * | 2020-10-13 | 2020-12-29 | 武汉鲸鱼座机器人技术有限公司 | Chassis architecture meeting automatic driving redundancy requirement and control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109774791B (en) | Drive-by-wire four-wheel active steering electric wheel system and steering fault-tolerant control method thereof | |
| CN107685767B (en) | Multiaxis wheel-hub motor driven vehicle rear-wheel steering-by-wire driving device and forward method | |
| CN102180194B (en) | Adaptive steering system of timely four-wheel drive electric wheel automobile and control method thereof | |
| CN110126643B (en) | Control method and system for distributed driving electric automobile in motor failure state | |
| CN101596915B (en) | Linear control based automobile steering system | |
| WO2017028788A1 (en) | Auxiliary steering system and auxiliary steering method for electric vehicle and electric vehicle | |
| CN111108035A (en) | Method and system for controlling lane keeping of vehicle | |
| CN109017974A (en) | Assist steering system and its control method with active steering function | |
| CN110077418B (en) | Differential auxiliary steering and shared control system modeling method considering driver characteristics | |
| CN106080753A (en) | A kind of Electric Motor Wheel steering control system merging active steering, power-assisted steering and direct yaw moment control function and control method thereof | |
| KR101734277B1 (en) | Method for controlling vehicle using in wheel system | |
| CN106627747B (en) | A kind of modified sliding-mode control of the anti-side interference of wire controlled four wheel steering automobile | |
| CN107089261A (en) | A kind of integrated EPS distributed driving automobile steering control system and method | |
| CN108163044A (en) | The steering redundancy of four motorized wheels electric vehicle and integrated control system and method | |
| CN109159816B (en) | Four-wheel steering-by-wire automobile and control method thereof | |
| CN109664937A (en) | Multi-mode line traffic control four-wheel independent steering/drive system and its steering pattern control method | |
| JPH1178950A (en) | Steering control device of vehicle | |
| CN105774902A (en) | Automobile power steering control device with fault-tolerant function and control method | |
| CN105966263B (en) | A kind of electric wheel truck differential steering road feel control method of In-wheel motor driving | |
| CN108749919B (en) | Fault-tolerant control system and control method for wire-controlled four-wheel independent steering system | |
| CN111605610B (en) | Dual-motor coupling drive-by-wire steering system and energy optimization method thereof | |
| US11472471B2 (en) | Differential cooperative active steering for a front-axle independent-drive vehicle with electric wheels and control method therefor | |
| CN108909828A (en) | A kind of steering-by-wire and braking system and its control method | |
| CN114735076B (en) | Fault-tolerant control method for differential cooperative steer-by-wire | |
| CN112026777B (en) | Vehicle composite steering system and mode switching control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |