CN112677955B

CN112677955B - Vehicle torque distribution method, device and equipment

Info

Publication number: CN112677955B
Application number: CN202011561870.8A
Authority: CN
Inventors: 智晋宁; 王晓伟; 史青录; 连晋毅; 张喜清; 要志斌; 齐亚攀
Original assignee: Taiyuan University of Science and Technology
Current assignee: Taiyuan University of Science and Technology
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2022-03-04
Anticipated expiration: 2040-12-25
Also published as: CN112677955A

Abstract

The application provides a vehicle torque distribution method, a vehicle torque distribution device and vehicle torque distribution equipment, wherein the method comprises the steps of determining the number of faults of the faulty motors and the installation positions of the faulty motors in a vehicle body when the motors are in fault; and selecting a pre-configured torque distribution strategy corresponding to the installation position according to the number of faults and the installation position, and distributing torque to each fault-free motor of the vehicle according to the distribution strategy so as to keep the vehicle running normally. Therefore, by applying the technical scheme provided by the embodiment of the application, the correct running track of the vehicle can be controlled under the condition that the driving motor fails, so that the running stability and safety of the vehicle can be improved.

Description

Vehicle torque distribution method, device and equipment

Technical Field

The invention relates to the technical field of electric automobiles, in particular to a vehicle torque distribution method, device and equipment.

Background

The distributed driving electric vehicle comprises a plurality of independent driving units, and has the advantages of good controllability, space-saving layout, high efficiency and energy conservation. Since the distributed drive units form a redundant drive system, the torque coordination control of the drive wheels is a precondition for ensuring the normal running of the vehicle.

During running of the distributed drive electric vehicle, due to uncertainty of operation of a motor for driving the vehicle to rotate, faults can happen suddenly, driving capability is lost, the yaw angle of the vehicle is suddenly increased, sideslip occurs, and stability is lost. Especially when the vehicle runs at high speed, the motor is invalid, and when the yaw angle of the vehicle is large, the brake torque of the hub motor reaches the saturation limit, but the mechanical brake does not play a role, and the vehicle loses stability. Therefore, how to control the yaw stability of the vehicle and maintain the normal running track is significantly more important.

Disclosure of Invention

In view of the above, the present invention provides a vehicle torque distribution method, device and apparatus, so as to control the normal driving track of the vehicle in case of motor failure.

Specifically, the method is realized through the following technical scheme:

in a first aspect, an embodiment of the present application provides a vehicle torque distribution method, including:

when determining that the motor for driving the wheel has a fault, determining the number of faults of the fault motor and the installation position of each fault motor in the vehicle body;

selecting a pre-configured torque distribution strategy corresponding to the installation position according to the fault number and the installation position, and distributing torque to each fault-free motor of the vehicle according to the distribution strategy so as to enable the vehicle to keep running normally; the allocation strategy is determined according to the fault number of the fault motor, the installation position of the fault motor on the vehicle body, the current running state of the vehicle and the maximum torque limiting condition of the motor under the condition that the normal running of the vehicle is met.

In an embodiment of the present application, when the number of faults is 1, selecting a pre-configured torque distribution strategy corresponding to the installation location according to the number of faults and the installation location, and distributing a torque to each non-faulty motor of the vehicle according to the distribution strategy includes:

determining an expected mass center slip angle according to the steering wheel rotation angle and the vehicle speed of the vehicle at the current moment;

when the current running state of the vehicle is accelerated running and the vehicle speed is in a preset high-speed running range, or the current running state of the vehicle is accelerated running and the vehicle speed is in a preset low-speed running range, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of an accelerator pedal at the current moment, meanwhile, calculating the difference value between the actual centroid sideslip angle and the expected centroid sideslip angle of the vehicle, inputting the difference value into a fuzzy PID controller, enabling the fuzzy PID controller to control the torque of a second motor through a motor controller corresponding to the second motor according to the difference value, and adjusting the torque of the second motor to enable the actual centroid sideslip angle to tend to the expected centroid sideslip angle while each first motor rotates according to the distributed torque, keeping the posture of the vehicle to be normal; the first motor is a motor which belongs to a normal side opposite to the side where the fault motor is located in the vehicle body, and the second motor is a non-fault motor which belongs to the side where the fault motor is located in the vehicle body;

when the current running state of the vehicle is the speed reduction running and the speed of the vehicle is in the preset high-speed running range, or when the current running state of the vehicle is the speed reduction running and is within the preset low-speed running range, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric valve opening degree of the brake pedal at the current moment, meanwhile, calculating a difference value between an actual centroid slip angle of the vehicle and the desired centroid slip angle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through the motor controller corresponding to the second motor according to the difference value, so as to adjust the torque of the second motor while each of the first motors rotates in accordance with the allocated torque, enabling the actual centroid slip angle to approach the expected centroid slip angle, and keeping the vehicle posture to be normal;

when the current running state of the vehicle is constant-speed running and the vehicle speed is within a preset medium-high speed running range, setting a torque signal of a third motor to be 0, meanwhile, calculating a difference value between an actual mass center slip angle and the expected mass center slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller respectively controls the torque of the second motor and the torque of a fourth motor correspondingly through a motor controller corresponding to the second motor and a motor controller corresponding to the fourth motor according to the difference value, so that the actual mass center slip angle tends to the expected mass center slip angle by adjusting the torque of the second motor and the torque of the fourth motor, and the vehicle posture is kept to tend to be normal; the third motor is a first motor opposite to the fault motor in the normal side motor, and the fourth motor is the first motor except the third motor in the normal side motor;

when the current running state of the vehicle is constant-speed running and the vehicle speed is in a preset low-speed range, setting the torque signal of each first motor to be 0, meanwhile, calculating a difference value between an actual centroid slip angle and the expected centroid slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through a motor controller corresponding to the second motor according to the difference value, so that the actual centroid slip angle tends to the expected centroid slip angle by adjusting the torque of the second motor, and the vehicle is controlled to stop running under the condition that the vehicle is stable.

In an embodiment of the present application, when the number of faults is 2, selecting a pre-configured torque distribution strategy corresponding to the installation location according to the number of faults and the installation location, and distributing a torque to each non-faulty motor of the vehicle according to the distribution strategy includes:

if it is determined that two motors of the vehicle at different coaxial sides or different shaft installation positions are in failure, if the total demand torque is less than or equal to the maximum output torque of a single motor, the total demand torque is averagely distributed to the remaining non-failure motors so as to enable the vehicle to normally run by adjusting the torques of the remaining non-failure motors, wherein the total demand torque is determined according to the vehicle speed of the vehicle at the current moment and the electric door opening degree of an accelerator pedal at the current moment,

and/or the first and/or second light sources,

and if the two motors of the vehicle at the same-side different-shaft installation positions are determined to be in fault, cutting off the current of the rest non-fault motors, and setting the torque signals of the rest non-fault motors to be 0.

In an embodiment of the present application, when the number of faults is 3, selecting a pre-configured torque distribution strategy corresponding to the installation location according to the number of faults and the installation location, and distributing a torque to each non-faulty motor of the vehicle according to the distribution strategy includes:

the current of the remaining non-faulty motor is cut off and the torque signals of the remaining non-faulty motor are all set to 0.

In one embodiment of the present application, the determining the desired centroid slip angle according to the steering wheel angle and the vehicle speed of the vehicle at the current time comprises:

acquiring the steering wheel angle and the vehicle speed of the vehicle at the current moment;

and respectively inputting the acquired steering wheel rotation angle and the acquired vehicle speed into a two-degree-of-freedom linear model to obtain an expected mass center slip angle.

In one embodiment of the application, the determining the torque allocated to each first motor according to the maximum torque limit condition of the motor and the electric door opening of the brake pedal at the current time includes:

distributing torque to each first motor according to a first expression;

the first expression is: t ═ T_max*0.5*A_PT，

Where T is the torque allocated to the individual motor on the normal side, T_maxThe maximum torque of the single motor, and A _ PT is the electric valve opening degree of the accelerator pedal at the current moment.

distributing torque to each first motor according to a second expression;

the second expression is: t ═ T_max*0.5*B_PT，

Where T is the torque allocated to the individual motor on the normal side, T_maxAnd B _ PT is the maximum torque of a single motor, and B _ PT is the electric valve opening degree of the brake pedal at the current moment.

In a second aspect, embodiments of the present application provide a vehicle torque distribution apparatus, the apparatus comprising:

the number and position determining module is used for determining the number of faults of the fault motors and the installation positions of the fault motors in the vehicle body when the motors for driving the wheels are determined to be in fault;

the motor torque distribution module is used for selecting a pre-configured torque distribution strategy corresponding to the installation position according to the fault number and the installation position, and distributing torque to each fault-free motor of the vehicle according to the distribution strategy so as to enable the vehicle to keep running normally; the allocation strategy is determined according to the fault number of the fault motor, the installation position of the fault motor on the vehicle body, the current running state of the vehicle and the maximum torque limiting condition of the motor under the condition that the normal running of the vehicle is met.

In an embodiment of the present application, when the number of faults is 1, the motor torque distribution module is specifically configured to:

In a third aspect, an embodiment of the present application provides an electronic device, which includes a processor and a memory;

the memory for storing machine executable instructions;

the processor is configured to read and execute the machine executable instructions stored in the memory to implement the method steps of the vehicle torque distribution method according to the above embodiments.

According to the technical scheme, in the embodiment of the application, when the motor fails, the number of the failed motors and the installation positions of the failed motors in the vehicle body are determined; and selecting a pre-configured torque distribution strategy corresponding to the installation position according to the number of faults and the installation position, and distributing torque to each fault-free motor of the vehicle according to the distribution strategy so as to keep the vehicle running normally. Therefore, by applying the technical scheme provided by the embodiment of the application, the correct running track of the vehicle can be controlled under the condition that the driving motor fails, so that the running stability and safety of the vehicle can be improved.

Drawings

FIG. 1 is a schematic flow chart diagram of a vehicle torque distribution method provided by an embodiment of the present application;

FIG. 2 is a schematic flow chart diagram of another vehicle torque distribution method provided by an embodiment of the present application;

FIG. 3(a) is a schematic diagram of a vehicle corresponding to different driving states at different initial speeds according to an embodiment of the present application;

FIG. 3(b) is a schematic diagram of the comparison between the torque distribution strategy provided by the embodiment of the present application and the vehicle yaw angle change under the ordinary PID control at the initial speed of 50 km/h;

FIG. 3(c) is a schematic diagram of the comparison between the torque distribution strategy provided by the embodiment of the present application and the vehicle yaw angle change under the ordinary PID control at the initial speed of 80 km/h;

FIG. 3(d) is a schematic diagram of the comparison between the torque distribution strategy provided by the embodiment of the present application and the vehicle yaw angle change under the ordinary PID control at the initial speed of 120 km/h;

FIG. 3(e) is a schematic diagram of a comparison between the torque distribution strategy provided by the embodiment of the present application and the yaw rate variation of a vehicle under a normal PID control at an initial speed of 50 km/h;

FIG. 3(f) is a schematic diagram of a comparison between the torque distribution strategy provided by the embodiment of the present application and the yaw rate variation of a vehicle under the ordinary PID control at an initial speed of 80 km/h;

FIG. 3(g) is a schematic diagram of the torque distribution strategy provided by the embodiment of the present application compared with the conventional PID control for the yaw rate variation of the vehicle at the initial speed of 120 km/h;

FIG. 3(h) is a schematic diagram of comparison of side-to-side slip angle changes of each wheel of an uncontrolled vehicle at an initial speed of 50km/h according to an embodiment of the application;

FIG. 3(i) is a schematic diagram showing the comparison of the change of each wheel lateral slip angle of a common PID at an initial speed of 50km/h, provided by the embodiment of the application;

FIG. 3(j) is a schematic diagram of a comparison of the change of each wheel lateral slip angle at an initial speed of 50km/h for the torque distribution strategy provided by the embodiment of the present application;

FIG. 3(k) is a schematic diagram of comparison of lateral slip angle change of each wheel of an uncontrolled vehicle at an initial speed of 80km/h according to an embodiment of the present application;

FIG. 3(l) is a schematic diagram of the comparison of the change of each wheel lateral slip angle of a common PID at an initial speed of 80km/h provided by the embodiment of the application;

FIG. 3(m) is a schematic diagram of a comparison of the change of each wheel lateral slip angle at an initial speed of 80km/h for the torque distribution strategy provided by the embodiment of the application;

FIG. 3(n) is a schematic diagram of comparison of side-to-side slip angle changes of each wheel of an uncontrolled vehicle at an initial speed of 120km/h according to an embodiment of the application;

FIG. 3(o) is a schematic diagram of a comparison of the change of each wheel lateral slip angle of a common PID at an initial speed of 120km/h provided by the embodiment of the application;

FIG. 3(p) is a schematic diagram of a comparison of the change of each wheel lateral slip angle at an initial speed of 120km/h for the torque distribution strategy provided by the embodiment of the present application;

FIG. 4 is a schematic diagram of a hardware structure of a vehicle torque distribution device provided by an embodiment of the present application;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a schematic flowchart of a vehicle torque distribution method provided in an embodiment of the present application, where the method is applied to a controller of a vehicle system, and the method may include:

step 1, when determining that a motor for driving wheels has a fault, determining the number of faults of the fault motor and the installation position of each fault motor in a vehicle body.

In the present embodiment, the number of motors is at least 4, and when the number of motors is 4, the number of failures may be 1, 2, or 3.

In practical application, the motors are generally arranged on two sides of a vehicle body in a pair mode, and the installation position of the fault motor can be arranged on one side of the vehicle body or on the other side of the vehicle body.

It should be noted that all the motors in the present application refer to motors for driving the vehicle to rotate, that is, driving motors.

Step 2, selecting a corresponding pre-configured torque distribution strategy according to the number of faults and the installation position, and distributing torque to each fault-free motor of the vehicle according to the distribution strategy so as to enable the vehicle to keep running normally; the allocation strategy is determined according to the fault number of the fault motor, the installation position of the fault motor on the vehicle body, the current running state of the vehicle and the maximum torque limiting condition of the motor under the condition that the normal running of the vehicle is met.

In the present embodiment, if the number of failed motors in the vehicle and the mounting positions of the failed motors in the vehicle body are different, the torque distribution strategy corresponding to the distribution of the torque to the non-failed motors is also different.

As an example, when the number of the faulty motors is 1, a torque distribution strategy corresponding to the installation position of the faulty motor may be selected according to the number of the faulty motors and the installation position of the faulty motor in the vehicle body, and a torque distribution strategy corresponding to the driving state of the vehicle at the current time may be selected from the selected torque distribution strategies according to the driving state of the vehicle at the current time.

When the number of the fault motors is 2 or 3, a torque distribution strategy corresponding to the installation position of the fault motor can be selected according to the number of the faults of the fault motors and the installation position of the fault motors in the vehicle body.

Thus, the flow shown in fig. 1 is completed.

As can be seen from the flow shown in fig. 1, in the embodiment of the present application, when a motor fails, the number of failures of the failed motor and the installation position of each failed motor in the vehicle body are determined; and selecting a pre-configured torque distribution strategy corresponding to the installation position according to the number of faults and the installation position, and distributing torque to each fault-free motor of the vehicle according to the distribution strategy so as to keep the vehicle running normally. Therefore, by applying the technical scheme provided by the embodiment of the application, the correct running track of the vehicle can be controlled under the condition that the driving motor fails, so that the running stability and safety of the vehicle can be improved.

As an embodiment, referring to fig. 2, when the number of faults is 1, an implementation manner of implementing step 2 may include the following steps:

step 21, determining an expected mass center slip angle according to the steering wheel rotation angle and the vehicle speed of the vehicle at the current moment; when the current running state of the vehicle is acceleration running and the vehicle speed is within a preset high-speed running range or a preset medium-high speed running range, or the current running state of the vehicle is acceleration running and the vehicle speed is within a preset low-speed running range, step 22 is executed, when the current running state of the vehicle is deceleration running and the vehicle speed is within a preset high-speed running range, or the current running state of the vehicle is deceleration running and the preset low-speed running range, step 23 is executed, when the current running state of the vehicle is constant-speed running and the vehicle speed is within the preset medium-high speed running range, step 24 is executed, and when the current running state of the vehicle is constant-speed running and the vehicle speed is within the preset low-speed range, step 25 is executed.

In the present application, low-speed running is performed when the vehicle speed is lower than the first threshold, the first threshold may be 50Km/h, medium-high-speed running is performed when the vehicle speed is between the first threshold and the second threshold, the second threshold may be 80Km/h, high-speed running is performed when the vehicle speed is between the second threshold and the third threshold, the third threshold is 120Km/h, and accordingly, the low-speed running range is lower than the first threshold, the medium-high-speed running range is between the first threshold and the second threshold, and the high-speed running range is between the second threshold and the third threshold.

In the present embodiment, since the vehicle speed is high in both the medium-high speed running and the high speed running, step 22, which is the same torque distribution strategy, is adopted. Additionally, the vehicle speed is low and there is an acceleration signal, which may be a start-up phase or other low to high speed phase, based on which the torque distribution strategy described in step 22 is used. The vehicle speed is slow and there is a brake signal, the driver intends to stop at a reduced speed, and based on this, the same torque distribution strategy as that in step 23 is adopted as the torque distribution strategy in which the current running state of the vehicle is the reduced speed running and the vehicle speed is in the preset high-speed running range.

As an embodiment, the specific steps for implementing step 21 may be as follows, step 211 to step 212:

step 211, obtaining the steering wheel angle and the vehicle speed of the vehicle at the current time.

The steering wheel angle in this step is the front wheel steering angle.

And step 212, respectively inputting the acquired steering wheel rotation angle and the acquired vehicle speed into a two-degree-of-freedom linear model to obtain an expected mass center slip angle.

As an embodiment, the two-degree-of-freedom linear model is:

wherein: c_f、C_rThe cornering stiffness of the front and rear wheels, respectively; a is_yIs the lateral acceleration; i is_zIs the moment of inertia of the vehicle; l_f、l_rThe distances from the center of mass of the vehicle to the front and rear axles, respectively; m is the vehicle mass; f_yf、F_yrRespectively the transverse force of the front wheel and the transverse force of the rear wheel; delta_fIs the vehicle front wheel steering angle; v. of_xIs the longitudinal speed of the vehicle; gamma is a yaw angular velocity; beta is the vehicle centroid slip angle.

Step 22, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of the accelerator pedal at the current moment, meanwhile, calculating the difference value between the actual barycenter sideslip angle of the vehicle and the expected barycenter sideslip angle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through a motor controller corresponding to the second motor according to the difference value, so that when each first motor rotates according to the distributed torque, the torque of the second motor is adjusted, the actual barycenter sideslip angle tends to the expected barycenter sideslip angle, and the vehicle posture is kept to tend to be normal; the first motor is a motor in the vehicle body and belongs to a normal side opposite to the side where the fault motor is located, and the second motor is a non-fault motor in the vehicle body and belongs to the side where the fault motor is located.

In the present application, the first motor is only named for convenience of distinguishing from the following motors, and is not used to limit a certain motor.

Here, the second motor is named only for convenience of description, and is not intended to limit a certain motor.

In the present embodiment, the actual centroid slip angle of the own vehicle can be obtained from the vehicle state observer.

The motors on the normal side are all fault-free motors.

Considering the vehicle driving the free pedal travel, the vehicle enters the acceleration phase when the driving pedal travel exceeds a first set value of the total driving travel, which may be 5%.

The first motor can be considered as a normal motor on the side where the fault-free motor is located, for example, if the vehicle has 4 motors and is uniformly distributed on two sides of the vehicle body, if there are 1 fault motors, then 2 motors in fault-free are located on one side of the vehicle body, and the fault motor and 1 fault-free motor are located on the other side of the vehicle body.

The second motor may be considered to be the motor located on the same side as the failed motor.

In a vehicle, each motor for driving a wheel corresponds to a motor controller belonging to the motor for controlling a torque of the motor.

The fuzzy PID controller inputs controlled quantity errors and error change rates into a fuzzy control module on the basis of original PID control, a fuzzy control rule is formulated, a proportional parameter P, an integral parameter I and a differential parameter D of the original PID control are output to realize the requirements of different errors and error change rates on PID self-tuning, in the application, a corresponding fuzzy control rule is formulated through the difference value of the actual barycenter slip angle and the barycenter slip angle of a vehicle and the error change rate of the barycenter slip angle, and a control signal for representing and controlling the torque of a second motor (namely the normal motor torque on the failure side) is output.

In practical application, the master controller obtains the electric door opening degree of the accelerator pedal at the current moment, calculates the torque distributed to each first motor according to the obtained electric door opening degree and the maximum motor torque limiting condition, and simultaneously sends a control signal for representing the corresponding torque output to the second motor to the motor controller for controlling the torque of the second motor according to the difference value, and the motor controller receives the control signal and controls the torque of the second motor according to the control signal so as to adjust the torque of the second motor when each first motor rotates according to the distributed torque, so that the actual centroid sideslip angle tends to the expected centroid sideslip angle and the vehicle attitude tends to be normal.

As an example, the specific implementation manner of determining the torque allocated to each first motor according to the maximum torque limit condition of the motor and the electric valve opening degree of the brake pedal at the current time in this step may include:

distributing torque to each first motor according to a first expression;

the first expression is: t ═ T_max*0.5*A_PT，

In the present embodiment, when a _ PT is larger than the first setting value and B _ PT is 0, the vehicle is in acceleration running.

And step 23, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of the brake pedal at the current moment, meanwhile, calculating the difference value between the actual centroid slip angle and the expected centroid slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through a motor controller corresponding to the second motor according to the difference value, and adjusting the torque of the second motor while each first motor rotates according to the distributed torque, so that the actual centroid slip angle tends to the expected centroid slip angle, and the vehicle posture tends to be normal.

Considering the free pedal travel of the vehicle, when the brake pedal travel exceeds a second set value of the total pedal braking travel, the vehicle enters the braking stage, and the second set value may be the same as or different from the first set value, but the present embodiment is not limited thereto, and the second set value may also be 5%.

In practical application, the master controller obtains the electric door opening degree of the brake pedal at the current moment, calculates the torque distributed to each first motor according to the obtained electric door opening degree of the brake pedal at the current moment and the maximum torque limiting condition of the motor, and simultaneously sends a control signal for representing the corresponding torque output to the second motor to the motor controller for controlling the torque of the second motor according to the difference value, and the motor controller receives the control signal and controls the torque of the second motor according to the control signal so as to adjust the torque of the second motor while each first motor rotates according to the distributed torque, so that the actual centroid sideslip angle tends to the expected centroid sideslip angle and the vehicle posture tends to be normal.

distributing torque to each first motor according to a second expression;

the second expression is: t ═ T_max*0.5*B_PT，

In the present embodiment, when a _ PT is 0 and B _ PT is greater than 0, the vehicle is in deceleration running.

Step 24, setting a torque signal of a third motor to 0, calculating a difference value between an actual centroid slip angle and the expected centroid slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller respectively controls the torque of the second motor and the torque of the fourth motor through a motor controller corresponding to the second motor and a motor controller corresponding to the fourth motor according to the difference value, so that the actual centroid slip angle tends to the expected centroid slip angle by adjusting the torque of the second motor and the torque of the fourth motor, and the vehicle posture is kept to tend to be normal; the third motor is a first motor that is opposite to the faulty motor among the normal-side motors, and the fourth motor is a first motor excluding the third motor among the normal-side motors.

In the present application, the third motor is named only for convenience of description, and is not intended to limit a certain motor.

Here, the fourth motor is named only for convenience of description and is not intended to limit a certain motor.

The third motor and the fault motor are respectively positioned on two sides of the vehicle body and are opposite to each other in the mounting position in the vehicle body.

The fourth motor and the third motor are positioned on the using side.

In the step, the vehicle is in a uniform deceleration running state with a high speed, after the motor fails, the vehicle speed is reduced according to a safe first principle and a driving experience second principle, a torque signal of a third motor is set to 0, a fuzzy PID controller is adopted for a fourth motor and the second motor according to the difference value, the torque of the second motor is controlled through a motor controller corresponding to the second motor, and meanwhile the torque of the fourth motor is controlled through a motor controller corresponding to the fourth motor according to the difference value.

And 25, setting each first motor to be 0, calculating a difference value between the actual centroid slip angle and the expected centroid slip angle of the vehicle, inputting the difference value into a fuzzy PID controller, enabling the fuzzy PID controller to respectively control the torque of a second motor through a motor controller corresponding to the second motor according to the difference value, enabling the actual centroid slip angle to approach the expected centroid slip angle by adjusting the torque of the second motor, and controlling the vehicle to stop running under the condition that the vehicle is stable.

In practical application, the fuzzy PID controller sends a control signal for representing the output of the corresponding torque to the second motor to the motor controller for controlling the torque of the second motor according to the difference value between the actual mass center slip angle and the expected mass center slip angle of the vehicle, the motor controller controls the torque of the second motor according to the control signal after receiving the control signal, so that the torque of the second motor is adjusted while each first motor rotates according to the distributed torque, the actual mass center slip angle tends to the expected mass center slip angle, the vehicle slowly tends to be stable, and the vehicle is controlled to stop running under the condition that the vehicle is completely stable.

Thus, the flow shown in fig. 2 is completed.

As can be seen from the flow shown in fig. 2, in the embodiment of the present application, when the number of the faulty motors is 1, a pre-configured torque distribution strategy corresponding to the installation location and the driving state of the vehicle is selected, and the torques are distributed to the non-faulty motors of the vehicle according to the distribution strategy, so that the vehicle keeps driving normally. Therefore, by applying the technical scheme provided by the embodiment of the application, the correct running track of the vehicle can be controlled under the condition that the motor for driving the vehicle is in failure, so that the running stability and safety of the vehicle can be improved.

As an embodiment, when the number of faults is 2, the implementation manner of implementing step 2 may include the following steps:

if two motors of the vehicle at the different coaxial sides or different shaft installation positions are determined to be in fault, if the total required torque is smaller than or equal to the maximum output torque of a single motor, the total required torque is averagely distributed to the remaining non-fault motors so as to enable the vehicle to normally run by adjusting the torque of the remaining non-fault motors, wherein the total required torque is determined according to the vehicle speed of the vehicle at the current moment and the electric door opening of an accelerator pedal at the current moment.

As can be seen, the present embodiment can improve the stability and safety of vehicle running by distributing the total required torque to the remaining non-faulty motor on average to make the own vehicle run normally by adjusting the torque of the remaining non-faulty motor.

As another embodiment, when the number of faults is 2, the implementation manner of implementing step 2 may further include the following steps:

Therefore, the present embodiment improves the driving stability and safety of the vehicle by interrupting the current of the remaining non-faulty motor and setting the torque signals of the remaining non-faulty motor to 0.

Once the failure condition of multiple motors such as 3 motors and more than 3 motors occurs, the master controller immediately cuts off the current of the residual motor after receiving the failure sensor signal of each failed motor, the torque signal is set to be 0, and the torque is not distributed any more. As an embodiment, when the number of faults is 3, the implementation manner of implementing step 2 may include: cutting off the current of the rest motor without faults, and setting the torque signals of the rest motor without faults to be 0; so as to improve the running stability and safety of the vehicle.

The method provided by the present application is described below by a specific embodiment:

the distributed drive electric vehicle of this embodiment has 4 motors for driving the wheel motion, and the symmetrical arrangement is in the both sides of automobile body, and it describes specifically to take the left front wheel to break down as an example in this embodiment, specifically is:

the first step, the total controller confirms the trouble quantity of trouble motor and the mounted position of each trouble motor on the automobile body, and based on this, total controller confirms that the trouble motor is 1, and is that the left front wheel breaks down.

Secondly, when the master controller determines the steering wheel angle of the vehicle at the current moment and the vehicle speed at the current moment, the expected mass center slip angle is calculated; assuming that the master controller determines that the vehicle speed is 60km/h, the vehicle is in medium-high speed running, meanwhile, the fact that the electric door opening degree of the accelerator pedal at the current moment is greater than 5% of the maximum electric door opening degree of the accelerator pedal, and the electric door opening degree of the brake pedal at the current moment is 0 is detected, the vehicle is in accelerated running, and based on the fact, the master controller selects the strategy described in the third step from the vehicle torque distribution strategies. Assuming that the master controller determines that the vehicle speed is 100km/h, the vehicle is in medium-high speed running, meanwhile, the fact that the electric door opening degree of the brake pedal at the current moment is less than 5% of the maximum electric door opening degree of the brake pedal, and the electric door opening degree of the accelerator pedal at the current moment is 0 is detected, the vehicle is in deceleration running, and based on the fact, the master controller selects the strategy described in the fourth step from vehicle torque distribution strategies. And if the master controller determines that the vehicle speed is 80km/h, the vehicle is in medium-high speed running, meanwhile, the fact that the electric door opening degree of the brake pedal at the current moment is 0 and the electric door opening degree of the accelerator pedal at the current moment is 0 is detected, the vehicle is in constant speed running, and based on the fact that the master controller selects the strategy described in the fifth step from the vehicle torque distribution strategies. And assuming that the vehicle speed at the current moment is 30km/h, the vehicle is running at a low speed, and meanwhile, detecting that the electric door opening degree of the brake pedal at the current moment is 0 and the electric door opening degree of the accelerator pedal at the current moment is 0, the vehicle is running at a constant speed, and based on the fact that the overall controller selects the strategy described in the sixth step from the vehicle torque distribution strategies.

And thirdly, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of an accelerator pedal at the current moment, meanwhile, calculating the difference value between the actual barycenter slip angle and the expected barycenter slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the left rear wheel motor through a motor controller corresponding to the left rear wheel according to the difference value, and the torque of the left rear wheel motor is adjusted while the right front wheel motor and the right rear wheel motor rotate according to the distributed torque, so that the actual barycenter slip angle tends to the expected barycenter slip angle, and the vehicle posture tends to be normal.

And fourthly, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of the brake pedal at the current moment, meanwhile, calculating the difference value between the actual barycenter slip angle and the expected barycenter slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the left rear wheel motor through a motor controller corresponding to the left rear wheel motor according to the difference value, and the torque of the left rear wheel motor is adjusted while the right front wheel motor and the right rear wheel motor rotate according to the distributed torque, so that the actual barycenter slip angle tends to the expected barycenter slip angle, and the vehicle posture tends to be normal.

And fifthly, setting a torque signal of the right front wheel motor to be 0, calculating a difference value between the actual centroid sideslip angle and the expected centroid sideslip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller respectively controls the torque of the left rear wheel motor and the torque of the right rear wheel motor correspondingly through a motor controller corresponding to the left rear wheel motor and a motor controller corresponding to the right rear wheel motor according to the difference value, so that the actual centroid sideslip angle tends to the expected centroid sideslip angle by adjusting the torque of the left rear wheel motor and the torque of the right rear wheel motor, and the vehicle posture is kept to tend to be normal.

And sixthly, setting a torque signal of a right front wheel motor to be 0, calculating a difference value between an actual mass center slip angle and the expected mass center slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of a left rear wheel motor through a motor controller corresponding to the left rear wheel motor according to the difference value, so that the actual mass center slip angle tends to the expected mass center slip angle by adjusting the torque of the left rear wheel motor, and the vehicle is controlled to stop running under the condition that the vehicle is stable.

In order to enable the stability effect brought by the torque distribution method described in the application to be more intuitively felt, the application adopts combined simulation of CarSim and MATLAB/Simulink software to establish an integrated simulation model, and the feasibility of the torque distribution strategy is verified by simulating single-motor failure torque distribution strategy intervention and non-intervention motor failure. Table 1 shows the main parameters of the vehicle.

TABLE 1 Main parameters of the complete vehicle

Under the straight-line running working condition, simulation comparative analysis of the torque distribution strategy and the ordinary PID control strategy is carried out under the running states of high-speed (middle-high speed) acceleration, high-speed (middle-high speed) braking, high-speed (middle-high speed) uniform deceleration, low-speed acceleration, low-speed braking, low-speed uniform deceleration and the like. Selecting the initial speeds of 50km/h, 80km/h and 120km/h of the vehicle as vehicle joint simulation representative values of a low-speed stage, a medium-high speed stage and a high-speed stage of the vehicle speed; specifically, referring to fig. 3(a), 0-2s of the vehicle is in a uniform deceleration state, 2-5s are in an acceleration running state, 5-6s are in a uniform deceleration running state, 6-9s are in a braking running state, and 9-10s are in a uniform deceleration running state. Referring specifically to fig. 3(b) - (d), fig. 3(b) - (d) respectively show the comparison between the yaw angle change of the vehicle under different initial speeds in the torque distribution strategy and the ordinary PID control strategy, and after the comparison, see table 2 below, where table 2 shows the comparison between the corresponding yaw angle change data under different initial speeds in the accelerating and braking driving states.

Watch (A)1Comparison of yaw angles in acceleration and braking driving states at different initial speeds

Note: the change value is an absolute value obtained by subtracting the maximum value and the minimum value of the yaw angle under different working conditions and different vehicle speeds; 0 is an uncontrolled vehicle; 1 is a common PID control vehicle; and 2, controlling the vehicle by fuzzy PID rules.

As can be seen from Table 2, during acceleration running, the yaw angle of the ordinary PID control vehicle is reduced by 2.39, 2.81 and 2.56 compared with that of the uncontrolled vehicle, and the yaw angle of the vehicle controlled by the torque distribution strategy of the application is reduced by 0.33, 0.68 and 0.84 compared with that of the PID control vehicle, and the reduction amplitudes are respectively 58%, 88% and 89%; in a braking driving state, the yaw angle of the ordinary PID control vehicle is reduced by 1.08, 2.4 and 2.66 compared with the yaw angle of an uncontrolled vehicle, and the yaw angle of the torque distribution strategy control vehicle is reduced by 0.51, 0.76 and 0.99 compared with the yaw angle of the PID control vehicle, wherein the reduction amplitudes respectively reach 77%, 90% and 92%, which shows that the torque distribution strategy provided by the application has obvious effectiveness on a single-motor fault vehicle.

Referring specifically to fig. 3(e) - (g), fig. 3(e) - (g) respectively show the comparison between the yaw rate variation of the vehicle under different initial speeds in the torque distribution strategy and the ordinary PID control strategy, and after the comparison, see table 3 below, table 3 shows the comparison between the yaw rate variation data corresponding to the acceleration and braking driving under different initial speeds.

Watch (A)2Comparison of yaw rates of acceleration and braking conditions at different initial speeds

Note: the change value is an absolute value obtained by subtracting the maximum value and the minimum value of the yaw angular velocity under different vehicle speeds under different working conditions; 0 is an uncontrolled vehicle; 1 is a common PID control vehicle; and 2, controlling the vehicle by fuzzy PID rules.

As can be seen from Table 3, in the acceleration running state, the yaw angle of the PID-controlled vehicle is reduced by 0.025rad · s as compared with the uncontrolled vehicle^-1、0.029rad·s^-1、0.028rad·s^-1The yaw angle of the torque distribution strategy controlled vehicle is reduced by 0.004rad & s compared with the yaw angle of the PID controlled vehicle^-1、0.006rad·s^-1、0.009rad·s^-1The amplitude reduction reaches 66%, 75% and 96% respectively; when the vehicle is braked and driven, the yaw angle of the ordinary PID control vehicle is reduced by 0.011rad & s compared with that of the uncontrolled vehicle^-1、0.024rad·s^-1、0.028rad·s^-1The yaw angle of the torque distribution strategy controlled vehicle is reduced by 0.004rad & s compared with the yaw angle of the PID controlled vehicle^-1、0.007rad·s^-1、0.009 rad·s^-1The reduction is 70%, 83% and 90% respectively.

As can be seen from fig. 3(e) - (g) and table 3, in the accelerating and braking running states, the yaw rate of the vehicle controlled by the torque distribution strategy and the yaw rate of the vehicle controlled by the ordinary PID control have significant control effects, but the yaw rate peak value of the vehicle controlled by the torque distribution strategy is significantly reduced compared with the yaw rate peak value of the vehicle controlled by the PID, and the time corresponding to the first peak value of the yaw rate of the vehicle controlled by the torque distribution strategy is significantly shorter than that of the ordinary PID control vehicle.

From fig. 3(h) - (p), it can be seen that, at the initial speeds of 50km/h, 80km/h and 120km/h, when the front left motor fails and the uncontrolled vehicle is in an acceleration stage for 2-5s, the side slip angles of both Tire L1 and Tire R1 increase towards the motor failure side, the vehicle deflects towards the motor failure side, and the vehicle brakes for 6-9s, and the vehicle deflects towards the motor non-failure side. The common PID control vehicle at each initial speed has obvious improvement compared with the lateral slip angles of each wheel of an uncontrolled vehicle, the torque distribution strategy controls the vehicle to be equal in size and opposite in direction to the lateral slip angles of the Tire L1 and the Tire R1 and the Tire L2 and the Tire R2 in any phase of 0-10s, and the common PID control is further optimized compared with the common PID control.

By combining the two control strategies, the torque distribution strategy enables the yaw angle and the yaw velocity of the vehicle to be rapidly stabilized near the target values, the lateral slip angles of the wheels are distributed more uniformly, and the running stability of the vehicle with single motor failure is remarkably improved.

Based on the same application concept as the method, the embodiment of the application also provides a vehicle torque distribution device 400 which can comprise the device.

A number and position determination module 401 for determining the number of failed motors and the mounting positions of the respective failed motors in the vehicle body when it is determined that the motors for driving the wheels are failed;

a motor torque distribution module 402, configured to select a pre-configured torque distribution strategy corresponding to the installation position according to the number of faults and the installation position, and distribute a torque to each non-fault motor of the vehicle according to the distribution strategy, so that the vehicle keeps running normally; the allocation strategy is determined according to the fault number of the fault motor, the installation position of the fault motor on the vehicle body, the current running state of the vehicle and the maximum torque limiting condition of the motor under the condition that the normal running of the vehicle is met.

As an example, when the number of faults is 1, the motor torque distribution module 402 may be specifically configured to:

when the current running state of the vehicle is accelerated running and the vehicle speed is in a preset high-speed running range or a preset middle-high speed running range, or the current running state of the vehicle is accelerated running and the vehicle speed is in a preset low-speed running range, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of an accelerator pedal at the current moment, simultaneously calculating the difference value between the actual centroid slip angle and the expected centroid slip angle of the vehicle, inputting the difference value into a fuzzy PID controller, enabling the fuzzy PID controller to control the torque of the second motor through a motor controller corresponding to the second motor according to the difference value, and adjusting the torque of the second motor when each first motor rotates according to the distributed torque so as to enable the actual centroid slip angle to tend to the expected centroid slip angle, keeping the posture of the vehicle to be normal; the first motor is a motor which belongs to a normal side opposite to the side where the fault motor is located in the vehicle body, and the second motor is a non-fault motor which belongs to the side where the fault motor is located in the vehicle body;

when the current running state of the vehicle is in deceleration running and the vehicle speed is in a preset high-speed running range or a preset middle-high speed running range, or the current running state of the vehicle is in deceleration running and a preset low-speed running range, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric door opening degree of the brake pedal at the current moment, simultaneously calculating the difference value between the actual centroid slip angle and the expected centroid slip angle of the vehicle, inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through a motor controller corresponding to the second motor according to the difference value, and adjusting the torque of the second motor while each first motor rotates according to the distributed torque so that the actual centroid slip angle tends to the expected centroid slip angle, keeping the posture of the vehicle to be normal;

when the current running state of the vehicle is constant-speed running and the vehicle speed is within a preset medium-high speed running range, setting a torque signal of the third motor to be 0, meanwhile, calculating a difference value between an actual mass center slip angle and the expected mass center slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller respectively controls the torque of the second motor and the torque of the fourth motor correspondingly through a motor controller corresponding to the second motor and a motor controller corresponding to the fourth motor according to the difference value, so that the actual slip angle tends to the expected mass center slip angle by adjusting the torque of the second motor and the torque of the fourth motor, and the vehicle posture is kept to tend to be normal; the third motor is a first motor opposite to the fault motor in the normal side motor, and the fourth motor is the first motor except the third motor in the normal side motor;

when the current running state of the vehicle is constant-speed running and the vehicle speed is in a preset low-speed range, setting each first motor to be 0, meanwhile, calculating a difference value between an actual centroid slip angle and the expected centroid slip angle of the vehicle, inputting the difference value into a fuzzy PID controller, enabling the fuzzy PID controller to respectively control the torque of the second motor through a motor controller corresponding to the second motor according to the difference value, enabling the actual centroid slip angle to tend to the expected centroid slip angle by adjusting the torque of the second motor, and controlling the vehicle to stop running under the condition that the vehicle is stable.

As an embodiment, when the number of faults is 2, the motor torque distribution module 402 may be further specifically configured to:

and/or the first and/or second light sources,

As an embodiment, when the number of faults is 3, the motor torque distribution module 402 may be further specifically configured to:

For one embodiment, the motor torque distribution module 402 includes a desired centroid slip angle determination submodule configured to determine a desired centroid slip angle based on the steering wheel angle of the subject vehicle at the current time and the vehicle speed.

The desired centroid slip angle determination submodule is specifically configured to:

As an embodiment, the motor torque distribution module 402 further includes a first torque distribution submodule, configured to determine the torque distributed to each first motor according to a maximum torque limit condition of the motor and a throttle opening of the brake pedal at the current time.

The first torque distribution submodule is specifically configured to:

distributing torque to each first motor according to a first expression;

the first expression is: t ═ T_max*0.5*A_PT，

As an embodiment, the motor torque distribution module 402 further includes a second torque distribution submodule for determining the torque distributed to each first motor according to the motor maximum torque limit condition and the electric valve opening of the brake pedal at the current time.

The second torque distribution submodule is specifically configured to:

distributing torque to each first motor according to a second expression;

the second expression is: t ═ T_max*0.5*B_PT，

The implementation process of the functions and actions of each unit in the above device is specifically described in the implementation process of the corresponding step in the above method, and is not described herein again.

In the electronic device provided in the embodiment of the present application, from a hardware level, a schematic diagram of a hardware architecture can be seen as shown in fig. 5. The method comprises the following steps: a machine-readable storage medium and a processor, wherein: the machine-readable storage medium stores machine-executable instructions executable by the processor; the processor is configured to execute machine-executable instructions to implement the vehicle torque distribution operations disclosed in the above examples.

Machine-readable storage media are provided in embodiments of the present application that store machine-executable instructions that, when invoked and executed by a processor, cause the processor to implement the vehicle torque distribution operations disclosed in the above examples.

Here, a machine-readable storage medium may be any electronic, magnetic, optical, or other physical storage device that can contain or store information such as executable instructions, data, and so forth. For example, the machine-readable storage medium may be: a RAM (random Access Memory), a volatile Memory, a non-volatile Memory, a flash Memory, a storage drive (e.g., a hard drive), a solid state drive, any type of storage disk (e.g., an optical disk, a dvd, etc.), or similar storage medium, or a combination thereof.

The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. A typical implementation device is a computer, which may take the form of a personal computer, laptop computer, cellular telephone, camera phone, smart phone, personal digital assistant, media player, navigation device, email messaging device, game console, tablet computer, wearable device, or a combination of any of these devices.

For convenience of description, the above devices are described as being divided into various units by function, and are described separately. Of course, the functionality of the units may be implemented in one or more software and/or hardware when implementing the present application.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Furthermore, these computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

For the device embodiments, since they substantially correspond to the method embodiments, reference may be made to the partial description of the method embodiments for relevant points. The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the scheme of the application. One of ordinary skill in the art can understand and implement it without inventive effort.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A vehicle torque distribution method, characterized in that the method comprises:

when the number of the faults is 1, determining an expected mass center slip angle according to the steering wheel rotation angle and the vehicle speed of the vehicle at the current moment; when the current running state of the vehicle is acceleration running and the speed of the vehicle is in a preset high-speed running range, or when the current running state of the vehicle is acceleration running and the speed of the vehicle is in the preset low-speed running range, determining the torque distributed to each first motor according to the maximum torque limiting condition of the motor and the electric valve opening degree of an accelerator pedal at the current moment, meanwhile, calculating a difference value between an actual centroid slip angle of the vehicle and the desired centroid slip angle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through the motor controller corresponding to the second motor according to the difference value, so as to adjust the torque of the second motor while each of the first motors rotates in accordance with the allocated torque, enabling the actual centroid slip angle to approach the expected centroid slip angle, and keeping the vehicle posture to be normal; the first motor is a motor which belongs to a normal side opposite to the side where the fault motor is located in the vehicle body, and the second motor is a non-fault motor which belongs to the side where the fault motor is located in the vehicle body; when the current running state of the vehicle is the speed reduction running and the speed of the vehicle is in the preset high-speed running range, or when the current running state of the vehicle is the speed reduction running and is within the preset low-speed running range, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric valve opening degree of the brake pedal at the current moment, meanwhile, calculating a difference value between an actual centroid slip angle of the vehicle and the desired centroid slip angle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through the motor controller corresponding to the second motor according to the difference value, so as to adjust the torque of the second motor while each of the first motors rotates in accordance with the allocated torque, enabling the actual centroid slip angle to approach the expected centroid slip angle, and keeping the vehicle posture to be normal; when the current running state of the vehicle is constant-speed running and the vehicle speed is within a preset medium-high speed running range, setting a torque signal of a third motor to be 0, meanwhile, calculating a difference value between an actual mass center slip angle and the expected mass center slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller respectively controls the torque of the second motor and the torque of a fourth motor correspondingly through a motor controller corresponding to the second motor and a motor controller corresponding to the fourth motor according to the difference value, so that the actual mass center slip angle tends to the expected mass center slip angle by adjusting the torque of the second motor and the torque of the fourth motor, and the vehicle posture is kept to tend to be normal; the third motor is a first motor opposite to the fault motor in the normal side motor, and the fourth motor is the first motor except the third motor in the normal side motor; when the current running state of the vehicle is constant-speed running and the vehicle speed is in a preset low-speed range, setting the torque signal of each first motor to be 0, meanwhile, calculating a difference value between an actual centroid slip angle and the expected centroid slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through a motor controller corresponding to the second motor respectively according to the difference value, so that the actual centroid slip angle tends to the expected centroid slip angle by adjusting the torque of the second motor, and the vehicle is controlled to stop running under the condition that the vehicle is stable, so that the vehicle keeps normal running.

2. The method of claim 1, wherein when the number of faults is 2, the method further comprises:

and/or the first and/or second light sources,

3. The method of claim 1, wherein when the number of faults is 3, the method further comprises:

4. The method of claim 1, wherein determining the desired centroid slip angle as a function of the steering wheel angle of the host vehicle at the current time and the vehicle speed comprises:

5. The method of claim 1, wherein determining the torque allocated to each first motor based on the motor maximum torque limit and the electric valve opening of the brake pedal at the current time comprises:

distributing torque to each first motor according to a first expression;

the first expression is: t ═ T_max*0.5*A_PT，

6. The method of claim 1, wherein determining the torque allocated to each first motor based on the motor maximum torque limit and the electric valve opening of the brake pedal at the current time comprises:

distributing torque to each first motor according to a second expression;

the second expression is: t ═ T_max*0.5*B_PT，

7. A vehicle torque distribution device, characterized in that the device comprises:

the motor torque distribution module is used for determining an expected mass center slip angle according to the steering wheel rotation angle and the vehicle speed of the vehicle at the current moment when the number of faults is 1; when the current running state of the vehicle is acceleration running and the speed of the vehicle is in a preset high-speed running range, or when the current running state of the vehicle is acceleration running and the speed of the vehicle is in the preset low-speed running range, determining the torque distributed to each first motor according to the maximum torque limiting condition of the motor and the electric valve opening degree of an accelerator pedal at the current moment, meanwhile, calculating a difference value between an actual centroid slip angle of the vehicle and the desired centroid slip angle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through the motor controller corresponding to the second motor according to the difference value, so as to adjust the torque of the second motor while each of the first motors rotates in accordance with the allocated torque, enabling the actual centroid slip angle to approach the expected centroid slip angle, and keeping the vehicle posture to be normal; the first motor is a motor which belongs to a normal side opposite to the side where the fault motor is located in the vehicle body, and the second motor is a non-fault motor which belongs to the side where the fault motor is located in the vehicle body; when the current running state of the vehicle is the speed reduction running and the speed of the vehicle is in the preset high-speed running range, or when the current running state of the vehicle is the speed reduction running and is within the preset low-speed running range, determining the distributed torque for each first motor according to the maximum torque limiting condition of the motor and the electric valve opening degree of the brake pedal at the current moment, meanwhile, calculating a difference value between an actual centroid slip angle of the vehicle and the desired centroid slip angle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through the motor controller corresponding to the second motor according to the difference value, so as to adjust the torque of the second motor while each of the first motors rotates in accordance with the allocated torque, enabling the actual centroid slip angle to approach the expected centroid slip angle, and keeping the vehicle posture to be normal; when the current running state of the vehicle is constant-speed running and the vehicle speed is within a preset medium-high speed running range, setting a torque signal of a third motor to be 0, meanwhile, calculating a difference value between an actual mass center slip angle and the expected mass center slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller respectively controls the torque of the second motor and the torque of a fourth motor correspondingly through a motor controller corresponding to the second motor and a motor controller corresponding to the fourth motor according to the difference value, so that the actual mass center slip angle tends to the expected mass center slip angle by adjusting the torque of the second motor and the torque of the fourth motor, and the vehicle posture is kept to tend to be normal; the third motor is a first motor opposite to the fault motor in the normal side motor, and the fourth motor is the first motor except the third motor in the normal side motor; when the current running state of the vehicle is constant-speed running and the vehicle speed is in a preset low-speed range, setting the torque signal of each first motor to be 0, meanwhile, calculating a difference value between an actual centroid slip angle and the expected centroid slip angle of the vehicle, and inputting the difference value into a fuzzy PID controller, so that the fuzzy PID controller controls the torque of the second motor through a motor controller corresponding to the second motor respectively according to the difference value, so that the actual centroid slip angle tends to the expected centroid slip angle by adjusting the torque of the second motor, and the vehicle is controlled to stop running under the condition that the vehicle is stable, so that the vehicle keeps normal running.

8. An electronic device, comprising: a processor and a memory;

the memory for storing machine executable instructions;

the processor is used for reading and executing the machine executable instructions stored by the memory so as to realize the method of any one of claims 1 to 6.