Vehicle auxiliary steering control method and apparatus, controller, vehicle and medium

Abstract

A vehicle auxiliary steering control method, which is applied to a vehicle having a controller, and comprises: in response to the vehicle satisfying a preset auxiliary steering condition, controlling the vehicle to execute an auxiliary steering operation, wherein the auxiliary steering operation comprises adjusting the braking force of an inner front wheel and controlling two rear wheels to slip.

Description

Vehicle auxiliary steering control method, device, controller, vehicle and medium

[0001] The present application claims priority to Chinese application No. 2024106580663, filed on May 24, 2024, entitled: Vehicle auxiliary steering control method, device, controller, vehicle and medium, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to, but are not limited to, the vehicle steering technical field, and specifically relate to a vehicle auxiliary steering control method, device, controller, vehicle and medium. BACKGROUND

[0003] When the vehicle is steering in a narrow road section, the related art can assist steering by adding a rear wheel steering system in the vehicle, but this scheme needs to additionally add a rear wheel steering device on the vehicle, increasing the development cost. Some other schemes need to control the driving torque of the inner and outer vehicles respectively to achieve auxiliary steering, but the above scheme can only be applied to distributed drive vehicles, and its versatility is poor. TECHNICAL SOLUTION

[0004] The present application provides a vehicle auxiliary steering control method, device, controller, vehicle and medium to solve the technical problems of high cost and poor versatility in the prior art auxiliary steering technology.

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] The present application provides a vehicle auxiliary steering control method, comprising:

[0007] When the vehicle meets a preset auxiliary steering condition, the vehicle is controlled to perform an auxiliary steering operation; wherein the auxiliary steering operation comprises:

[0008] adjusting the braking force of the inner front wheel; and

[0009] controlling the slip of the two rear wheels.

[0010] The present application also provides a vehicle auxiliary steering control device, comprising:

[0011] an auxiliary steering device for controlling the vehicle to perform an auxiliary steering operation when the vehicle meets a preset auxiliary steering condition; wherein the auxiliary steering operation comprises:

[0012] adjusting the braking force of the inner front wheel; and

[0013] controlling the slip of the two rear wheels.

[0014] The application further provides a controller, comprising a memory, a processor, and computer readable instructions stored in the memory and executable on the processor, wherein the processor executes the computer readable instructions to implement the vehicle auxiliary steering control method.

[0015] The application further provides a vehicle comprising the controller or the vehicle auxiliary steering control device.

[0016] The application further provides a computer readable storage medium, which stores computer readable instructions, wherein the computer readable instructions are executed by a processor to implement the vehicle auxiliary steering control method.

[0017] The vehicle auxiliary steering control method, device, controller, vehicle and medium provided by the application comprise the following steps: when a vehicle meets a preset auxiliary steering condition, controlling the vehicle to perform an auxiliary steering operation; wherein the auxiliary steering operation comprises adjusting the braking force of an inner front wheel and controlling the slip of two rear wheels.

[0018] In the application, when the vehicle is steering, if it is confirmed that the vehicle meets the preset auxiliary steering condition, the auxiliary steering operation is performed, specifically, a braking torque is given to the inner front wheel by adjusting the braking force of the inner front wheel, so as to increase an additional yaw moment to the vehicle, thereby assisting the vehicle to ensure that the front axle has sufficient lateral force to steer while steering; meanwhile, the slip of the two rear wheels is controlled to reduce the lateral adhesion coefficient of the rear axle, so that the rear wheels can break through the lateral adhesion of the ground to generate a side slip phenomenon, thereby reducing the turning radius of the vehicle. In the application, the auxiliary steering operation can greatly reduce the minimum turning radius of the vehicle, so that the driver can steer more conveniently; and the application combines the front wheel braking and rear wheel slip scheme, so that the rear wheels slip during the auxiliary steering process to make the vehicle spin, so that ordinary drivers can master the skills of professional drivers to perform drift, and the control process is accompanied by the effects of "responsive tire" and "burning tire" caused by driving slip, so that ordinary drivers can experience the atmosphere and interest of drift.

[0019] Meanwhile, the application can realize the auxiliary steering operation only by using the common driving system, steering system and brake control components on the ordinary vehicle, without the need to additionally increase new components, thereby reducing the cost of realizing the auxiliary steering; and the application can realize automatic control, the control method is simple and reliable, and the control process conforms to the operation habit of ordinary drivers, so that the driver can easily master and operate; and the application can be applied to distributed driving vehicles or other vehicles except distributed driving vehicles, and has strong universality. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

[0021] Fig. 1 is a flow chart of a vehicle auxiliary steering control method according to an embodiment of the present application;

[0022] Fig. 2 is a schematic structural diagram of a vehicle according to an embodiment of the present application;

[0023] Fig. 3 is a schematic force diagram of wheels of a vehicle according to an embodiment of the present application;

[0024] Fig. 4 is a schematic diagram of lateral force coefficients and longitudinal force coefficients at different slip rates according to an embodiment of the present application;

[0025] Fig. 5 is a flow chart of step S10 of a vehicle auxiliary steering control method according to an embodiment of the present application;

[0026] Fig. 6 is a flow chart of step S101 of a vehicle auxiliary steering control method according to an embodiment of the present application;

[0027] Fig. 7 is a flow chart of step S102 of a vehicle auxiliary steering control method according to another embodiment of the present application;

[0028] Fig. 8 is a flow chart of step S10 of a vehicle auxiliary steering control method according to another embodiment of the present application;

[0029] Fig. 9 is a flow chart of a vehicle auxiliary steering control method according to another embodiment of the present application;

[0030] Fig. 10 is a schematic block diagram of a vehicle auxiliary steering control device according to an embodiment of the present application;

[0031] Fig. 11 is a schematic diagram of a controller according to an embodiment of the present application.

[0032] The reference signs in the description are as follows:

[0033] 1, controller; 2, steering system; 3, sensing system; 4, brake control component; 5, motor controller; 6, front axle motor; 7, rear axle motor; 8, wheel.

[0034] Embodiments of the present application

[0035] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are some of the embodiments of the present application, but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0036] The present application provides a vehicle auxiliary steering control method, wherein the vehicle includes a controller 1, a drive system (including a motor controller 5, a front axle motor 6, a rear axle motor 7, etc.), a steering system 2, a CAN network, a perception system 3, and a brake control component 4 that can independently control the braking force of each wheel 8. The controller 1 is used to execute the above-mentioned vehicle auxiliary steering control method. The controller 1 can include an auxiliary steering controller as shown in FIG. 2, or can include a vehicle controller. The auxiliary steering controller can be integrated into the vehicle controller (VCU) to make full use of existing electronic and electrical architecture resources and save development costs.

[0037] The CAN network is used to transmit signals between systems and devices, so that the vehicle controller 1 (such as the auxiliary steering controller) can obtain vehicle information (such as wheel speed, lateral acceleration, longitudinal acceleration and yaw rate, vehicle speed, steering wheel angle, accelerator pedal depth, brake pedal depth, etc.) sent by other systems and devices in real time to execute the above-mentioned vehicle auxiliary steering control method. The perception system 3 collects vehicle information through related sensors and sends it to the controller 1. The perception system 3 includes but is not limited to a wheel speed sensor and a yaw rate sensor, and the perception system 3 can collect and send wheel speed, lateral acceleration, longitudinal acceleration and yaw rate information to the auxiliary steering controller in real time.

[0038] The motor controller 5 is connected to the front axle motor 6 and the rear axle motor 7. When the vehicle auxiliary steering control method is executed, the controller 1 instructs the motor controller 5 to control the front motor torque and the rear motor torque output by the front axle motor 6 and the rear axle motor 7, respectively, and feedback to the controller 1 in real time.

[0039] The steering system 2 is a system for determining the current steering demand of the driver. Specifically, the steering system 2 can send the steering wheel angle to the controller 1 through the CAN network, so that the controller 1 can determine the current steering demand of the driver according to the steering wheel angle, determine the corresponding inner front wheel of the current steering demand, and then execute the above-mentioned vehicle auxiliary steering control method. The brake control component 4 can brake a single wheel 8. Specifically, the controller 1 can instruct the brake control component 4 to control the braking force and the electromagnetic valve to brake a single wheel 8.

[0040] In an embodiment, as shown in FIG. 1, the vehicle auxiliary steering control method comprises the following step S10:

[0041] S10, when the vehicle meets a preset auxiliary steering condition, controlling the vehicle to perform an auxiliary steering operation; it can be understood that in the embodiments of the present application, when the vehicle is currently steering, if an auxiliary steering request is received, it is further judged whether the vehicle meets the preset auxiliary steering condition. In the embodiments of the present application, the preset auxiliary steering condition can be judged according to the vehicle state and the driver demand, and the driver demand can include but is not limited to at least one of the demand data corresponding to the steering wheel angle, the current accelerator pedal depth, and the current brake pedal depth. It can be understood that the auxiliary steering request can be generated when the vehicle is currently steering, that is, while the vehicle is steering, the auxiliary steering request can be triggered by a user (such as a driver) to generate an auxiliary steering request by a preset button on the vehicle and send it to the controller 1, wherein the preset button can be an entity button on the vehicle or a virtual button on the display screen. While the vehicle is steering, the auxiliary steering request can also be generated by the user sending a voice instruction to the controller 1 through a voice device on the vehicle or a mobile terminal. While the vehicle is steering, the auxiliary steering request can also be sent to the vehicle by the user through the mobile terminal; that is, the generation method of the auxiliary steering request is not limited in the embodiments of the present application, and can be set according to the demand.

[0042] In an embodiment, the preset auxiliary steering condition comprises at least one of the following four conditions:

[0043] (1) The absolute value of the steering wheel angle of the vehicle is greater than a preset steering wheel angle threshold; that is, since the situation requiring auxiliary steering operation is often in a narrow space, at this time the driver often turns the steering wheel to the maximum and cannot realize steering, and the auxiliary steering operation is used to reduce the turning radius and assist the driver in steering. Therefore, when the absolute value of the steering wheel angle of the vehicle is greater than the preset steering wheel angle threshold, the auxiliary steering operation is performed, which can avoid the driver from entering the auxiliary steering operation when the steering wheel angle is small, avoid frequent auxiliary steering operation, and improve safety.

[0044] (2) the current vehicle speed belongs to a preset speed range; that is, since in the embodiment of the application, the auxiliary steering operation needs to brake the inner front wheels and cause the rear wheels to slip, the auxiliary steering operation in the case of a high current vehicle speed (for example, higher than the maximum value of the preset speed range) is likely to cause the vehicle to spin out of control, and therefore, in this condition, the current vehicle speed needs to be limited to be lower than the maximum value of the preset speed range; and in the case of a low current vehicle speed (for example, lower than the minimum value of the preset speed range), the auxiliary steering operation is not needed to help with the auxiliary steering, and therefore, the current vehicle speed also needs to be set to be greater than the minimum value of the preset speed range to perform the auxiliary steering operation.

[0045] (3) the current accelerator pedal depth of the vehicle is less than a preset accelerator pedal depth threshold; that is, in the case where the current accelerator pedal depth is less than the preset accelerator pedal depth threshold, the auxiliary steering operation is performed, which can ensure that after the driver finishes steering, the driver only needs to step on the accelerator to generate an auxiliary steering exit instruction, and then exits the auxiliary steering operation to enter the normal driving state according to the auxiliary steering exit instruction, instead of having to stop the vehicle and turn off the auxiliary steering operation before normal driving.

[0046] (4) the current brake pedal depth of the vehicle is less than a preset brake pedal depth threshold; that is, in the case where the current brake pedal depth of the vehicle is less than the preset brake pedal depth threshold, the auxiliary steering operation is performed, which can ensure that the vehicle can respond to the driver's parking demand to ensure driving safety.

[0047] Understandably, the preset auxiliary steering condition can be configured to include one or more of the above four conditions according to requirements, and in an embodiment, the preset auxiliary steering condition includes the above four conditions, and when it is confirmed that the vehicle meets the above four conditions, it is confirmed that the preset auxiliary steering condition is met, and then the auxiliary steering control is performed. Based on the above embodiment, when the auxiliary steering operation needs to be performed, the driver only needs to control the current vehicle speed to be within the preset speed range, and then turn the steering wheel so that the absolute value of the steering wheel angle is greater than the preset steering wheel angle threshold, and then release the brake pedal and the accelerator pedal, and the vehicle will meet the preset auxiliary steering condition, and then enter the control logic of the auxiliary steering operation. The above control method is simple and reliable, the control process conforms to the operation habit of ordinary drivers, and is easy for the driver to master.

[0048] Understandably, the control vehicle performs auxiliary steering operation, that is, enters the auxiliary steering control of the vehicle, in this embodiment, the auxiliary steering operation mainly includes judging the steering demand of the driver (that is, determining the inner front wheel of the vehicle current steering according to the steering wheel angle), and then synchronously controlling the braking force of the inner front wheel and the torque of the rear motor, and then achieving the purpose of assisting the vehicle steering through the driving and braking cooperative control. As shown in FIG. 5, the auxiliary steering operation includes the following specific steps S101-S102:

[0049] S101, adjusting the braking force of the inner front wheel; that is, when the vehicle is steering, if the auxiliary steering request is received and it is confirmed that the vehicle meets the preset auxiliary steering condition, the auxiliary steering operation is performed, at this time, the inner front wheel of the vehicle current steering needs to be determined first, and then the braking force of the inner front wheel is adjusted.

[0050] In a specific embodiment, before the step of adjusting the braking force of the inner front wheel, the step of determining the inner front wheel according to the steering wheel angle or the steering direction of the steering wheel is included. That is, in this embodiment, the inner front wheel can be determined according to the steering wheel angle or the steering direction of the steering wheel.

[0051] Further, in the above embodiment, the step of determining the inner front wheel according to the steering wheel angle specifically includes:

[0052] When the steering wheel angle of the vehicle is greater than 0, the left front wheel of the vehicle is determined as the inner front wheel; that is, when the steering wheel angle is greater than 0, it is judged that the driver wants to turn left, at this time, the left front wheel is the inner front wheel, and an additional yaw moment for assisting the vehicle steering is obtained by braking the left front wheel.

[0053] When the steering wheel angle of the vehicle is less than 0, the right front wheel of the vehicle is determined as the inner front wheel. That is, when the steering wheel angle is less than 0, it is judged that the driver wants to turn right, at this time, the right front wheel is the inner front wheel, and an additional yaw moment for assisting the vehicle steering is obtained by braking the right front wheel.

[0054] After determining the inner front wheel, the controller 1 instructs the brake control component 4 to adjust the braking force of the inner front wheel according to the target slip ratio, gives the inner front wheel a braking torque, and increases an additional yaw moment for the vehicle (so that the current slip ratio of the inner front wheel is near the preset target slip ratio) to assist the vehicle to have enough lateral force for steering while steering.

[0055] Further, the step of adjusting the braking force of the inner front wheel includes adjusting the braking force of the inner front wheel according to the target slip ratio. That is, in this embodiment, the braking force of the inner front wheel can be adjusted according to the target slip ratio. The target slip ratio refers to the slip ratio corresponding to the inner front wheel preset according to the demand.

[0056] In an embodiment, as shown in FIG. 6, the adjusting the braking force of the inner front wheel according to the target slip ratio comprises:

[0057] S1011, determining the current slip ratio and the current wheel acceleration of the inner front wheel. Further, the step S1011 comprises: determining the current slip ratio and the current wheel acceleration of the inner front wheel according to the current vehicle speed and the current wheel speed information of the inner front wheel. Wherein, the wheel slip ratio refers to the proportion of the sliding component in the wheel 8 movement, and the size of the slip ratio can represent the proportion of the sliding component in the wheel 8 movement. The current slip ratio can be determined according to the current wheel speed information (such as current wheel speed, angular velocity, angular acceleration, wheel radius, etc.) of the inner front wheel, which will not be repeated here. And the current wheel acceleration can also be determined according to the above-mentioned vehicle speed and current wheel speed information.

[0058] S1012, adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration. That is, in this embodiment, the braking control of the inner front wheel is performed to adjust the braking force of the inner front wheel according to the target slip ratio. First, the target slip ratio is set, and then the braking force of the inner front wheel is controlled according to the target slip ratio, the current slip ratio and the current wheel acceleration of the inner front wheel (the left upper wheel 8 shown in FIG. 3 is the inner front wheel corresponding to the current steering of the vehicle, so the braking force of the inner front wheel at this time is Fbrake shown in FIG. 3) to adjust the current slip ratio to the target slip ratio. At this time, the braking of the inner front wheel can generate an additional yaw moment for assisting steering, thereby increasing the vehicle yaw angular velocity while ensuring that the inner front wheel has sufficient lateral force for steering.

[0059] In an embodiment, before the step S1012, that is, before the adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, further comprising: adjusting and maintaining the braking force of all non-braking wheels in the vehicle to 0, wherein the non-braking wheel refers to the other wheels in the vehicle except the inner front wheel. That is, in this embodiment, before the adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, first, the three non-braking wheels corresponding to the three non-braking wheels on the vehicle are closed, and the pressure valve is opened to release the pressure of the three non-braking wheel cylinders, so that the pressure of the three non-braking wheel cylinders is equal to 0. At this time, the pressure valve is kept closed, and the pressure valve is kept closed to enter the pressure maintaining control, so that the braking force of all non-braking wheels is maintained to 0. At this time, the inner front wheel as a braking wheel needs to keep the pressure valve open and the pressure valve closed, so that the main cylinder pressure of the braking control component 4 will respond to the instruction of the controller 1 (such as the auxiliary steering controller) to control and adjust the braking force of the single inner front wheel.

[0060] S102, controlling the two rear wheels to slip. Specifically, in an embodiment, the step S102 includes: controlling the rear motor torque output by the rear axle motor 7 to cause the two rear wheels to slip; that is, while the vehicle is turning, if an auxiliary turning request is received and it is confirmed that the vehicle meets the preset auxiliary turning condition, an auxiliary turning operation is performed, at this time, the rear axle motor 7 also needs to output a larger rear motor torque to the rear axle to cause the two rear wheels to slip under the driving force F shown in FIG. 3 to reduce the lateral adhesion coefficient of the rear axle. Understandably, the greater the rear wheel slip rate, the smaller the lateral adhesion coefficient, and as the lateral adhesion coefficient decreases, the rear wheels can break through the lateral adhesion of the ground to produce a side slip phenomenon, thereby reducing the turning radius of the vehicle.

[0061] In an embodiment, the step S102, that is, the control of the rear motor torque output by the rear axle motor 7 to cause the two rear wheels to slip, includes the following steps:

[0062] When the rear axle motor 7 meets the preset slip driving force requirement, the rear motor torque output by the vehicle rear axle motor is controlled according to the rear wheel slip rate and the current yaw rate of the vehicle, and the target slip rate corresponding to the rear wheels of the vehicle to cause the two rear wheels to slip. Specifically, that is, if the rear motor torque output by the rear axle motor 7 needs to be controlled to cause the two rear wheels to slip, a target slip rate corresponding to the rear wheels of the vehicle needs to be set in advance, which can be set according to the relationship between the rear wheel slip rate and the lateral adhesion coefficient; in addition, the rear wheel slip rate and the current yaw rate of the vehicle are also needed to be obtained, and then the rear motor torque output by the vehicle rear axle motor is controlled according to the rear wheel slip rate, the current yaw rate, and the target slip rate corresponding to the rear wheels of the vehicle to cause the two rear wheels to slip; wherein the rear wheel slip rate is the slip rate of the rear wheels, which is an index for measuring the degree of wheel 8 slip, and is used to represent the slip proportion of the wheel 8 relative to the theoretical driving speed in the actual driving process. In this embodiment, the rear wheel slip rate can be determined according to the current driving data of the wheel 8, which will not be described here, and the current yaw rate can be detected by the above-mentioned sensing system 3.

[0063] In an embodiment, before the rear motor torque output by the vehicle rear axle motor is controlled according to the rear wheel slip rate and the current yaw rate of the vehicle, and the target slip rate corresponding to the rear wheels of the vehicle to cause the two rear wheels to slip, the following steps are included: obtaining two real-time slip rates corresponding to the two rear wheels of the vehicle respectively, and determining the minimum value of the two real-time slip rates as the rear wheel slip rate. That is, the rear wheel slip rate is the smaller value of the two real-time slip rates corresponding to the two rear wheels.

[0064] In one embodiment, step S10, determining that the rear axle motor meets the preset slip drive force requirement, includes: determining that the rear axle motor meets the preset slip drive force requirement when the rear axle drive force corresponding to the maximum output torque of the rear axle motor is greater than the maximum adhesion force of the rear axle corresponding to the minimum driving weight of the vehicle.

[0065] In this embodiment, the rear axle driving force is the driving force corresponding to the maximum output torque of the rear axle motor 7. Understandably, as shown in Figure 4, when wheel 8 slips, the slip ratio increases. At this time, the lateral adhesion coefficient (i.e., the lateral force coefficient in Figure 4) decreases continuously with the increase in slip ratio. Therefore, the lateral adhesion coefficient can be controlled by controlling the slip ratio of wheel 8. Thus, in this embodiment, since it is necessary to control the rear axle motor 7 to provide a larger rear motor torque to the rear axle so that the two rear wheels are driven by the driving force F shown in Figure 3 to slip, the lateral adhesion coefficient of the rear axle is reduced. This causes the lateral adhesion coefficient of the rear axle to gradually decrease as the rear wheel slip ratio increases, ultimately causing the rear wheels to break through the lateral adhesion of the ground and produce a sideslip phenomenon, thereby reducing the turning radius of the vehicle. Therefore, in this embodiment, the magnitude of the rear axle driving force corresponding to the maximum output torque of the rear axle motor 7 can be determined first, and then it can be determined whether the rear axle motor 7 is capable of providing a larger rear motor torque to the rear axle to cause the two rear wheels to slip.

[0066] Specifically, in this embodiment, the rear axle driving force is Among them, T max is the maximum output torque of the rear axle motor 7, i is the speed ratio of the reducer, and r is the radius of the rear wheel.

[0067] Understandably, in this embodiment, the maximum rear axle adhesion force is the maximum value of the lateral adhesion coefficient of the rear axle when the vehicle's mass is at its minimum driving weight. The minimum driving weight of the vehicle can be set according to requirements, for example, as the total vehicle weight plus the weight of a single passenger. This is because at least one driver is required during vehicle operation, and the minimum driving weight is the sum of the total vehicle weight and the weight of a single passenger (the weight of a single passenger can be set within a range and then selected according to requirements). In other scenarios, the minimum driving weight can be determined according to requirements.

[0068] Specifically, in this embodiment, the maximum adhesion force of the rear axle is

[0069] Where M is the total vehicle mass in kg; m is the mass of a single person in kg, and its value can range from 75 to 100 kg; g is the gravitational acceleration; a is the distance between the vehicle's center of gravity and the front axle; b is the distance between the vehicle's center of gravity and the rear axle; and μ is the ground adhesion coefficient, which is generally taken as 0.95 to 1.

[0070] In this embodiment, when the rear axle driving force corresponding to the maximum output torque of the rear axle motor 7 is greater than the rear axle maximum adhesion force corresponding to the minimum running mass of the vehicle, it can be determined that the rear axle motor 7 meets the preset slip driving force requirement; that is, when the vehicle is turning, a lateral force will be generated, and the ground will also generate a side force on the rear wheel, and the balance of the side force and the lateral force will not cause the wheel 8 to slide sideways, and the decrease of the lateral adhesion coefficient will cause the side force to decrease, at this time, the side force cannot balance the lateral force, so the rear wheel will slide sideways; and the sliding of the rear wheel will reduce the turning radius of the vehicle. Therefore, in this embodiment, when the maximum output torque of the rear axle motor 7 corresponds to the rear axle driving force greater than the rear axle maximum adhesion force corresponding to the minimum running mass of the vehicle, the rear axle will slip when the rear axle motor 7 outputs at the maximum output torque. Therefore, in this embodiment, in order to make the rear axle driving force greater than the rear axle maximum adhesion force, it can be determined that the rear axle motor 7 meets the preset slip driving force requirement, and the rear motor torque output by the rear axle motor 7 can be controlled to cause the two rear wheels to slip. Otherwise, in the case where the rear axle driving force is less than or equal to the rear axle maximum adhesion force, there may be a case that even if the rear axle motor 7 outputs at the maximum output torque, the corresponding rear axle driving force may be less than the current adhesion force, and the rear wheel will not slip.

[0071] Further, when the rear axle driving force corresponding to the maximum output torque of the rear axle motor is less than or equal to the rear axle maximum adhesion force corresponding to the minimum running mass of the vehicle, it can be determined that the rear axle motor 7 does not meet the preset slip driving force requirement. That is, since in the case where the rear axle driving force is less than or equal to the rear axle maximum adhesion force, there may be a case that even if the rear axle motor 7 outputs at the maximum output torque, the corresponding rear axle driving force may be less than the current adhesion force, and the rear wheel will not slip; therefore, when the rear axle driving force is less than or equal to the rear axle maximum adhesion force, it is necessary to determine that the rear axle motor 7 does not meet the preset slip driving force requirement, and the rear motor torque output by the rear axle motor 7 will not be adjusted and controlled at this time.

[0072] In a further embodiment, as shown in FIG. 7, the rear motor torque output by the vehicle rear axle motor is controlled according to the rear wheel slip rate and the current yaw angular velocity of the vehicle and the target slip rate corresponding to the rear wheel of the vehicle, so that the two rear wheels slip, comprising:

[0073] S1021, performing second control on the rear motor torque output by the rear axle motor based on the target slip ratio, to adjust the rear wheel slip ratio to the target slip ratio. Specifically, in this step, the second control can refer to the process of performing PID (Proportion Integration Differentiation) control on the rear motor torque output by the rear axle motor 7 based on the target slip ratio in the auxiliary steering control process, to adjust the rear wheel slip ratio of the left and right rear wheels to the target slip ratio.

[0074] S1022, adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw rate in the process of performing the second control, so that the rear motor torque output by the rear axle motor 7 causes the two rear wheels to slip. Further, in this embodiment, the target slip ratio can also be adjusted according to the rear wheel slip ratio and the current yaw rate in the process of performing the second control on the rear motor torque, so that the rear motor torque output by the rear axle motor 7 causes the two rear wheels to slip. Specifically, as the rear wheel slip ratio increases, the current yaw rate will also increase; when the rear wheel slip ratio decreases, the current yaw rate will also decrease; therefore, in this embodiment, it is necessary to ensure that the current yaw rate fluctuates within a certain preset yaw rate range without exceeding the preset yaw rate range, so as to ensure the driving stability of the vehicle when the two rear wheels slip.

[0075] In the embodiment of the present application, the above-mentioned auxiliary steering operation can greatly reduce the minimum turning radius of the vehicle, making it more convenient for the driver to turn; and the embodiment of the present application combines the front wheel braking and rear wheel slipping scheme, which makes the rear wheel slip in the auxiliary steering process to make the vehicle spin, so that ordinary drivers can master the skills of professional drivers like drifting, and the control process is accompanied by the effects of "responsive tire" and "burning tire" of driving slip, which can make ordinary drivers experience the atmosphere and interest of drifting. At the same time, the embodiment of the present application can realize the auxiliary steering operation only by using the common driving system, steering system 2 and brake control components 4 on ordinary vehicles, without the need to add new components, thereby reducing the cost of realizing auxiliary steering; and the embodiment of the present application can realize automatic control, the control method is simple and reliable, and the control process conforms to the operation habit of ordinary drivers, which is easy for drivers to master and easy to operate; and the embodiment of the present application can be applied to distributed driving vehicles or other vehicles other than distributed driving vehicles, and has strong universality.

[0076] The embodiment of the present application can, while the vehicle is turning, if it is confirmed that the vehicle meets the preset auxiliary steering condition, simultaneously apply different forces (corresponding to the braking force of the inner front wheel and the rear motor torque, respectively) to each wheel 8 through the brake control component 4, the motor controller 5 and the rear axle motor 7, so that the target of reducing the turning radius of the vehicle is achieved through the cooperation of the various forces. Among them, the braking force of the inner front wheel generates the vehicle yaw moment, and the rear motor torque makes the rear wheel produce slip to reduce the lateral adhesion coefficient, so that the auxiliary steering is achieved through cooperative control. Moreover, the embodiment of the present application is suitable for various working conditions. If the vehicle is running on the road surface with small adhesion coefficient such as ice, the auxiliary steering operation is performed through the auxiliary steering control method of the embodiment of the present application, and the motor driving force is sufficient to overcome the adhesion force of the wheel 8 to produce slip, without the need to increase the design value of the maximum driving force of the rear axle. However, if the auxiliary steering control method of the embodiment of the present application is applied to the working condition that the vehicle is running on the conventional road surface with large adhesion coefficient, it is necessary to increase the design value of the maximum driving force of the rear axle by increasing the peak torque of the motor or increasing the speed ratio of the reducer, etc. Compared with the need to additionally increase the driving system, the need to replace the vehicle with a distributed drive, or the need to change the vehicle steering system 2 to use other auxiliary steering solutions in related technologies, the embodiment of the present application is easier to implement.

[0077] In an embodiment, as shown in FIG. 8, the auxiliary steering operation further includes:

[0078] S103, controlling the output of the front motor torque of the front axle motor to adjust the current vehicle speed of the vehicle to the target vehicle speed.

[0079] Specifically, the step S103 specifically includes: controlling the front axle motor 6 to output the front motor torque according to the rear motor torque and the brake torque corresponding to the braking force of the inner front wheel.

[0080] In this embodiment, while the vehicle is turning, if the auxiliary steering request is received and it is confirmed that the vehicle meets the preset auxiliary steering condition, the auxiliary steering operation is performed. At this time, it is also necessary to control the front axle motor 6 to give the front axle a negative torque (the negative torque is the front motor torque, and the force corresponding to the front motor torque is Ffeedback shown in FIG. 3) to offset part of the rear motor torque output by the rear axle motor 7, so as to adjust the current vehicle speed of the vehicle to the target vehicle speed and maintain the current vehicle speed of the vehicle substantially equal to the target vehicle speed, thereby ensuring the stability of the vehicle while sufficiently reducing the turning radius of the vehicle. Understandably, in this embodiment, the auxiliary steering operation includes synchronous control of the braking force of the inner front wheel, the rear motor torque and the front motor torque, so as to achieve the purpose of auxiliary steering of the vehicle through driving and braking cooperative control. Among them, the control of the rear motor torque can achieve the slip of the rear wheel, and the control of the front motor torque can maintain the current vehicle speed of the vehicle at the target vehicle speed.

[0081] In the above embodiments of the present application, the auxiliary steering operation can greatly reduce the minimum turning radius of the vehicle, making it more convenient for the driver to steer; and the present application combines the front wheel braking and rear wheel slipping scheme, which can make the vehicle spin during the auxiliary steering process, but through the coordinated control of the braking control component 4 and the drive system, the vehicle speed can be stabilized, so that ordinary drivers can master the skills of professional drivers like drifting, and the control process is accompanied by the effects of "responsive tire" and "burning tire" during driving slipping, which can make ordinary drivers experience the atmosphere and interest of drifting. The present application can receive an auxiliary steering request while the vehicle is steering, and confirm that the vehicle meets the preset auxiliary steering conditions, and through the braking control component 4, the motor controller 5 and the front axle motor 6 and the rear axle motor 7, different forces are applied to each wheel 8 (corresponding to the braking force of the inner front wheel, the front motor torque and the rear motor torque respectively), and the forces are cooperated to realize the goal of reducing the turning radius of the vehicle. Among them, the braking force of the inner front wheel controls the vehicle yaw moment, the rear motor torque controls the rear wheel to slip to reduce the lateral adhesion coefficient, and the front motor torque controls the vehicle speed, so that the auxiliary vehicle steering is realized through the coordinated control of the three aspects.

[0082] In an embodiment, the step S103 includes: controlling the front motor torque of the front axle motor according to the rear motor torque and the braking torque corresponding to the braking force of the inner front wheel. In this embodiment, the front axle motor 6 needs to output a negative torque to the front axle to offset part of the rear motor torque output by the rear axle motor 7 according to the rear motor torque and the braking torque corresponding to the braking force of the inner front wheel, so as to adjust the current vehicle speed to the target vehicle speed. In this embodiment, while the vehicle is steering, if it is confirmed that the vehicle meets the preset auxiliary steering conditions, the auxiliary steering operation is performed, specifically, by adjusting the braking force of the inner front wheel to give the inner front wheel a braking torque according to the target slip ratio, so as to give the vehicle an additional yaw moment to assist the vehicle to steer while ensuring that the front axle has enough lateral force to steer; at the same time, by controlling the rear motor torque output by the rear axle motor 7, the two rear wheels are made to slip to reduce the lateral adhesion coefficient of the rear axle, so that the rear wheels can break through the lateral adhesion of the ground to produce side slip phenomenon, thereby reducing the turning radius of the vehicle; then, the front motor torque of the front axle motor 6 is controlled according to the rear motor torque and the braking torque corresponding to the braking force of the inner front wheel, so as to adjust the current vehicle speed to the target vehicle speed and maintain it, thereby ensuring the stability of the vehicle while sufficiently reducing the turning radius of the vehicle.

[0083] Further, the controlling the front motor torque of the front axle motor according to the rear motor torque and the braking torque corresponding to the braking force of the inner front wheel includes:

[0084] determining a feedforward value according to the current demand torque, the rear motor torque and the braking torque; in this embodiment, the torque corresponding to the current depth of the accelerator pedal is the current demand torque required by the driver at present, thus, the current demand torque can be determined according to the current depth of the accelerator pedal of the vehicle. And the braking torque corresponding to the braking force of the inner front wheel can be determined according to the braking force of the inner front wheel and the size of the wheel 8 and the like. Then, the current demand torque and the braking torque are added to obtain a torque sum, and the difference between the rear motor torque and the torque sum is the feedforward value.

[0085] performing a third control on the front motor torque of the front axle motor 6 according to the feedforward value and the target speed, so as to adjust the current speed of the vehicle to the target speed. That is, the front axle motor 6 can control the front motor torque output by the front and rear motors according to the feedforward value, so as to keep the wheel 8 running stably, but at this time, the current speed of the stable running is not necessarily equal to the target speed, thus, it is still necessary to continue to perform the third control on the front motor torque of the front axle motor 6, and the third control can refer to the process of adjusting the current speed of the vehicle to the target speed by PID control on the front motor torque in the auxiliary steering control process. In an embodiment, the target speed is set as a small fixed speed value according to the demand, so that only the current speed equal to the target speed needs to be controlled, and then the minimum turning radius of the vehicle can be controlled to be reduced by the above auxiliary steering control operation, so as to complete the auxiliary steering.

[0086] In another embodiment, before the step S1034, that is, before the third control on the front motor torque of the front axle motor 6 according to the feedforward value and the target speed, it includes:

[0087] The target vehicle speed is determined according to the current accelerator pedal depth of the vehicle and preset reference data. Specifically, the preset reference data includes a plurality of accelerator-vehicle speed reference groups; each of the accelerator-vehicle speed reference groups includes an accelerator pedal depth value and an associated auxiliary steering vehicle speed; that is, in this embodiment, the target vehicle speed is not a fixed value, but can be set to different vehicle speed values according to the current accelerator pedal depth. Specifically, the correspondence between the current accelerator pedal depth and the target vehicle speed is determined through experiments and recorded in the preset reference data in the form of accelerator-vehicle speed reference groups. In this embodiment, the accelerator pedal depth value matching the current accelerator pedal depth can be queried from the preset reference data, and the auxiliary steering vehicle speed associated with the matched accelerator pedal depth value is determined as the target vehicle speed. Further, the accelerator pedal depth value in the accelerator-vehicle speed reference group can be a single value or a range of values. Understandably, when the current accelerator pedal depth is equal to the accelerator pedal depth value or belongs to the value range corresponding to the accelerator pedal depth value, it is considered that the current accelerator pedal depth matches the accelerator pedal depth value, and the target vehicle speed corresponding to the current accelerator pedal depth is the auxiliary steering vehicle speed associated with the above-mentioned accelerator pedal depth value. Each current accelerator pedal depth can find a matching accelerator pedal depth value in the preset reference data. In this way, the target vehicle speed can be set according to the current accelerator pedal depth, and thus the turning radius of the vehicle at different speeds can be better reduced through the auxiliary steering control method.

[0088] In an embodiment, the step S1012, i.e., the adjusting the brake force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, includes:

[0089] When the current slip ratio belongs to a preset slip ratio range and the current wheel acceleration is greater than a preset acceleration threshold, a first control is performed on the brake force of the inner front wheel based on the target slip ratio to adjust the current slip ratio to the target slip ratio. The target slip ratio is one of the slip ratio values in the preset slip ratio range, and the first control can refer to a process of performing PID control on the brake force of the inner front wheel based on the target slip ratio to adjust the current slip ratio to the target slip ratio in the auxiliary steering control process.

[0090] In the embodiment, the control of the braking force of the inner front wheel is controlled in a segmented manner with the target slip ratio as the target. Therefore, in this step, it is first needed to determine whether the current slip ratio belongs to the preset slip ratio range and whether the current wheel acceleration is greater than the preset acceleration threshold, and then determine the specific control strategy according to the determination result; specifically, since the current slip ratio represents the current wheel speed state, and the current wheel acceleration represents the change trend of the future wheel speed. Therefore, in this embodiment, since the current slip ratio belongs to the preset slip ratio range, it means that the current wheel speed is moderate and will not be too large or too small, but since the current wheel acceleration is greater than the preset acceleration threshold, the change trend of the future wheel speed is fast. At this time, if the first control is not performed, the current slip ratio may quickly change to be too large or too small out of the preset slip ratio range. Therefore, the embodiment can only need to adjust the braking force of the inner front wheel through the first control, and then adjust the current slip ratio to the target slip ratio which also belongs to the preset slip ratio range and keep it around the target slip ratio; that is, if the current slip ratio is less than the target slip ratio within the preset slip ratio range, the current slip ratio is gradually increased through the first control until the current slip ratio is equal to the target slip ratio; and if the current slip ratio is greater than the target slip ratio within the preset slip ratio range, the current slip ratio is gradually decreased through the first control until the current slip ratio is equal to the target slip ratio.

[0091] In an embodiment, the step S1012, that is, the adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, comprises:

[0092] When the current slip ratio is less than the minimum value of the preset slip ratio range and the current wheel acceleration is greater than a preset acceleration threshold, the braking force of the inner front wheel is increased at a first preset adjustment rate to increase the current slip ratio to the target slip ratio. The target slip ratio is one of the slip ratio values ​​within the preset slip ratio range. In this embodiment, the braking force of the inner front wheel is controlled in segments with the target slip ratio as the objective. Therefore, it is first necessary to determine whether the current slip ratio falls within the preset slip ratio range and whether the current wheel acceleration is greater than the preset acceleration threshold, and then determine the subsequent specific control strategy based on the determination results. Specifically, the current slip ratio represents the current wheel speed state, while the current wheel acceleration represents the future trend of wheel speed change. Therefore, in this embodiment, since the current slip ratio is less than the minimum value of the preset slip ratio range, it indicates that the current wheel speed is too low, and the current slip ratio needs to be increased to the target slip ratio to improve the current wheel speed. However, since the current wheel acceleration is greater than the preset acceleration threshold, the future wheel speed will change rapidly. If the braking force of the inner front wheel is adjusted at a large rate to increase the current slip ratio, it may cause a sudden change in the slip ratio. Therefore, in this embodiment, it is only necessary to control the braking force of the inner front wheel to increase slowly at a lower first preset adjustment rate (slowly increasing the master cylinder pressure of the brake control component 4 corresponding to the inner front wheel) so that the current slip ratio increases to the target slip ratio. Understandably, the first preset adjustment rate can be set according to needs, and the first preset adjustment rate is greater than the adjustment rate of the braking force of the inner front wheel during the execution of the first control.

[0093] In one embodiment, step S1012, namely adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio, and the current wheel acceleration, includes:

[0094] When the current slip ratio is greater than the maximum value of the preset slip ratio range, or / and the current wheel acceleration is less than the preset acceleration threshold, the brake force of the inner front wheel is controlled to decrease at a second preset adjustment rate, so as to decrease the current slip ratio to the target slip ratio. In this embodiment, the target slip ratio is one of the slip ratio values in the preset slip ratio range, and the control of the brake force of the inner front wheel is controlled in a segmented manner with the target slip ratio as the target. Therefore, it is first needed to determine whether the current slip ratio belongs to the preset slip ratio range, and to determine whether the current wheel acceleration is greater than the preset acceleration threshold, and then to determine the subsequent specific control strategy according to the determination result. Specifically, since the current slip ratio represents the current wheel speed state, and the current wheel acceleration represents the change trend of the future wheel speed. Therefore, in this embodiment, when the current slip ratio is greater than the maximum value of the preset slip ratio range, it indicates that the current wheel speed of the inner front wheel is too large, and when the current wheel acceleration is less than the preset acceleration threshold, it indicates that the change trend of the future wheel speed is slow. In the above cases (the current slip ratio is greater than the maximum value of the preset slip ratio range, or / and the current wheel acceleration is less than the preset acceleration threshold), it is needed to quickly decrease the current slip ratio to the target slip ratio, so as to avoid the locking of the inner front wheel and to ensure the slip ratio of the wheel 8. Therefore, it is needed to quickly decrease the brake force of the inner front wheel (quickly decrease the master cylinder pressure of the brake control component 4 corresponding to the inner front wheel) at a second preset adjustment rate, so as to quickly decrease the current slip ratio to the target slip ratio. The second preset adjustment rate is greater than the first preset adjustment rate.

[0095] In an embodiment, the step S1022, i.e., the step of adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw rate in the process of performing the second control, comprises:

[0096] In the embodiment, it is required to ensure that the current yaw rate fluctuates within the preset yaw rate range without exceeding the preset yaw rate range, so as to ensure the driving stability of the vehicle when the two rear wheels are slipping. Therefore, when the current yaw rate is greater than the maximum value of the preset yaw rate range, it indicates that the current yaw rate is too large, and thus it is required to reduce the rear wheel slip ratio to reduce the current yaw rate. However, since the rear wheel slip ratio is less than or equal to the target slip ratio at this time, and the rear wheel slip ratio needs to be controlled to be close to the target slip ratio in the process of the second control, the rear wheel slip ratio will actually be controlled to increase to be close to the target slip ratio in the second control when the rear wheel slip ratio is less than the target slip ratio, and the rear wheel slip ratio remains unchanged when the rear wheel slip ratio is equal to the target slip ratio. Therefore, in the embodiment, the rear wheel slip ratio is greater than the changed target slip ratio by reducing the target slip ratio, so as to control the rear wheel slip ratio to decrease to be close to the target slip ratio in the process of the second control, and thus the current yaw rate decreases with the decrease of the rear wheel slip ratio.

[0097] When the current yaw rate is reduced to be less than the maximum value of the preset yaw rate range, the current target slip ratio is kept unchanged. It can be understood that, when the current yaw rate is reduced to be less than the maximum value of the preset yaw rate range, the current yaw rate fluctuates within the preset yaw rate range without exceeding the preset yaw rate range, and thus the driving stability of the vehicle can be ensured when the two rear wheels are slipping, and thus the adjustment of the target slip ratio can be stopped, and the current target slip ratio can be kept unchanged.

[0098] In an embodiment, the step S1022, that is, the adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw rate in the process of the second control, comprises:

[0099] when the current yaw rate is less than the minimum value of the preset yaw rate range and the rear wheel slip ratio is greater than or equal to the target slip ratio, increasing the target slip ratio so that the current yaw rate increases; specifically, when the current yaw rate is less than the minimum value of the preset yaw rate range and the rear wheel slip ratio is greater than or equal to the target slip ratio, increasing the target slip ratio so that the rear wheel slip ratio increases along with the target slip ratio in the process of performing the second control, and then the current yaw rate increases along with the rear wheel slip ratio; it can be understood that when the rear wheel slip ratio increases, the current yaw rate also increases; when the rear wheel slip ratio decreases, the current yaw rate also decreases. In this embodiment, it is necessary to ensure that the current yaw rate fluctuates within the preset yaw rate range without exceeding the preset yaw rate range, so as to ensure the driving stability of the vehicle when the two rear wheels slip. Therefore, when the current yaw rate is less than the minimum value of the preset yaw rate range, it means that the current yaw rate is too small, and at this time, the rear wheel slip ratio needs to be increased to increase the current yaw rate. However, since the rear wheel slip ratio is greater than or equal to the target slip ratio at this time, and in the process of the second control, it is necessary to control the rear wheel slip ratio to approach the target slip ratio, therefore, when the rear wheel slip ratio is greater than the target slip ratio, the second control will actually control the rear wheel slip ratio to decrease to approach the target slip ratio, and when the rear wheel slip ratio is equal to the target slip ratio, the rear wheel slip ratio remains unchanged. Therefore, in this embodiment, the target slip ratio is increased to make the rear wheel slip ratio less than the changed target slip ratio, and then the rear wheel slip ratio is controlled to increase to approach the target slip ratio in the process of performing the second control, and then the current yaw rate increases along with the increase of the rear wheel slip ratio.

[0100] when the current yaw rate increases to be greater than the minimum value of the preset yaw rate range, keeping the current target slip ratio unchanged. It can be understood that when the current yaw rate increases to be greater than the minimum value of the preset yaw rate range, the current yaw rate fluctuates within the preset yaw rate range without exceeding the preset yaw rate range, and at this time, the driving stability of the vehicle can be ensured when the two rear wheels slip, therefore, the adjustment of the target slip ratio can be stopped, and the current target slip ratio can be kept unchanged.

[0101] In an embodiment, in the step S1022, the adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw rate in the process of performing the second control comprises:

[0102] When one of the rear wheel slip ratio and the current yaw rate meets a preset non-adjustment condition, the target slip ratio is kept unchanged during the execution of the second control until the preset non-adjustment condition is no longer met, and then the target slip ratio is adjusted again according to the latest rear wheel slip ratio and the current yaw rate.

[0103] Further, the preset non-adjustment condition includes at least one of the following conditions:

[0104] The current yaw rate belongs to a preset yaw rate range. Understandably, when the current yaw rate belongs to the preset yaw rate range, the current yaw rate fluctuates within the preset yaw rate range without exceeding the preset yaw rate range, and at this time, the two rear wheels can ensure the driving stability of the vehicle when they slip, so the current target slip ratio can be kept unchanged.

[0105] The current yaw rate is greater than the maximum value of the preset yaw rate range, and the rear wheel slip ratio is greater than the target slip ratio. Understandably, when the current yaw rate is greater than the maximum value of the preset yaw rate range, although the current yaw rate is too large, at this time, since the rear wheel slip ratio is greater than the target slip ratio, the second control currently being executed will actually control the rear wheel slip ratio to decrease to approach the target slip ratio, and therefore, the target slip ratio does not need to be adjusted at present, and only the execution result of the second control is needed.

[0106] The current yaw rate is less than the minimum value of the preset yaw rate range, and the rear wheel slip ratio is less than the target slip ratio. Understandably, when the current yaw rate is less than the minimum value of the preset yaw rate range, although the current yaw rate is too small, at this time, since the rear wheel slip ratio is less than the target slip ratio, the second control currently being executed will actually control the rear wheel slip ratio to increase to approach the target slip ratio, and therefore, the target slip ratio does not need to be adjusted at present, and only the execution result of the second control is needed.

[0107] In an embodiment, as shown in FIG. 9, the step S10, after the vehicle is controlled to perform the auxiliary steering operation, includes the following steps S20-S30:

[0108] S20, when the vehicle no longer meets the preset auxiliary steering condition or receives an auxiliary steering exit instruction, performing a pre-exit operation; that is, the preset auxiliary steering condition includes at least one of the following four conditions: the absolute value of the steering wheel angle of the vehicle is greater than a preset steering wheel angle threshold; the current vehicle speed of the vehicle belongs to a preset vehicle speed range; the current accelerator pedal depth of the vehicle is less than a preset accelerator pedal depth threshold; and the current brake pedal depth of the vehicle is less than a preset brake pedal depth threshold. Therefore, when one of all the conditions included in the preset auxiliary steering condition is no longer met, the pre-exit operation will be performed. In addition, the vehicle can also perform the pre-exit operation after receiving the auxiliary steering exit instruction. Based on the above embodiment, if the driver returns the steering wheel angle or steps on the brake pedal to make the current brake pedal depth greater than or equal to the preset brake pedal depth threshold, or steps on the accelerator pedal to make the current accelerator pedal depth greater than or equal to the preset accelerator pedal depth threshold, the preset auxiliary steering condition is no longer met, and the vehicle responds to the driver's demand to perform the pre-exit operation. The above control method is simple and reliable, and the control process conforms to the operation habit of ordinary drivers and is easy for drivers to master. If the driver encounters an emergency and needs to stop steering, he or she can only need to return the direction or step on the brake pedal, and the emergency handling method completely conforms to the intuitive reaction of the driver.

[0109] Understandably, the auxiliary steering exit instruction can be triggered and sent to the controller 1 by stepping on the accelerator after the driver completes the steering, and then the controller 1 can perform the pre-exit operation according to the auxiliary steering exit instruction. In some embodiments, the auxiliary steering exit instruction can also be sent to the controller 1 by a user (such as a driver) triggering a preset button on the vehicle, wherein the preset button can be a physical button on the vehicle or a virtual button on the display screen. The auxiliary steering exit instruction can also be sent to the controller 1 by the user generating a voice instruction through a voice device on the vehicle or a mobile terminal. The auxiliary steering exit instruction can also be sent to the controller 1 by the user through the mobile terminal; that is, the generation method of the auxiliary steering request is not limited in the embodiments of the present application, and can be set according to the demand.

[0110] Further, the performing the pre-exit operation includes:

[0111] The first demand torque corresponding to the front axle motor of the vehicle and the second demand torque corresponding to the rear axle motor are obtained, and the current demand braking force is determined according to the current brake pedal depth of the vehicle; the sum of the first demand torque and the second demand torque is equal to the current demand torque, and the current demand torque is determined according to the current accelerator pedal depth of the vehicle. Wherein, the torque corresponding to the current accelerator pedal depth is the current demand torque required by the driver at present, and the current demand torque has been allocated to the first demand torque corresponding to the front axle motor and the second demand torque corresponding to the rear axle motor according to the actual running information of the vehicle when the accelerator pedal is stepped on, that is, the sum of the first demand torque and the second demand torque is equal to the current demand torque. The braking force corresponding to the current brake pedal depth is the current demand braking force required by the driver at present.

[0112] When the front motor torque output by the front axle motor 6 is adjusted to the first required torque at a first preset rate, the rear motor torque output by the rear axle motor 7 is adjusted to the second required torque, and the braking force of all the wheels 8 is adjusted to the current required braking force at a second preset rate, it is confirmed that the pre-exit operation is completed. That is, in this embodiment, if the vehicle is immediately controlled to stop performing the auxiliary steering operation when it is confirmed that the vehicle no longer meets the preset auxiliary steering condition or the auxiliary steering exit instruction is received; at this time, the motor torque will immediately change to the current required torque, that is, the front motor torque output by the front axle motor 6 will immediately change to the first required torque, the rear motor torque output by the rear axle motor 7 will immediately change to the second required torque, and the braking force corresponding to all the wheels 8 will also immediately change to the front required braking force, which will cause a sudden change in torque and braking force, and adversely affect the driving safety of the vehicle and the performance of the wheels 8. Therefore, in this embodiment, after performing the pre-exit operation, the motor torque is controlled to gradually return to the current required torque at a first preset rate (that is, the front motor torque output by the front axle motor 6 is adjusted to the first required torque at a first preset rate, and the rear motor torque output by the rear axle motor 7 is adjusted to the second required torque at a first preset rate), and the braking force of the wheels 8 is controlled to gradually return to the current required braking force at a second preset rate, and then the vehicle is controlled to stop performing the auxiliary steering operation to avoid a sudden change in torque and braking force. Understandably, the first preset rate and the second preset rate can be set to be equal or unequal according to requirements, and in an embodiment, the first preset rate and the second preset rate can be set according to the following condition: the time length for adjusting the front motor torque of the front axle motor 6 and the rear motor torque of the rear axle motor 7 to the first required torque and the second required torque at the first preset rate is a first time length, the time length for adjusting the braking force of all the wheels 8 to the current required braking force at the second preset rate is a second time length, and the time difference between the first time length and the second time length does not exceed a preset waiting time length. The preset waiting time length can be set according to requirements, such as 0.

[0113] S30, when the pre-exit operation is completed, the vehicle is controlled to stop performing the auxiliary steering operation. That is, when the front motor torque of the front axle motor 6 is completely adjusted to the first required torque, the rear motor torque of the rear axle motor 7 is completely adjusted to the second required torque, and the braking force corresponding to all the wheels 8 is also completely adjusted to the current required braking force, it is confirmed that the pre-exit operation is completed, and at this time the vehicle can be controlled to stop performing the auxiliary steering operation without a sudden change in torque and braking force after the pre-exit operation is completed.

[0114] It can be understood that the size of the serial number of each step in the above embodiments does not mean the order of execution, and the execution order of each process can be determined by its function and internal logic, and can not constitute any limitation on the implementation process of the embodiments of the present application.

[0115] In an embodiment, as shown in FIG. 10, a vehicle auxiliary steering control device is provided, which corresponds to the vehicle auxiliary steering control method in the above embodiments. The vehicle auxiliary steering control device comprises:

[0116] An auxiliary steering device 100 is configured to control the vehicle to perform an auxiliary steering operation when the vehicle meets a preset auxiliary steering condition; wherein the auxiliary steering operation comprises:

[0117] Adjusting the braking force of the inner front wheel; and

[0118] Controlling the slip of the two rear wheels.

[0119] In the device of the above embodiments of the present application, when the vehicle is steering, if it is confirmed that the vehicle meets the preset auxiliary steering condition, the auxiliary steering operation is performed, specifically, a braking torque is given to the inner front wheel by adjusting the braking force of the inner front wheel, so as to add an additional yaw moment to the vehicle, so as to assist the vehicle to ensure that the front axle has sufficient lateral force to steer while steering; at the same time, the slip of the two rear wheels is controlled to reduce the lateral adhesion coefficient of the rear axle, so that the rear wheels can break through the lateral adhesion of the ground to produce side slip phenomenon, thereby reducing the turning radius of the vehicle. In the embodiments of the present application, the above auxiliary steering operation can greatly reduce the minimum turning radius of the vehicle, so that the driver can steer more conveniently; and the embodiments of the present application combine the front wheel braking and rear wheel slipping scheme, which can make the rear wheels slip during the auxiliary steering process to make the vehicle spin, so that ordinary drivers can master the skills of professional drivers like drifting, and the control process is accompanied by the effects of "responsive tire" and "burning tire" of driving slip, which can make ordinary drivers experience the atmosphere and interest of drifting. At the same time, the embodiments of the present application can realize the auxiliary steering operation only by using the common driving system, steering system and brake control components on ordinary vehicles, without the need to add new components, thereby reducing the cost of realizing auxiliary steering; and the embodiments of the present application can realize automatic control, the control method is simple and reliable, and the control process conforms to the operation habit of ordinary drivers, which is easy for drivers to master and easy to operate; and the embodiments of the present application can be applied to distributed drive vehicles or other vehicles except distributed drive vehicles, and has strong universality.

[0120] The specific definitions of the vehicle auxiliary steering control device can refer to the definitions of the vehicle auxiliary steering control method, which will not be repeated here. Each device in the vehicle auxiliary steering control device can be implemented by software, hardware, or a combination thereof. Each device can be embedded in the processor of the computer device in hardware form or independent of the processor, or stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each device.

[0121] The embodiments of the present application also provide a vehicle comprising the vehicle auxiliary steering control device. Understandably, the vehicle can also comprise a drive system (including a motor controller, a front axle motor, a rear axle motor, etc.), a steering system, a CAN network, a perception system, and a brake control component capable of independently controlling the braking force of each wheel, and the like. For details, refer to the embodiments described in the vehicle auxiliary steering control method, which will not be repeated here.

[0122] In one embodiment, a controller 1 is provided, which can be a server, and the internal structure diagram thereof can be as shown in FIG. 11. The controller 1 comprises a processor, a memory, a network interface and a database connected through a system bus. The processor of the controller 1 is used to provide computing and control capabilities. The memory of the controller 1 comprises a readable storage medium and an internal memory. The readable storage medium stores an operating system, computer readable instructions and a database. The internal memory provides an environment for the operating system and computer readable instructions in the readable storage medium to run. The computer readable instructions are executed by the processor to implement a vehicle auxiliary steering control method. The readable storage medium provided by the embodiment comprises a non-volatile readable storage medium and a volatile readable storage medium.

[0123] In one embodiment, a controller 1 is provided, comprising a memory, a processor and computer readable instructions stored in the memory and executable on the processor, and the processor executes the computer readable instructions to implement the steps of the vehicle auxiliary steering control method.

[0124] The embodiments of the present application also provide a vehicle comprising the controller 1. Understandably, as shown in FIG. 2, the vehicle comprises the controller 1, a drive system (including a motor controller 5, a front axle motor 6, a rear axle motor 7, etc.), a steering system 2, a CAN network, a perception system 3, and a brake control component 4 capable of independently controlling the braking force of each wheel 8. The controller 1 is used to execute the vehicle auxiliary steering control method. The controller 1 can comprise an auxiliary steering controller as shown in FIG. 2, or can comprise a vehicle controller. The auxiliary steering controller can be integrated into the vehicle controller (VCU) to make full use of existing electronic and electrical architecture resources and save development costs.

[0125] The CAN network is used to transmit signals between each system and device, so that the vehicle controller 1 (such as an auxiliary steering controller) can obtain vehicle information (such as wheel speed, lateral acceleration, longitudinal acceleration and yaw rate, vehicle speed, steering wheel angle, accelerator pedal depth, brake pedal depth, etc.) sent by other systems and devices in real time to perform the vehicle auxiliary steering control method described above. The perception system 3 collects vehicle information and the like through related sensors and sends them to the controller 1. The perception system 3 includes but is not limited to a wheel speed sensor and a yaw rate sensor, and the perception system 3 can collect and send wheel speed, lateral acceleration, longitudinal acceleration and yaw rate information and the like to the auxiliary steering controller in real time.

[0126] The motor controller 5 is connected to the front axle motor 6 and the rear axle motor 7, and when the vehicle auxiliary steering control method is performed, the controller 1 instructs the motor controller 5 to control the front axle motor 6 and the rear axle motor 7 to adjust the front motor torque and the rear motor torque and the like, and feedback to the controller 1 in real time.

[0127] The steering system 2 is a system for determining the current steering demand of the driver, specifically, the steering system 2 can send the steering wheel angle to the controller 1 through the CAN network, so that the controller 1 can determine the current steering demand of the driver according to the steering wheel angle, determine the corresponding inner front wheel of the current steering demand, and then perform the vehicle auxiliary steering control method described above. The brake control component 4 can realize braking of a single wheel 8, specifically, the controller 1 can instruct the brake control component 4 to control the braking force and the electromagnetic valve to brake the single wheel 8.

[0128] The controller 1 of the vehicle is specifically limited as described above for the vehicle auxiliary steering control method, and will not be described here.

[0129] In the vehicle described above, when the vehicle is turning, if it is determined that the vehicle meets the preset auxiliary turning condition, an auxiliary turning operation is performed, specifically, a brake torque is given to the inner front wheel by adjusting the brake force of the inner front wheel, so as to give the vehicle an additional yaw moment, so as to assist the vehicle to ensure that the front axle has sufficient lateral force to turn while turning; at the same time, the lateral adhesion coefficient of the rear axle is reduced by controlling the slip of the two rear wheels, so that the rear wheels can break through the lateral adhesion of the ground to produce side slip phenomenon, thereby reducing the turning radius of the vehicle. In the embodiment of the application, the auxiliary turning operation described above can greatly reduce the minimum turning radius of the vehicle, making it more convenient for the driver to turn; and the embodiment of the application combines the front wheel braking and rear wheel slipping scheme, which makes the rear wheels slip during the auxiliary turning process, so that the vehicle produces a fishtail, so that ordinary drivers can master the skills of professional drivers like drifting, and the control process is accompanied by the effects of "responsive tire" and "burning tire" of driving slip, which can make ordinary drivers experience the atmosphere and interest of drifting. At the same time, the embodiment of the application can only use the common driving system, steering system and brake control components on ordinary vehicles to realize the auxiliary turning operation, without the need to add new components, thereby reducing the cost of realizing the auxiliary turning; and the embodiment of the application can realize automatic control, the control method is simple and reliable, and the control process conforms to the operation habit of ordinary drivers, which is easy for drivers to master and easy to operate; and the embodiment of the application can be applied to distributed drive vehicles or other vehicles other than distributed drive vehicles, and has strong universality.

[0130] In one embodiment, a computer readable storage medium is provided, and computer readable instructions are stored on the computer readable storage medium, and the computer readable instructions are executed by a processor to implement the steps of the vehicle auxiliary turning control method described above.

[0131] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by computer readable instructions instructing relevant hardware, and the computer readable instructions can be stored in a readable storage medium, including non-volatile readable storage medium and volatile readable storage medium. When the computer readable instructions are executed, the processes of the above-mentioned embodiments of the methods can be included. In the embodiments provided in the present application, any reference to memory, storage, database or other medium can include non-volatile and / or volatile memory. The non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. The volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), memory bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0132] The above-mentioned embodiments are used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and can be included in the protection scope of the present application.

Claims

1. A vehicle assist steering control method wherein, Comprising: in response to the vehicle satisfying a preset auxiliary steering condition, controlling the vehicle to perform an auxiliary steering operation; wherein the auxiliary steering operation comprises: adjusting the braking force of the inner front wheel; and controlling the slip of the two rear wheels.

2. The vehicle assist control method according to claim 1, wherein The preset auxiliary steering condition comprises at least one of the following conditions: the absolute value of the steering wheel angle of the vehicle is greater than a preset steering wheel angle threshold value; the current vehicle speed of the vehicle belongs to a preset vehicle speed range; the current accelerator pedal depth of the vehicle is less than a preset accelerator pedal depth threshold value; and the current brake pedal depth of the vehicle is less than a preset brake pedal depth threshold value.

3. The vehicle assist control method according to claim 1 or 2, wherein Before the adjusting the braking force of the inner front wheel, comprising: determining the inner front wheel according to the steering wheel angle or the steering wheel rotation direction.

4. The vehicle assist control method according to claim 3, wherein The determining the inner front wheel according to the steering wheel angle, comprising: in response to the steering wheel angle of the vehicle being greater than 0, determining the left front wheel of the vehicle as the inner front wheel; and in response to the steering wheel angle of the vehicle being less than 0, determining the right front wheel of the vehicle as the inner front wheel.

5. The vehicle assist control method according to any one of claims 1-4, wherein, The adjusting the braking force of the inner front wheel, comprising: adjusting the braking force of the inner front wheel according to the target slip ratio.

6. The vehicle assist control method according to claim 5, wherein The adjusting the braking force of the inner front wheel according to the target slip ratio, comprising: determining the current slip ratio and the current wheel acceleration of the inner front wheel; adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration.

7. The vehicle assist control method according to claim 6, wherein The determining the current slip ratio and the current wheel acceleration of the inner front wheel, comprising: determining the current slip ratio and the current wheel acceleration of the inner front wheel according to the current vehicle speed of the vehicle and the current wheel speed information of the inner front wheel.

8. The vehicle assist control method according to claim 6, wherein The adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, comprising: in response to the current slip ratio belonging to a preset slip ratio range and the current wheel acceleration being greater than a preset acceleration threshold value, performing a first control on the braking force of the inner front wheel based on the target slip ratio to adjust the current slip ratio to the target slip ratio.

9. The vehicle assist control method according to claim 6, wherein The adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, comprising: in response to the current slip ratio being less than the minimum value of the preset slip ratio range and the current wheel acceleration being greater than a preset acceleration threshold value, controlling the braking force of the inner front wheel to increase at a first preset adjustment rate, so that the current slip ratio increases to the target slip ratio.

10. The vehicle assist control method according to claim 6, wherein The adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, comprising: in response to the current slip ratio being greater than the maximum value of the preset slip ratio range or / and the current wheel acceleration being less than a preset acceleration threshold value, controlling the braking force of the inner front wheel to decrease at a second preset adjustment rate, so that the current slip ratio decreases to the target slip ratio.

11. The vehicle assist control method according to claim 6, wherein Before the adjusting the braking force of the inner front wheel according to the target slip ratio, the current slip ratio and the current wheel acceleration, further comprising: adjusting and keeping the braking force of all non-braking wheels in the vehicle to 0, the non-braking wheels referring to other wheels in the vehicle except the inner front wheel.

12. The vehicle assist control method according to any one of claims 1-11, wherein, The controlling the slip of the two rear wheels, comprising: Controlling a rear motor torque output by a rear axle motor of the vehicle to cause the two rear wheels to slip.

13. The vehicle assist control method according to claim 12, wherein The controlling a rear motor torque output by a rear axle motor of the vehicle to cause the two rear wheels to slip includes: In response to the rear axle motor satisfying a preset slip drive power requirement, controlling a rear motor torque output by a rear axle motor of the vehicle to cause the two rear wheels to slip according to a rear wheel slip ratio of the vehicle, a current yaw angular velocity, and a target slip ratio corresponding to the rear wheels of the vehicle.

14. The vehicle assist control method according to claim 13, wherein The controlling a rear motor torque output by a rear axle motor of the vehicle to cause the two rear wheels to slip according to a rear wheel slip ratio of the vehicle, a current yaw angular velocity, and a target slip ratio corresponding to the rear wheels of the vehicle includes: Performing a second control on the rear motor torque output by the rear axle motor based on the target slip ratio to adjust the rear wheel slip ratio to the target slip ratio; and In a process of performing the second control, adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw angular velocity to cause the rear motor torque output by the rear axle motor to cause the two rear wheels to slip.

15. The vehicle assist control method according to claim 14, wherein The adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw angular velocity in the process of performing the second control includes: In response to the current yaw angular velocity being greater than a maximum value of a preset yaw angular velocity range and the rear wheel slip ratio being less than or equal to the target slip ratio, decreasing the target slip ratio to cause the current yaw angular velocity to decrease; and In response to the current yaw angular velocity decreasing to be less than the maximum value of the preset yaw angular velocity range, keeping the current target slip ratio unchanged.

16. The vehicle assist control method according to claim 14, wherein The adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw angular velocity in the process of performing the second control includes: In response to the current yaw angular velocity being less than a minimum value of a preset yaw angular velocity range and the rear wheel slip ratio being greater than or equal to the target slip ratio, increasing the target slip ratio to cause the current yaw angular velocity to increase; and In response to the current yaw angular velocity increasing to be greater than the minimum value of the preset yaw angular velocity range, keeping the current target slip ratio unchanged.

17. The vehicle assist control method according to claim 14, wherein The adjusting the target slip ratio according to the rear wheel slip ratio and the current yaw angular velocity in the process of performing the second control includes: In response to the rear wheel slip ratio and the current yaw angular velocity satisfying one of preset non-adjustment conditions, keeping the target slip ratio unchanged in the process of performing the second control; the preset non-adjustment conditions include at least one of the following conditions: The current yaw angular velocity belongs to a preset yaw angular velocity range; The current yaw angular velocity is greater than a maximum value of a preset yaw angular velocity range and the rear wheel slip ratio is greater than the target slip ratio; and The current yaw angular velocity is less than a minimum value of a preset yaw angular velocity range and the rear wheel slip ratio is less than the target slip ratio.

18. The vehicle assist control method according to claim 13, wherein Before the controlling a rear motor torque output by a rear axle motor of the vehicle to cause the two rear wheels to slip according to a rear wheel slip ratio of the vehicle, a current yaw angular velocity, and a target slip ratio corresponding to the rear wheels of the vehicle, the method further includes: Obtain two real-time slip ratios corresponding to two rear wheels of the vehicle respectively, and determine the minimum value of the two real-time slip ratios as the rear wheel slip ratio.

19. The vehicle assist control method according to claim 13, wherein The determination that the rear axle motor meets the preset slip drive requirement comprises: In response to the rear axle drive force corresponding to the maximum output torque of the rear axle motor being greater than the rear axle maximum adhesion force corresponding to the minimum running mass of the vehicle, it is determined that the rear axle motor meets the preset slip drive requirement.

20. The vehicle auxiliary steering control method of any one of claims 1-19, wherein, The auxiliary steering operation further comprises: Controlling the output of the front motor torque of the front axle motor to adjust the current vehicle speed of the vehicle to the target vehicle speed.

21. The vehicle assist control method according to claim 20, wherein The controlling of the output of the front motor torque of the front axle motor comprises: Controlling the front axle motor to output the front motor torque according to the rear motor torque and the brake torque corresponding to the brake force of the inner front wheel.

22. The vehicle assist control method according to claim 21, wherein The controlling of the front axle motor to output the front motor torque according to the rear motor torque and the brake torque corresponding to the brake force of the inner front wheel comprises: Determining a feedforward value according to the current demand torque, the rear motor torque and the brake torque; the current demand torque is determined according to the current accelerator pedal depth of the vehicle, and the brake torque is determined according to the brake force of the inner front wheel; and Performing third control on the front motor torque of the front axle motor based on the feedforward value and the target vehicle speed to adjust the current vehicle speed of the vehicle to the target vehicle speed.

23. The vehicle assist control method of claim 22 wherein, Before the performing of the third control on the front motor torque of the front axle motor based on the feedforward value and the target vehicle speed, it comprises: Determining the target vehicle speed according to the current accelerator pedal depth of the vehicle and preset reference data.

24. The vehicle auxiliary steering control method of any one of claims 1-23, wherein, After the controlling of the vehicle to perform the auxiliary steering operation, it comprises: In response to the vehicle no longer meeting the preset auxiliary steering condition or receiving an auxiliary steering exit instruction, performing a pre-exit operation; and In response to the pre-exit operation being performed, controlling the vehicle to stop performing the auxiliary steering operation.

25. The vehicle auxiliary steering control method of claim 24, wherein, The performing of the pre-exit operation comprises: Obtaining a first demand torque corresponding to the front axle motor of the vehicle and a second demand torque corresponding to the rear axle motor, and determining a current demand brake force according to a current brake pedal depth of the vehicle; the sum of the first demand torque and the second demand torque is equal to a current demand torque, and the current demand torque is determined according to a current accelerator pedal depth of the vehicle; and In response to adjusting the front motor torque output by the front axle motor to the first demand torque at a first preset rate, adjusting the rear motor torque output by the rear axle motor to the second current demand torque, and adjusting the brake force of all wheels to the current demand brake force at a second preset rate, confirming that the pre-exit operation is performed.

26. A vehicle auxiliary steering control device, wherein, It comprises: An auxiliary steering device is configured to control a vehicle to perform an auxiliary steering operation in response to the vehicle meeting a preset auxiliary steering condition; wherein the auxiliary steering operation comprises: Adjusting the brake force of the inner front wheel; and Controlling the slip of the two rear wheels.

27. A controller, wherein, It comprises a memory, a processor and computer readable instructions stored in the memory and executable on the processor, wherein the processor implements the vehicle auxiliary steering control method according to any one of claims 1 to 25 when executing the computer readable instructions.

28. A vehicle for use in the method of any one of claims 1-25, wherein, including the controller of claim 27, or the vehicle auxiliary steering control device of claim 26.

29. A computer readable storage medium for use in the method of any one of claims 1-25, the computer readable storage medium having stored thereon computer readable instructions, wherein, The computer readable instructions, when executed by the processor, implement the vehicle auxiliary steering control method of any one of claims 1 to 25.

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