Control method and device for rear wheel steering, vehicle and storage medium

Abstract

The application provides a rear wheel steering control method and device, a vehicle and a storage medium. During vehicle driving, the vehicle determines a compensation coefficient for gain compensation and phase compensation of a rear wheel steering angle during rear wheel steering in response to a rear wheel steering control instruction, through a response speed parameter and an oscillation damping parameter of a rear wheel steering system. Further, the rear wheel is controlled to rotate through a product (rear wheel steering angle) of the compensation coefficient and a front wheel steering angle to realize rear wheel steering. Since the rear wheel steering angle is a steering angle after gain compensation and phase compensation, during vehicle steering control through the rear wheel steering angle, the vehicle can steer with high stability through the rear wheel steering angle after gain compensation, and the vehicle can respond to a steering instruction through the rear wheel steering angle more quickly through phase compensation, so as to realize smaller steering delay and improve the response speed of the rear wheel steering system of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicles, and more particularly, to a rear wheel steering control method and device, a vehicle and a storage medium. BACKGROUND

[0002] With the development of electronic control technology and sensor technology, rear wheel steering technology has begun to be applied in more and more vehicles, providing drivers with a more comfortable, safe and enjoyable driving experience. The control strategy of the rear wheel steering system has become an important research direction.

[0003] The control strategy of the rear wheel steering system refers to changing the vehicle yaw angular velocity by controlling the rear wheel steering angle. In general, the related technology determines the rear wheel steering angle through an existing model, and the existing model is obtained by simulating the actual steering process of the vehicle multiple times. However, the actual steering process of the vehicle is complex and variable, and the existing model cannot simulate all actual steering processes. Therefore, the rear wheel steering angle determined based on the existing model has errors.

[0004] Therefore, there is an urgent need for a rear wheel steering control method to improve the control accuracy of rear wheel steering and improve the maneuverability and stability of the vehicle. SUMMARY

[0005] The present application provides a rear wheel steering control method, device, vehicle and storage medium, which can improve the control accuracy of rear wheel steering and improve the maneuverability and stability of the vehicle.

[0006] In a first aspect, a rear wheel steering control method is provided, the method comprising: in the process of driving a vehicle, in response to a rear wheel steering control instruction, acquiring a front wheel steering angle; determining a compensation coefficient based on a response speed parameter and an oscillation decay parameter of a rear wheel steering system in the vehicle, the compensation coefficient being used to indicate gain compensation and phase compensation for the rear wheel steering angle when the rear wheel is steered; determining a rear wheel steering angle based on the product of the front wheel steering angle and the compensation coefficient, and controlling the rear wheel of the vehicle to rotate at the rear wheel steering angle.

[0007] In the technical solution, during the driving of the vehicle, the vehicle can determine a compensation coefficient for gain compensation and phase compensation of the rear wheel steering angle when the rear wheel is steered, in response to the control instruction of the rear wheel steering, by using the response speed parameter and the oscillation damping parameter of the rear wheel steering system in the vehicle. Further, the rear wheel is controlled to rotate by using the product of the compensation coefficient and the front wheel steering angle (rear wheel steering angle) to realize the rear wheel steering. Since the rear wheel steering angle is the steering angle after gain compensation and phase compensation, during the steering of the vehicle by using the rear wheel steering angle, the vehicle can steer with high stability by using the rear wheel steering angle after gain compensation, and the vehicle can respond to the steering instruction by using the rear wheel steering angle more quickly by phase compensation, so that the response speed of the rear wheel steering system of the vehicle is improved. Especially in the case of emergency obstacle avoidance, the rear wheel is steered in advance, which can effectively reduce the side slip tendency of the vehicle and improve the dynamic stability and safety of the vehicle.

[0008] In combination with the first aspect, in some possible implementation manners, the compensation coefficient is determined based on the response speed parameter and the oscillation damping parameter of the rear wheel steering system in the vehicle, including: determining a phase compensation coefficient based on the response speed parameter and the oscillation damping parameter, the phase compensation coefficient being used to indicate phase compensation of the rear wheel steering angle when the rear wheel is steered in a steady state; determining a first gain compensation coefficient based on the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation damping parameter, the first gain compensation coefficient being used to indicate gain compensation of the rear wheel steering angle when the rear wheel is steered in a steady state; and determining the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0009] In the technical solution, the phase compensation is related to the response speed and the oscillation damping of the rear wheel steering system. Therefore, the method can accurately determine the phase compensation coefficient of the rear wheel steering angle when the rear wheel is steered in a steady state by using the response speed parameter and the oscillation damping parameter of the rear wheel steering system in the vehicle. This can ensure that the response speed and the oscillation damping of the rear wheel steering system of the vehicle are in the best state. In addition, the actual gain coefficient of the front wheel and the gain adjustment coefficient directly affect the stability and responsiveness of the rear wheel steering system, and the gain compensation can enable the vehicle to steer with high stability. Therefore, the method can accurately determine the first gain compensation coefficient of the rear wheel steering angle when the rear wheel is steered in a steady state by using the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation damping parameter. This can ensure that the rear wheel steering system has good performance and high stability.

[0010] In some possible implementation manners, based on the response speed parameter and the oscillation decay parameter, the phase compensation coefficient is determined, including: obtaining an actual response speed parameter and an actual oscillation decay parameter of the rear wheel steering system; and determining the phase compensation coefficient based on the actual response speed parameter, the actual oscillation decay parameter, an expected response speed parameter and an expected oscillation decay parameter of the rear wheel steering system.

[0011] In the technical solution, the actual response speed parameter, the actual oscillation decay parameter, the expected response speed parameter and the expected oscillation decay parameter can be used to determine whether phase lead or phase lag is needed. The phase lead can improve the phase margin of the rear wheel steering system and improve the response speed, and the phase lag can increase the stability of the rear wheel steering system and reduce oscillation. Therefore, the method can accurately determine the phase compensation coefficient based on the formula, to ensure that the response speed and the oscillation decay of the rear wheel steering system of the vehicle reach the best state based on the phase compensation coefficient.

[0012] In some possible implementation manners, based on the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation decay parameter, the first gain compensation coefficient is determined, including: constructing a first coefficient based on the expected response speed parameter and the expected oscillation decay parameter of the rear wheel steering system, the first coefficient being used to indicate the response sensitivity of the rear wheel steering system to the control instruction; and determining the product of the first coefficient, the actual gain coefficient of the front wheel and the gain adjustment coefficient as the first gain compensation coefficient.

[0013] In the technical solution, the actual response speed parameter, the actual oscillation decay parameter, the expected response speed parameter, the expected oscillation decay parameter, the actual gain coefficient of the front wheel and the gain adjustment coefficient directly determine the response characteristics of the rear wheel steering system to the steering input, including the response speed, the stability and the oscillation decay, to ensure that the vehicle maintains good steering performance in different working conditions. Therefore, the method can accurately determine the first gain compensation coefficient based on the formula, to ensure that the rear wheel steering system has good performance and high stability based on the first gain compensation coefficient.

[0014] In some possible implementation manners, based on the first gain compensation coefficient and the phase compensation coefficient, the compensation coefficient is determined, including: determining a theoretical steering torque of the wheel in the vehicle; correcting the first gain compensation coefficient based on the actual gain coefficient of the front wheel, the actual gain coefficient of the rear wheel, the response speed parameter, the oscillation decay parameter and the theoretical steering torque, to obtain a second gain compensation coefficient; and determining the compensation coefficient based on the second gain compensation coefficient and the phase compensation coefficient.

[0015] In the technical solution, the front wheels and the rear wheels have different contributions to the steering response in different driving states of the vehicle. By considering the actual gain coefficient of the front wheels and the actual gain coefficient of the rear wheels, the steering characteristics of the vehicle in a specific condition can be more accurately reflected, and the stability of the rear wheel steering system is affected. In addition, due to factors such as road conditions and load changes, the actual steering torque of the wheels may be different from the theoretical steering torque. The gain compensation coefficient is modified to better match the actual steering torque and ensure accurate control of the rear wheel steering system. Therefore, the above scheme modifies the first gain compensation coefficient through the actual gain coefficient of the front wheels, the actual gain coefficient of the rear wheels, the response speed parameter, the oscillation decay parameter, and the theoretical steering torque, and then accurately determines the compensation coefficient through the modified gain compensation coefficient (second gain compensation coefficient) and the phase compensation coefficient. This can improve the response speed and dynamic stability of the rear wheel steering system of the vehicle during rear wheel steering through the compensation coefficient.

[0016] In combination with the first aspect and the above implementation, in some possible implementations, based on the actual gain coefficient of the front wheels, the actual gain coefficient of the rear wheels, the response speed parameter, the oscillation decay parameter, and the theoretical steering torque, the first gain compensation coefficient is modified to obtain a second gain compensation coefficient, including: determining a first transfer model of a front wheel steering system in the vehicle based on the actual gain coefficient of the front wheels, the theoretical steering torque of the front wheels, the response speed parameter, and the oscillation decay parameter, the first transfer model being used to describe the relationship between the front wheel steering torque and the change in the front wheel steering angle; determining a second transfer model of a rear wheel steering system in the vehicle based on the actual gain coefficient of the rear wheels, the theoretical steering torque of the rear wheels, the response speed parameter, and the oscillation decay parameter, the second transfer model being used to describe the relationship between the rear wheel steering torque and the change in the rear wheel steering angle; and modifying the first gain compensation coefficient based on the first transfer model and the second transfer model to obtain the second gain compensation coefficient.

[0017] In the technical solution, the first gain compensation coefficient is set based on a preset vehicle model (expected response speed parameter, expected oscillation decay parameter, gain adjustment coefficient, and actual gain coefficient of the front wheels). However, in actual driving, the uncertainty of road conditions and vehicle states requires the rear wheel steering system to have adaptive ability. Therefore, by dynamically adjusting the gain compensation coefficient based on the actual effect of the front wheel steering torque and the change in the steering angle, and the actual effect of the rear wheel steering torque and the change in the steering angle, that is, obtaining the second gain compensation coefficient, the rear wheel steering can be more accurately controlled, and the dynamic response and stability of the vehicle are improved.

[0018] In some possible implementation manners, based on the first gain compensation coefficient and the phase compensation coefficient, the compensation coefficient is determined, including: determining a second coefficient based on a product between the first gain compensation coefficient and the phase compensation coefficient; and determining the compensation coefficient based on a difference between a preset value and the second coefficient.

[0019] In the technical solution, in the rear wheel steering system of the vehicle, the gain compensation and the phase compensation can improve the stability and dynamic response of the rear wheel steering system. The gain compensation generally adjusts the gain parameter to change the amplification of the rear wheel steering system, and the phase compensation adjusts the phase margin of the rear wheel steering system by introducing a lag or lead network to improve the stability and response speed of the rear wheel steering system. In the above method, the first gain compensation coefficient is multiplied by the phase compensation coefficient to obtain a second coefficient, and a difference between a preset value (1) and the second coefficient is determined as the compensation coefficient for gain compensation and phase compensation of the rear wheel steering angle. The use of 1 minus the second coefficient in the above process can ensure that the response of the rear wheel steering system is not excessively amplified in the compensation process, thereby avoiding the rear wheel steering system from entering an unstable state. Through the combination of multiplication and subtraction, the response of the rear wheel steering system can be finely adjusted to achieve a control effect of fast and stable steering of the vehicle.

[0020] In a second aspect, a rear wheel steering control device is provided, including: an acquisition module configured to acquire a front wheel steering angle in response to a rear wheel steering control instruction during vehicle driving; a determination module configured to determine a compensation coefficient based on a response speed parameter and an oscillation decay parameter of a rear wheel steering system in the vehicle, the compensation coefficient being used to indicate gain compensation and phase compensation of a rear wheel steering angle when the rear wheel is steered; and a control module configured to determine a rear wheel steering angle based on a product between the front wheel steering angle and the compensation coefficient, and control the rear wheel of the vehicle to rotate at the rear wheel steering angle.

[0021] In some possible implementation manners of the second aspect, the determination module is specifically configured to: determine a phase compensation coefficient based on the response speed parameter and the oscillation decay parameter, the phase compensation coefficient being used to indicate phase compensation of a rear wheel steering angle when the rear wheel is steered in a steady state; determine a first gain compensation coefficient based on a front wheel actual gain coefficient, a gain adjustment coefficient, the response speed parameter, and the oscillation decay parameter, the first gain compensation coefficient being used to indicate gain compensation of the rear wheel steering angle when the rear wheel is steered in the steady state; and determine the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0022] With reference to the second aspect and the foregoing implementation manners, in some possible implementation manners, the acquisition module is specifically configured to acquire the actual response speed parameter and the actual oscillation decay parameter of the rear wheel steering system; and the determination module is specifically further configured to determine the phase compensation coefficient based on the actual response speed parameter, the actual oscillation decay parameter, the expected response speed parameter and the expected oscillation decay parameter of the rear wheel steering system.

[0023] With reference to the second aspect and the foregoing implementation manners, in some possible implementation manners, the determination module is specifically further configured to: construct a first coefficient based on the expected response speed parameter and the expected oscillation decay parameter of the rear wheel steering system, the first coefficient being used to indicate the response sensitivity of the rear wheel steering system to the control instruction; and determine the first gain compensation coefficient as a product of the first coefficient, the actual gain coefficient of the front wheel and the gain adjustment coefficient.

[0024] With reference to the second aspect and the foregoing implementation manners, in some possible implementation manners, the determination module is specifically further configured to: determine a theoretical steering torque of the wheel in the vehicle; correct the first gain compensation coefficient based on the actual gain coefficient of the front wheel, the actual gain coefficient of the rear wheel, the response speed parameter, the oscillation decay parameter and the theoretical steering torque, to obtain a second gain compensation coefficient; and determine the compensation coefficient based on the second gain compensation coefficient and the phase compensation coefficient.

[0025] With reference to the second aspect and the foregoing implementation manners, in some possible implementation manners, the determination module is specifically further configured to: determine a first transfer model of the front wheel steering system in the vehicle based on the actual gain coefficient of the front wheel, a theoretical steering torque of the front wheel, the response speed parameter and the oscillation decay parameter, the first transfer model being used to describe a relationship between the front wheel steering torque and a change in the front wheel steering angle; determine a second transfer model of the rear wheel steering system in the vehicle based on the actual gain coefficient of the rear wheel, a theoretical steering torque of the rear wheel, the response speed parameter and the oscillation decay parameter, the second transfer model being used to describe a relationship between the rear wheel steering torque and a change in the rear wheel steering angle; and correct the first gain compensation coefficient based on the first transfer model and the second transfer model, to obtain the second gain compensation coefficient.

[0026] With reference to the second aspect and the foregoing implementation manners, in some possible implementation manners, the determination module is specifically further configured to: determine a second coefficient based on a product of the first gain compensation coefficient and the phase compensation coefficient; and determine the compensation coefficient as a difference between a preset value and the second coefficient.

[0027] In a third aspect, a vehicle is provided, including a memory and a processor. The memory is configured to store executable program code, and the processor is configured to invoke and run the executable program code from the memory, so that the vehicle performs the method in the first aspect or any possible implementation manner of the first aspect.

[0028] In a fourth aspect, a computer-readable storage medium is provided, which stores executable program code, when the executable program code is run on a computer, so that the computer performs the method in the first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a scene schematic diagram using a vehicle provided by an embodiment of the present application;

[0030] Figure 2 is a schematic flow chart of a rear wheel steering control method provided by an embodiment of the present application;

[0031] Figure 3 is a schematic diagram of determining a first gain compensation coefficient and a phase compensation coefficient provided by an embodiment of the present application;

[0032] Figure 4 is a schematic block diagram of determining a compensation coefficient provided by an embodiment of the present application;

[0033] Figure 5 is a schematic block diagram of determining a yaw rate response provided by an embodiment of the present application;

[0034] Figure 6 is a structural schematic diagram of a rear wheel steering control device provided by an embodiment of the present application;

[0035] Figure 7 is a structural schematic diagram of a vehicle provided by an embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the present application will be described clearly and exhaustively in combination with the drawings. In the description of the embodiments of the present application, unless otherwise specified, “ / ” represents or, for example, A / B can represent A or B: “and / or” in the text only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, in the description of the embodiments of the present application, “multiple” means two or more than two.

[0037] The terms "first", "second", "third", etc. are used only for the purpose of description, and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features.

[0038] Figure 1 is a schematic diagram of a scenario using a vehicle provided by an embodiment of the present application.

[0039] As shown in Figure 1 , in the case that the vehicle A is in a reversing scenario, the vehicle A detects, through a vehicle-mounted camera, that there is an obstacle B in front of the vehicle A. At this time, the vehicle A can control the rear wheel C through a rear wheel steering system to realize vehicle steering, so as to more easily avoid the obstacle B.

[0040] The control strategy of the rear wheel steering system refers to changing the vehicle yaw rate through control of the rear wheel steering angle. In general, the related art determines the rear wheel steering angle through an existing model, and the existing model is obtained through multiple simulations of the actual steering process of the vehicle. However, the actual steering process of the vehicle is complex and variable, and the existing model cannot simulate all the actual steering processes. Therefore, the rear wheel steering angle determined based on the existing model has errors, and there may be a situation that the vehicle A collides with the obstacle B.

[0041] To solve the above problems, the present application provides a rear wheel steering control method to improve the control accuracy of the rear wheel steering and improve the controllability and stability of the vehicle. For details, please refer to the following Figure 2 .

[0042] Figure 2 is a schematic flowchart of a rear wheel steering control method provided by an embodiment of the present application.

[0043] It should be understood that the rear wheel steering control method provided by an embodiment of the present application can be applied to a vehicle (for example, the vehicle A) as shown in Figure 1 . Specifically, the rear wheel steering control method can be applied to a target controller in the vehicle. The target controller is any one of a vehicle controller and a body domain controller. The body domain controller is used to control various vehicle components in the vehicle. In the rear wheel steering control method of the present application, the vehicle components include the rear wheel.

[0044] As shown in Figure 2 , the method 200 includes:

[0045] Step 201, in the process of driving the vehicle, the vehicle controller acquires the front wheel steering angle in response to the rear wheel steering control instruction.

[0046] It should be understood that the "control instruction of rear wheel steering" in the above step 201 refers to an instruction for steering the vehicle by the rear wheels. In addition, the "front wheel steering angle" in the above step 201 specifically includes a direction and an angle value when the front wheels are steered.

[0047] In some embodiments, the vehicle controller in step 201 acquires the front wheel steering angle by: the vehicle controller acquiring a steering angle of a steering wheel in the vehicle by a steering angle sensor; and the vehicle controller determining the front wheel steering angle based on a product of the steering angle of the steering wheel and a target transmission ratio between the steering wheel and the front wheels.

[0048] It should be understood that the "steering angle of the steering wheel" in the above scheme specifically includes a steering direction and an angle value.

[0049] It should also be understood that, due to the steering angle characteristics of the vehicle, the "target transmission ratio" in the above scheme gradually decreases as the steering angle of the steering wheel increases. This is for the safety of the vehicle.

[0050] In step 202, the vehicle controller determines a compensation coefficient based on a response speed parameter and an oscillation damping parameter of a rear wheel steering system in the vehicle, the compensation coefficient being used to indicate gain compensation and phase compensation for a rear wheel steering angle when the rear wheels are steered.

[0051] It should be understood that the "response speed parameter" in the above step 202 can be reflected by a frequency of the rear wheel steering system, and refers to a dynamic characteristic (fastness and vehicle handling stability at different speeds) of the response of the rear wheel steering system. In the rear wheel steering system, a higher frequency can make the vehicle more stable at high speed; a lower frequency can make the turning radius of the vehicle smaller when turning at low speed, thereby improving the maneuverability of the vehicle. In addition, the response speed of the rear wheel steering system is also related to the frequency. The "oscillation damping parameter" in the above step 202 can be reflected by a damping of the rear wheel steering system, and refers to an ability of the rear wheel steering system to resist vehicle vibration or oscillation. The damping can ensure that the rear wheel steering system can smoothly transition during steering, thereby avoiding instability caused by too violent movement. The greater the damping, the faster the oscillation damping of the rear wheel steering system.

[0052] It should also be understood that the "gain compensation" in step 202 above refers to adjusting the degree of response of the rear-wheel steering system to the front-wheel steering action in the rear-wheel steering system to achieve better vehicle stability and handling performance. Specifically, it is to adjust a magnification or reduction ratio of the rear-wheel steering angle with respect to the front-wheel steering angle, and this ratio factor (i.e., the first gain compensation coefficient or the second gain compensation coefficient in the following scheme) can be dynamically adjusted according to different driving conditions. The "phase compensation" in step 202 above refers to adjusting the timing (phase) of the start and end of the rear-wheel steering in the rear-wheel steering system to achieve the best match in time with the front-wheel steering action to optimize the dynamic performance of the vehicle, including but not limited to improving stability, reducing understeer or oversteer, and enhancing handling responsiveness. Phase compensation is used to focus on the time lag or advance of the rear-wheel steering action with respect to the front-wheel steering action. Specifically, it is to adjust the time relationship to ensure that the rear wheels start steering at the most suitable time to work better with the front wheels.

[0053] In one possible implementation, the vehicle controller in step 202 determines the compensation coefficient based on the response speed parameter and the oscillation decay parameter of the rear-wheel steering system in the vehicle, including: the vehicle controller determines a phase compensation coefficient based on the response speed parameter and the oscillation decay parameter, the phase compensation coefficient being used to indicate the phase compensation of the rear-wheel steering angle when the rear wheels are in steady-state steering; the vehicle controller determines a first gain compensation coefficient based on the actual gain coefficient of the front wheels, the gain adjustment coefficient, the response speed parameter and the oscillation decay parameter, the first gain compensation coefficient being used to indicate the gain compensation of the rear-wheel steering angle when the rear wheels are in steady-state steering; and the vehicle controller determines the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0054] It should be understood that in the above scheme, the "phase compensation coefficient" is a specific value of the phase compensation of the rear-wheel steering angle when the rear wheels are in steady-state steering, and the "first gain compensation coefficient" is a specific value of the gain compensation of the rear-wheel steering angle when the rear wheels are in steady-state steering.

[0055] It should also be understood that the "gain adjustment factor" in the above technical solution can be adjusted, and the gain adjustment factor is different for different vehicle types, different steering system types, and different driver preferences. For example, some drivers prefer a more direct steering response and may tend to have a higher gain, while some drivers may prefer stability and prefer a lower gain. The difference between the gain adjustment factor and the first gain compensation factor is that the gain adjustment factor focuses on the adjustment of the rear wheel steering system gain, and the gain adjustment factor can make the obtained gain compensation factor more accurate, while the gain compensation factor (the first gain compensation factor or the second gain compensation factor) focuses on improving the specific dynamic characteristics of the rear wheel steering system through compensation design. The "front wheel actual gain factor" refers to the amplification degree of the front wheel angle with respect to the steering input (such as the steering wheel angle or the steering system applied torque) in the steering control system. That is, if the front wheel actual gain factor is high, the same steering input will result in a larger change in the front wheel angle, indicating that the steering control system responds more sensitively; on the contrary, a lower front wheel actual gain factor results in a smaller change in the front wheel angle under a given steering input, and the response is relatively slow. The front wheel actual gain factor affects the steering feel, straight-line stability, and agility of the vehicle when turning.

[0056] In the above technical solution, the phase compensation is related to the response speed and oscillation decay of the rear wheel steering system. Therefore, the method can accurately determine the phase compensation factor of the rear wheel steering angle when the rear wheel is steered stably by using the response speed parameter and the oscillation decay parameter of the rear wheel steering system in the vehicle. This can ensure that the response speed and oscillation decay of the rear wheel steering system of the vehicle are in the best state. In addition, the front wheel actual gain factor and the gain adjustment factor directly affect the stability and responsiveness of the rear wheel steering system, and the gain compensation can enable the vehicle to steer with high stability. Therefore, the method can accurately determine the first gain compensation factor of the rear wheel steering angle when the rear wheel is steered stably by using the front wheel actual gain factor, the gain adjustment factor, the response speed parameter, and the oscillation decay parameter. This can ensure better performance and higher stability of the rear wheel steering system.

[0057] In a possible implementation manner, the vehicle controller determines the phase compensation factor based on the response speed parameter and the oscillation decay parameter, including: the vehicle controller acquires the actual response speed parameter and the actual oscillation decay parameter of the rear wheel steering system; and the vehicle controller determines the phase compensation factor based on the actual response speed parameter, the actual oscillation decay parameter, the expected response speed parameter, and the expected oscillation decay parameter of the rear wheel steering system.

[0058] In some embodiments, the vehicle controller determines the phase compensation coefficient based on the actual response speed parameter, the actual oscillation damping parameter, the expected response speed parameter of the rear wheel steering system, and the expected oscillation damping parameter, including: the vehicle controller determines the phase compensation coefficient based on the following formula (1);

[0059] (1)

[0060] wherein, is the actual response speed parameter, is the actual oscillation damping parameter, is the expected response speed parameter, is the expected oscillation damping parameter, is a complex variable in Laplace transform, is the phase compensation coefficient.

[0061] It should be understood that in the above formula (1), is the actual frequency of the rear wheel steering system, is the actual damping of the rear wheel steering system, is the expected frequency, is the expected damping. In addition, is a complex variable in Laplace transform, specifically, . is the real part, affects the stability and transient response of the rear wheel steering system, related to damping, is the imaginary part, reflects the response characteristics of the rear wheel steering system, related to frequency. For example, high frequency corresponds to rapid driving operation, while low frequency involves slower or continuous steering action. The rear wheel steering system responds differently, which is reflected in its amplitude-frequency characteristics and phase-frequency characteristics of the transfer model, which is crucial for optimizing the handling stability of the vehicle and the response speed of the rear wheel steering system.

[0062] It should also be understood that by adjusting and in the above formula (1), the rear wheel can start steering at the most appropriate time to achieve smaller steering delay, thereby improving the response speed of the rear wheel steering system. In addition, is the frequency determined based on the yaw rate of the front wheel steering angle when the rear wheel steering angle is zero, which can be the natural vibration frequency. When > 1, the rear wheel steering angle is opposite to the front wheel steering angle; when < 1, the rear wheel steering angle is the same as the front wheel steering angle. The phase compensation coefficient a transient response that can affect the target yaw rate.

[0063] In the technical solution, the phase lead or phase lag can be determined according to the actual response speed parameter, the actual oscillation decay parameter, the expected response speed parameter and the expected oscillation decay parameter. The phase lead can improve the phase margin of the rear wheel steering system and improve the response speed. The phase lag can increase the stability of the rear wheel steering system and reduce the oscillation. Therefore, the phase compensation coefficient can be accurately determined according to the above formula, and the response speed and the oscillation decay of the rear wheel steering system of the vehicle can be ensured to be in the best state based on the phase compensation coefficient.

[0064] In a possible implementation, the vehicle controller determines the first gain compensation coefficient based on the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation decay parameter, including: the vehicle controller constructs a first coefficient based on the expected response speed parameter and the expected oscillation decay parameter of the rear wheel steering system, the first coefficient being used to indicate the response sensitivity of the rear wheel steering system to the control instruction; and the vehicle controller determines the product of the first coefficient, the actual gain coefficient of the front wheel and the gain adjustment coefficient as the first gain compensation coefficient.

[0065] In some embodiments, the vehicle controller constructs a first coefficient based on the expected response speed parameter and the expected oscillation decay parameter of the rear wheel steering system, including: the vehicle controller determines the first coefficient based on formula (2) as follows; and the vehicle controller determines the first gain compensation coefficient based on formula (3) as follows.

[0066] (2)

[0067] (3)

[0068] wherein, is the first coefficient, is the actual gain coefficient of the front wheel, is the gain adjustment coefficient, is the first gain compensation coefficient.

[0069] It should be understood that, , , and are determined by the damping coefficient (damping) and the natural vibration frequency (frequency) of the rear wheel steering system. In addition, the , and the in formula (3) can be adjusted to ensure that the vehicle has better vehicle stability and handling performance when steering based on the rear wheel steering angle in the rear wheel steering system. The first gain compensation coefficient a steady-state gain for the target yaw rate.

[0070] In the technical solution, the actual response speed parameter, the actual oscillation damping parameter, the expected response speed parameter, the expected oscillation damping parameter, the actual gain coefficient of the front wheel, and the gain adjustment coefficient directly determine the response characteristics of the rear wheel steering system to the steering input, including response speed, stability, oscillation damping, etc., and can ensure that the vehicle maintains good steering performance in different working conditions. Therefore, the method can accurately determine the first gain compensation coefficient based on the above formula to ensure better performance and higher stability of the rear wheel steering system.

[0071] In a possible implementation, the vehicle control unit determines the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient, including: the vehicle control unit determines a second coefficient based on the product between the first gain compensation coefficient and the phase compensation coefficient; and the vehicle control unit determines the compensation coefficient based on the difference between a preset value and the second coefficient.

[0072] In some embodiments, the vehicle control unit determines the compensation coefficient based on the difference between a preset value and the second coefficient, including: the vehicle control unit determines the compensation coefficient based on the following formula (4):

[0073] (4)

[0074] wherein, the compensation coefficient is K, the product between the first gain compensation coefficient and the phase compensation coefficient is a second coefficient .

[0075] It should be understood that in the above scheme, the phase compensation coefficient is multiplied by the first gain compensation coefficient (referred to as the second coefficient) to comprehensively consider the phase and gain changes of the rear wheel steering system at different frequencies. This multiplication operation can reflect the combined effect of phase and gain on the performance of the rear wheel steering system in the compensation process. The "1" in the above formula (4) is used to maintain the data relationship brought by the transfer model of the original rear wheel steering system, and subtracting the "second coefficient" adds the compensation effect to ensure that the closed-loop performance of the entire rear wheel steering system is improved, including but not limited to increasing the phase margin, reducing the steady-state error, improving the response speed, etc.

[0076] In the above technical solution, in the rear wheel steering system of the vehicle, the gain compensation and the phase compensation can improve the stability and dynamic response of the rear wheel steering system. The gain compensation generally adjusts the gain parameter to change the amplification multiple of the rear wheel steering system, and the phase compensation adjusts the phase margin of the rear wheel steering system by introducing a lag or lead network to improve the stability and response speed of the rear wheel steering system. The above method obtains a second coefficient by multiplying the first gain compensation coefficient and the phase compensation coefficient, and determines the difference between 1 and the second coefficient as the compensation coefficient for gain compensation and phase compensation of the rear wheel steering angle when the rear wheel is steered. The above process uses 1 minus the second coefficient to ensure that the response of the rear wheel steering system is not excessively amplified during compensation, thereby avoiding the rear wheel steering system entering an unstable state. Through the combination of multiplication and subtraction, the response of the rear wheel steering system can be finely adjusted to achieve a fast and stable control effect on the steering of the vehicle.

[0077] The modification process of the "first gain compensation coefficient" is discussed as follows.

[0078] In a possible implementation manner, the vehicle controller determines the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient, including: the vehicle controller determines a theoretical steering torque of a wheel in the vehicle; the vehicle controller modifies the first gain compensation coefficient based on the front wheel actual gain coefficient, the rear wheel actual gain coefficient, the response speed parameter, the oscillation damping parameter and the theoretical steering torque to obtain a second gain compensation coefficient; and the vehicle controller determines the compensation coefficient based on the second gain compensation coefficient and the phase compensation coefficient.

[0079] It should be understood that the "theoretical steering torque of a wheel" in the above solution refers to a torque that makes the vehicle steer when the wheel in the vehicle is deflected. The theoretical steering torque is generated by the friction between the wheel and the ground and the wheel deflection angle.

[0080] It should also be understood that the "rear wheel actual gain coefficient" in the above scheme refers to the degree of amplification or reduction of the rear wheel steering angle relative to the front wheel steering angle in the steering control system, and the rear wheel actual gain coefficient describes the response characteristics of the rear wheel steering system to the front wheel steering input (front wheel steering angle). That is, if the rear wheel actual gain coefficient is high, it means that a small change in the front wheel steering angle can cause a large adjustment in the rear wheel steering angle, which can increase the flexibility of the vehicle at low speed, making the vehicle more agile in narrow spaces, such as turning and U-turn in a parking lot. In addition, in dynamic driving scenarios such as emergency obstacle avoidance or high-speed lane changing, a high rear wheel actual gain coefficient can make the vehicle respond more quickly to the driver's operation, improving the handling stability of the vehicle. However, if the rear wheel actual gain coefficient is low, it means that the rear wheel responds slowly to the small change in the front wheel steering angle, and the steering angle adjustment is relatively gentle. This helps to maintain the straight stability of the vehicle at high speed, reduces unnecessary direction correction caused by slight changes in the road surface, and improves the smoothness of driving. In addition, a low rear wheel actual gain coefficient can avoid overreaction of the rear wheel steering system of the vehicle to road bumps or slight operations of the driver, improving ride comfort.

[0081] It should also be understood that the process of "determining the compensation coefficient based on the second gain compensation coefficient and the phase compensation coefficient" in the above scheme is similar to the process of "determining the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient", which will not be repeated here.

[0082] In the above technical scheme, the contributions of the front wheel and the rear wheel to the steering response are different when the vehicle is in different driving states. By considering the front wheel actual gain coefficient and the rear wheel actual gain coefficient, the steering characteristics of the vehicle under certain conditions can be more accurately reflected, and the stability of the rear wheel steering system can be affected. In addition, due to factors such as road conditions and load changes, the actual steering torque of the wheel may be different from the theoretical steering torque. The gain compensation coefficient is corrected to better match the actual steering torque and ensure accurate control of the rear wheel steering system. Therefore, the above scheme corrects the first gain compensation coefficient through the front wheel actual gain coefficient, the rear wheel actual gain coefficient, the response speed parameter, the oscillation decay parameter, and the theoretical steering torque, and then accurately determines the compensation coefficient through the corrected gain compensation coefficient (second gain compensation coefficient) and the phase compensation coefficient. This can improve the response speed and dynamic stability of the rear wheel steering system of the vehicle during rear wheel steering through the compensation coefficient.

[0083] In some embodiments, the vehicle controller determines the theoretical steering torque of the wheels in the vehicle, including: the vehicle controller determines the theoretical steering torque of the front wheels based on the following formula (5); and the vehicle controller determines the theoretical steering torque of the rear wheels based on the following formula (6);

[0084] (5)

[0085] (6)

[0086] wherein, is the mass of the vehicle, is the distance from the center of mass of the vehicle to the front axle, is the driving speed of the vehicle, is the distance between the front and rear axles, is the lateral stiffness of the rear wheels, is the theoretical steering torque of the front wheels, is the distance from the center of mass of the vehicle to the rear axle, is the lateral stiffness of the front wheels, is the theoretical steering torque of the rear wheels.

[0087] In a possible implementation, the vehicle controller corrects the first gain compensation coefficient based on the actual gain coefficient of the front wheels, the actual gain coefficient of the rear wheels, the response speed parameter, the oscillation damping parameter and the theoretical steering torque, to obtain a second gain compensation coefficient, including: the vehicle controller determines a first transfer model of a front wheel steering system in the vehicle based on the actual gain coefficient of the front wheels, the theoretical steering torque of the front wheels, the response speed parameter and the oscillation damping parameter, the first transfer model being used to describe the relationship between the front wheel steering torque and the change in the front wheel steering angle; the vehicle controller determines a second transfer model of a rear wheel steering system in the vehicle based on the actual gain coefficient of the rear wheels, the theoretical steering torque of the rear wheels, the response speed parameter and the oscillation damping parameter, the second transfer model being used to describe the relationship between the rear wheel steering torque and the change in the rear wheel steering angle; and the vehicle controller corrects the first gain compensation coefficient based on the first transfer model and the second transfer model, to obtain the second gain compensation coefficient.

[0088] In some embodiments, the vehicle controller determines the first transfer model of the front wheel steering system in the vehicle based on the actual gain coefficient of the front wheels, the theoretical steering torque of the front wheels, the response speed parameter and the oscillation damping parameter, including: the vehicle controller determines the first transfer model of the front wheel steering system in the vehicle based on the following formula (7);

[0089] (7)

[0090] and the vehicle controller determines the second transfer model of the rear wheel steering system in the vehicle based on the actual gain coefficient of the rear wheels, the theoretical steering torque of the rear wheels, the response speed parameter and the oscillation damping parameter, including:

[0091] the vehicle controller determines the second transfer model of the rear wheel steering system in the vehicle based on the following formula (8);

[0092] (8)

[0093] And the vehicle controller corrects the first gain compensation coefficient based on the first transfer model and the second transfer model to obtain the second gain compensation coefficient, including: the vehicle controller corrects the first gain compensation coefficient based on the following formula (9) to obtain the second gain compensation coefficient;

[0094] (9)

[0095] Wherein, is the theoretical steering torque of the front wheel, is the first transfer model, is the actual gain coefficient of the rear wheel, is the theoretical steering torque of the rear wheel, is the second transfer model, is the second gain compensation coefficient.

[0096] It should be understood that in the above scheme, the actual gain coefficient of the rear wheel can reflect the actual contribution of the rear wheel steering to the overall steering effect of the vehicle. It can help the rear wheel steering system to more accurately understand the steering efficiency of the rear wheel at different speeds and road conditions, so as to adjust the first gain compensation coefficient and ensure that the vehicle can obtain ideal steering response in various situations. Secondly, the response speed parameter can quantify the response speed of the rear wheel steering system to the steering command. Fast response means that the rear wheel steering system can quickly adjust the rear wheel angle, and slow response is the opposite. The consideration of the response speed parameter helps to correct the gain compensation, ensures that the execution of the steering command matches the vehicle dynamics, and avoids excessive or insufficient steering. Furthermore, during the rear wheel steering process, oscillation may occur in the wheels and the vehicle. The oscillation damping parameter is used to evaluate and control the oscillation amplitude and damping speed that may occur during the rear wheel steering process, to ensure smooth steering of the vehicle, reduce unnecessary swinging, and improve the stability and safety of driving. In addition, the theoretical steering torque of the wheel is the estimated steering torque during vehicle design, which is used to overcome the steering resistance and realize steering. By comparing the actual steering torque with the theoretical steering torque, the efficiency of the rear wheel steering system can be evaluated, and the first gain compensation coefficient can be further adjusted to ensure that the steering torque in the actual use scene is consistent with the design expectation, and the steering precision is improved. Therefore, by comprehensively considering the above multiple parameters, the rear wheel steering system can dynamically adjust the first gain compensation coefficient to obtain a more accurate, rapid and stable second gain compensation coefficient, thereby optimizing the steering performance of the vehicle and ensuring driving safety and comfort.

[0097] In the aforementioned technical solution, the first gain compensation coefficient is set based on a preset vehicle model (desired response speed parameters, desired oscillation attenuation parameters, gain adjustment coefficient, and actual front wheel gain coefficient). However, in actual driving, the uncertainties of road conditions and vehicle status require the rear-wheel steering system to have adaptive capabilities. Therefore, by observing the actual effects of changes in front-wheel steering torque and angle, as well as changes in rear-wheel steering torque and angle, the gain compensation coefficient can be dynamically adjusted to obtain the second gain compensation coefficient. This allows for more accurate control of rear-wheel steering, improving the vehicle's dynamic response and stability.

[0098] Step 203: The vehicle controller determines the rear wheel angle based on the product of the front wheel angle and the compensation coefficient, and controls the rear wheels of the vehicle to rotate at the rear wheel angle.

[0099] It should be understood that "controlling the rear wheels of the vehicle to rotate at the rear wheel angle" in step 203 above specifically means achieving the rotation of the rear wheels at the rear wheel angle through the electric power steering system or hydraulic power steering system in the vehicle.

[0100] Figure 3 This is a schematic diagram illustrating the determination of a first gain compensation coefficient and a phase compensation coefficient, provided in an embodiment of this application.

[0101] For example, such as Figure 3 As shown, to improve the applicability of phase compensation for gain compensation in method 200, the constant in formula (2) can be changed based on the vehicle's speed. Depending on the vehicle speed range, as follows: Figure 3 The settings are shown below. In the low-speed region where you want to reduce the turning radius, Figure 3 The one shown in (a) is and ,as well as Figure 3 As shown in (b) and Setting the same value results in a smaller phase compensation effect. Furthermore, when aiming to improve yaw rate response in the mid-speed range, it is set to... >1, so the rear wheel steering angle is opposite to the front wheel steering angle. This is set to improve stability at high speeds. <1, so the rear wheel steering angle is in the same direction as the front wheel steering angle.

[0102] Figure 4 This is a schematic block diagram illustrating the determination of a compensation coefficient provided in an embodiment of this application.

[0103] For example, such as Figure 4 As shown, the gain compensation in method 200 is related to vehicle speed because a theoretical steering torque based on vehicle speed is used in the process of correcting the first gain compensation coefficient to obtain the second gain compensation coefficient. FromFigure 4 From this, we can deduce that: multiplying the gain compensation coefficient by the phase compensation coefficient yields the second coefficient; multiplying this second coefficient by -1 yields the third coefficient; multiplying this second coefficient by the front wheel steering angle yields the first steering angle; adding this first steering angle to the front wheel steering angle yields the rear wheel steering angle, i.e., the rear wheel steering angle equals... * ,in, This is either the first gain compensation coefficient or the second gain compensation coefficient. Furthermore, when the vehicle steers at this rear wheel angle, the yaw rate of the vehicle can be controlled.

[0104] Figure 5 This is a schematic block diagram illustrating the determination of yaw rate response provided in an embodiment of this application.

[0105] For example, such as Figure 5 As shown in (a), given the front wheel steering angle, the desired yaw rate response is as follows: Figure 5 The gray solid line shown in Figure (a) represents the actual yaw rate response obtained through related technologies, as shown in Figure (a). Figure 5 The black dashed line shown in (a) is illustrated. By observing... Figure 5 The trend between the gray solid line and the black dashed line shown in (a) indicates that there is a significant difference between the actual yaw rate response obtained by the relevant technology and the expected yaw rate response.

[0106] like Figure 5 As shown in (b), given the front wheel steering angle, the desired yaw rate response is as follows: Figure 5 The gray solid line shown in (b) represents the actual yaw rate response obtained through method 200. Figure 5 The black dashed line shown in (b) is illustrated. By observing... Figure 5 As shown in (b), the trend between the gray solid line and the black dashed line indicates that the actual yaw rate response obtained by method 200 of this application is similar to the expected yaw rate response. Therefore, compared with related technologies, method 200 of this application can reduce the deviation between the expected response and the actual response.

[0107] It should be understood that step 202 in method 200 of this application is to perform gain compensation and phase compensation on the rear wheel steering angle when the rear wheels are turning. Of course, it is also possible to only perform gain compensation on the rear wheel steering angle when the rear wheels are turning, multiply the first gain compensation coefficient (or the second gain compensation coefficient) of the gain compensation by the front wheel steering angle to obtain the rear wheel steering angle, and then use the rear wheel steering angle to turn.

[0108] Figure 6 This is a schematic diagram of the structure of a rear wheel steering control device provided in an embodiment of this application.

[0109] For example, such asFigure 6 As shown in FIG. 6, the apparatus 600 includes:

[0110] The acquisition module 601 is configured to acquire a front wheel steering angle in response to a control instruction of rear wheel steering during vehicle driving.

[0111] The determination module 602 is configured to determine a compensation coefficient based on a response speed parameter and an oscillation attenuation parameter of a rear wheel steering system in the vehicle, the compensation coefficient being used to indicate gain compensation and phase compensation of the rear wheel steering angle during rear wheel steering.

[0112] The control module 603 is configured to determine a rear wheel steering angle based on a product of the front wheel steering angle and the compensation coefficient, and control the rear wheel of the vehicle to rotate at the rear wheel steering angle.

[0113] Optionally, the determination module 602 is specifically configured to determine a phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter, the phase compensation coefficient being used to indicate phase compensation of the rear wheel steering angle during steady-state steering of the rear wheel; determine a first gain compensation coefficient based on the actual gain coefficient of the front wheel, a gain adjustment coefficient, the response speed parameter and the oscillation attenuation parameter, the first gain compensation coefficient being used to indicate gain compensation of the rear wheel steering angle during steady-state steering of the rear wheel; and determine the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0114] Optionally, the acquisition module is specifically configured to acquire an actual response speed parameter and an actual oscillation attenuation parameter of the rear wheel steering system; and the determination module is specifically further configured to determine the phase compensation coefficient based on the actual response speed parameter, the actual oscillation attenuation parameter, an expected response speed parameter and an expected oscillation attenuation parameter of the rear wheel steering system.

[0115] Optionally, the determination module is specifically further configured to construct a first coefficient based on the expected response speed parameter and the expected oscillation attenuation parameter of the rear wheel steering system, the first coefficient being used to indicate response sensitivity of the rear wheel steering system to the control instruction; and determine a product of the first coefficient, the actual gain coefficient of the front wheel and the gain adjustment coefficient as the first gain compensation coefficient.

[0116] Optionally, the determination module 602 is specifically further configured to determine a theoretical steering torque of the wheel in the vehicle; correct the first gain compensation coefficient based on the actual gain coefficient of the front wheel, an actual gain coefficient of the rear wheel, the response speed parameter, the oscillation attenuation parameter and the theoretical steering torque to obtain a second gain compensation coefficient; and determine the compensation coefficient based on the second gain compensation coefficient and the phase compensation coefficient.

[0117] Optionally, the determining module 602 is further configured to: determine a first transfer model of a front wheel steering system in the vehicle based on the actual gain coefficient of the front wheel, the theoretical steering torque of the front wheel, the response speed parameter and the oscillation damping parameter, the first transfer model being used to describe a relationship between the front wheel steering torque and a change in the front wheel steering angle; determine a second transfer model of a rear wheel steering system in the vehicle based on the actual gain coefficient of the rear wheel, the theoretical steering torque of the rear wheel, the response speed parameter and the oscillation damping parameter, the second transfer model being used to describe a relationship between the rear wheel steering torque and a change in the rear wheel steering angle; and correct the first gain compensation coefficient based on the first transfer model and the second transfer model to obtain the second gain compensation coefficient.

[0118] Optionally, the determining module 602 is further configured to: determine a second coefficient based on a product of the first gain compensation coefficient and the phase compensation coefficient; and determine the compensation coefficient based on a difference between a preset value and the second coefficient.

[0119] Figure 7 is a structural schematic diagram of a vehicle provided by an embodiment of the present application.

[0120] As shown in Figure 7 The vehicle 700 includes a memory 701 and a processor 702, where the memory 701 stores executable program code 703, and the processor 702 is configured to invoke and execute the executable program code 703 to perform a rear wheel steering control method.

[0121] In addition, an apparatus provided by an embodiment of the present application can include a memory and a processor, where the memory stores executable program code, and the processor is configured to invoke and execute the executable program code to perform a rear wheel steering control method provided by an embodiment of the present application.

[0122] The embodiment can divide the apparatus into functional modules according to the above method examples, for example, corresponding to each functional module, or two or more functions can be integrated into one processing module, and the integrated module can be implemented in the form of hardware. It should be noted that the division of modules in the embodiment is illustrative, and is only a logical function division, and another division mode can be used in actual implementation.

[0123] In the case of dividing each functional module corresponding to each function, the apparatus can further include an obtaining module, a determining module and a control module, etc. It should be noted that all related contents involved in the above method embodiments can be referred to the function description of the corresponding functional module, and will not be repeated here.

[0124] It should be understood that the device provided by the embodiment is used to execute the rear wheel steering control method described above, and thus the same effects as the implementation method described above can be achieved.

[0125] In the case of using the integrated unit, the device can include a processing module and a storage module. When the device is applied to a vehicle, the processing module can be used to control and manage the actions of the vehicle. The storage module can be used to support the vehicle to execute relevant executable program codes and the like.

[0126] The processing module can be a processor or a controller, which can implement or execute various exemplary logical blocks, modules and circuits shown in combination with the disclosure of the present application. The processor can also be a combination of computing functions, such as including one or more microprocessor combinations, combinations of digital signal processing (digital signal processing, DSP) and microprocessors, and the like. The storage module can be a memory.

[0127] In addition, the device provided by the embodiment of the present application can be a chip, an assembly or a module. The chip can include a connected processor and a memory. The memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute the rear wheel steering control method provided by the above embodiment.

[0128] The embodiment also provides a computer readable storage medium, which stores executable program codes. When the executable program codes run on the computer, the computer executes the related method steps to implement the rear wheel steering control method provided by the above embodiment.

[0129] The embodiment also provides a computer program product, which makes the computer execute the related steps to implement the rear wheel steering control method provided by the above embodiment when the computer program product runs on the computer.

[0130] The device, computer readable storage medium, computer program product or chip provided by the embodiment are used to execute the corresponding method provided above, and thus the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding method provided above, which will not be described here.

[0131] Through the description of the above embodiments, those skilled in the art can understand that, for the convenience and brevity of description, only the division of the above functional modules is taken as an example for illustration. In actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0132] In the embodiments of the present disclosure, it should be understood that the disclosed apparatus and method can be implemented in other ways. For example, the apparatus embodiments described above are merely schematic, and the division of the modules or units is merely a logical function division. In actual implementation, another division manner can be adopted, for example, a plurality of units or components can be combined or integrated into another apparatus, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, apparatuses or units, and can be electrical, mechanical or in other forms.

[0133] The above merely describes specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present disclosure, which should be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A rear-wheel steering control method, characterized in that, The method includes: During vehicle operation, the front wheel steering angle is obtained in response to the control command for rear wheel steering. Based on the response speed parameters and oscillation attenuation parameters of the rear wheel steering system in the vehicle, a compensation coefficient is determined. The compensation coefficient is used to indicate the gain compensation and phase compensation of the rear wheel steering angle when the rear wheels are steering. Based on the product between the front wheel steering angle and the compensation coefficient, the rear wheel steering angle is determined, and the rear wheels of the vehicle are controlled to rotate at the rear wheel steering angle. The determination of the compensation coefficient based on the response speed parameters and oscillation decay parameters of the rear-wheel steering system in the vehicle includes: Based on the response speed parameter and the oscillation attenuation parameter, a phase compensation coefficient is determined, which is used to indicate the phase compensation of the rear wheel angle when the rear wheel is steered in a steady state; based on the front wheel actual gain coefficient, gain adjustment coefficient, the response speed parameter, and the oscillation attenuation parameter, a first gain compensation coefficient is determined, which is used to indicate the gain compensation of the rear wheel angle when the rear wheel is steered in a steady state; based on the first gain compensation coefficient and the phase compensation coefficient, the compensation coefficient is determined. The determination of the first gain compensation coefficient based on the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter, and the oscillation attenuation parameter includes: Based on the expected response speed parameters and expected oscillation attenuation parameters of the rear wheel steering system, a first coefficient is constructed, which is used to indicate the response sensitivity of the rear wheel steering system to the control command; the product of the first coefficient, the actual gain coefficient of the front wheel, and the gain adjustment coefficient is determined as the first gain compensation coefficient.

2. The method according to claim 1, characterized in that, The determination of the phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter includes: Obtain the actual response speed parameters and actual oscillation decay parameters of the rear wheel steering system; The phase compensation coefficient is determined based on the actual response speed parameters, the actual oscillation decay parameters, the expected response speed parameters of the rear wheel steering system, and the expected oscillation decay parameters.

3. The method according to claim 1, characterized in that, Determining the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient includes: Determine the theoretical steering torque of the wheels in the vehicle; Based on the actual gain coefficient of the front wheel, the actual gain coefficient of the rear wheel, the response speed parameter, the oscillation attenuation parameter, and the theoretical steering torque, the first gain compensation coefficient is corrected to obtain the second gain compensation coefficient; The compensation coefficient is determined based on the second gain compensation coefficient and the phase compensation coefficient.

4. The method according to claim 3, characterized in that, The process of correcting the first gain compensation coefficient based on the actual gain coefficient of the front wheel, the actual gain coefficient of the rear wheel, the response speed parameter, the oscillation attenuation parameter, and the theoretical steering torque to obtain the second gain compensation coefficient includes: Based on the actual gain coefficient of the front wheel, the theoretical steering torque of the front wheel, the response speed parameter, and the oscillation decay parameter, a first transmission model of the front wheel steering system in the vehicle is determined. The first transmission model is used to describe the relationship between the front wheel steering torque and the change in the front wheel angle. Based on the actual gain coefficient of the rear wheel, the theoretical steering torque of the rear wheel, the response speed parameter, and the oscillation decay parameter, a second transmission model of the rear wheel steering system in the vehicle is determined. The second transmission model is used to describe the relationship between the rear wheel steering torque and the change in the rear wheel angle. Based on the first transfer model and the second transfer model, the first gain compensation coefficient is modified to obtain the second gain compensation coefficient.

5. A rear-wheel steering control device, characterized in that, The device includes: The acquisition module is used to acquire the front wheel steering angle in response to the rear wheel steering control command during vehicle operation; The determination module is used to determine the compensation coefficient based on the response speed parameters and oscillation attenuation parameters of the rear wheel steering system in the vehicle. The compensation coefficient is used to indicate the gain compensation and phase compensation for the rear wheel steering angle when the rear wheels are steering. The control module is used to determine the rear wheel angle based on the product between the front wheel angle and the compensation coefficient, and to control the rear wheels of the vehicle to rotate at the rear wheel angle. The determining module is specifically used for: Based on the response speed parameter and the oscillation attenuation parameter, a phase compensation coefficient is determined, which is used to indicate the phase compensation of the rear wheel angle when the rear wheel is steered in a steady state; based on the front wheel actual gain coefficient, gain adjustment coefficient, the response speed parameter, and the oscillation attenuation parameter, a first gain compensation coefficient is determined, which is used to indicate the gain compensation of the rear wheel angle when the rear wheel is steered in a steady state; based on the first gain compensation coefficient and the phase compensation coefficient, the compensation coefficient is determined. The determination of the first gain compensation coefficient based on the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter, and the oscillation attenuation parameter includes: Based on the expected response speed parameters and expected oscillation attenuation parameters of the rear wheel steering system, a first coefficient is constructed, which is used to indicate the response sensitivity of the rear wheel steering system to the control command; the product of the first coefficient, the actual gain coefficient of the front wheel, and the gain adjustment coefficient is determined as the first gain compensation coefficient.

6. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores executable program code that, when executed, implements the method as described in any one of claims 1 to 4.

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