Rear wheel steering control method and device, vehicle and storage medium

Abstract

The invention provides a rear wheel steering control method and device, a vehicle and a storage medium. In the running process of the vehicle, the vehicle responds to a rear wheel steering control instruction, and compensation coefficients for gain compensation and phase compensation of a rear wheel steering angle during rear wheel steering are determined through response speed parameters and oscillation attenuation parameters of a rear wheel steering system. Furthermore, the rear wheels are controlled to rotate through the product of the compensation coefficient and the front wheel rotation angle (the rear wheel rotation angle), so that rear wheel steering is achieved. Due to the fact that the rear wheel rotation angle is the rotation angle obtained after gain compensation and phase compensation, in the process that the rear wheel rotation angle controls the vehicle to steer, the vehicle can steer with high stability through the rear wheel rotation angle obtained after gain compensation, and the vehicle can rapidly respond to a steering instruction through the rear wheel rotation angle through phase compensation. A smaller steering delay is achieved, thereby improving the response speed of a rear wheel steering system of a vehicle.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a control method, device, vehicle and storage medium for rear wheel steering in the field of vehicles. Background Art

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

[0003] The control strategy of the rear-wheel steering system is to change the vehicle's yaw rate by controlling the rear wheel steering angle. Usually, the relevant 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 changeable, 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.

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

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

[0006] In a first aspect, a method for controlling rear-wheel steering is provided, the method comprising: obtaining a front wheel steering angle in response to a rear-wheel steering control instruction during vehicle driving; determining 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 for the rear wheel steering angle during rear-wheel steering; determining a rear wheel steering angle based on the product of the front wheel steering angle and the compensation coefficient, and controlling the rear wheels of the vehicle to rotate at the rear wheel steering angle.

[0007] In the above technical solution, during the driving process of the vehicle, the vehicle can respond to the control command of the rear wheel steering, and determine the compensation coefficient for gain compensation and phase compensation of the rear wheel angle during the rear wheel steering through the response speed parameter and oscillation attenuation parameter of the rear wheel steering system in the vehicle. Further, the rear wheel is controlled to rotate by the product between the compensation coefficient and the front wheel angle (rear wheel angle) to achieve rear wheel steering. Since the rear wheel angle is the angle after gain compensation and phase compensation, therefore, in the process of controlling the steering of the vehicle with the rear wheel angle, the vehicle can turn with higher stability through the rear wheel angle after gain compensation, and through phase compensation, the vehicle can respond to the steering command through the rear wheel angle more quickly, achieving smaller steering delay, thereby improving the response speed of the rear wheel steering system of the vehicle. Especially in the case of emergency obstacle avoidance, the rear wheel steering in advance 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 implementations, a compensation coefficient is determined based on a response speed parameter and an oscillation attenuation 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 attenuation parameter, the phase compensation coefficient being used to indicate phase compensation of the rear wheel steering angle when the rear wheels are subjected to steady-state steering; determining a first gain compensation coefficient based on an actual gain coefficient of the front wheels, 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 when the rear wheels are subjected to steady-state steering; and determining the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0009] In the above technical solution, phase compensation is related to the response speed and oscillation attenuation 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 turned in a steady state through the response speed parameter and oscillation attenuation parameter of the rear wheel steering system in the vehicle. This can ensure that the response speed and oscillation attenuation of the rear wheel steering system of the vehicle reach the optimal state. In addition, the actual gain coefficient and gain adjustment coefficient of the front wheel directly affect the stability and responsiveness of the rear wheel steering system, and gain compensation can enable the vehicle to turn with higher stability. Therefore, the method can accurately determine the first gain compensation coefficient of the rear wheel steering angle when the rear wheel is turned in a steady state through the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation attenuation parameter. This can ensure better performance and higher stability of the rear wheel steering system.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the phase compensation coefficient is determined based on the response speed parameter and the oscillation attenuation parameter, including: obtaining the actual response speed parameter and the actual oscillation attenuation parameter of the rear-wheel steering system; based on the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system, determining the phase compensation coefficient.

[0011] In the above technical solution, the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter, and the expected oscillation attenuation parameter can determine whether phase advance or phase lag is required. Phase advance can increase the phase margin of the rear-wheel steering system and improve the response speed; 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 through the above formula to ensure that the response speed and oscillation attenuation of the vehicle's rear-wheel steering system reach the optimal state based on the phase compensation coefficient.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, a first gain compensation coefficient is determined based on the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation attenuation parameter, including: constructing 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 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 above technical solution, the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter, the expected oscillation attenuation 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, stability, oscillation attenuation, etc., which can ensure that the vehicle maintains good steering performance under different working conditions. Therefore, the method can accurately determine the first gain compensation coefficient through the above formula to ensure better performance and higher stability of the rear-wheel steering system based on the first gain compensation coefficient.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the compensation coefficient is determined based on the first gain compensation coefficient and the phase compensation coefficient, including: determining 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 a second gain compensation coefficient; based on the second gain compensation coefficient and the phase compensation coefficient, the compensation coefficient is determined.

[0015] In the above technical solution, when the vehicle is in different driving states, the front wheel and the rear wheel contribute differently to the steering response. By considering the actual gain coefficient of the front wheel and the actual gain coefficient of the rear wheel, the steering characteristics of the vehicle under specific conditions can be more accurately reflected, affecting the stability of the rear-wheel steering system. In addition, due to factors such as road conditions and load changes, the actual steering torque of the wheel may differ from the theoretical steering torque. Correcting the gain compensation coefficient can better match the actual steering torque and ensure the precise control of the rear-wheel steering system. Therefore, the above solution corrects the first gain compensation coefficient by 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, and then accurately determines the compensation coefficient by the corrected gain compensation coefficient (the 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 the rear-wheel steering process through the compensation coefficient.

[0016] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, 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, including: 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 attenuation parameter, determining a first transfer model of the front wheel steering system in the vehicle, the first transfer model being used to describe the relationship between the front wheel steering torque and the front wheel steering angle change; 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 attenuation parameter, determining a second transfer model of the rear wheel steering system in the vehicle, the second transfer model being used to describe the relationship between the rear wheel steering torque and the rear wheel steering angle change; based on the first transfer model and the second transfer model, correcting the first gain compensation coefficient to obtain the second gain compensation coefficient.

[0017] In the above technical solution, the first gain compensation coefficient is set based on a preset vehicle model (expected response speed parameter, expected oscillation attenuation parameter, gain adjustment coefficient and actual gain coefficient of the front wheel). However, in actual driving, the uncertainty of road conditions and vehicle status requires the rear-wheel steering system to have adaptive capabilities. Therefore, through the actual effects of the front wheel steering torque and angle changes, as well as the rear wheel steering torque and angle changes, the gain compensation coefficient can be dynamically adjusted, that is, the second gain compensation coefficient is obtained, which can more accurately control the rear wheel steering and improve the dynamic response and stability of the vehicle.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the compensation coefficient is determined based on the first gain compensation coefficient and the phase compensation coefficient, including: determining the second coefficient based on the product between the first gain compensation coefficient and the phase compensation coefficient; and determining the compensation coefficient by the difference between the preset value and the second coefficient.

[0019] In the above technical solution, in the rear-wheel steering system of the vehicle, gain compensation and phase compensation can improve the stability and dynamic response of the rear-wheel steering system. Gain compensation usually adjusts the gain parameter to change the amplification factor of the rear-wheel steering system, while 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 with the phase compensation coefficient, and then determines the difference between the preset value (1) and the second coefficient as the compensation coefficient for gain compensation and phase compensation of the rear wheel steering angle during rear-wheel steering. The above process uses 1 minus the second coefficient to ensure that the response of the rear-wheel steering system will not be over-amplified during the compensation process, thereby preventing the rear-wheel steering system from entering an unstable state. Through this combination of multiplication and subtraction, the response of the rear-wheel steering system can be finely adjusted to achieve a control effect that is both fast and stable for vehicle steering.

[0020] In a second aspect, a rear-wheel steering control device is provided, which includes: an acquisition module for acquiring a front wheel steering angle in response to a rear-wheel steering control instruction during vehicle driving; a determination module for determining a compensation coefficient based on a response speed parameter and an oscillation attenuation parameter of a rear-wheel steering system in the vehicle, wherein the compensation coefficient is used to indicate gain compensation and phase compensation for the rear wheel steering angle during rear-wheel steering; and a control module for determining the rear wheel steering angle based on the product of the front wheel steering angle and the compensation coefficient, and controlling the rear wheels of the vehicle to rotate at the rear wheel steering angle.

[0021] In combination with the second aspect, in some possible implementations, the determination module is specifically used to: determine a phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter, wherein the phase compensation coefficient is used to indicate the phase compensation of the rear wheel steering angle when the rear wheel is subjected to steady-state steering; determine 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 attenuation parameter, wherein the first gain compensation coefficient is used to indicate the gain compensation of the rear wheel steering angle when the rear wheel is subjected to steady-state steering; determine the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0022] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the acquisition module is specifically used to obtain the actual response speed parameter and the actual oscillation attenuation parameter of the rear-wheel steering system; the determination module is also specifically used to determine the phase compensation coefficient based on the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system.

[0023] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination module is specifically used to: construct a first coefficient based on the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system, and the first coefficient is used to indicate the response sensitivity of the rear-wheel steering system to the control instruction; and determine 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.

[0024] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination module is specifically used to: 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, correct the first gain compensation coefficient to obtain a second gain compensation coefficient; based on the second gain compensation coefficient and the phase compensation coefficient, determine the compensation coefficient.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination module is further specifically used 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, the theoretical steering torque of the front wheel, the response speed parameter and the oscillation attenuation parameter, and the first transfer model is used to describe the relationship between the front wheel steering torque and the front wheel steering angle change; determine a second transfer model of the 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 attenuation parameter, and the second transfer model is used to describe the relationship between the rear wheel steering torque and the rear wheel steering angle change; based on the first transfer model and the second transfer model, correct the first gain compensation coefficient to obtain the second gain compensation coefficient.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination module is specifically used to: determine the second coefficient based on the product between the first gain compensation coefficient and the phase compensation coefficient; determine the compensation coefficient by the difference between the preset value and the second coefficient.

[0027] In a third aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method in the first aspect or any possible implementation of the first aspect.

[0028] In a fourth aspect, a computer-readable storage medium is provided, which stores an executable program code. When the executable program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0036] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0037] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

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

[0039] For example, Figure 1 In the vehicle A shown in the figure, when the vehicle A is in a reversing scene, the vehicle A detects the presence of an obstacle B in front of the vehicle through the vehicle-mounted camera. At this time, the vehicle A can control the rear wheels C through the rear-wheel steering system to achieve vehicle steering, making it easier to avoid the obstacle B.

[0040] Among them, the control strategy of the rear-wheel steering system refers to changing the vehicle's yaw rate by controlling the rear wheel steering angle. Generally, the relevant 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 changeable, and the existing model cannot simulate all actual steering processes. Therefore, there is an error in the rear wheel steering angle determined based on the existing model, and there may be a situation where vehicle A collides with obstacle B.

[0041] In order to solve the above problems, the present application proposes a control method for rear wheel steering to improve the control accuracy of rear wheel steering and improve the maneuverability and stability of the vehicle. For details, please refer to the following Figure 2 .

[0042] Figure 2 It is a schematic flow chart of a rear-wheel steering control method provided in an embodiment of the present application.

[0043] It should be understood that the rear wheel steering control method provided in the embodiment of the present application can be applied to the following examples: Figure 1 The vehicle shown (e.g., vehicle A). Specifically, the control method for rear-wheel steering 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 control method for rear-wheel steering of the present application, the vehicle component includes a rear wheel.

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

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

[0046] It should be understood that the "rear wheel steering control instruction" in the above step 201 refers to an instruction to achieve vehicle steering through the rear wheels. In addition, the "front wheel turning angle" in the above step 201 specifically includes the direction and angle value when the front wheels turn.

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

[0048] It should be understood that the "steering wheel rotation angle" in the above solution specifically includes the rotation direction and the angle value.

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

[0050] Step 202: The vehicle controller determines 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 is used to indicate gain compensation and phase compensation for the rear wheel steering angle during rear wheel steering.

[0051] It should be understood that the "response speed parameter" in the above step 202 can be reflected by the frequency of the rear-wheel steering system, which refers to the dynamic characteristics of the response of the rear-wheel steering system (rapidity and the handling stability of the vehicle at different speeds). In the rear-wheel steering system, a higher frequency can make the vehicle more stable when driving at high speeds; a lower frequency can reduce the turning radius of the vehicle when turning at low speeds, 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 attenuation parameter" in the above step 202 can be reflected by the damping of the rear-wheel steering system, which refers to the ability of the rear-wheel steering system to resist vehicle vibration or swing. Damping can ensure that the rear-wheel steering system can smoothly transition during the steering process to avoid instability caused by excessively violent movement. The greater the damping, the faster the oscillation of the rear-wheel steering system decays.

[0052] It should also be understood that the "gain compensation" in the above step 202 refers to adjusting the 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 the ratio of the rear wheel steering angle to the front wheel steering angle. This proportional 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 the above step 202 refers to adjusting the timing (phase) of the start and end of the rear wheel steering in the rear-wheel steering system so that it can achieve the best time match 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 pay attention to the time lag or lead of the rear wheel steering action relative to the front wheel steering action. Specifically, this time relationship is adjusted to ensure that the rear wheel starts steering at the most suitable time so as to work better with the front wheel.

[0053] In one possible implementation, the vehicle controller in step 202 determines the compensation coefficient based on the response speed parameter and the oscillation attenuation parameter of the rear-wheel steering system in the vehicle, including: the vehicle controller determines the phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter, and the phase compensation coefficient is used to indicate the phase compensation of the rear wheel steering angle when the rear wheels are subjected to steady-state steering; the vehicle controller determines the 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 attenuation parameter, and the first gain compensation coefficient is used to indicate the gain compensation of the rear wheel steering angle when the rear wheels are subjected to steady-state steering; 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 numerical value for phase compensation of the rear wheel steering angle when the rear wheel performs steady-state steering, and the "first gain compensation coefficient" is a specific numerical value for gain compensation of the rear wheel steering angle when the rear wheel performs steady-state steering.

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

[0056] In the above technical solution, phase compensation is related to the response speed and oscillation attenuation 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 turned in a steady state through the response speed parameter and oscillation attenuation parameter of the rear wheel steering system in the vehicle. This can ensure that the response speed and oscillation attenuation of the rear wheel steering system of the vehicle reach the optimal state. In addition, the actual gain coefficient and gain adjustment coefficient of the front wheel directly affect the stability and responsiveness of the rear wheel steering system, and gain compensation can enable the vehicle to turn with higher stability. Therefore, the method can accurately determine the first gain compensation coefficient of the rear wheel steering angle when the rear wheel is turned in a steady state through the actual gain coefficient of the front wheel, the gain adjustment coefficient, the response speed parameter and the oscillation attenuation parameter. This can ensure better performance and higher stability of the rear wheel steering system.

[0057] In one possible implementation, the vehicle controller determines the phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter, including: the vehicle controller obtains the actual response speed parameter and the actual oscillation attenuation parameter of the rear-wheel steering system; the vehicle controller determines the phase compensation coefficient based on the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter and the expected oscillation attenuation 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 attenuation parameter, the expected response speed parameter of the rear wheel steering system and the expected oscillation attenuation parameter, including: the vehicle controller determines the phase compensation coefficient based on the following formula (1);

[0059]

[0060] Among them, ω is the actual response speed parameter, ξ is the actual oscillation attenuation parameter, ω ref is the desired response speed parameter, ξ ref is the desired oscillation attenuation parameter, s is the complex variable in the Laplace transform, G phase (s) is the phase compensation coefficient.

[0061] It should be understood that ω in the above formula (1) is the actual frequency of the rear-wheel steering system, ξ is the actual damping of the rear-wheel steering system, and ω ref is the desired frequency, ξ ref is the desired damping. In addition, s is a complex variable in the Laplace transform, specifically s = σ + jw. σ is the real part, σ is used to affect the stability and transient response of the rear-wheel steering system, σ is related to damping, and w is the imaginary part, w is used to reflect the response characteristics of the rear-wheel steering system, and w is related to frequency. For example, high frequency corresponds to rapidly changing driving operations, while low frequency involves slower or continuous steering actions. The different responses of the rear-wheel steering system are reflected in the amplitude-frequency characteristics and phase-frequency characteristics of its transfer model, which is crucial to optimizing the vehicle's handling stability and the response speed of the rear-wheel steering system.

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

[0063] In the above technical solution, the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter, and the expected oscillation attenuation parameter can determine whether phase advance or phase lag is required. Phase advance can increase the phase margin of the rear-wheel steering system and improve the response speed; 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 through the above formula to ensure that the response speed and oscillation attenuation of the vehicle's rear-wheel steering system reach the optimal state based on the phase compensation coefficient.

[0064] In one possible implementation, the vehicle controller determines 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 attenuation parameter, including: the vehicle controller constructs a first coefficient based on the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system, and the first coefficient is used to indicate the response sensitivity of the rear-wheel steering system to the control instruction; 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 attenuation parameter of the rear-wheel steering system, including: the vehicle controller determines the first coefficient based on the following formula (2); the vehicle controller determines the first gain compensation coefficient based on the following formula (3);

[0066]

[0067] Among them, ε 1 is the first coefficient, is the actual gain coefficient of the front wheel, g ref is the gain adjustment coefficient, is the first gain compensation coefficient.

[0068] It should be understood that ξ, ω, ξ ref and ω ref It is determined by the attenuation coefficient (damping) and natural vibration frequency (frequency) of the rear wheel steering system. In addition, it can be determined by adjusting ω in the above formula (2) ref , ref and g in formula (3) ref Ensures that the vehicle has better vehicle stability and handling performance when steering based on the rear wheel angle in the rear-wheel steering system. First gain compensation coefficient is the steady-state gain of the target yaw rate.

[0069] In the above technical solution, the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter, the expected oscillation attenuation 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, stability, oscillation attenuation, etc., which can ensure that the vehicle maintains good steering performance under different working conditions. Therefore, the method can accurately determine the first gain compensation coefficient through the above formula to ensure better performance and higher stability of the rear-wheel steering system based on the first gain compensation coefficient.

[0070] In one possible implementation, the vehicle controller determines the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient, including: the vehicle controller determines the second coefficient based on the product of the first gain compensation coefficient and the phase compensation coefficient; the vehicle controller determines the compensation coefficient based on the difference between a preset value and the second coefficient.

[0071] In some embodiments, the vehicle controller determines the compensation coefficient based on the difference between the preset value and the second coefficient, including: the vehicle controller determines the compensation coefficient based on the following formula (4);

[0072]

[0073] Among them, FF(s) is the compensation coefficient, is the product of the first gain compensation coefficient and the phase compensation coefficient, that is, the second coefficient ε 2 .

[0074] It should be understood that in the above scheme, the phase compensation coefficient is multiplied by the first gain compensation coefficient (called the second coefficient) in order to comprehensively consider the phase and gain changes of the rear-wheel steering system at different frequencies. This multiplication operation can reflect the joint influence of phase and gain on the performance of the rear-wheel steering system during the compensation process. The "1" in the above method (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" is to add the compensation effect to ensure that the closed-loop performance of the entire rear-wheel steering system is improved, including but not limited to an increase in phase margin, a reduction in steady-state error, and an increase in response speed.

[0075] In the above technical solution, in the rear-wheel steering system of the vehicle, gain compensation and phase compensation can improve the stability and dynamic response of the rear-wheel steering system. Gain compensation usually adjusts the gain parameter to change the amplification factor of the rear-wheel steering system, while 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 the second coefficient by multiplying the first gain compensation coefficient with the phase compensation coefficient, and then 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 during rear-wheel steering. The above process uses 1 minus the second coefficient to ensure that the response of the rear-wheel steering system will not be over-amplified during the compensation process, thereby avoiding the rear-wheel steering system from entering an unstable state. Through this combination of multiplication and subtraction, the response of the rear-wheel steering system can be finely adjusted to achieve a control effect that is both fast and stable for vehicle steering.

[0076] The correction process of the “first gain compensation coefficient” is discussed as follows.

[0077] In one possible implementation, the vehicle controller determines the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient, including: the vehicle controller determines the theoretical steering torque of the wheels in the vehicle; 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 attenuation parameter and the theoretical steering torque to obtain the second gain compensation coefficient; the vehicle controller determines the compensation coefficient based on the second gain compensation coefficient and the phase compensation coefficient.

[0078] It should be understood that the "theoretical steering torque of the wheel" in the above solution refers to the torque generated by the wheel deflection in the vehicle to make the vehicle turn. The theoretical steering torque is generated by the friction between the wheel and the ground and the wheel deflection angle.

[0079] It should also be understood that the "actual gain coefficient of the rear wheel" in the above scheme refers to the degree of enlargement or reduction of the rear wheel angle relative to the front wheel angle in the steering control system. The actual gain coefficient of the rear wheel describes the response characteristics of the rear wheel steering system to the front wheel steering input (front wheel angle). In other words, if the actual gain coefficient of the rear wheel is high, it means that a small change in the front wheel angle can cause a larger steering angle adjustment of the rear wheel, which can increase the flexibility of the vehicle at low speeds and make the vehicle more agile in a small space, such as turning and turning in a parking lot. In addition, in dynamic driving scenarios, such as emergency obstacle avoidance or high-speed lane changes, a high actual gain coefficient of the rear wheel can enable the vehicle to respond to the driver's operation more quickly and improve the vehicle's handling stability. However, if the actual gain coefficient of the rear wheel is low, it means that the rear wheel reacts slowly to small changes in the front wheel angle, and the steering angle adjustment is relatively gentle. This helps to maintain the straight-line stability of the vehicle when driving at high speeds, reduce unnecessary direction corrections caused by subtle changes in the road surface, and improve the sense of driving stability. In addition, a low rear wheel actual gain coefficient can prevent the vehicle's rear wheel steering system from over-reacting to road bumps or subtle operations by the driver, thereby improving ride comfort.

[0080] 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.

[0081] In the above technical solution, when the vehicle is in different driving states, the front wheel and the rear wheel contribute differently to the steering response. By considering the actual gain coefficient of the front wheel and the actual gain coefficient of the rear wheel, the steering characteristics of the vehicle under specific conditions can be more accurately reflected, affecting the stability of the rear-wheel steering system. In addition, due to factors such as road conditions and load changes, the actual steering torque of the wheel may differ from the theoretical steering torque. Correcting the gain compensation coefficient can better match the actual steering torque and ensure the precise control of the rear-wheel steering system. Therefore, the above solution corrects the first gain compensation coefficient by 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, and then accurately determines the compensation coefficient by the corrected gain compensation coefficient (the 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 the rear-wheel steering process through the compensation coefficient.

[0082] 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); the vehicle controller determines the theoretical steering torque of the rear wheels based on the following formula (6);

[0083]

[0084] Where m is the mass of the vehicle, l f is the distance from the center of mass of the vehicle to the front axle, v is the speed of the vehicle, l is the distance between the front and rear axles, K r is the lateral stiffness of the rear wheel, T γ is the theoretical steering torque of the front wheel, l r is the distance from the center of mass of the vehicle to the rear axle, K f is the lateral stiffness of the front wheel, T γr is the theoretical steering torque of the rear wheels.

[0085] In a possible implementation, the vehicle controller corrects 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 a second gain compensation coefficient, including: the vehicle controller determines a first transfer model of the 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 attenuation parameter, and the first transfer model is used to describe the relationship between the front wheel steering torque and the front wheel steering angle change; the vehicle controller determines a second transfer model of the 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 attenuation parameter, and the second transfer model is used to describe the relationship between the rear wheel steering torque and the rear wheel steering angle change; 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.

[0086] In some embodiments, the vehicle controller determines a first transfer model of the 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 attenuation 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);

[0087]

[0088] And, the vehicle controller determines a second transfer model of the 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 attenuation parameter, including:

[0089] The vehicle controller determines a second transfer model of the rear wheel steering system in the vehicle based on the following formula (8);

[0090]

[0091] 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;

[0092]

[0093] Among them, T γ is the theoretical steering torque of the front wheel, G f (s) is the first transfer model, is the actual gain coefficient of the rear wheel, T γr is the theoretical steering torque of the rear wheels, G r (s) is the second transfer model, is the second gain compensation coefficient.

[0094] 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, thereby adjusting the first gain compensation coefficient to ensure that the vehicle can obtain an ideal steering response under various conditions. Secondly, the response speed parameter can quantify the response speed of the rear wheel steering system to the steering command. A fast response means that the rear wheel steering system can quickly adjust the rear wheel steering angle, and a slow response is the opposite. Consideration of the response speed parameter helps to correct the gain compensation, ensure that the execution of the steering command matches the vehicle dynamics, and avoid over- or under-steering. Furthermore, during the rear wheel steering process, the wheels and the vehicle may oscillate. The oscillation attenuation parameter is used to evaluate and control the oscillation amplitude and attenuation speed that may occur during the rear wheel steering process, ensure that the vehicle turns smoothly, reduce unnecessary swings, and improve driving stability and safety. In addition, the theoretical steering torque of the wheel is the steering torque estimated when the vehicle is designed, which is used to overcome the steering resistance and achieve 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 is consistent with the design expectations in the actual vehicle use scenario and improve the steering accuracy. 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, responsive and stable second gain compensation coefficient, thereby optimizing the vehicle's steering performance and ensuring driving safety and comfort.

[0095] In the above technical solution, the first gain compensation coefficient is set based on a preset vehicle model (expected response speed parameter, expected oscillation attenuation parameter, gain adjustment coefficient and actual gain coefficient of the front wheel). However, in actual driving, the uncertainty of road conditions and vehicle status requires the rear-wheel steering system to have adaptive capabilities. Therefore, through the actual effects of the front wheel steering torque and angle changes, as well as the rear wheel steering torque and angle changes, the gain compensation coefficient can be dynamically adjusted, that is, the second gain compensation coefficient is obtained, which can more accurately control the rear wheel steering and improve the dynamic response and stability of the vehicle.

[0096] It should be understood that the relationship between the front wheel steering torque and the front wheel steering angle change described in the above formula (7) can be regarded as the yaw rate response of the front wheel steering angle, and the relationship between the rear wheel steering torque and the rear wheel steering angle change described in the above formula (8) can be regarded as the yaw rate response of the rear wheel steering angle. Based on formulas (7) and (8), the vehicle controller can derive the yaw rate of the vehicle as shown in the following formula (10);

[0097] γ(s)=G f (s)δ f +G r (s)δ r (10)

[0098] Assuming that the target yaw rate of the vehicle is as follows:

[0099] γ ref (s) = G ref (s)δ f (11)

[0100] Among them, γ(s) is the yaw rate of the vehicle, δ f is the front wheel turning angle, δ r is the rear wheel turning angle, γ ref (s) is the target yaw rate of the vehicle;

[0101] If it is assumed that formula (10) and formula (11) are equal, the vehicle controller obtains the following formula (12):

[0102]

[0103] Therefore, the second gain compensation coefficient can be obtained as the coefficient before the front wheel turning angle in formula (12).

[0104] Step 203: The vehicle controller determines the rear wheel steering angle based on the product of the front wheel steering angle and the compensation coefficient, and controls the rear wheels of the vehicle to rotate at the rear wheel steering angle.

[0105] It should be understood that "controlling the rear wheels of the vehicle to rotate at the rear wheel turning angle" in the above step 203 specifically means that the rear wheels are rotated at the rear wheel turning angle through the electric power steering system or the hydraulic power steering system in the vehicle.

[0106] Figure 3 It is a schematic diagram of determining a first gain compensation coefficient and a phase compensation coefficient provided in an embodiment of the present application.

[0107] For example, Figure 3 As shown, in order to improve the applicability of the phase compensation of the gain compensation in the method 200, the constant in the formula (2) can be changed based on the vehicle's driving speed. According to the vehicle speed range, as follows Figure 3 In the low speed area where you want to reduce the turning radius, Figure 3 As shown in (a), ω and ξ, and Figure 3 ω shown in (b) ref and ref If the same value is set, the effect of phase compensation is also set to be small. In addition, if you want to improve the yaw rate responsiveness in the medium speed range, set K>1 so that the rear wheel angle is opposite to the front wheel angle. If you want to improve the stability in the high speed range, set K<1 so that the rear wheel angle is in the same direction as the front wheel angle.

[0108] Figure 4 It is a schematic block diagram of determining a compensation coefficient provided in an embodiment of the present application.

[0109] For example, Figure 4 As shown, the gain compensation in the method 200 is related to the vehicle speed, because in the process of correcting the first gain compensation coefficient to obtain the second gain compensation coefficient, the theoretical steering torque based on the vehicle speed is used. Figure 4 It can be concluded that: after the gain compensation coefficient is multiplied by the phase compensation coefficient, a second coefficient is obtained; the second coefficient is multiplied by -1 to obtain a second coefficient; the second coefficient is multiplied by the front wheel angle to obtain a first angle, and the first angle is added to the front wheel angle to obtain the rear wheel angle, that is, the rear wheel angle is equal to (1-G gain G phase )*δ f , where G gain is the first gain compensation coefficient or the second gain compensation coefficient. In addition, when the vehicle turns at the rear wheel turning angle, the yaw rate of the vehicle can be controlled.

[0110] Figure 5 It is a schematic block diagram of determining a yaw rate response provided in an embodiment of the present application.

[0111] For example, Figure 5As shown in (a) of , given the front wheel steering angle, the expected yaw rate response is Figure 5 The gray solid line shown in (a) is the actual yaw rate response obtained by the related technology. Figure 5 The black dotted line shown in (a) is shown in Figure 5 From the trend between the grey solid line and the black dotted line shown in (a), it can be concluded that there is a large difference between the actual yaw rate response obtained by the related art and the expected yaw rate response.

[0112] like Figure 5 As shown in (b) of , given the front wheel steering angle, the expected yaw rate response is Figure 5 The gray solid line shown in (b) shows the actual yaw rate response obtained by the method 200. Figure 5 The black dotted line shown in (b) is shown in Figure 5 From the trend between the gray solid line and the black dotted line shown in (b), it can be concluded that the actual yaw rate response obtained by the method 200 of the present application is similar to the expected yaw rate response. Therefore, compared with the related art, the method 200 of the present application can reduce the deviation between the expected response and the actual response.

[0113] It should be understood that step 202 in the method 200 of the present application is to perform gain compensation and phase compensation on the rear wheel steering angle when the rear wheels are turned. Of course, it is also possible to perform gain compensation only on the rear wheel steering angle when the rear wheels are turned, and 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 steer with the rear wheel steering angle.

[0114] Figure 6 It is a structural schematic diagram of a rear-wheel steering control device provided in an embodiment of the present application.

[0115] For example, Figure 6 As shown, the device 600 includes:

[0116] An acquisition module 601 is used to acquire a front wheel steering angle in response to a rear wheel steering control instruction during vehicle driving;

[0117] A determination module 602, 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 for a rear wheel steering angle during rear wheel steering;

[0118] The control module 603 is used to determine the rear wheel steering angle based on the product of the front wheel steering angle and the compensation coefficient, and control the rear wheels of the vehicle to rotate at the rear wheel steering angle.

[0119] Optionally, the determination module 602 is specifically used to: determine a phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter, wherein the phase compensation coefficient is used to indicate the phase compensation of the rear wheel steering angle when the rear wheel is subjected to steady-state steering; determine 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 attenuation parameter, wherein the first gain compensation coefficient is used to indicate the gain compensation of the rear wheel steering angle when the rear wheel is subjected to steady-state steering; determine the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient.

[0120] Optionally, the acquisition module is specifically used to obtain an actual response speed parameter and an actual oscillation attenuation parameter of the rear-wheel steering system; the determination module is also specifically used to determine the phase compensation coefficient based on the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system.

[0121] Optionally, the determination module is further specifically used to: construct a first coefficient based on the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system, wherein the first coefficient is used to indicate the response sensitivity of the rear-wheel steering system to the control instruction; and determine the product of the first coefficient, the actual front wheel gain coefficient and the gain adjustment coefficient as the first gain compensation coefficient.

[0122] Optionally, the determination module 602 is further specifically used to: 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, correct the first gain compensation coefficient to obtain a second gain compensation coefficient; based on the second gain compensation coefficient and the phase compensation coefficient, determine the compensation coefficient.

[0123] Optionally, the determination module 602 is further specifically used 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, the theoretical steering torque of the front wheel, the response speed parameter and the oscillation attenuation parameter, the first transfer model being used to describe the relationship between the front wheel steering torque and the front wheel steering angle change; determine a second transfer model of the 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 attenuation parameter, the second transfer model being used to describe the relationship between the rear wheel steering torque and the rear wheel steering angle change; 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.

[0124] Optionally, the determination module 602 is further specifically used to: determine a second coefficient based on the product of the first gain compensation coefficient and the phase compensation coefficient; and determine the compensation coefficient based on the difference between a preset value and the second coefficient.

[0125] Figure 7 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0126] For example, Figure 7 As shown, the vehicle 700 includes: a memory 701 and a processor 702, wherein the memory 701 stores an executable program code 703, and the processor 702 is used to call and execute the executable program code 703 to perform a rear wheel steering control method.

[0127] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute a rear-wheel steering control method provided by an embodiment of the present application.

[0128] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0129] In the case of dividing each functional module according to each function, the device may further include an acquisition module, a determination module, a control module, etc. It should be noted that all relevant contents involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0130] It should be understood that the device provided in this embodiment is used to execute the above-mentioned rear-wheel steering control method, and thus can achieve the same effect as the above-mentioned implementation method.

[0131] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing related executable program codes, etc.

[0132] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0133] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a rear-wheel steering control method provided in the above-mentioned embodiments.

[0134] This embodiment also provides a computer-readable storage medium, in which executable program code is stored. When the executable program code is run on a computer, the computer executes the above-mentioned related method steps to implement a rear-wheel steering control method provided in the above embodiment.

[0135] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a rear-wheel steering control method provided in the above embodiment.

[0136] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0137] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0138] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0139] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A rear wheel steering control method, characterized in that: The method comprises: During the driving of the vehicle, in response to a control instruction for steering the rear wheels, a front wheel steering angle is obtained; Determining a compensation coefficient based on a response speed parameter and an oscillation attenuation parameter of a rear-wheel steering system in the vehicle, wherein the compensation coefficient is used to indicate gain compensation and phase compensation for a rear-wheel steering angle during rear-wheel steering; Based on the product between the front wheel turning angle and the compensation coefficient, a rear wheel turning angle is determined, and the rear wheels of the vehicle are controlled to turn at the rear wheel turning angle.

2. The method according to claim 1, characterized in that The determining of the compensation coefficient based on the response speed parameter and the oscillation attenuation parameter of the rear wheel steering system in the vehicle comprises: Determining a phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter, wherein the phase compensation coefficient is used to indicate a phase compensation of a rear wheel steering angle when the rear wheel is subjected to steady-state steering; 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 attenuation parameter, wherein the first gain compensation coefficient is used to indicate the gain compensation of the rear wheel steering angle when the rear wheel is subjected to steady-state steering; The compensation coefficient is determined based on the first gain compensation coefficient and the phase compensation coefficient.

3. The method according to claim 2, characterized in that The determining of the phase compensation coefficient based on the response speed parameter and the oscillation attenuation parameter comprises: Acquiring an actual response speed parameter and an actual oscillation attenuation parameter of the rear-wheel steering system; The phase compensation coefficient is determined based on the actual response speed parameter, the actual oscillation attenuation parameter, the expected response speed parameter of the rear-wheel steering system, and the expected oscillation attenuation parameter.

4. The method according to claim 2, characterized in that: The determining 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 comprises: Based on the expected response speed parameter and the expected oscillation attenuation parameter of the rear-wheel steering system, constructing a first coefficient, wherein the first coefficient 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 front wheel gain coefficient and the gain adjustment coefficient is determined as the first gain compensation coefficient.

5. The method according to claim 4, characterized in that The determining the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient comprises: determining a theoretical steering torque of a wheel 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 a second gain compensation coefficient; The compensation coefficient is determined based on the second gain compensation coefficient and the phase compensation coefficient.

6. The method according to claim 5, characterized in that The first gain compensation coefficient is corrected 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, including: Determining a first transfer model of a front wheel steering system in the vehicle based on the front wheel actual gain coefficient, the theoretical steering torque of the front wheel, the response speed parameter and the oscillation attenuation parameter, wherein the first transfer model is used to describe the relationship between the front wheel steering torque and the front wheel steering angle change; Determining a second transfer model of a rear wheel steering system in the vehicle based on the rear wheel actual gain coefficient, the theoretical steering torque of the rear wheel, the response speed parameter and the oscillation attenuation parameter, wherein the second transfer model is used to describe the relationship between the rear wheel steering torque and the rear wheel steering angle change; Based on the first transfer model and the second transfer model, the first gain compensation coefficient is corrected to obtain the second gain compensation coefficient.

7. The method according to claim 2, characterized in that The determining the compensation coefficient based on the first gain compensation coefficient and the phase compensation coefficient comprises: determining a second coefficient based on a product between the first gain compensation coefficient and the phase compensation coefficient; The compensation coefficient is determined by taking the difference between the preset value and the second coefficient.

8. A rear wheel steering control device, characterized in that: The device comprises: An acquisition module, used for acquiring 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 attenuation parameter of a rear-wheel steering system in the vehicle, wherein the compensation coefficient is used to indicate gain compensation and phase compensation for a rear wheel steering angle during rear-wheel steering; A control module is used to determine a rear wheel steering angle based on the product between the front wheel steering angle and the compensation coefficient, and control the rear wheels of the vehicle to rotate at the rear wheel steering angle.

9. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores an executable program code, and when the executable program code is executed, the method according to any one of claims 1 to 7 is implemented.

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