Steering control method and device for rear wheels of a vehicle, vehicle and storage medium

Abstract

The application discloses a kind of vehicle rear wheel's steering control method, device, vehicle and storage medium.Therein, the method comprises: obtaining the first real-time steering data of vehicle in the process of driving, wherein the first real-time steering data is used to represent the vehicle state parameter related to the steering operation of vehicle;Determine the target corner value of vehicle rear wheel based on the first real-time steering data and preset control model, wherein the preset control model is used to represent the mapping relationship between the first real-time steering data and target corner value, and the preset control model is the model generated based on the dynamic adjustment of expected yaw angular velocity changing with time;According to the first real-time steering data and target corner value, control vehicle steering.The present application solves the technical problem that the steering system stability of vehicle is poor due to directly using yaw angular velocity to adjust the corner value of vehicle rear wheel.

Description

Technical Field

[0001] This invention relates to the field of vehicles, and more specifically, to a method, apparatus, vehicle, and storage medium for steering control of the rear wheels of a vehicle. Background Technology

[0002] To improve both vehicle handling and stability, rear-wheel steering technology was developed. Traditional cars use front-wheel steering to control the vehicle's direction of movement and lateral stability. However, at high speeds or during emergency maneuvers, front-wheel steering can easily cause lateral instability or even loss of control. Vehicles equipped with rear-wheel steering can achieve more precise and agile vehicle handling by controlling the steering of the rear wheels, improving lateral stability and safety. It enhances lateral stability, making the vehicle more stable at high speeds or during sharp turns, reducing the risk of skidding and slippage, and ultimately improving driving safety.

[0003] In existing rear-wheel control technologies, the steering angle of the vehicle's rear wheels is usually adjusted directly using the yaw rate collected in real time. However, directly using the yaw rate collected in real time is subject to the physical influence of the sensor that determines the yaw rate, resulting in poor stability of the vehicle's steering system.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a method, device, vehicle, and storage medium for steering control of the rear wheels of a vehicle, to at least solve the technical problem of poor vehicle steering system stability caused by directly adjusting the steering angle value of the rear wheels using yaw rate.

[0006] According to one aspect of the present invention, a method for steering control of the rear wheels of a vehicle is provided, comprising: acquiring first real-time steering data of the vehicle during driving, wherein the first real-time steering data is used to characterize vehicle state parameters related to steering operations; determining a target steering angle value of the rear wheels of the vehicle based on the first real-time steering data and a preset control model, wherein the preset control model is used to characterize the mapping relationship between the first real-time steering data and the target steering angle value, and the preset control model is a model generated based on a dynamically adjusted desired yaw rate that changes over time; and controlling the vehicle to steer according to the first real-time steering data and the target steering angle value.

[0007] Optionally, the first real-time steering data includes: vehicle driving mode, vehicle speed, and front wheel steering angle. Based on the first real-time steering data and a preset control model, the target steering angle value of the vehicle's rear wheels is determined: a first parameter corresponding to the vehicle driving mode is obtained, wherein the first parameter is used to characterize the mapping relationship between the vehicle's front wheel steering angle and rear wheel steering angle; the preset control model is updated based on the first parameter to obtain an updated preset control model; and the target steering angle value is determined based on the vehicle speed, front wheel steering angle, and the updated preset control model.

[0008] Optionally, the first real-time steering data further includes: rear wheel steering angle. Controlling the vehicle to steer according to the first real-time steering data and the target steering angle value includes: acquiring the steering angle difference between the rear wheel steering angle and the target steering angle value; controlling the rear wheel steering angle of the vehicle to return to zero at a first preset speed in response to the steering angle difference being greater than or equal to a preset steering angle threshold, wherein the first preset speed is determined by the vehicle speed; and adjusting the rear wheel steering angle based on the steering angle difference in response to the steering angle difference being less than the preset steering angle threshold.

[0009] Optionally, the first real-time steering data further includes: yaw rate, and the method further includes: obtaining the yaw rate difference between the yaw rate and the desired yaw rate; and controlling the rear wheel steering angle of the vehicle to return to zero at a second preset speed in response to the yaw rate difference being greater than a preset yaw rate threshold.

[0010] Optionally, before determining the target steering angle value of the vehicle's rear wheels based on real-time steering data and a preset control model, the method further includes: acquiring the vehicle's hardware parameters and second real-time steering data of the vehicle in a preset driving scenario, wherein the real-time steering data includes at least the center of gravity sideslip angle; constructing a four-wheel vehicle model based on the second real-time steering data and hardware parameters; determining the steering angle coefficient based on the four-wheel vehicle model with the center of gravity sideslip angle being zero, wherein the steering angle coefficient is used to characterize the coefficient required for converting between the vehicle's front wheel steering angle and the vehicle's rear wheel steering angle under preset conditions; and generating a preset control model based on the four-wheel vehicle model and the steering angle coefficient.

[0011] Optionally, the second real-time steering data includes vehicle speed. Based on the four-wheel vehicle model and steering angle coefficient, generating a preset control model includes: calibrating the vehicle under a preset driving scenario to obtain longitudinal vehicle speed, yaw damping, and yaw frequency, wherein longitudinal vehicle speed, yaw damping, and yaw frequency are all correlated with vehicle speed; determining the dynamic increment of the vehicle's yaw rate based on the longitudinal vehicle speed, yaw damping, and yaw frequency; generating the desired yaw rate based on hardware parameters, steering angle coefficient, and vehicle speed; and generating the preset control model based on the four-wheel vehicle model, the dynamic increment of the yaw rate, and the desired yaw rate.

[0012] Optionally, a preset control model is generated based on the four-wheel vehicle model, the dynamic increment of the yaw rate, and the desired yaw rate, including: generating a dynamic desired yaw rate based on the dynamic increment of the yaw rate and the desired yaw rate; and replacing the yaw rate in the four-wheel vehicle model with the dynamic desired yaw rate to obtain the preset control model.

[0013] According to another aspect of the present invention, a vehicle rear wheel steering control device is also provided, comprising: an acquisition module, configured to acquire first real-time steering data of the vehicle during driving, wherein the first real-time steering data is used to characterize vehicle state parameters related to steering operations; a determination module, configured to determine a target steering angle value of the vehicle's rear wheels based on the first real-time steering data and a preset control model, wherein the preset control model is used to characterize the mapping relationship between the first real-time steering data and the target steering angle value, and the preset control model is a model generated based on a dynamically adjusted desired yaw rate that changes over time; and a steering module, configured to control the vehicle to steer according to the first real-time steering data and the target steering angle value.

[0014] Optionally, the first real-time steering data includes: vehicle driving mode, vehicle speed, and front wheel steering angle. The determination module includes: an acquisition unit for acquiring a first parameter corresponding to the vehicle driving mode, wherein the first parameter is used to characterize the mapping relationship between the front wheel steering angle and the rear wheel steering angle of the vehicle; an update unit for updating a preset control model based on the first parameter to obtain an updated preset control model; and a determination unit for determining a target steering angle value based on the vehicle speed, front wheel steering angle, and the updated preset control model.

[0015] Optionally, the first real-time steering data further includes: rear wheel angle. The steering module includes: a difference acquisition unit for acquiring the angle difference between the rear wheel angle and the target angle value; a first control unit for controlling the rear wheel angle of the vehicle to return to zero at a first preset speed in response to the angle difference being greater than or equal to a preset angle threshold, wherein the first preset speed is determined by the vehicle speed; and a first adjustment unit for adjusting the rear wheel angle based on the angle difference in response to the angle difference being less than the preset angle threshold.

[0016] Optionally, the first real-time steering data further includes: yaw rate. The device further includes: a difference acquisition module, which acquires the yaw rate difference between the yaw rate and the desired yaw rate; and a control module, which controls the rear wheel steering angle of the vehicle to return to zero at a second preset speed in response to the yaw rate difference being greater than a preset yaw rate threshold.

[0017] Optionally, the device further includes: a second data acquisition unit, used to acquire the vehicle's hardware parameters and second real-time steering data of the vehicle in a preset driving scenario before determining the target steering angle value of the vehicle's rear wheels based on real-time steering data and a preset control model, wherein the real-time steering data includes at least the center of gravity sideslip angle; a model building unit, used to build a four-wheel vehicle model based on the second real-time steering data and hardware parameters; a coefficient determination unit, used to determine the steering angle coefficients based on the four-wheel vehicle model with the center of gravity sideslip angle being zero, wherein the steering angle coefficients are used to characterize the coefficients required for converting between the vehicle's front wheel steering angle and the vehicle's rear wheel steering angle under preset conditions; and a model generation unit, used to generate a preset control model based on the four-wheel vehicle model and the steering angle coefficients.

[0018] Optionally, the second real-time steering data includes vehicle speed, and the model generation unit includes: a calibration subunit, used to calibrate the vehicle under a preset driving scenario to obtain longitudinal vehicle speed, yaw damping, and yaw frequency, wherein longitudinal vehicle speed, yaw damping, and yaw frequency are all related to vehicle speed; an enhancement determination subunit, used to determine the dynamic increment of the vehicle's yaw rate based on the longitudinal vehicle speed, yaw damping, and yaw frequency; an expectation generation subunit, used to generate the expected yaw rate based on hardware parameters, steering coefficient, and vehicle speed; and a model generation subunit, used to generate a preset control model based on a four-wheel vehicle model, the dynamic increment of the yaw rate, and the expected yaw rate.

[0019] Optionally, the model generation subunit is also used to generate a dynamic desired yaw rate based on the dynamic increment of the yaw rate and the desired yaw rate; and to replace the yaw rate in the four-wheel vehicle model with the dynamic desired yaw rate to obtain a preset control model.

[0020] According to one aspect of the present invention, a vehicle rear wheel steering control method is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the vehicle rear wheel steering control method according to any one of the embodiments of the present invention.

[0021] According to one aspect of the present invention, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, wherein the computer program is configured to execute the vehicle rear wheel steering control method described in any one of the embodiments of the present invention when a processor is executed.

[0022] In this embodiment of the invention, after acquiring the first real-time steering data of the vehicle during driving, the target steering angle value of the rear wheels of the vehicle is determined based on the first real-time steering data and the preset control model. Then, the vehicle is controlled to steer according to the first real-time steering data and the target steering angle value. It is worth noting that the preset control model used in this application is a model generated based on the expected yaw rate that is dynamically adjusted over time. It does not use the yaw rate directly collected by the sensor, but uses the expected yaw rate that is dynamically adjusted over time. It no longer depends on the physical characteristics of the yaw rate sensor, thus achieving the technical effect of improving the robustness of the vehicle steering system. This solves the technical problem of poor stability of the vehicle steering system caused by directly using the yaw rate to adjust the steering angle value of the rear wheels. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0024] Figure 1 This is a method for controlling the steering of the rear wheels of a vehicle according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the hardware control device of the rear wheel steering system in a vehicle rear wheel steering control method according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the fault protection mechanism triggered by the rear wheel steering system in a vehicle rear wheel steering control method according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of a vehicle rear wheel steering control device according to an embodiment of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] According to an embodiment of the present invention, a method for steering control of the rear wheels of a vehicle is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] From a vehicle performance perspective, the requirements for a rear-wheel steering system are as follows: First, the rear-wheel steering system needs to possess high-precision steering control capabilities to ensure that the vehicle's steering angle and direction meet the driver's requirements. Second, the rear-wheel steering system also needs to have rapid response capabilities to ensure that the vehicle's steering response in emergency situations meets the driver's needs. Third, the rear-wheel steering system needs to have anti-interference capabilities; under different driving scenarios, the rear-wheel steering system requires control adjustments and optimizations to ensure its good control effect and stability.

[0032] This invention introduces a dynamically adjusted desired yaw rate based on time-varying changes in existing rear-wheel steering control technology, effectively improving the response speed of feedforward control. By introducing a first-order lag element, the yaw rate estimation accuracy is significantly improved. The rear-wheel steering control method proposed in this invention also considers variable driving characteristics. As the driver switches between different driving modes, the vehicle's yaw gain requirements vary, and the size of the provided rear wheel steering angle also varies.

[0033] Figure 1 This is a vehicle rear wheel steering control method according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0034] Step S102: Obtain the first real-time steering data of the vehicle during driving, wherein the first real-time steering data is used to characterize the vehicle state parameters related to the vehicle's steering operation.

[0035] Specifically, the first real-time steering data may include, but is not limited to, steering wheel angle, front wheel angle, vehicle speed, lateral acceleration, and longitudinal acceleration, and may be acquired through various sensors pre-installed in the vehicle. For example, vehicle speed can be obtained by weighted averaging of signals collected by four pre-installed wheel speed sensors. Steering wheel angle can be obtained through the TAS (TorchAngele Sensor) steering wheel angle sensor signal. The aforementioned front wheel angle can be obtained by converting the TAS steering wheel angle sensor signal into a steering ratio, or by acquiring it through the EPS (Electric Power Steering) travel sensor. It should be noted that when receiving both the TAS sensor signal and the EPS travel sensor signal, redundancy verification of the two signals can ensure that the determined front wheel angle reaches a certain functional safety level.

[0036] Step S104: Based on the first real-time steering data and the preset control model, determine the target steering angle value of the vehicle's rear wheels. The preset control model is used to characterize the mapping relationship between the first real-time steering data and the target steering angle value, and the preset control model is a model generated based on the expected yaw rate that changes dynamically over time.

[0037] Specifically, the values ​​in the first real-time steering data can be substituted into the preset control model to obtain the target steering angle value of the vehicle's rear wheels.

[0038] As an optional implementation, the preset control model can be as follows:

[0039] ,in, Used to characterize the target steering angle value of the vehicle's rear wheels Used to characterize the front wheel steering angle For the front axle equivalent lateral stiffness, For the equivalent lateral stiffness of the rear axle, The longitudinal speed can be determined based on the vehicle's speed. The lateral velocity can be determined based on the vehicle's speed; 'a' is the distance from the vehicle's center of gravity to the front wheel; 'b' is the distance from the vehicle's center of gravity to the rear wheel; and 'm' is the vehicle's mass. It is a stability factor. Used to characterize vehicle wheelbase The proportional control coefficient used to characterize the relationship between the front wheel steering angle and the rear wheel steering angle of a vehicle, i.e., the steering angle coefficient mentioned elsewhere in this application, and t used to characterize time. Used to characterize yaw damping Used to characterize the frequency of yaw rate The first parameter, used to characterize the vehicle's driving mode, has the same meaning in subsequent formulas within this application, and will not be repeated here. In the aforementioned preset control model, The desired yaw rate is used to characterize the dynamic adjustment that changes over time.

[0040] The stability factor can be expressed by the following formula: .

[0041] The proportional control coefficient between the front wheel steering angle and the rear wheel steering angle of the vehicle can be expressed by the following formula:

[0042] .

[0043] Step S106: Control the vehicle to steer according to the first real-time steering data and the target steering angle value.

[0044] As an optional implementation method, Figure 2 This is a schematic diagram of the hardware control device of the rear wheel steering system in a vehicle rear wheel steering control method according to an embodiment of the present invention, as shown below. Figure 2 As shown, the data acquisition unit includes a TAS steering wheel angle sensor, an EPS travel sensor, an ABS (Anti-lock Brake System) wheel speed sensor, a rear wheel steering travel sensor, and an acceleration sensor. After acquiring data, the data acquisition unit transmits it to the upper-level control unit for processing and analysis via CAN (Controller Area Network) communication. The electronic control unit receives the acquired steering-related data, i.e., the aforementioned first real-time steering data, and converts it based on a preset control model. It determines the dynamic desired yaw rate based on the vehicle's current speed and then calculates the target rear wheel steering angle for the next moment based on the dynamic desired yaw rate. The steering control unit receives the rear wheel target steering angle command from the upper-level controller, parses it into the motor's given torque and target speed, and sends the torque and target speed to the steering actuator. The steering actuator converts the rotational motion of the motor rotor into the lateral movement of the rack of the rear wheel steering actuator through a rack and pinion or belt drive, generating the actual rear wheel steering angle.

[0045] As an optional implementation, the first real-time steering data includes vehicle speed, rear wheel steering angle, and yaw rate. To ensure safety during rear wheel steering, this application also provides two rear wheel steering fault triggering and protection mechanisms. Figure 3 This is a schematic diagram illustrating the fault protection mechanism triggered by the rear wheel steering system in a vehicle rear wheel steering control method according to an embodiment of the present invention. Figure 3As shown, the target steering angle of the vehicle's rear wheels is determined based on the vehicle speed (i.e., Figure 3 The "given threshold" in the text, and then the target corner value (i.e. Figure 3 The "target rear wheel angle" and the actual collected rear wheel angle (i.e. Figure 3 The system compares the target steering angle with the "actual rear wheel steering angle" in the target steering angle model. If the difference between the target steering angle and the rear wheel steering angle is greater than or equal to a preset steering angle threshold, the system controls the rear wheel steering angle to return to zero at a first preset speed. It can also input vehicle speed, front wheel steering angle, and steering wheel angle into a preset control model (i.e.,...). Figure 3 The feedforward control model and the actual vehicle model are used to obtain the desired yaw rate (i.e., Figure 3 The "estimated yaw rate" in the text is then compared with the actual yaw rate (i.e., the estimated yaw rate). Figure 3 The measured yaw rate is compared with the expected yaw rate. If the difference between the actual yaw rate and the expected yaw rate is greater than or equal to the preset yaw rate threshold, the rear wheel yaw rate of the vehicle is controlled to return to zero at the first preset speed.

[0046] In this embodiment of the invention, after acquiring the first real-time steering data of the vehicle during driving, the target steering angle value of the rear wheels of the vehicle is determined based on the first real-time steering data and the preset control model. Then, the vehicle is controlled to steer according to the first real-time steering data and the target steering angle value. It is worth noting that the preset control model used in this application is a model generated based on the expected yaw rate that is dynamically adjusted over time. It does not use the yaw rate directly collected by the sensor, but uses the expected yaw rate that is dynamically adjusted over time. It no longer depends on the physical characteristics of the yaw rate sensor, thus achieving the technical effect of improving the robustness of the vehicle steering system. This solves the technical problem of poor stability of the vehicle steering system caused by directly using the yaw rate to adjust the steering angle value of the rear wheels.

[0047] Optionally, the first real-time steering data includes: vehicle driving mode, vehicle speed, and front wheel steering angle. Based on the first real-time steering data and a preset control model, the target steering angle value of the vehicle's rear wheels is determined: a first parameter corresponding to the vehicle driving mode is obtained, wherein the first parameter is used to characterize the mapping relationship between the vehicle's front wheel steering angle and rear wheel steering angle; the preset control model is updated based on the first parameter to obtain an updated preset control model; and the target steering angle value is determined based on the vehicle speed, front wheel steering angle, and the updated preset control model.

[0048] Specifically, the vehicle driving modes include Sport mode and Comfort mode. With the same steering wheel rotation angle, the vehicle responds more responsively and with greater steering amplitude in Sport mode compared to Comfort mode. Since the driver can change the driving model during driving, the first parameter corresponding to the current driving mode can be obtained before determining the target steering angle value. Alternatively, to improve response efficiency, the preset control model can be updated only upon detecting a driving mode change signal. After obtaining the updated preset control model, the vehicle speed, front wheel angle, and other parameters are substituted into the updated preset control model to obtain the target steering angle value.

[0049] Optionally, the first real-time steering data further includes: rear wheel steering angle. Controlling the vehicle to steer according to the first real-time steering data and the target steering angle value includes: acquiring the steering angle difference between the rear wheel steering angle and the target steering angle value; controlling the rear wheel steering angle of the vehicle to return to zero at a first preset speed in response to the steering angle difference being greater than or equal to a preset steering angle threshold, wherein the first preset speed is determined by the vehicle speed; and adjusting the rear wheel steering angle based on the steering angle difference in response to the steering angle difference being less than the preset steering angle threshold.

[0050] Specifically, the aforementioned first preset speed can be a safe speed determined by researchers through experiments. When the angle difference is less than the preset angle threshold, the rear wheel angle can be adjusted based on the current speed at which the driver is steering the vehicle.

[0051] Optionally, the first real-time steering data further includes: yaw rate, and the method further includes: obtaining the yaw rate difference between the yaw rate and the desired yaw rate; and controlling the rear wheel steering angle of the vehicle to return to zero at a second preset speed in response to the yaw rate difference being greater than a preset yaw rate threshold.

[0052] Specifically, the aforementioned second preset speed can be a safe speed determined by researchers through experiments. When the yaw rate is less than the preset steering angle threshold, the rear wheel steering angle can be adjusted according to the current speed at which the driver is operating the vehicle's steering wheel.

[0053] Optionally, before determining the target steering angle value of the vehicle's rear wheels based on real-time steering data and a preset control model, the method further includes: acquiring the vehicle's hardware parameters and second real-time steering data of the vehicle in a preset driving scenario, wherein the real-time steering data includes at least the center of gravity sideslip angle; constructing a four-wheel vehicle model based on the second real-time steering data and hardware parameters; determining the steering angle coefficient based on the four-wheel vehicle model with the center of gravity sideslip angle being zero, wherein the steering angle coefficient is used to characterize the coefficient required for converting between the vehicle's front wheel steering angle and the vehicle's rear wheel steering angle under preset conditions; and generating a preset control model based on the four-wheel vehicle model and the steering angle coefficient.

[0054] Specifically, the aforementioned four-wheeled vehicle model can be a two-degree-of-freedom four-wheeled vehicle model.

[0055] As an optional implementation, the hardware parameters include: front axle equivalent lateral stiffness, rear axle equivalent lateral stiffness, distance from the vehicle's center of gravity to the front wheel, distance from the vehicle's center of gravity to the rear wheel, vehicle mass, and vehicle wheelbase. The four-wheel vehicle mode can be as follows:

[0056]

[0057] ,in, The sideslip angle is the angle of the centroid. Let be the moment of inertia.

[0058] As an alternative implementation, the four-wheel vehicle model with a sideslip angle of 0 is as follows:

[0059] ; This allows us to obtain the rotation coefficient. The dynamic ratio between the front and rear wheels is shown below: ,in, Used to characterize yaw rate.

[0060] Optionally, the second real-time steering data includes vehicle speed. Based on a four-wheel vehicle model and steering angle coefficients, generating a preset control model includes: calibrating the vehicle under a preset driving scenario to obtain longitudinal vehicle speed, yaw damping, and yaw rate frequency, wherein longitudinal vehicle speed, yaw damping, and yaw rate frequency are all correlated with vehicle speed; determining the dynamic increment of the vehicle's yaw rate based on the longitudinal vehicle speed, yaw damping, and yaw rate frequency; generating a desired yaw rate based on hardware parameters, steering angle coefficients, and vehicle speed; and generating a preset control model based on the four-wheel vehicle model, the dynamic increment of the yaw rate, and the desired yaw rate.

[0061] Specifically, the aforementioned preset driving scenario can be a standard driving scenario. Calibration is performed in the standard driving scenario to obtain the longitudinal vehicle speed, yaw damping, and yaw rate frequency corresponding to each vehicle speed.

[0062] As an alternative implementation, the dynamic increment of the vehicle's yaw rate can be The desired yaw rate can be .

[0063] Optionally, a preset control model is generated based on the four-wheel vehicle model, the dynamic increment of the yaw rate, and the desired yaw rate, including: generating a dynamic desired yaw rate based on the dynamic increment of the yaw rate and the desired yaw rate; and replacing the yaw rate in the four-wheel vehicle model with the dynamic desired yaw rate to obtain the preset control model.

[0064] As an optional implementation, the dynamically desired yaw rate can be .

[0065] According to another aspect of the present invention, a vehicle rear wheel steering control device is also provided. Figure 4 This is a schematic diagram of the structure of a vehicle rear wheel steering control device according to an embodiment of the present invention, as shown below. Figure 4 As shown, the device includes:

[0066] The acquisition module 42 is used to acquire the first real-time steering data of the vehicle during driving, wherein the first real-time steering data is used to characterize the vehicle state parameters related to the vehicle's steering operation.

[0067] The determination module 44 is used to determine the target steering angle value of the rear wheels of the vehicle based on the first real-time steering data and the preset control model. The preset control model is used to characterize the mapping relationship between the first real-time steering data and the target steering angle value, and the preset control model is a model generated based on the expected yaw rate that changes dynamically over time.

[0068] Steering module 46 is used to control the vehicle to steer according to the first real-time steering data and the target steering angle value.

[0069] Optionally, the first real-time steering data includes: vehicle driving mode, vehicle speed, and front wheel steering angle. The determination module includes: an acquisition unit for acquiring a first parameter corresponding to the vehicle driving mode, wherein the first parameter is used to characterize the mapping relationship between the front wheel steering angle and the rear wheel steering angle of the vehicle; an update unit for updating a preset control model based on the first parameter to obtain an updated preset control model; and a determination unit for determining a target steering angle value based on the vehicle speed, front wheel steering angle, and the updated preset control model.

[0070] Optionally, the first real-time steering data further includes: rear wheel angle. The steering module includes: a difference acquisition unit for acquiring the angle difference between the rear wheel angle and the target angle value; a first control unit for controlling the rear wheel angle of the vehicle to return to zero at a first preset speed in response to the angle difference being greater than or equal to a preset angle threshold, wherein the first preset speed is determined by the vehicle speed; and a first adjustment unit for adjusting the rear wheel angle based on the angle difference in response to the angle difference being less than the preset angle threshold.

[0071] Optionally, the first real-time steering data further includes: yaw rate. The device further includes: a difference acquisition module, which acquires the yaw rate difference between the yaw rate and the desired yaw rate; and a control module, which controls the rear wheel steering angle of the vehicle to return to zero at a second preset speed in response to the yaw rate difference being greater than a preset yaw rate threshold.

[0072] Optionally, the device further includes: a second data acquisition unit, used to acquire the vehicle's hardware parameters and second real-time steering data of the vehicle in a preset driving scenario before determining the target steering angle value of the vehicle's rear wheels based on real-time steering data and a preset control model, wherein the real-time steering data includes at least the center of gravity sideslip angle; a model building unit, used to build a four-wheel vehicle model based on the second real-time steering data and hardware parameters; a coefficient determination unit, used to determine the steering angle coefficients based on the four-wheel vehicle model with the center of gravity sideslip angle being zero, wherein the steering angle coefficients are used to characterize the coefficients required for converting between the vehicle's front wheel steering angle and the vehicle's rear wheel steering angle under preset conditions; and a model generation unit, used to generate a preset control model based on the four-wheel vehicle model and the steering angle coefficients.

[0073] Optionally, the second real-time steering data includes vehicle speed, and the model generation unit includes: a calibration subunit, used to calibrate the vehicle under a preset driving scenario to obtain longitudinal vehicle speed, yaw damping, and yaw rate frequency, wherein longitudinal vehicle speed, yaw damping, and yaw rate frequency are all related to vehicle speed; an enhancement determination subunit, used to determine the dynamic increment of the vehicle's yaw rate based on the longitudinal vehicle speed, yaw damping, and yaw rate frequency; an expectation generation subunit, used to generate the expected yaw rate based on hardware parameters, steering coefficient, and vehicle speed; and a model generation subunit, used to generate a preset control model based on a four-wheel vehicle model, the dynamic increment of the yaw rate, and the expected yaw rate.

[0074] Optionally, the model generation subunit is also used to generate a dynamic desired yaw rate based on the dynamic increment of the yaw rate and the desired yaw rate; and to replace the yaw rate in the four-wheel vehicle model with the dynamic desired yaw rate to obtain a preset control model.

[0075] According to one aspect of the present invention, a vehicle rear wheel steering control method is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the vehicle rear wheel steering control method according to any one of the embodiments of the present invention.

[0076] According to one aspect of the present invention, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, and the computer program is configured to execute the vehicle rear wheel steering control method described in any one of the embodiments of the present invention when a processor is executed.

[0077] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0078] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0079] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0080] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0081] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0082] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of controlling the steering of a rear wheel of a vehicle, characterized by, include: Acquire first real-time steering data of the vehicle during driving, wherein the first real-time steering data is used to characterize vehicle state parameters related to the vehicle's steering operation; Based on the first real-time steering data and the preset control model, the target steering angle value of the vehicle's rear wheels is determined, wherein the preset control model is used to characterize the mapping relationship between the first real-time steering data and the target steering angle value, and the preset control model is a model generated based on the expected yaw rate that is dynamically adjusted over time. The vehicle is controlled to steer according to the first real-time steering data and the target steering angle value; Before determining the target steering angle value of the vehicle's rear wheels based on the real-time steering data and the preset control model, the method further includes: acquiring the vehicle's hardware parameters and second real-time steering data of the vehicle in a preset driving scenario, wherein the second real-time steering data includes at least the center of gravity sideslip angle; constructing a four-wheel vehicle model based on the second real-time steering data and the hardware parameters; determining a steering angle coefficient based on the four-wheel vehicle model when the center of gravity sideslip angle is zero, wherein the steering angle coefficient is used to characterize the coefficient required for converting between the vehicle's front wheel steering angle and the vehicle's rear wheel steering angle under the preset state; and generating the preset control model based on the four-wheel vehicle model and the steering angle coefficient.

2. The method of claim 1, wherein, The first real-time steering data includes: vehicle driving mode, vehicle speed, and front wheel steering angle. Based on the first real-time steering data and a preset control model, the target steering angle value of the vehicle's rear wheels is determined. Obtain a first parameter corresponding to the vehicle driving mode, wherein the first parameter is used to characterize the mapping relationship between the front wheel steering angle and the rear wheel steering angle of the vehicle; The preset control model is updated based on the first parameter to obtain the updated preset control model; The target steering angle value is determined based on the vehicle speed, the front wheel steering angle, and the updated preset control model.

3. The method of claim 1, wherein, The first real-time steering data further includes: rear wheel steering angle. Controlling the vehicle to steer according to the first real-time steering data and the target steering angle value includes: Obtain the angle difference between the rear wheel angle and the target angle value; In response to the angle difference being greater than or equal to a preset angle threshold, the rear wheel angle of the vehicle is controlled to return to zero at a first preset speed, wherein the first preset speed is determined by the vehicle speed; In response to the angle difference being less than the preset angle threshold, the rear wheel angle is adjusted based on the angle difference.

4. The method of claim 1, wherein, The first real-time steering data further includes: yaw rate, and the method further includes: Obtain the yaw rate difference between the stated yaw rate and the desired yaw rate; In response to the yaw rate difference being greater than a preset yaw rate threshold, the rear wheel steering angle of the vehicle is controlled to return to zero at a second preset speed.

5. The method of claim 1, wherein, The second real-time steering data includes vehicle speed. Based on the four-wheel vehicle model and the steering angle coefficient, the preset control model is generated by: The vehicle is calibrated under the preset driving scenario to obtain longitudinal speed, yaw damping and yaw frequency, wherein the longitudinal speed, yaw damping and yaw frequency are all related to the vehicle speed; Based on the longitudinal vehicle speed, the yaw damping, and the yaw frequency, the dynamic increment of the vehicle's yaw rate is determined; Based on the hardware parameters, the steering coefficient, and the vehicle speed, the desired yaw rate is generated; Based on the four-wheeled vehicle model, the dynamic increment of the yaw rate, and the desired yaw rate, the preset control model is generated.

6. The method of claim 1, wherein, Based on the four-wheeled vehicle model, the dynamic increment of the yaw rate, and the desired yaw rate, the preset control model is generated, including: Based on the dynamic increment of the yaw rate and the desired yaw rate, a dynamic desired yaw rate is generated; The preset control model is obtained by replacing the yaw rate in the four-wheel vehicle model with the dynamic expected yaw rate.

7. A vehicle rear wheel steering control device characterized by comprising: include: The acquisition module is used to acquire the first real-time steering data of the vehicle during driving, wherein the first real-time steering data is used to characterize the vehicle state parameters related to the vehicle's steering operation. The determination module is used to determine the target steering angle value of the vehicle's rear wheels based on the first real-time steering data and the preset control model, wherein the preset control model is used to characterize the mapping relationship between the first real-time steering data and the target steering angle value, and the preset control model is a model generated based on the expected yaw rate that is dynamically adjusted over time. A steering module is used to control the vehicle to steer according to the first real-time steering data and the target steering angle value; Before determining the target steering angle value of the vehicle's rear wheels based on the real-time steering data and the preset control model, the device is further configured to acquire the vehicle's hardware parameters and the vehicle's second real-time steering data in a preset driving scenario, wherein the second real-time steering data includes at least the center of gravity sideslip angle; construct a four-wheel vehicle model based on the second real-time steering data and the hardware parameters; determine the steering angle coefficient based on the four-wheel vehicle model when the center of gravity sideslip angle is zero, wherein the steering angle coefficient is used to characterize the coefficient required for converting between the vehicle's front wheel steering angle and the vehicle's rear wheel steering angle in the preset state; and generate the preset control model based on the four-wheel vehicle model and the steering angle coefficient.

8. A vehicle comprising a memory and a processor, characterized in that The memory stores a computer program, and the processor is configured to run the computer program to perform the vehicle rear wheel steering control method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program is configured to execute, when run by a processor, the steering control method for the rear wheels of a vehicle as described in any one of claims 1 to 6.

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