Vehicle steering control method and device, vehicle-mounted controller, vehicle and medium

Abstract

The embodiment of the invention provides a vehicle steering control method and device, a vehicle-mounted controller, a vehicle and a medium. The method comprises the following steps: acquiring vehicle actual measurement data, wherein the vehicle actual measurement data comprises a front wheel turning angle; processing the actually measured data of the vehicle based on the rear wheel steering angle control model, and determining an original rear wheel steering angle; wherein the original rear wheel steering angle corresponding to the first steering stage and the front wheel steering angle keep reverse steering smaller than a preset angle, the original rear wheel steering angle corresponding to the second steering stage and the front wheel steering angle keep steering in the same direction, and the first steering stage and the second steering stage are two stages sequentially formed in the vehicle steering process; determining a target rear wheel rotation angle based on the original rear wheel rotation angle and the calibrated rear wheel rotation angle; and controlling a rear wheel steering gear to work based on the target rear wheel steering angle. The method. According to the method, the target rear wheel steering angle corresponding to the rear wheel is controlled in real time through the rear wheel steering angle control model, the maneuverability and stability in the vehicle steering process are guaranteed, and the driving experience of a user is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of control technologies, and in particular, to a vehicle steering control method, device, vehicle-mounted controller, vehicle, and medium. Background Art

[0002] During the vehicle steering process, ensuring the maneuverability and stability of the vehicle is crucial for improving the vehicle's safety performance and user experience. In the prior art, during the vehicle steering process, the rear-wheel steering is usually controlled according to the front-wheel steering angle of the vehicle. This control method can only maintain the maneuverability and stability of the vehicle steering at low vehicle speeds. At high vehicle speeds, the maneuverability and stability of the vehicle cannot be guaranteed, greatly reducing the vehicle's safety performance and user experience. Therefore, how to control vehicle steering to ensure the maneuverability and stability of the vehicle is a technical problem that needs to be solved currently. Summary of the Invention

[0003] The embodiments of the present application provide a vehicle steering control method, device, vehicle-mounted controller, vehicle, and medium, aiming to solve the technical problem of how to control vehicle steering to ensure the maneuverability and stability of the vehicle.

[0004] A vehicle steering control method includes: Obtaining vehicle measured data, where the vehicle measured data includes the front-wheel steering angle; Processing the vehicle measured data based on a rear-wheel steering angle control model to determine an original rear-wheel steering angle; wherein, in the first steering stage, the original rear-wheel steering angle corresponding to the first steering stage has a reverse steering with the front-wheel steering angle that is less than a preset angle, and in the second steering stage, the original rear-wheel steering angle corresponding to the second steering stage has the same steering direction as the front-wheel steering angle. The first steering stage and the second steering stage are two stages formed successively during the vehicle steering process; Determining a target rear-wheel steering angle based on the original rear-wheel steering angle and the calibrated rear-wheel steering angle corresponding to the original rear-wheel steering angle; Controlling the rear-wheel steering gear to work based on the target rear-wheel steering angle.

[0005] The vehicle steering control method, device, vehicle-mounted controller, vehicle, and medium provided in this embodiment determine the original rear-wheel steering angle at each moment in the first steering stage and the second steering stage during the vehicle steering process through the rear-wheel steering angle control model, realizing the control of the rear-wheel steering angle at each moment during the vehicle steering process, ensuring that the original rear-wheel steering angle corresponding to the first steering stage has a reverse steering angle less than the preset angle with the front-wheel steering angle, and the original rear-wheel steering angle corresponding to the second steering stage has the same steering direction as the front-wheel steering angle. According to the original rear-wheel steering angle and the calibrated rear-wheel steering angle at each moment, the target rear-wheel steering angle at each moment is controlled to be within the range corresponding to the calibrated rear-wheel steering angle, ensuring the maneuverability of the vehicle during the steering process while ensuring the safety and stability of the vehicle. This method realizes the real-time control of the target rear-wheel steering angle corresponding to the rear wheels through the rear-wheel steering angle control model, achieving the purpose of ensuring the maneuverability and stability of the vehicle during the steering process, thereby improving the user's driving experience, and can be widely applied to the vehicle steering control scenarios of intelligent driving and autonomous driving.

[0006] Preferably, the processing of the vehicle measured data based on the rear-wheel steering angle control model to determine the original rear-wheel steering angle includes: Based on the vehicle measured data, vehicle steering data is determined, and the vehicle steering data is data related to vehicle steering; Based on the rear-wheel steering angle control model, the vehicle steering data is processed to determine the original rear-wheel steering angle.

[0007] In this embodiment, the original rear-wheel steering angle at each moment during the vehicle steering process is determined to facilitate the real-time control of the rear wheels according to the real-time determined original rear-wheel steering angle, ensuring the maneuverability and stability of the vehicle.

[0008] Preferably, the vehicle measured data further includes the vehicle speed; The vehicle steering data includes the front-wheel steering angle and the target parameters determined based on the vehicle speed, and the target parameters include the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the rear-wheel reverse steering angle ratio coefficient, the front and rear wheel steering angle ratio coefficient, and the filtering coefficient; The original rear-wheel steering angle is the angle determined by processing the target parameters and the front-wheel steering angle based on the rear-wheel steering angle control model.

[0009] In this embodiment, according to the real-time collected vehicle speed, target parameters including the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the rear-wheel reverse steering angle ratio coefficient, the front and rear wheel steering angle ratio coefficient, and the filtering coefficient are determined to facilitate the real-time control of vehicle steering according to the real-time determined target parameters, improving the maneuverability and stability of vehicle steering control.

[0010] Preferably, the rear-wheel steering angle control model includes a first control term and a second control term; The first control item is determined based on the reverse steering angle ratio coefficient of the rear wheels, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, and the steering angle of the front wheels, and is used to make the angle between the original rear wheel steering angle corresponding to the first steering stage and the steering angle of the front wheels in reverse steering less than a preset angle; The second control item is determined based on the reverse steering angle ratio coefficient of the rear wheels, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the front and rear wheel steering angle ratio coefficient, the filtering coefficient, and the steering angle of the front wheels, and is used to control the duration of the first steering stage and make the original rear wheel steering angle corresponding to the second steering stage and the steering angle of the front wheels in the same direction of steering.

[0011] In this embodiment, the first steering stage of the vehicle during steering is controlled by the first control item, and the original rear wheel steering angle corresponding to each moment and the steering angle of the front wheels at the same moment maintain reverse steering within a small angle range. The duration of the first steering stage is adjusted in real time by the second control item, and the rear wheels and the front wheels of the vehicle maintain the same direction of steering during the second steering stage.

[0012] Preferably, the target rear wheel steering angle is the smaller value of the original rear wheel steering angle and the calibrated rear wheel steering angle; Controlling the rear wheel steering gear to work based on the target rear wheel steering angle includes: Determining the steering tie rod displacement based on the target rear wheel steering angle; Controlling the rear wheel steering gear to work based on the steering tie rod displacement.

[0013] In this embodiment, the steering tie rod displacement is determined based on the real-time target rear wheel steering angle during vehicle steering, and the rear wheel steering gear is controlled to move the steering tie rod to the position corresponding to the steering tie rod displacement in real time, thereby effectively ensuring the steering maneuverability and stability of the vehicle and achieving real-time control of vehicle steering.

[0014] Preferably, controlling the rear wheel steering gear to work based on the steering tie rod displacement includes: Determining the original rear wheel steering angular velocity based on the original rear wheel steering angle; Determining the target rear wheel steering angular velocity based on the original rear wheel steering angular velocity and the calibrated rear wheel steering angular velocity; the target rear wheel steering angular velocity is the smaller value of the original rear wheel steering angular velocity and the calibrated rear wheel steering angular velocity; Determining the steering tie rod moving speed based on the target rear wheel steering angular velocity; Controlling the rear wheel steering gear to work based on the steering tie rod displacement and the steering tie rod moving speed.

[0015] In this embodiment, the original rear wheel angular velocity is limited by calibrating the rear wheel angular velocity, and the target rear wheel angular velocity and steering rod movement speed are determined. This can effectively ensure that the steering rod corresponding to the rear wheel is stably moved to the steering rod displacement according to the steering rod movement speed, and then the rear wheel is controlled to be stably moved to the target rear wheel angle according to the target rear wheel angular velocity, thereby ensuring the maneuverability, safety and stability during the target rear wheel steering process, and improving the user's driving experience.

[0016] Preferably, the rear wheel steering angle control model is = ,in, is the first control item, is the second control item, is the rear wheel reverse steering angle proportional coefficient, is the front and rear wheel angle proportional coefficient, is the front axle equivalent cornering stiffness, is the equivalent cornering stiffness of the rear axle, is the filter coefficient, is the front wheel turning angle, is the original rear wheel turning angle.

[0017] In this embodiment, a rear wheel steering angle control model is constructed to adjust the rear wheel steering angle in real time, to ensure that during the steering process, the original rear wheel steering angle corresponding to the first steering stage and the front wheel steering angle maintain an angle of reverse steering less than a preset angle, to control the duration of the first steering stage, and to keep the original rear wheel steering angle corresponding to the second steering stage and the front wheel steering angle in the same direction, so that the vehicle is in the best vehicle steering response performance at every moment during the steering process, to improve the vehicle's dynamic characteristics and dynamic response characteristics, and to effectively improve the vehicle's maneuverability and stability. Compared with the existing steering control method, the control method of the rear wheel steering angle control model can improve the yaw response of the vehicle center area during the vehicle steering process, and the stability performance of the linear and nonlinear areas, thereby improving the user's driving experience, and can be widely used in the fields of intelligent driving and automatic driving.

[0018] A vehicle steering control device, comprising: A data acquisition module, used to acquire vehicle measured data, wherein the vehicle measured data includes a front wheel steering angle; an original rear wheel steering angle determination module, processing the vehicle measured data based on a rear wheel steering angle control model to determine an original rear wheel steering angle; wherein the original rear wheel steering angle corresponding to a first steering stage and the front wheel steering angle maintain an opposite steering angle less than a preset angle, and the original rear wheel steering angle corresponding to a second steering stage and the front wheel steering angle maintain a same steering direction, and the first steering stage and the second steering stage are two stages formed successively during the vehicle steering process; A target rear wheel steering angle determination module determines a target rear wheel steering angle based on the original rear wheel steering angle and the calibrated rear wheel steering angle corresponding to the original rear wheel steering angle; A steering control module controls the operation of a rear wheel steering gear based on the target rear wheel steering angle.

[0019] A vehicle-mounted controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above vehicle steering control method is implemented.

[0020] A vehicle includes the above vehicle-mounted controller.

[0021] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the above vehicle steering control method is implemented. Description of the Drawings

[0022] Figure 1 is a flowchart of a vehicle steering control method provided by an embodiment of the present application; Figure 2 is a control schematic diagram of a rear wheel steering angle control model provided by an embodiment of the present application; Figure 3 is a schematic diagram of the change of the front wheel steering angle and the original rear wheel steering angle over time when controlling vehicle steering through a rear wheel steering angle control model provided by an embodiment of the present application; Figure 4 is a structural diagram of a vehicle steering control device provided by an embodiment of the present application; Figure 5 is a structural diagram of a vehicle-mounted controller provided by an embodiment of the present application. Detailed Description of the Embodiments

[0023] In order to make the technical problems, technical solutions, and beneficial effects solved by the present application clearer and more understandable, the present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] The vehicle steering control method provided by the embodiments of the present invention is applicable to a vehicle-mounted controller for controlling vehicle steering and ensuring the maneuverability and stability of the vehicle. The vehicle-mounted controller here is a controller installed on the vehicle.

[0025] An embodiment of the present application provides a vehicle steering control method. Please refer to Figure 1 , which includes the following steps: S101: Obtain vehicle measured data, where the vehicle measured data includes the front wheel steering angle; S102: Process the measured vehicle data based on the rear wheel steering angle control model to determine the original rear wheel steering angle. Among them, the original rear wheel steering angle corresponding to the first steering stage has a reverse steering with the front wheel steering angle that is less than a preset angle, and the original rear wheel steering angle corresponding to the second steering stage has the same direction of steering as the front wheel steering angle. The first steering stage and the second steering stage are two successive stages formed during the vehicle steering process. S103: Determine the target rear wheel steering angle based on the original rear wheel steering angle and the calibrated rear wheel steering angle corresponding to the original rear wheel steering angle. S104: Control the operation of the rear wheel steering gear based on the target rear wheel steering angle.

[0026] Among them, the measured vehicle data refers to the data related to vehicle steering collected in real time.

[0027] As an example, in step S101, when the vehicle is in a steering state, the vehicle-mounted controller obtains the measured vehicle data related to vehicle steering, such as the front wheel steering angle, collected by the sensor in real time, which is used to determine the original rear wheel steering angle during the vehicle steering process to achieve the steering control of the vehicle. It can be understood that during the vehicle steering process (for example, turning or changing lanes), it is necessary to control the rear wheel steering angle in real time. Therefore, the measured vehicle data is obtained in real time to facilitate the real-time steering control of the vehicle based on the measured vehicle data and ensure the maneuverability and stability of the vehicle steering.

[0028] Among them, the rear wheel steering angle control model is a model for controlling vehicle steering.

[0029] As an example, in step S102, the vehicle-mounted controller processes the measured vehicle data. Specifically, the measured vehicle data is determined as the input data of the rear wheel steering angle control model, and the rear wheel steering angle control model is used to process the input data, and the rear wheel steering angle output by the rear wheel steering angle control model is determined as the original rear wheel steering angle. In this example, the rear wheel steering angle control model can be a pre-established algorithm model or a pre-trained deep learning model, which is used to accurately determine the original rear wheel steering angle of the vehicle based on the measured vehicle data, so as to control the vehicle to steer according to the original rear wheel steering angle and ensure the maneuverability and stability of the vehicle. In this example, when the rear wheel steering angle control model is a pre-established algorithm model, the vehicle-mounted controller substitutes the measured vehicle data as the input data into the pre-established algorithm model to calculate the original rear wheel steering angle. When the rear wheel steering angle control model is a pre-trained deep learning model, the measured vehicle data is input as the input data into the pre-trained deep learning model to output the real-time original rear wheel steering angle. In this example, when the vehicle is in a steering state, the original rear wheel steering angle is accurately determined according to the rear wheel steering angle control model, so as to accurately control the vehicle steering according to the original rear wheel steering angle, which can effectively ensure the maneuverability and stability during the vehicle steering process.

[0030] In this example, a rear-wheel steering angle control model is adopted to determine in real time the original rear-wheel steering angle corresponding to each moment during the vehicle steering process based on the actual measured vehicle data obtained in real time. During the first steering stage when the vehicle is controlled to steer according to the original rear-wheel steering angle, it is ensured that the original rear-wheel steering angle corresponding to the rear wheels is opposite to the front-wheel steering angle corresponding to the front wheels, and the rear wheels maintain a relatively small original rear-wheel steering angle less than a preset angle during the first steering stage, so as to ensure the maneuverability and stability of the vehicle during the first steering stage of turning. Moreover, during the second steering stage in the vehicle steering process, it is controlled that the original rear-wheel steering angle corresponding to the rear wheels is in the same direction as the front-wheel steering angle corresponding to the front wheels, ensuring the safety and stability of the vehicle during the second steering stage. Among them, the first steering stage and the second steering stage are two consecutive stages in the vehicle steering process. The first steering stage is at the initial stage of vehicle steering, and the second steering stage is at the middle and later stages of vehicle steering. The first steering stage refers to the stage during vehicle steering when the rear wheels and the front wheels steer in opposite directions. The second steering stage refers to the stage during vehicle steering when the rear wheels and the front wheels steer in the same direction. The first steering stage precedes the second steering stage. The preset angle refers to a preset angle, specifically the angle used to control the original rear-wheel steering angle at each moment to take a smaller value during the first steering stage of the vehicle.

[0031] Among them, the target rear-wheel steering angle refers to the angle that needs to control the rear wheels to rotate during the vehicle steering process. The calibrated rear-wheel steering angle refers to the angle pre-calibrated to limit the magnitude of the original rear-wheel steering angle.

[0032] As an example, in step S103, the vehicle-mounted controller determines whether the original rear-wheel steering angle meets the range requirements corresponding to the calibrated rear-wheel steering angle. When it is determined that the original rear-wheel steering angle meets the range requirements corresponding to the calibrated rear-wheel steering angle, the original rear-wheel steering angle is determined as the target rear-wheel steering angle. When it is determined that the original rear-wheel steering angle does not meet the range requirements corresponding to the calibrated rear-wheel steering angle, the original rear-wheel steering angle is processed to ensure that the original rear-wheel steering angle meets the range requirements corresponding to the calibrated rear-wheel steering angle, and the original rear-wheel steering angle that meets the range requirements corresponding to the calibrated rear-wheel steering angle is determined as the target rear-wheel steering angle. In this example, the calibrated rear-wheel steering angle can be an angle range limited by the calibrated rear-wheel steering angle to control the target rear-wheel steering angle within a reasonable steering angle range, ensuring the safety and stability of the vehicle. It can be understood that during the vehicle steering process, especially when the vehicle is changing lanes at medium and high speeds, due to the high vehicle speed, if the rear-wheel steering angle is too large, the stability and safety of the vehicle will be significantly reduced. Therefore, the target rear-wheel steering angle used to control the rear wheels to rotate needs to meet the range requirements corresponding to the calibrated rear-wheel steering angle to ensure that the vehicle has high stability and safety during the steering process.

[0033] Among them, the rear-wheel steering actuator refers to the component in the vehicle that controls the rear-wheel steering.

[0034] As an example, in step S104, the vehicle-mounted controller controls the rear-wheel steering gear of the vehicle to drive the rear wheels to stably rotate to the target rear-wheel angle corresponding to each moment in the first steering stage and the second steering stage of vehicle steering according to the target rear-wheel angle at each moment determined in real time based on the rear-wheel angle control model. By controlling the rear wheels to stably rotate to the angular position corresponding to the target rear-wheel angle in real time, the real-time control of the rear-wheel angle during vehicle steering is achieved, ensuring the maneuverability and stability of vehicle steering.

[0035] In this embodiment, the original rear-wheel angle at each moment in the first steering stage and the second steering stage during vehicle steering is determined through the rear-wheel angle control model, so as to control the rear-wheel angle at each moment during vehicle steering, ensuring that the original rear-wheel angle corresponding to the first steering stage has a reverse steering with the front-wheel angle less than the preset angle, and the original rear-wheel angle corresponding to the second steering stage has the same direction of steering as the front-wheel angle. According to the original rear-wheel angle and the calibrated rear-wheel angle at each moment, the target rear-wheel angle at each moment is controlled to be within the range corresponding to the calibrated rear-wheel angle, ensuring the safety and stability of the vehicle while ensuring the maneuverability during vehicle steering. This method realizes the purpose of ensuring the maneuverability and stability during vehicle steering by controlling the target rear-wheel angle corresponding to the rear wheels in real time through the rear-wheel angle control model, thereby improving the driving experience of users, and can be widely applied to vehicle steering control scenarios in intelligent driving and autonomous driving.

[0036] In one embodiment, step S102, that is, processing the measured vehicle data based on the rear-wheel angle control model to determine the original rear-wheel angle, includes: S1021: Based on the measured vehicle data, determine the vehicle steering data, where the vehicle steering data is data related to vehicle steering; S1022: Process the vehicle steering data based on the rear-wheel angle control model to determine the original rear-wheel angle.

[0037] As an example, in step S1021, the vehicle-mounted controller processes the measured vehicle data obtained in real time to determine the vehicle steering data for inputting into the rear-wheel angle control model. For example, the vehicle-mounted controller screens the obtained measured vehicle data and obtains the vehicle steering data required for processing by the rear-wheel angle control model from the measured vehicle data.

[0038] As an example, in step S1022, the vehicle-mounted controller inputs the vehicle steering data into the rear-wheel angle control model and outputs the original rear-wheel angle corresponding to the rear wheels. In this example, when the vehicle is in a steering state, the original rear-wheel angle is accurately determined according to the rear-wheel angle control model, so as to accurately control vehicle steering according to the original rear-wheel angle, effectively ensuring the maneuverability and stability during vehicle steering.

[0039] In this embodiment, according to the actually measured vehicle data obtained in real time, during the vehicle steering process, the vehicle steering data at each moment is determined, and the rear-wheel steering angle control model is used to process the vehicle steering data at each moment to determine the original rear-wheel steering angle during the vehicle steering process, so as to perform real-time control on the rear wheels according to the originally determined rear-wheel steering angle in real time, and ensure the maneuverability and stability of the vehicle.

[0040] In one embodiment, the actually measured vehicle data further includes the vehicle speed; The vehicle steering data includes the front-wheel steering angle and the target parameters determined based on the vehicle speed. The target parameters include the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the rear-wheel reverse steering angle ratio coefficient, the front-and-rear wheel steering angle ratio coefficient, and the filtering coefficient; The original rear-wheel steering angle is the steering angle determined by processing the target parameters and the front-wheel steering angle based on the rear-wheel steering angle control model.

[0041] Among them, the target parameter refers to the numerical value corresponding to the parameter in the rear-wheel steering angle control model. The equivalent cornering stiffness of the front axle refers to the equivalent cornering stiffness corresponding to the front axle of the vehicle. The equivalent cornering stiffness of the rear axle refers to the equivalent cornering stiffness corresponding to the rear axle of the vehicle. The rear-wheel reverse steering angle ratio coefficient refers to the ratio coefficient used to characterize the magnitude of the reverse steering angle of the rear wheel relative to the front wheel in the first steering stage of vehicle steering. It can be understood that when the vehicle is in the first steering stage of just starting to turn, it is necessary to make the rear wheel have a reverse steering angle with respect to the front wheel, and the rear-wheel reverse steering angle ratio coefficient is used to control the magnitude of the reverse steering angle of the rear wheel with respect to the front wheel. The front-and-rear wheel steering angle ratio coefficient refers to the ratio of the steering angle corresponding to the rear wheel to the steering angle corresponding to the front wheel. The filtering coefficient refers to the filtering coefficient of the filter in the rear-wheel steering angle control model. The front-wheel steering angle refers to the magnitude of the steering angle of the front wheel collected in real time during the vehicle steering process.

[0042] As an example, the vehicle-mounted controller collects in real time the measured vehicle data during the vehicle steering process, including but not limited to the vehicle speed and the front wheel steering angle of the vehicle. According to the vehicle speed, it queries the mapping relationship table of the target parameters required for the vehicle speed and the rear wheel steering angle control model pre-stored in the system database, obtains the target parameters corresponding to the vehicle speed at each moment, and determines the front wheel steering angle and the target parameters at each moment as the vehicle steering data at each moment. In this example, the vehicle-mounted controller queries the mapping relationship table of the vehicle speed, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the reverse steering angle ratio coefficient of the rear wheel, the steering angle ratio coefficient of the front and rear wheels, and the filtering coefficient pre-stored in the system database according to the vehicle speed, and determines the target parameters such as the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the reverse steering angle ratio coefficient of the rear wheel, the steering angle ratio coefficient of the front and rear wheels, and the filtering coefficient corresponding to the vehicle speed. It can be understood that the vehicle is pre-tested to determine the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the reverse steering angle ratio coefficient of the rear wheel, the steering angle ratio coefficient of the front and rear wheels, and the filtering coefficient of the vehicle at different vehicle speeds, and a mapping relationship table is formed and pre-stored in the system database, so as to query the system database in real time according to the vehicle speed collected in real time during the vehicle steering process to obtain the target parameters including the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the reverse steering angle ratio coefficient of the rear wheel, the steering angle ratio coefficient of the front and rear wheels, and the filtering coefficient, and use them to control the vehicle steering in real time according to the target parameters queried in real time, so as to improve the maneuverability and stability of the vehicle steering control.

[0043] In one embodiment, the rear wheel steering angle control model includes a first control term and a second control term; The first control term is determined based on the reverse steering angle ratio coefficient of the rear wheel, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, and the front wheel steering angle, and is used to make the angle between the original rear wheel steering angle and the front wheel steering angle corresponding to the first steering stage less than a preset angle; The second control term is determined based on the reverse steering angle ratio coefficient of the rear wheel, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the steering angle ratio coefficient of the front and rear wheels, the filtering coefficient, and the front wheel steering angle, and is used to control the duration of the first steering stage and make the original rear wheel steering angle and the front wheel steering angle corresponding to the second steering stage keep the same steering direction.

[0044] As an example, the vehicle-mounted controller processes the reverse steering angle proportional coefficient of the rear wheels, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, and the steering angle of the front wheels to determine the first control term in the rear-wheel steering angle control model. In this example, the first control term is used to calculate the original rear-wheel steering angle, and is mainly the control term for making the angle of the original rear-wheel steering angle corresponding to the first steering stage and the steering angle of the front wheels in reverse steering less than a preset angle. It can be understood that the reverse steering angle proportional coefficient of the rear wheels is used to characterize the magnitude ratio of the reverse steering angle of the rear wheels relative to the front wheels in the first steering stage of vehicle steering. By processing with the reverse steering angle proportional coefficient of the rear wheels, the obtained first control term is used to ensure that the original rear-wheel steering angle is a small angle in reverse steering with the steering angle of the front wheels, that is, to ensure that the rear wheels are in reverse steering with the front wheels in the first steering stage, and can reduce the steering angle of the rear wheels in the first steering stage. Therefore, considering the reverse steering angle proportional coefficient of the rear wheels in the first control term and processing the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, and the steering angle of the front wheels can control the first steering stage in the vehicle steering process, so that the original rear-wheel steering angle corresponding to each moment is in reverse steering with the steering angle of the front wheels at the same moment, and ensure that the original rear-wheel steering angle of the rear wheels remains within a small angle range less than the preset angle.

[0045] As an example, the vehicle-mounted controller determines the second control term in the rear-wheel steering angle control model according to the reverse steering angle proportional coefficient of the rear wheels, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the front and rear wheel steering angle proportional coefficient, the filtering coefficient, and the steering angle of the front wheels. The second control term is another term for calculating the original rear-wheel steering angle, and is mainly used to control the duration of the first steering stage and make the original rear-wheel steering angle corresponding to the second steering stage in the same direction as the steering angle of the front wheels. In this example, the vehicle-mounted controller processes the reverse steering angle proportional coefficient of the rear wheels, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the front and rear wheel steering angle proportional coefficient, and the steering angle of the front wheels by using the filter corresponding to the filtering coefficient. According to different filtering coefficients, the duration of the original rear-wheel steering angle of the rear wheels and the steering angle of the front wheels in the opposite direction is delayed, and the duration of the first steering stage is adjusted in real time. Moreover, in the second control term, by processing the reverse steering angle proportional coefficient of the rear wheels, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the front and rear wheel steering angle proportional coefficient, and the steering angle of the front wheels, the first control term is offset to achieve the purpose of offsetting the reverse steering angle between the rear wheels and the front wheels, and keeping the rear wheels and the front wheels in the same direction in the second steering stage of the vehicle.

[0046] In this embodiment, the first control term is used to control the first steering stage in the vehicle steering process, so that the original rear-wheel steering angle corresponding to each moment is in reverse steering within a small angle range with the steering angle of the front wheels at the same moment. The second control term is used to adjust the duration of the first steering stage in real time and keep the rear wheels and the front wheels in the same direction in the second steering stage of the vehicle.

[0047] In one embodiment, the rear wheel steering angle control model is = , where is the first control term, is the second control term, is the rear wheel reverse steering angle ratio coefficient, is the front and rear wheel steering angle ratio coefficient, is the equivalent cornering stiffness of the front axle, is the equivalent cornering stiffness of the rear axle, is the filtering coefficient, is the front wheel steering angle, is the original rear wheel steering angle.

[0048] As an example, the vehicle-mounted controller controls the vehicle's center of mass offset angle and the derivative of the center of mass offset angle to be 0 to process the vehicle's two-degree-of-freedom model to determine the rear wheel steering angle of the vehicle. The corresponding equation relationship is: = + , where is the equivalent cornering stiffness of the front axle, is the equivalent cornering stiffness of the rear axle, is the vehicle's center of mass offset angle, is the distance from the vehicle's center of mass to the front axle, is the distance from the vehicle's center of mass to the rear axle, is the vehicle speed, is the vehicle's yaw rate, is the vehicle's front wheel steering angle, is the vehicle's rear wheel steering angle, is the vehicle's mass, is the derivative of the vehicle's longitudinal vehicle speed. It can be understood that when the derivative of the center of mass offset angle is 0, is 0.

[0049] During the actual test process, it is found that if the rear wheel steering angle corresponding to the equation relationship = + obtained by processing the vehicle's two-degree-of-freedom model is directly used to calculate the rear wheel steering angle during vehicle steering to control vehicle steering, since it is impossible to control when the rear wheel's steering angle is the same as or opposite to that of the front wheel, resulting in a relatively low driving experience of the vehicle. Therefore, according to the form of the equation relationship corresponding to the rear wheel steering angle , the equation relationship corresponding to the rear wheel steering angle is modified, and a new rear wheel steering angle control model for calculating the rear wheel steering angle is: = , where is the rear-wheel reverse steering angle proportionality coefficient, is the front and rear wheel steering angle proportionality coefficient, is the filtering coefficient. Among them, is the first control term, is the second control term. As Figure 2 shown, it is the control schematic diagram of the rear-wheel steering angle control model. It can be known from Figure 2 that the filter in the rear-wheel steering angle control model adopts a smoothing filter. During the process of determining the original rear-wheel steering angle in the rear-wheel steering angle control model, it is determined by the sum of the first control term and the second control term . Among them, the first control term is determined by the product of the rear-wheel reverse steering angle proportionality coefficient , the side slip stiffness ratio and the front-wheel steering angle . The side slip stiffness ratio is the ratio of the equivalent side slip stiffness of the front axle to the equivalent side slip stiffness of the rear axle . The second control term is determined by filtering the reverse cancellation term by the filter corresponding to the filtering coefficient ; the reverse cancellation term is determined by the sum of the opposite number of the first control term and the rear-wheel steering delay processing term . The rear-wheel steering delay processing term is the product of the front and rear wheel steering angle proportionality coefficient and the front-wheel steering angle .

[0050] As Figure 3 shown, when controlling the vehicle steering through the rear-wheel steering angle control model, it is the schematic diagram of the change of the front-wheel steering angle and the original rear-wheel steering angle with time. Figure 3 shows the change images of the front-wheel steering angle and the original rear-wheel steering angle with time during a vehicle steering control process by the newly established rear-wheel steering angle control model. Figure 3 Among them, the horizontal axis represents time, the vertical axis represents angle, and point A represents the critical point where the original rear-wheel steering angle of the vehicle changes from being opposite to the front-wheel steering angle to being the same as the front-wheel steering angle. It can be known from Figure 3It can be seen that by using the newly established rear-wheel steering angle control model to control the vehicle steering process, it is possible to ensure that before point A, the rear wheels and the front wheels turn in the opposite direction, and the original rear-wheel steering angle corresponding to the rear wheels remains a small angle less than the preset angle, so as to ensure that in the first steering stage when the vehicle starts to turn, it not only has high maneuverability but also strong stability. The preset angle can be less than 5 degrees. After point A, the rear-wheel steering angle control model ensures that the rear wheels and the front wheels turn in the same direction to achieve vehicle steering control. From the newly established rear-wheel steering angle control model = It can be seen that according to the real-time collected vehicle speed, the filtering coefficient of the filter can be modified to control the position of point A, that is, to control the duration of the rear wheels and the front wheels maintaining a small reverse angle, so as to realize the delay of the duration of the rear wheels and the front wheels maintaining a small reverse angle. And, through the rear-wheel reverse steering angle proportional coefficient for the rear-wheel steering angle corresponding equation relationship = + in the term is scaled proportionally, which can ensure that before point A, the rear wheels and the front wheels are controlled to maintain a small reverse angle, and the reverse cancellation term through the cancellation effect on the first control term , realizes that after point A, the rear wheels and the front wheels turn in the same direction. Therefore, the newly established rear-wheel steering angle control model = , can not only control the original rear-wheel steering angle of the rear wheels to be opposite to the front-wheel steering angle and less than the preset angle in the first steering stage (before point A) of vehicle steering, but also control the duration of the rear wheels and the front wheels maintaining a small reverse angle, and after the first steering stage, in the second steering stage (after point A), cancel the small reverse angle between the rear wheels and the front wheels to realize the same-direction turning of the rear wheels and the front wheels, thereby realizing the control of vehicle steering, which can not only ensure the maneuverability of vehicle steering but also ensure the safety and stability during the vehicle steering process.

[0051] In this embodiment, based on parameters such as the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the reverse steering angle ratio coefficient of the rear wheels, the steering angle ratio coefficient of the front and rear wheels, the filtering coefficient, and the steering angle of the front wheels obtained in real time, the vehicle two-degree-of-freedom model is modified to construct a rear-wheel steering angle control model for real-time adjustment of the rear-wheel steering angle, ensuring that during the vehicle steering process, the angle of reverse steering between the original rear-wheel steering angle and the front-wheel steering angle corresponding to the first steering stage is less than a preset angle, controlling the duration of the first steering stage, and making the original rear-wheel steering angle and the front-wheel steering angle corresponding to the second steering stage maintain the same-direction steering, so that the vehicle is in the best vehicle steering response performance at each moment during the steering process, improving the dynamic characteristics and dynamic response characteristics of the vehicle, and effectively enhancing the maneuverability and stability of the vehicle. Compared with the existing steering control methods, the control method of this rear-wheel steering angle control model can improve the yaw response, stability performance in the linear region and non-linear region in the vehicle center area during the vehicle steering process, and thus enhance the user's driving experience. This vehicle steering control method can be widely applied to the fields of intelligent driving and autonomous driving.

[0052] In one embodiment, the target rear-wheel steering angle is the smaller value of the original rear-wheel steering angle and the calibrated rear-wheel steering angle; As an example, the vehicle-mounted controller compares the original rear-wheel steering angle with the calibrated rear-wheel steering angle and, when it is determined that the original rear-wheel steering angle is not greater than the calibrated rear-wheel steering angle , determines the original rear-wheel steering angle as the target rear-wheel steering angle . When it is determined that the original rear-wheel steering angle is greater than the calibrated rear-wheel steering angle , determines the calibrated rear-wheel steering angle as the target rear-wheel steering angle . Understandably, when the original rear-wheel steering angle is greater than the calibrated rear-wheel steering angle , if the original rear-wheel steering angle is determined as the target rear-wheel steering angle , the safety and stability of vehicle steering will be reduced. To ensure the safety and stability of vehicle steering, the smaller value of the original rear-wheel steering angle and the calibrated rear-wheel steering angle is determined as the target rear-wheel steering angle . At this time, the target rear-wheel steering angle ensures safety while meeting the requirements of the original rear-wheel steering angle output by the rear-wheel steering angle control model, effectively ensuring the steering maneuverability, safety and stability performance of the vehicle, and enhancing the user's driving experience.

[0053] In one embodiment, step S104, that is, controlling the rear-wheel steering gear to operate based on the target rear-wheel steering angle, includes: S1041: Determining the tie-rod displacement based on the target rear-wheel steering angle; S1042: Controlling the rear-wheel steering gear to operate based on the tie-rod displacement.

[0054] As an example, in step S1041, after the vehicle-mounted controller determines the smaller value between the original rear-wheel steering angle and the calibrated rear-wheel steering angle as the target rear-wheel steering angle, it determines the tie-rod displacement according to the target rear-wheel steering angle. In this example, the vehicle-mounted controller queries in the correspondence conversion table between the target rear-wheel steering angle and the tie-rod displacement pre-stored in the system database to determine the tie-rod displacement corresponding to the target rear-wheel steering angle, which is convenient and fast without complex calculations and improves the real-time performance of vehicle steering control.

[0055] As an example, in step S1042, the vehicle-mounted controller controls the tie-rod to move to the tie-rod displacement in real time through the rear-wheel steering gear, so as to control the steering angle of the rear wheel to reach the target rear-wheel steering angle. Among them, the tie-rod displacement is the tie-rod displacement corresponding to the rear-wheel tie-rod for controlling the rear-wheel steering, and the rear-wheel steering gear controls the rear-wheel tie-rod to move according to the tie-rod displacement corresponding to the target rear-wheel steering angle.

[0056] In this embodiment, the tie-rod displacement is determined based on the real-time target rear-wheel steering angle during the vehicle steering process, and the rear-wheel steering gear is controlled to make the tie-rod move to the position corresponding to the tie-rod displacement in real time, so as to control the steering angle of the rear wheel to reach the target rear-wheel steering angle, which can effectively ensure the steering performance and stability of the vehicle and realize the real-time control of vehicle steering.

[0057] In one embodiment, step S1041, that is, controlling the rear-wheel steering gear to operate based on the tie-rod displacement, includes: S1041A: Determining the original rear-wheel steering angular velocity based on the original rear-wheel steering angle; S1041B: Determining the target rear-wheel steering angular velocity based on the original rear-wheel steering angular velocity and the calibrated rear-wheel steering angular velocity; the target rear-wheel steering angular velocity is the smaller value between the original rear-wheel steering angular velocity and the calibrated rear-wheel steering angular velocity; S1041C: Determining the tie-rod moving speed based on the target rear-wheel steering angular velocity; S1041D: Controlling the rear-wheel steering gear to operate based on the tie-rod displacement and the tie-rod moving speed.

[0058] Among them, the original rear-wheel steering angular velocity refers to the rotational speed during the process of the vehicle's rear wheel rotating to the original rear-wheel steering angle.

[0059] As an example, in step S1041A, after the vehicle-mounted controller obtains the original rear-wheel steering angle through the newly established rear-wheel steering angle control model, it differentiates the original rear-wheel steering angle with respect to time to determine the original rear-wheel steering angular velocity. It can be understood that during the process of controlling the vehicle's steering, it is necessary to control the rear wheels to rotate at a certain angle and speed. Moreover, to ensure the safety and stability of the vehicle's steering process, it is necessary to control the rear-wheel steering angular velocity of the vehicle within a certain range. Therefore, the original rear-wheel steering angular velocity is determined to ensure the safety and stability of the vehicle based on the original rear-wheel steering angular velocity.

[0060] Among them, the calibrated rear-wheel steering angular velocity is the pre-set rear-wheel steering angular velocity.

[0061] As an example, in step S1041B, when the vehicle-mounted controller determines that the original rear-wheel steering angular velocity is not greater than the calibrated rear-wheel steering angular velocity , it determines the original rear-wheel steering angular velocity as the target rear-wheel steering angular velocity . When it determines that the original rear-wheel steering angular velocity is greater than the calibrated rear-wheel steering angular velocity , the calibrated rear-wheel steering angular velocity is determined as the target rear-wheel steering angular velocity . It can be understood that when the original rear-wheel steering angular velocity is greater than the limit value of the rear-wheel steering angular velocity , if the original rear-wheel steering angular velocity is determined as the target rear-wheel steering angular velocity , the safety and stability of the vehicle's steering will be greatly reduced. To ensure the safety and stability of the vehicle's steering, the smaller value between the original rear-wheel steering angular velocity and the calibrated rear-wheel steering angular velocity is determined as the target rear-wheel steering angular velocity . At this time, the target rear-wheel steering angular velocity ensures safety while being closest to the original rear-wheel steering angular velocity . Therefore, it can effectively ensure the steering maneuverability of the vehicle. It can be understood that to ensure that the vehicle has safety and stability while having maneuverability during the steering process, it is necessary to ensure that both the target rear-wheel steering angle and the target rear-wheel steering angular velocity are within a controllable safety range. Therefore, the calibrated rear-wheel steering angle and the calibrated rear-wheel steering angular velocity are set to ensure the safety and stability during the vehicle's steering process.

[0062] As an example, in step S1041C, after the vehicle-mounted controller determines the target steering angle and the target steering angle speed, it determines the steering tie rod displacement according to the target rear wheel steering angle, and determines the steering tie rod moving speed according to the target rear wheel steering angle speed. The steering tie rod moving speed is the moving speed of the rear wheel steering tie rod for controlling the rear wheel steering, and is used to enable the rear wheel steering gear to control the rear wheel steering tie rod to stably move according to the steering tie rod displacement corresponding to the steering tie rod moving speed. In this example, the vehicle-mounted controller queries in the correspondence conversion table between the target rear wheel steering angle and the steering tie rod displacement prestored in the system database to determine the steering tie rod displacement corresponding to the target rear wheel steering angle, and queries in the correspondence conversion table between the target rear wheel steering angle speed and the steering tie rod moving speed prestored in the system database to determine the steering tie rod moving speed corresponding to the target rear wheel steering angle speed. This method does not require complex calculations, is relatively convenient and fast, and improves the real-time performance of vehicle steering control.

[0063] As an example, in step S1041D, the vehicle-mounted controller controls the steering tie rod to stably move to the steering tie rod displacement in real time according to the steering tie rod moving speed through the rear wheel steering gear, so as to achieve the purpose of controlling the steering angle of the rear wheel to stably move to the target rear wheel steering angle according to the target rear wheel steering angle speed.

[0064] In this embodiment, by performing limit processing on the original rear wheel steering angle speed to determine the target rear wheel steering angle speed and the steering tie rod moving speed, it can effectively ensure that the steering tie rod corresponding to the rear wheel stably moves to the steering tie rod displacement according to the steering tie rod moving speed, and further achieve the control of the rear wheel to stably move to the target rear wheel steering angle according to the target rear wheel steering angle speed, ensuring the maneuverability, safety and stability during the process of target rear wheel steering, and improving the user's driving and riding experience.

[0065] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0066] In one embodiment, a vehicle steering control device is provided, and the vehicle steering control device corresponds one-to-one to the vehicle steering control method in the above embodiment. As Figure 4 shown, the vehicle steering control device includes a data acquisition module 401, an original rear wheel steering angle determination module 402, a target rear wheel steering angle determination module 403, and a steering control module 404. The detailed descriptions of each functional module are as follows: The data acquisition module 401 is configured to acquire vehicle measured data, and the vehicle measured data includes the front wheel steering angle; The original rear-wheel steering angle determination module 402 processes the measured vehicle data based on the rear-wheel steering angle control model to determine the original rear-wheel steering angle. Among them, the original rear-wheel steering angle corresponding to the first steering stage has a reverse steering with the front-wheel steering angle that is less than the preset angle, and the original rear-wheel steering angle corresponding to the second steering stage has the same-direction steering as the front-wheel steering angle. The first steering stage and the second steering stage are two successive stages formed during the vehicle steering process. The target rear-wheel steering angle determination module 403 determines the target rear-wheel steering angle based on the original rear-wheel steering angle and the calibrated rear-wheel steering angle corresponding to the original rear-wheel steering angle. The steering control module 404 controls the operation of the rear-wheel steering gear based on the target rear-wheel steering angle.

[0067] In one embodiment, the original rear-wheel steering angle determination module 402 includes: The vehicle steering data determination sub-module determines the vehicle steering data based on the measured vehicle data. The vehicle steering data is the data related to vehicle steering. The original rear-wheel steering angle determination sub-module processes the vehicle steering data based on the rear-wheel steering angle control model to determine the original rear-wheel steering angle.

[0068] In one embodiment, the steering control module 404 includes: The first steering control module sub-module determines the steering tie rod displacement based on the target rear-wheel steering angle. The rear-wheel steering gear control sub-module controls the operation of the rear-wheel steering gear based on the steering tie rod displacement.

[0069] In one embodiment, the rear-wheel steering gear control sub-module includes: The original rear-wheel steering angle speed determination unit determines the original rear-wheel steering angle speed based on the original rear-wheel steering angle. The target rear-wheel steering angle speed determination unit determines the target rear-wheel steering angle speed based on the original rear-wheel steering angle speed and the calibrated rear-wheel steering angle speed. The target rear-wheel steering angle speed is the smaller value of the original rear-wheel steering angle speed and the calibrated rear-wheel steering angle speed. The steering tie rod movement speed determination unit determines the steering tie rod movement speed based on the target rear-wheel steering angle speed. The rear-wheel steering gear control unit controls the operation of the rear-wheel steering gear based on the steering tie rod displacement and the steering tie rod movement speed.

[0070] For the specific limitations of the vehicle steering control device, reference can be made to the limitations on the vehicle steering control method in the above text, which will not be elaborated here. Each module in the above vehicle steering control device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0071] In one embodiment, as Figure 5 shown, a vehicle-mounted controller is provided, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the vehicle steering control method in the above embodiment is implemented, such as Figure 1 S101 - S104 shown. To avoid repetition, it will not be elaborated here. Alternatively, when the processor executes the computer program, the functions of each module / unit in the above embodiment of the vehicle steering control device are implemented, such as Figure 4 the functions of the data acquisition module 401, the original rear-wheel steering angle determination module 402, the target rear-wheel steering angle determination module 403, and the steering control module 404 shown. To avoid repetition, it will not be elaborated here.

[0072] In one embodiment, a vehicle is provided, which includes the vehicle-mounted controller in the above embodiment and is used to implement the vehicle steering control method in any of the above embodiments.

[0073] In one embodiment, a computer-readable storage medium is provided. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the vehicle steering control method in the above embodiment is implemented, such as Figure 1 S101 - S104 shown. To avoid repetition, it will not be elaborated here. Alternatively, when the computer program is executed by a processor, the functions of each module / unit in the above embodiment of the vehicle steering control device are implemented, such as Figure 4 the functions of the data acquisition module 401, the original rear-wheel steering angle determination module 402, the target rear-wheel steering angle determination module 403, and the steering control module 404 shown. To avoid repetition, it will not be elaborated here.

[0074] In this application, "a plurality of" means two or more.

[0075] In this application, unless otherwise clearly defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0076] The terms "first", "second", "third", "fourth", etc. (if any) in this application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence.

[0077] In this application, the term "and / or" is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0078] If there is no special indication, all steps of this application can be carried out sequentially or randomly. For example, the method includes steps A and B, which means that the method may include steps A and B carried out sequentially, or may also include steps B and A carried out sequentially. For example, when it is mentioned that the method may further include step C, it means that step C can be added to the method in any order. For example, the method may include steps A, B, and C, or may also include steps A, C, and B, or may include steps C, A, and B, etc.

[0079] The above are only the preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

1. A vehicle steering control method, characterized in that Including: Obtain the actual vehicle data, where the actual vehicle data includes the front wheel steering angle; Process the actual vehicle data based on the rear wheel steering angle control model to determine the original rear wheel steering angle; wherein, the original rear wheel steering angle corresponding to the first steering stage has a reverse steering with the front wheel steering angle less than a preset angle, and the original rear wheel steering angle corresponding to the second steering stage has the same steering direction as the front wheel steering angle. The first steering stage and the second steering stage are two stages formed successively during the vehicle steering process; Determine the target rear wheel steering angle based on the original rear wheel steering angle and the calibrated rear wheel steering angle corresponding to the original rear wheel steering angle; Control the operation of the rear wheel steering gear based on the target rear wheel steering angle.

2. The vehicle steering control method according to claim 1, wherein, The processing of the actual vehicle data based on the rear wheel steering angle control model to determine the original rear wheel steering angle includes: Determine the vehicle steering data based on the actual vehicle data, where the vehicle steering data is data related to vehicle steering; Process the vehicle steering data based on the rear wheel steering angle control model to determine the original rear wheel steering angle.

3. The vehicle steering control method according to claim 1, wherein The actual vehicle data further includes the vehicle speed; The vehicle steering data includes the front wheel steering angle and the target parameters determined based on the vehicle speed. The target parameters include the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the rear wheel reverse steering angle ratio coefficient, the front and rear wheel steering angle ratio coefficient, and the filtering coefficient; The original rear wheel steering angle is the steering angle determined by processing the target parameters and the front wheel steering angle based on the rear wheel steering angle control model.

4. The vehicle steering control method according to claim 3, wherein The rear wheel steering angle control model includes a first control term and a second control term; The first control term is determined based on the rear wheel reverse steering angle ratio coefficient, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, and the front wheel steering angle, and is used to make the original rear wheel steering angle corresponding to the first steering stage have a reverse steering angle with the front wheel steering angle less than a preset angle; The second control term is determined based on the rear wheel reverse steering angle ratio coefficient, the equivalent cornering stiffness of the front axle, the equivalent cornering stiffness of the rear axle, the front and rear wheel steering angle ratio coefficient, the filtering coefficient, and the front wheel steering angle, and is used to control the duration of the first steering stage and make the original rear wheel steering angle corresponding to the second steering stage have the same steering direction as the front wheel steering angle.

5. The vehicle steering control method according to claim 1, characterized in that, The target rear wheel steering angle is the smaller value of the original rear wheel steering angle and the calibrated rear wheel steering angle; The controlling the operation of the rear wheel steering gear based on the target rear wheel steering angle includes: Determine the steering tie rod displacement based on the target rear wheel steering angle; Control the operation of the rear wheel steering gear based on the steering tie rod displacement.

6. The vehicle steering control method according to claim 5, characterized in that The controlling the operation of the rear wheel steering gear based on the steering tie rod displacement includes: Determine the original rear wheel steering angular velocity based on the original rear wheel steering angle; Determine the target rear wheel steering angular velocity based on the original rear wheel steering angular velocity and the calibrated rear wheel steering angular velocity; the target rear wheel steering angular velocity is the smaller value of the original rear wheel steering angular velocity and the calibrated rear wheel steering angular velocity; Determine the steering tie rod moving speed based on the target rear wheel steering angular velocity; Control the operation of the rear wheel steering gear based on the steering tie rod displacement and the steering tie rod moving speed.

7. The vehicle steering control method according to any one of claims 1 to 6, characterized in that, The rear-wheel steering angle control model is = , where is the first control term, is the second control term, is the rear-wheel reverse steering angle ratio coefficient, is the front and rear wheel steering angle ratio coefficient, is the equivalent cornering stiffness of the front axle, is the equivalent cornering stiffness of the rear axle, is the filtering coefficient, is the front-wheel steering angle, is the original rear-wheel steering angle.

8. A vehicle steering control device, characterized in that, Including: A data acquisition module for acquiring actual vehicle data, where the actual vehicle data includes the front wheel steering angle; An original rear wheel steering angle determination module processes the actual vehicle data based on a rear wheel steering angle control model to determine an original rear wheel steering angle; wherein, the original rear wheel steering angle corresponding to the first steering stage has a reverse steering with the front wheel steering angle that is less than a preset angle, and the original rear wheel steering angle corresponding to the second steering stage has the same steering direction as the front wheel steering angle. The first steering stage and the second steering stage are two stages formed successively during the vehicle steering process; A target rear wheel steering angle determination module determines a target rear wheel steering angle based on the original rear wheel steering angle and the calibrated rear wheel steering angle corresponding to the original rear wheel steering angle; A steering control module controls the operation of the rear wheel steering gear based on the target rear wheel steering angle.

9. An in-vehicle controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the vehicle steering control method according to any one of claims 1 to 7.

10. A vehicle, characterized in that, It includes the vehicle-mounted controller according to claim 9.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the vehicle steering control method according to any one of claims 1 - 7.

Images