Vehicle steering control method, domain controller, vehicle, and storage medium

Abstract

The application discloses a vehicle steering control method, a domain controller, a vehicle and a storage medium, and belongs to the technical field of vehicles. In the method, when a front-wheel-by-wire steering system fails, a rear-wheel steering angle is determined through a steering wheel steering angle and a vehicle speed, and the vehicle is controlled to steer through the rear-wheel steering system based on the rear-wheel steering angle. It can be seen that the scheme adopts the rear-wheel steering system as an external redundant actuator after the front-wheel-by-wire steering system fails, and the two sets of steering systems are independent of each other, so that common factor failures that cannot be coped with by internal redundancy of the front-wheel-by-wire steering system can be avoided, and thus the vehicle is prevented from completely losing the steering function, and driving safety is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a vehicle steering control method, a domain controller, a vehicle, and a storage medium. Background Technology

[0002] The steer-by-wire front wheel steering system is a key component for controlling vehicle steering, and its reliability directly affects driving safety. Currently, reliability is mainly improved through internal redundancy in the steer-by-wire front wheel steering system (such as dual motors and dual controllers). However, this internal redundancy scheme can still lead to a complete loss of steering function when faced with common factor failures (such as shared power supply failure or controller software failure) or major hardware damage, thus affecting driving safety. Summary of the Invention

[0003] This application provides a vehicle steering control method, a domain controller, a vehicle, and a storage medium. The technical solution is as follows: On the one hand, a vehicle steering control method is provided, the method comprising: When the steer-by-wire front wheel steering system malfunctions, obtain the steering wheel angle and vehicle speed; The rear wheel angle is determined based on the steering wheel angle and the vehicle speed; Based on the rear wheel angle, the vehicle steering is controlled by the rear wheel steering system.

[0004] In one possible implementation, determining the rear wheel steering angle based on the steering wheel angle and the vehicle speed includes: Based on the correspondence between vehicle speed and steering wheel angle threshold and the vehicle speed, the steering wheel angle threshold is determined; If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is negative, the rear wheel angle is determined based on the opposite of the steering wheel angle threshold; if the steering wheel angle is positive, the rear wheel angle is determined based on the steering wheel angle threshold. If the absolute value of the steering wheel angle is not greater than the steering wheel angle threshold, the rear wheel angle is determined based on the steering wheel angle.

[0005] In another possible implementation, determining the rear wheel angle based on the steering wheel angle includes: Determine the ratio of the steering wheel angle to the first transmission ratio; If the ratio is negative and the absolute value of the ratio is greater than the rear wheel steering angle threshold, the opposite of the rear wheel steering angle threshold is determined as the rear wheel steering angle; if the absolute value of the ratio is not greater than the rear wheel steering angle threshold, the ratio is determined as the rear wheel steering angle. If the ratio is positive and greater than the rear wheel steering angle threshold, the rear wheel steering angle threshold is determined as the rear wheel steering angle; if the ratio is not greater than the rear wheel steering angle threshold, the ratio is determined as the rear wheel steering angle.

[0006] In another possible implementation, the method further includes: The rear wheel steering angle threshold is determined based on the correspondence between vehicle speed and rear wheel steering angle threshold and the vehicle speed.

[0007] In another possible implementation, the method further includes: If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold, a first control command is sent to the hand feel simulation system so that the hand feel simulation system outputs reverse torque based on the first control command.

[0008] In another possible implementation, the rear-wheel steering system includes: a rear-wheel steering controller and a rear-wheel steering actuation motor; The method of controlling vehicle steering via the rear wheel steering system based on the rear wheel steering angle includes: Based on the rear wheel angle, the target position and actual position of the rear wheel rack are determined by the rear wheel steering controller; a first position difference between the target position and the actual position of the rear wheel rack is determined; based on the first position difference, a second control command is generated and sent to the rear wheel steering actuator motor; The rear wheel steering actuator motor controls the vehicle steering based on the second control command.

[0009] On the other hand, a vehicle steering control device is provided, the device comprising: The acquisition module is used to acquire the steering wheel angle and vehicle speed when the steer-by-wire front wheel steering system malfunctions. The first determining module is used to determine the rear wheel angle based on the steering wheel angle and the vehicle speed; The control module is used to control the vehicle steering via the rear wheel steering system based on the rear wheel steering angle.

[0010] In one possible implementation, the first determining module is configured to determine a steering wheel angle threshold based on the correspondence between vehicle speed and steering wheel angle threshold and the vehicle speed; if the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is negative, determine the rear wheel angle based on the opposite of the steering wheel angle threshold; if the steering wheel angle is positive, determine the rear wheel angle based on the steering wheel angle threshold; if the absolute value of the steering wheel angle is not greater than the steering wheel angle threshold, determine the rear wheel angle based on the steering wheel angle.

[0011] In another possible implementation, the first determining module is configured to determine the ratio of the steering wheel angle to the first transmission ratio; if the ratio is negative and the absolute value of the ratio is greater than the rear wheel angle threshold, the negative of the rear wheel angle threshold is determined as the rear wheel angle; if the absolute value of the ratio is not greater than the rear wheel angle threshold, the ratio is determined as the rear wheel angle; if the ratio is positive and the ratio is greater than the rear wheel angle threshold, the rear wheel angle threshold is determined as the rear wheel angle; if the ratio is not greater than the rear wheel angle threshold, the ratio is determined as the rear wheel angle.

[0012] In another possible implementation, the device further includes: The second determining module is used to determine the rear wheel steering angle threshold based on the correspondence between vehicle speed and rear wheel steering angle threshold and the vehicle speed.

[0013] In another possible implementation, the device further includes: The sending module is used to send a first control command to the hand feel simulation system if the absolute value of the steering wheel angle is greater than the steering wheel angle threshold, so that the hand feel simulation system outputs a reverse torque based on the first control command.

[0014] In another possible implementation, the rear-wheel steering system includes: a rear-wheel steering controller and a rear-wheel steering actuation motor; The control module is used to determine the target position and the actual position of the rear wheel rack based on the rear wheel steering angle through the rear wheel steering controller; determine a first position difference between the target position and the actual position of the rear wheel rack; generate a second control command based on the first position difference and send the second control command to the rear wheel steering actuator motor; and control the vehicle steering through the rear wheel steering actuator motor based on the second control command.

[0015] On the other hand, a domain controller is provided, the domain controller including a processor and a memory, the memory storing at least one piece of program code, the at least one piece of program code being loaded and executed by the processor to implement the vehicle steering control method described in any of the preceding claims.

[0016] On the other hand, a vehicle is provided that includes the domain controller described above.

[0017] On the other hand, a computer-readable storage medium is provided, wherein at least one piece of program code is stored in the computer-readable storage medium, the at least one piece of program code being loaded and executed by a processor to implement the vehicle steering control method described in any of the preceding claims.

[0018] On the other hand, a computer program product is provided, wherein at least one piece of program code is stored in the computer program product, the at least one piece of program code being loaded and executed by a processor to implement the vehicle steering control method described in any of the preceding claims.

[0019] This application provides a vehicle steering control method. When the steer-by-wire front wheel steering system malfunctions, the rear wheel steering angle is determined by the steering wheel angle and vehicle speed. Based on the rear wheel steering angle, the vehicle steering is controlled by the rear wheel steering system. As can be seen, this solution uses the rear wheel steering system as an external redundant actuator after a steer-by-wire front wheel steering system failure. The two steering systems are independent of each other, avoiding common factor failures that the internal redundancy of the steer-by-wire front wheel steering system cannot handle, thereby preventing the vehicle from completely losing its steering function and improving driving safety. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an implementation environment provided in an embodiment of this application; Figure 2 This is a flowchart of a vehicle steering control method provided in an embodiment of this application; Figure 3 This is a schematic diagram of a vehicle structure equipped with a front-wheel steering system and a rear-wheel steering system, provided in an embodiment of this application. Figure 4 This is a schematic diagram of the structure of a steer-by-wire system provided in an embodiment of this application; Figure 5 This is a schematic diagram of the relationship between vehicle speed and steering wheel angle threshold provided in an embodiment of this application; Figure 6 This is a schematic diagram of the relationship between vehicle speed and rear wheel steering angle threshold provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a rear-wheel steering system provided in an embodiment of this application; Figure 8 This is a schematic diagram of the handshake logic between a domain controller and a rear wheel steering system provided in an embodiment of this application; Figure 9 This is a functional block diagram of a vehicle steering control provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of a vehicle steering control device provided in an embodiment of this application; Figure 11 This is a structural block diagram of a domain controller provided in an embodiment of this application. Detailed Implementation

[0021] To make the technical solution and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0022] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or means is not limited to the listed steps or means, but may optionally include steps or means not listed, or may optionally include other steps or means inherent to these processes, methods, products, or devices.

[0023] It should be noted that all information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in this application have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the steering wheel angle, vehicle speed, etc. involved in this application were obtained with full authorization.

[0024] Figure 1 This is a schematic diagram of an implementation environment provided in an embodiment of this application. See also... Figure 1 The implementation environment includes: a domain controller 101, a steer-by-wire front wheel steering system 102, a rear wheel steering system 103, and a hand feel simulation system 104, all of which are electrically connected to the domain controller 101.

[0025] The electrical connection can be either a circuit connection or a wireless connection, without specific limitations. If the connection is a circuit connection, the connection method can be a cable connection, such as a CAN (Controller Area Network) connection. If the connection is a wireless connection, the connection method can be an infrared connection, a wireless LAN, or a WiFi (Wireless Fidelity) network connection. In the embodiments of this application, no specific limitations are imposed.

[0026] In this embodiment, the domain controller 101 can be a chassis domain controller 101 or other domain controllers 101, without specific limitation. The domain controller 101 can monitor the operating status and fault conditions of the steer-by-wire front wheel steering system 102 in real time or periodically. When the steer-by-wire front wheel steering system 102 malfunctions and cannot perform steering, the domain controller 101 acquires the steering wheel angle and vehicle speed, determines the rear wheel angle based on the steering wheel angle and vehicle speed, and controls the vehicle steering through the rear wheel steering system 103 based on the rear wheel angle.

[0027] In this system, a wheel speed sensor 105 is installed on at least one wheel of the vehicle. The wheel speed sensor 105 outputs a wheel rotation pulse signal to a braking domain controller 106. The braking domain controller 106 calculates the vehicle speed based on the pulse signal and sends the vehicle speed to the domain controller 101. Accordingly, the implementation environment also includes: a wheel speed sensor 105 and a braking domain controller 106, with the wheel speed sensor 105 electrically connected to the braking domain controller 106, and the braking domain controller 106 electrically connected to the domain controller 101.

[0028] Regarding the steering wheel angle, when the steer-by-wire front wheel steering system 102 malfunctions, the feel simulation system 104 sends a steering wheel angle signal to the domain controller 101 in real time or periodically, and the domain controller 101 obtains the steering wheel angle based on the steering wheel angle signal.

[0029] The specific implementation process of domain controller 101 determining the rear wheel angle based on steering wheel angle and vehicle speed will be described in detail in the method embodiment, and will not be repeated here.

[0030] Figure 2 This is a flowchart of a vehicle steering control method provided in an embodiment of this application, executed by a domain controller. See also... Figure 2 The method includes: Step 201: When the steer-by-wire front wheel steering system malfunctions, the domain controller acquires the steering wheel angle and vehicle speed.

[0031] The domain controller can monitor the operating status and fault conditions of the steer-by-wire front wheel steering system in real time or periodically. When the steer-by-wire front wheel steering system fails and cannot perform steering function, the domain controller obtains the steering wheel angle and vehicle speed.

[0032] The domain controller can obtain the steering wheel angle through a tactile simulation system. This process involves the tactile simulation system sending steering wheel angle signals to the domain controller in real time or periodically, allowing the domain controller to obtain the steering wheel angle. The steering wheel angle itself can be positive or negative. For example, when the driver turns the steering wheel to the right, the steering wheel angle is positive; when the driver turns the steering wheel to the left, the steering wheel angle is negative.

[0033] Regarding vehicle speed, the domain controller can obtain the current vehicle speed sent by the braking domain controller, and the braking domain controller can calculate the current vehicle speed through the wheel speed sensors.

[0034] See Figure 3 , Figure 3 This is a schematic diagram of a vehicle structure equipped with a steer-by-wire front wheel steering system and a rear wheel steering system, provided in an embodiment of this application. Figure 3 As can be seen from the data, the vehicle includes a hand-feel simulation system 301, a steer-by-wire front wheel steering system 302, a wheel speed sensor 303, a chassis domain controller 304, and a rear wheel steering system 305.

[0035] It should be noted that when the steer-by-wire system is operating normally and without malfunction, it can interact directly with the steering simulation system or through the domain controller; there are no specific limitations on this.

[0036] In one possible implementation, the steer-by-wire front wheel steering system interacts directly with the feel simulation system. The feel simulation system sends steering wheel angle signals to the steer-by-wire front wheel steering system in real time or periodically. Based on the steering wheel angle, the steer-by-wire front wheel steering system determines the front wheel angle, thereby controlling the vehicle's steering.

[0037] In this implementation, the steer-by-wire system includes a front-wheel steer-by-wire system and a hand-feel simulation system. The hand-feel simulation system includes a steering wheel torque and angle sensor, a hand-feel simulation controller, and a hand-feel simulation actuator motor. The steering wheel torque and angle sensor is arranged on the column shaft and is used to detect the steering wheel angle and send the steering wheel angle to the hand-feel simulation controller. The hand-feel simulation sensor sends the steering wheel angle to the front-wheel steer-by-wire system.

[0038] The steer-by-wire front wheel steering system includes a gear shaft angle sensor, a front wheel steering controller, and a front wheel steering actuator motor. The gear shaft angle sensor is coaxially arranged with the steering input shaft and is used to detect the steering input shaft angle in real time or periodically, sending the steering input shaft angle to the front wheel steering controller. Based on the steering input shaft angle, the front wheel steering controller determines the actual position of the front wheel rack; based on the steering wheel angle and the second gear ratio, it determines the front wheel angle; based on the front wheel angle, it determines the target position of the front wheel rack; it determines a second position difference between the actual position and the target position of the front wheel rack; based on the second position difference, it generates a third control command and sends it to the front wheel steering actuator motor. Based on the third control command, the front wheel steering actuator motor drives the front wheel rack to push or pull the front wheel steering tie rod until the actual position of the front wheel rack matches the target position, thus achieving vehicle steering.

[0039] In this process, after determining the second position difference, the front wheel steering controller performs closed-loop adjustment calculations on the second position difference, generates a third control command in the form of motor current, and sends it to the front wheel steering actuator motor. The front wheel steering actuator motor responds to the third control command by outputting the corresponding torque, which drives the front wheel rack to push and pull the front wheel steering tie rod. The gear shaft angle sensor detects the steering input shaft angle in real time or periodically. Based on the steering input shaft angle, the front wheel steering controller determines the actual position of the front wheel rack in real time or periodically, repeatedly performing closed-loop adjustments until the second position difference between the actual position and the target position of the front wheel rack is less than the second error threshold. At this point, the front wheels reach the desired steering angle, completing the vehicle steering control.

[0040] In this embodiment, a closed-loop deviation adjustment logic is used between the target position and the actual position of the front wheel rack, which can drive the front wheel rack to continuously correct the position deviation, accurately follow the front wheel turning angle, and accurately control the vehicle steering.

[0041] In this embodiment, the steering wheel torque and angle sensor is further used to detect the angular deviation between the input and output shafts of the steering column and send the angular deviation to the feel simulation controller. The feel simulation controller determines the product of the angular deviation and the steering torsion bar stiffness to obtain the steering torque. The feel simulation controller also acquires the vehicle speed, and based on the steering torque and vehicle speed, determines the feedback torque by querying a table showing the relationship between steering torque, vehicle speed, and feedback torque. Based on the feedback torque, it generates a current request and sends the current request, which carries the feedback torque, to the feel simulation actuator motor. The feel simulation actuator motor outputs a reverse torque based on the feedback torque to counteract the driver's hand force, achieving automatic steering wheel return and a feel that adjusts to vehicle speed.

[0042] The above explanation uses a steer-by-wire front wheel steering system, which includes one front wheel steering controller and one front wheel steering actuator motor, as an example. In practical applications, dual front wheel steering controllers and dual front wheel steering actuator motors can also be configured to achieve internal redundancy within the steer-by-wire front wheel steering system; no specific limitations are imposed on this.

[0043] In another possible implementation, the steer-by-wire front wheel steering system interacts with the feel simulation system via a domain controller. Accordingly, the feel simulation system sends steering wheel angle signals to the domain controller in real-time or periodically. The domain controller then sends the steering wheel angle signals to the steer-by-wire front wheel steering system, which determines the front wheel angle based on the steering wheel angle, thereby controlling the vehicle's steering.

[0044] In this implementation, the process of the hand-feel simulation system sending steering wheel angle signals to the domain controller in real time or periodically is the same as the process of the hand-feel simulation system sending steering wheel angle signals to the steer-by-wire front wheel steering system in real time or periodically. The process of the steer-by-wire front wheel steering system determining the front wheel angle based on the steering wheel angle is the same as the process of the steer-by-wire front wheel steering system determining the front wheel angle based on the steering wheel angle in the above implementation, and will not be described again here.

[0045] It's important to note that if the steer-by-wire system interacts directly with the hand-feel simulation system, and the steer-by-wire system malfunctions and cannot receive steering wheel angle data, the domain controller sends a request to the hand-feel simulation system. The hand-feel simulation system receives this request and, based on it, sends the steering wheel angle data to the domain controller in real-time or periodically, allowing the domain controller to obtain the steering wheel angle. If the steer-by-wire system interacts with the hand-feel simulation system through the domain controller, the domain controller directly obtains the steering wheel angle data sent by the hand-feel simulation system.

[0046] See Figure 4 , Figure 4 This is a schematic diagram of a steer-by-wire system provided in an embodiment of this application. Figure 4 As can be seen from the diagram, the steer-by-wire system includes a steering wheel 401, a steering wheel torque and angle sensor 402, a hand feel simulation controller 403, a hand feel simulation actuator motor 404, a worm gear reduction mechanism 405, a steer-by-wire private CAN communication 406, a chassis domain private CAN communication 407, a gear shaft angle sensor 408, a front wheel steering controller 409, a front wheel steering actuator motor 410, a belt reduction mechanism 411, a ball screw nut mechanism 412, a front wheel steering inner tie rod 413, and a front wheel steering outer tie rod 414.

[0047] Step 202: The domain controller determines the rear wheel angle based on the steering wheel angle and vehicle speed.

[0048] This step can be achieved through the following steps (1) to (3), including: (1) The domain controller determines the steering wheel angle threshold based on the correspondence between vehicle speed and steering wheel angle threshold and vehicle speed.

[0049] The relationship between vehicle speed and steering wheel angle threshold is as follows: when the vehicle speed is less than the first vehicle speed threshold, the steering wheel angle threshold is the first fixed threshold; when the vehicle speed is not less than the first vehicle speed threshold and not greater than the second vehicle speed threshold, the steering wheel angle threshold is linearly related to the vehicle speed and decreases linearly as the vehicle speed increases; when the vehicle speed is greater than the second vehicle speed threshold, the steering wheel angle threshold is the second fixed threshold, and the first fixed threshold is greater than the second fixed threshold.

[0050] The domain controller determines the steering wheel angle threshold corresponding to the current vehicle speed based on the correspondence between vehicle speed and steering wheel angle threshold. After determining the steering wheel angle threshold, the domain controller can determine whether the steering wheel angle is greater than the steering wheel angle threshold. If the steering wheel angle is greater than the steering wheel angle threshold, step (2) is executed. If the steering wheel angle is not greater than the steering wheel angle threshold, step (3) is executed.

[0051] See Figure 5 , Figure 5 This is a schematic diagram of the relationship between vehicle speed and steering wheel angle threshold provided in an embodiment of this application. Figure 5 The steering wheel angle threshold only represents the magnitude, not the direction.

[0052] In this embodiment, the steering wheel angle threshold is dynamically limited based on vehicle speed. The higher the vehicle speed, the smaller the corresponding steering wheel angle threshold. This prevents large steering angle commands from being input into the rear wheel calculations from the source, thus suppressing fishtailing and oversteering caused by large rear wheel deflections at the root, and significantly improving high-speed driving stability under front wheel failure conditions. Furthermore, the large threshold at low speeds does not restrict normal U-turns, while the upper limit of the steering angle is tightened at high speeds, balancing steering flexibility and driving safety in failure modes.

[0053] (2) If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is negative, the domain controller determines the rear wheel angle based on the opposite of the steering wheel angle threshold; if the steering wheel angle is positive, the domain controller determines the rear wheel angle based on the steering wheel angle threshold.

[0054] In one possible implementation, if the absolute value of the steering wheel angle is greater than a steering wheel angle threshold and the steering wheel angle is negative, the domain controller determines the ratio of the negative of the steering wheel angle threshold to a first gear ratio. If this ratio is greater than the rear wheel angle threshold, the rear wheel angle threshold is determined as the rear wheel angle; if the ratio is not greater than the rear wheel angle threshold, the ratio is determined as the rear wheel angle. If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is positive, the domain controller determines the ratio of the steering wheel angle threshold to a first gear ratio. If the absolute value of this ratio is greater than the rear wheel angle threshold, the negative of the rear wheel angle threshold is determined as the rear wheel angle; if the absolute value of this ratio is not greater than the rear wheel angle threshold, the ratio is determined as the rear wheel angle.

[0055] The first gear ratio is the gear ratio corresponding to the rear wheel steering system, and the second gear ratio is the gear ratio corresponding to the front wheel steering system. The first gear ratio and the second gear ratio can be the same or different, and there is no specific limitation on this.

[0056] In this system, the first gear ratio is a negative value. It can be a fixed value or calibrated based on vehicle speed segments. For example, when the vehicle speed is less than a third speed threshold, the first gear ratio is the first value; when the vehicle speed is not less than the third speed threshold, the first gear ratio is the second value, where the first value is greater than the second value. Alternatively, the system can be further divided into multiple segments based on vehicle speed, with each segment corresponding to a different first gear ratio. Similarly, the second gear ratio can also be calibrated based on vehicle speed segments; no specific limitations are imposed on this.

[0057] In this embodiment of the application, the rear wheel steering angle is limited according to the rear wheel steering angle threshold, which can prevent the rear wheel steering angle from being too large and making the vehicle difficult to control.

[0058] In another possible implementation, if the absolute value of the steering wheel angle is greater than a steering wheel angle threshold and the steering wheel angle is negative, the domain controller determines the ratio of the negative of the steering wheel angle threshold to the first gear ratio. If this ratio is greater than the rear wheel angle threshold, then the rear wheel angle threshold is determined as the rear wheel angle. If the ratio is not greater than the rear wheel angle threshold, a target yaw rate is determined based on the steering wheel angle and vehicle speed. The actual yaw rate is obtained through an inertial measurement sensor. The angle difference between the target yaw rate and the actual yaw rate is determined. The product of this angle difference and a correction coefficient is determined to obtain a correction amount. The sum of the correction amount and the ratio is determined. If the sum is not greater than the rear wheel angle threshold, then the sum is determined as the rear wheel angle. If the sum is greater than the rear wheel angle threshold, then the rear wheel angle threshold is determined as the rear wheel angle.

[0059] If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is positive, the domain controller determines the ratio of the steering wheel angle threshold to the first gear ratio. If the absolute value of this ratio is greater than the rear wheel angle threshold, the negative of the rear wheel angle threshold is determined as the rear wheel angle. If the absolute value of this ratio is not greater than the rear wheel angle threshold, the target yaw rate is determined based on the steering wheel angle and vehicle speed. The actual yaw rate is obtained through an inertial measurement sensor. The angle difference between the target yaw rate and the actual yaw rate is determined. The product of this angle difference and a correction coefficient is determined to obtain the correction amount. The sum of the correction amount and the absolute value of the ratio is determined. If the sum is not greater than the rear wheel angle threshold, the negative of the sum is determined as the rear wheel angle. If the sum is greater than the rear wheel angle threshold, the negative of the rear wheel angle threshold is determined as the rear wheel angle.

[0060] The domain controller can substitute steering wheel angle and vehicle speed into the target relational data to obtain the target yaw rate. The target relational data represents the relationship between steering wheel angle, vehicle speed, and yaw rate. The specific expression of the target relational data can be calibrated as needed; no specific limitations are imposed here.

[0061] The correction factor can be a fixed value or it can be segmented according to vehicle speed. For example, when the vehicle speed is less than the fourth speed threshold, the correction factor is the first correction factor; when the vehicle speed is not less than the fourth speed threshold, the correction factor is the second correction factor, and the first correction factor is greater than the second correction factor. Of course, further subdivisions can be made, for example, dividing the vehicle speed into multiple segments, each corresponding to a correction factor.

[0062] In this embodiment, the correction amount is calculated by the deviation between the target yaw rate and the actual yaw rate, which can dynamically compensate for vehicle instability trends such as understeer and oversteer, thereby improving the vehicle's steering dynamics stability. Furthermore, at lower vehicle speeds, the correction coefficient is larger, resulting in a greater correction force, which can compensate for the weak steering torque of the rear wheels; at higher vehicle speeds, the correction coefficient is smaller, which can prevent overcorrection from causing vehicle vibration. In addition, a secondary threshold limit is applied to the rear wheel angle after the correction amount is superimposed, further limiting protection to prevent problems such as fishtailing and sideslip caused by exceeding the rear wheel angle limit.

[0063] For the rear wheel steering angle threshold, the domain controller can determine the rear wheel steering angle threshold when determining the steering wheel angle threshold based on vehicle speed. Accordingly, the process can be: the domain controller determines the rear wheel steering angle threshold based on the correspondence between vehicle speed and the rear wheel steering angle threshold, and the vehicle speed itself.

[0064] The relationship between vehicle speed and rear wheel steering angle threshold is as follows: when the vehicle speed is less than the fifth speed threshold, the rear wheel steering angle threshold is the third fixed threshold; when the vehicle speed is not less than the fifth speed threshold and not greater than the sixth speed threshold, the rear wheel steering angle threshold is linearly related to the vehicle speed and decreases linearly as the vehicle speed increases; when the vehicle speed is greater than the sixth speed threshold, the rear wheel steering angle threshold is the fourth fixed threshold, and the third fixed threshold is greater than the fourth fixed threshold.

[0065] The first and fifth speed thresholds can be the same or different; there are no specific restrictions on this. Similarly, the second and sixth speed thresholds can be the same or different; there are no specific restrictions on this.

[0066] See Figure 6 , Figure 6 This is a schematic diagram of the relationship between vehicle speed and rear wheel steering angle threshold provided in an embodiment of this application. Figure 6 The center and rear wheel steering angle thresholds only represent magnitude, not direction.

[0067] In this embodiment, the rear wheel steering angle threshold is dynamically determined based on vehicle speed, enabling the rear wheel steering angle threshold to adaptively adjust with vehicle speed. This ensures cornering ability at low speeds and suppresses fishtailing and sideslip at high speeds. Furthermore, it is coordinated and matched with the steering wheel angle threshold, unifying the vehicle control logic and reducing development costs.

[0068] It should be noted that if the absolute value of the steering wheel angle is greater than the steering wheel angle threshold, the domain controller can also send a first control command to the hand feel simulation system, so that the hand feel simulation system outputs reverse torque based on the first control command.

[0069] In one possible implementation, if the absolute value of the steering wheel angle is greater than a steering wheel angle threshold, the domain controller can determine the difference between the absolute value of the steering wheel angle and the steering wheel angle threshold, and determine the resistance torque based on this difference.

[0070] In this implementation, the domain controller can pre-establish a correspondence between the difference and the resistance torque, and then determine the resistance torque corresponding to the difference based on this correspondence. Alternatively, the domain controller can pre-establish a correspondence between the difference range and the resistance torque, then determine the difference range in which the difference lies, and then determine the resistance torque corresponding to the difference range based on this correspondence.

[0071] In this embodiment, if the resistance torque is determined based on the correspondence between the difference and the resistance torque, the resistance torque can be continuously and smoothly changed with the difference. When the steering wheel slightly exceeds the threshold, the resistance rises slowly. The more forcefully the steering wheel is turned, the greater the difference, and the resistance torque increases linearly in sync. There will be no sudden increase in weight or abrupt discomfort, thereby improving the driving experience.

[0072] If the resistance torque is determined based on the correspondence between the difference range and the resistance torque, then there is no need for massive single-point matching, which greatly reduces calibration time. Furthermore, segmented torque can form graded tactile warnings, and small signal fluctuations will not cause frequent changes in resistance, resulting in a more stable steering wheel feel.

[0073] In another possible implementation, if the absolute value of the steering wheel angle is greater than a steering wheel angle threshold, the domain controller can determine the difference between the absolute value of the steering wheel angle and the steering wheel angle threshold, and determine the resistance torque based on the difference and the vehicle speed.

[0074] In this implementation, the domain controller can pre-establish the correspondence between the difference, vehicle speed, and resistance torque, and then determine the resistance torque corresponding to the difference and the current vehicle speed based on the correspondence.

[0075] In this embodiment, the resistance torque is matched by combining the difference and vehicle speed. The magnitude of the resistance torque can be adjusted according to the difference in vehicle speed. The resistance is stronger at high speed to suppress dangerous sharp turns, while the resistance is gentler at low speed to ensure flexible steering.

[0076] For any of the above implementation methods, after the domain controller determines the resistance torque, it can add the resistance torque to the original feedback torque, that is, determine the sum of the feedback torque and the resistance torque to obtain the target torque, and carry this target torque in the first control command. After receiving the first control command, the steering wheel simulation system outputs a reverse torque based on the target torque to softly limit the steering wheel.

[0077] In this embodiment of the application, when the steer-by-wire front wheel steering system malfunctions and enters redundant steering control, since the rear wheel steering cannot perform the steering function as completely as the front wheel, it can only perform a certain range of steering actions. Therefore, the steering wheel is softly limited by the feel simulation system to restrict the steering wheel rotation.

[0078] (3) If the absolute value of the steering wheel angle is not greater than the steering wheel angle threshold, the domain controller determines the rear wheel angle based on the steering wheel angle.

[0079] In one possible implementation, if the absolute value of the steering wheel angle is not greater than a steering wheel angle threshold, the domain controller determines the ratio of the steering wheel angle to a first gear ratio; if the ratio is negative and its absolute value is greater than the rear wheel angle threshold, then the negative of the rear wheel angle threshold is determined as the rear wheel angle. If the absolute value of the ratio is not greater than the rear wheel angle threshold, then the ratio is determined as the rear wheel angle. If the ratio is positive and its value is greater than the rear wheel angle threshold, then the rear wheel angle threshold is determined as the rear wheel angle; if the ratio is not greater than the rear wheel angle threshold, then the ratio is determined as the rear wheel angle.

[0080] In this embodiment, a standardized conversion logic for steering wheel angle and rear wheel angle is established. A linear mapping of the steering angle is achieved by relying on a fixed first transmission ratio. The calculation logic is simple, the computational load is small, and real-time response to fault-tolerant steering is guaranteed. Furthermore, based on the steering wheel angle threshold, a rear wheel angle threshold judgment is added, forming a dual limit protection mechanism. First, the driver's input is constrained, and then the rear wheel's output is constrained, preventing the actual rear wheel deflection angle from exceeding the limit and further mitigating the risk of vehicle instability.

[0081] In another possible implementation, if the absolute value of the steering wheel angle is not greater than a steering wheel angle threshold, the domain controller determines the ratio of the steering wheel angle to the first gear ratio. If the ratio is negative and the absolute value of the ratio is greater than the rear wheel angle threshold, the negative of the rear wheel angle threshold is determined as the rear wheel angle. If the absolute value of the ratio is not greater than the rear wheel angle threshold, a target yaw rate is determined based on the steering wheel angle and vehicle speed. The actual yaw rate is obtained through an inertial measurement sensor. The angle difference between the target yaw rate and the actual yaw rate is determined. The product of the angle difference and a correction coefficient is determined to obtain a correction amount. The sum of the correction amount and the absolute value of the ratio is determined. If the sum is not greater than the rear wheel angle threshold, the negative of the sum is determined as the rear wheel angle. If the sum is greater than the rear wheel angle threshold, the negative of the rear wheel angle threshold is determined as the rear wheel angle.

[0082] If the ratio is positive and greater than the rear wheel angle threshold, the rear wheel angle threshold is determined as the rear wheel angle. If the ratio is not greater than the rear wheel angle threshold, the target yaw rate is determined based on the steering wheel angle and vehicle speed. The actual yaw rate is obtained through an inertial measurement sensor. The angle difference between the target yaw rate and the actual yaw rate is determined. The product of this angle difference and the correction coefficient is determined to obtain the correction amount. The sum of the correction amount and the ratio is determined. If the sum is not greater than the rear wheel angle threshold, the sum is determined as the rear wheel angle. If the sum is greater than the rear wheel angle threshold, the rear wheel angle threshold is determined as the rear wheel angle.

[0083] This implementation method is similar to the method in step (2) that calculates the correction amount based on the deviation between the target yaw rate and the actual yaw rate, and will not be repeated here.

[0084] In this embodiment, the rear wheel steering system follows a reverse steering control strategy. That is, when the driver turns the steering wheel to the right, the rear wheel steering system controls the rear wheels to turn to the left, and when the driver turns the steering wheel to the left, the rear wheel steering system controls the rear wheels to turn to the right.

[0085] For example, at a vehicle speed of 10 km / h, the corresponding steering wheel angle threshold is 300°, the rear wheel angle threshold is -10, the first gear ratio is -30, and the steering wheel angle is 120°. It can be seen that the steering wheel angle is positive and less than the steering wheel angle threshold. The ratio of the steering wheel angle to the first gear ratio is -4°. The absolute value of this ratio is less than the rear wheel angle threshold. Therefore, this ratio of -4° is taken as the rear wheel angle, and the rear wheels steer in the opposite direction to the steering wheel.

[0086] For example, if the vehicle speed is 120 km / h, the corresponding steering wheel angle threshold is 30°, the rear wheel angle threshold is 1°, the first gear ratio is -10, and the steering wheel angle is -120°. It can be seen that the steering wheel angle is negative, and its absolute value is greater than the steering wheel angle threshold. Therefore, the ratio of the negative of the steering wheel angle threshold to the first gear ratio is 3°. This ratio is greater than the rear wheel angle threshold, so the rear wheel angle threshold of 1° is taken as the rear wheel angle, and the rear wheels turn in the opposite direction to the steering wheel.

[0087] Step 203: The domain controller controls the vehicle steering through the rear wheel steering system based on the rear wheel angle.

[0088] The domain controller sends a fourth control command to the rear-wheel steering system, which carries the rear wheel steering angle. The rear-wheel steering system receives the fourth control command and, based on the rear wheel steering angle, controls the vehicle's steering.

[0089] Before sending the fourth control command to the rear-wheel steering system, the domain controller can first send a handshake request to the rear-wheel steering system to query its operating status and fault conditions. If the rear-wheel steering system is operating normally and without faults, it replies to the domain controller with a handshake response, reporting that it is operating normally and without faults. Upon receiving the handshake response, the domain controller confirms that the rear-wheel steering system is operating normally and without faults, and then sends the fourth control command to the rear-wheel steering system.

[0090] In addition, during the interaction between the domain controller and the rear wheel steering system, the domain controller can also periodically send handshake requests to the rear wheel steering system to confirm the operating status and fault conditions of the rear wheel steering system.

[0091] The rear wheel steering system includes a linear displacement sensor, a rear wheel steering controller, and a rear wheel steering actuator motor. Step 203 can be achieved through the following steps (1) to (2): (1) The domain controller determines the target position and actual position of the rear wheel rack based on the rear wheel angle and the rear wheel steering controller; determines the first position difference between the target position and the actual position of the rear wheel rack; and generates a second control command based on the first position difference and sends the second control command to the rear wheel steering actuator motor.

[0092] The domain controller sends the rear wheel angle to the rear wheel steering controller, which determines the target position of the rear wheel rack based on the preset angle-rack travel calibration relationship and the rear wheel angle.

[0093] A linear displacement sensor is used to detect the actual position of the rear wheel rack in real time or periodically, and sends the actual position of the rear wheel rack to the rear wheel steering controller, so that the rear wheel steering controller can obtain the actual position of the rear wheel rack. The rear wheel steering controller determines a first position difference between the actual position of the rear wheel rack and the target position of the rear wheel rack, performs closed-loop adjustment calculation on the first position difference, generates a second control command in the form of motor current, and sends it to the rear wheel steering actuator motor.

[0094] (2) The domain controller controls the vehicle steering by means of the rear wheel steering actuator motor based on the second control command.

[0095] The rear wheel steering actuator motor outputs corresponding torque based on the second control command, driving the rear wheel rack to push and pull the rear wheel steering tie rod. The linear displacement sensor continuously provides feedback on the actual position of the rear wheel rack, repeatedly adjusting in a closed loop until the first position difference between the actual position of the rear wheel rack and the target position of the rear wheel rack is less than the first error threshold. At this point, the rear wheels reach the target rear wheel steering angle, completing the vehicle steering control.

[0096] In this embodiment, the actual position of the rear wheel rack is directly detected by a linear displacement sensor, eliminating the indirect angle conversion step. This results in smaller position detection errors, faster feedback, and higher precision in rear wheel angle control. Furthermore, by employing closed-loop deviation adjustment logic between the target position and the actual position of the rear wheel rack, the rear wheel rack can be continuously corrected to precisely follow the rear wheel angle, thus stably achieving a rear wheel steering control strategy of low-speed reverse and high-speed same-direction steering.

[0097] The above description only illustrates a rear-wheel steering system that includes one rear-wheel steering controller and one rear-wheel steering actuator motor. In practical applications, dual rear-wheel steering controllers and dual rear-wheel steering actuator motors can also be configured to achieve redundancy within the rear-wheel steering system; no specific limitations are imposed on this.

[0098] Figure 7 This is a schematic diagram of a rear-wheel steering system provided in an embodiment of this application. Figure 7 As can be seen from the diagram, the rear wheel steering system includes a chassis domain proprietary CAN communication 701, a linear displacement sensor 702, a rear wheel steering controller 703, a rear wheel steering actuator motor 704, a belt reduction mechanism 705, a T-type lead screw self-locking mechanism 706, a rear wheel steering inner tie rod 707, and a rear wheel steering outer tie rod 708.

[0099] Figure 8 This is a schematic diagram illustrating the handshake logic between a domain controller and a rear-wheel steering system, as provided in an embodiment of this application. The handshake logic is as follows: C1: The following conditions must be met: (1) There is no fault inside the domain controller; (2) The hand-feel simulation system can send the steering wheel angle signal normally; (3) There is no fault affecting the function of the rear wheel steering system. When the above conditions are met, the rear wheel steering system enters the ready state, that is, the Available for control state, and is ready to respond to the request of the domain controller at any time.

[0100] C2: The following conditions must be met: (1) a serious malfunction occurs in the front wheel steering system; (2) the domain controller sends a handshake request; (3) the domain controller sends the rear wheel steering angle; (4) the rear wheel steering system experiences a malfunction that does not affect its function. When the above conditions are met, the rear wheel steering system enters the active state, i.e., the Active state.

[0101] C3: The following conditions must be met: (1) the domain controller no longer sends periodic handshake requests; (2) there is no functional failure in the rear wheel steering system. When the above conditions are met, the rear wheel steering system returns to the Available for control state, ready to respond to requests from the domain controller.

[0102] C4: When any of the following conditions are met: (1) the steering wheel angle signal of the hand-feel simulation system is lost; (2) the handshake request of the domain controller is lost; (3) the rear wheel angle of the domain controller is lost; (4) the rear wheel steering system itself has a fault affecting its function. When any of the above conditions are met, the rear wheel steering system enters a temporary inhibit state, that is, a Temporary inhibit state, and no longer responds.

[0103] C5: When any of the following conditions are met: (1) The rear wheel steering system produces a fault that affects the function and cannot be recovered in the current ignition cycle. At this time, the rear wheel steering system enters a fault state, namely the Permanent failed state, and no longer responds.

[0104] Figure 9 This is a functional block diagram of a vehicle steering control provided in an embodiment of this application. From... Figure 9 As can be seen, the driver inputs steering input, and the vehicle provides ignition, high-voltage enable, and vehicle speed signals. The domain controller acquires the operating status and fault conditions of the steer-by-wire front wheel steering system. When the following fault occurs: the steer-by-wire front wheel steering system experiences a serious malfunction and cannot perform steering, but the hand-feed simulation system can still send steering wheel angle signals normally, the domain controller sends control commands to the rear wheel steering system. The rear wheels steer in the opposite direction to the steering wheel, controlling the vehicle to change lanes, decelerate, and stop, ensuring vehicle safety. During the interaction between the domain controller and the rear wheel steering system, the domain controller can periodically send handshake requests to the rear wheel steering system. Based on these handshake requests, the rear wheel steering system periodically provides feedback on its operating status and fault conditions. Furthermore, when the steering wheel angle exceeds a steering wheel angle threshold, the hand-feed simulation system can also soft-limit the steering wheel.

[0105] This application provides a vehicle steering control method. When the steer-by-wire front wheel steering system malfunctions, the rear wheel steering angle is determined by the steering wheel angle and vehicle speed. Based on the rear wheel steering angle, the vehicle steering is controlled by the rear wheel steering system. As can be seen, this solution uses the rear wheel steering system as an external redundant actuator after a steer-by-wire front wheel steering system failure. The two steering systems are independent of each other, avoiding common factor failures that the internal redundancy of the steer-by-wire front wheel steering system cannot handle, thereby preventing the vehicle from completely losing its steering function and improving driving safety.

[0106] Figure 10 This is a schematic diagram of the structure of a vehicle steering control device provided in an embodiment of this application. See also... Figure 10 The device includes: The acquisition module 1001 is used to acquire the steering wheel angle and vehicle speed when the steer-by-wire front wheel steering system malfunctions. The first determining module 1002 is used to determine the rear wheel angle based on the steering wheel angle and vehicle speed; The control module 1003 is used to control the vehicle steering through the rear wheel steering system based on the rear wheel steering angle.

[0107] In one possible implementation, the first determining module 1002 is used to determine the steering wheel angle threshold based on the correspondence between vehicle speed and steering wheel angle threshold and the vehicle speed; if the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is negative, the rear wheel angle is determined based on the opposite of the steering wheel angle threshold; if the steering wheel angle is positive, the rear wheel angle is determined based on the steering wheel angle threshold; if the absolute value of the steering wheel angle is not greater than the steering wheel angle threshold, the rear wheel angle is determined based on the steering wheel angle.

[0108] In another possible implementation, the first determining module 1002 is used to determine the ratio of the steering wheel angle to the first transmission ratio; if the ratio is negative and the absolute value of the ratio is greater than the rear wheel angle threshold, the opposite of the rear wheel angle threshold is determined as the rear wheel angle; if the absolute value of the ratio is not greater than the rear wheel angle threshold, the ratio is determined as the rear wheel angle; if the ratio is positive and the ratio is greater than the rear wheel angle threshold, the rear wheel angle threshold is determined as the rear wheel angle; if the ratio is not greater than the rear wheel angle threshold, the ratio is determined as the rear wheel angle.

[0109] In another possible implementation, the device further includes: The second determining module is used to determine the rear wheel steering angle threshold based on the correspondence between vehicle speed and the rear wheel steering angle threshold and the vehicle speed.

[0110] In another possible implementation, the device further includes: The sending module is used to send a first control command to the hand feel simulation system if the absolute value of the steering wheel angle is greater than the steering wheel angle threshold, so that the hand feel simulation system outputs reverse torque based on the first control command.

[0111] In another possible implementation, the rear-wheel steering system includes: a rear-wheel steering controller and a rear-wheel steering actuator motor; The control module 1003 is used to determine the target position and the actual position of the rear wheel rack based on the rear wheel steering angle through the rear wheel steering controller; determine the first position difference between the target position and the actual position of the rear wheel rack; generate a second control command based on the first position difference and send the second control command to the rear wheel steering actuator motor; and control the vehicle steering through the rear wheel steering actuator motor based on the second control command.

[0112] This application provides a vehicle steering control device. When the steer-by-wire front wheel steering system malfunctions, the rear wheel steering angle is determined by the steering wheel angle and vehicle speed. Based on the rear wheel steering angle, the vehicle steering is controlled by the rear wheel steering system. Therefore, this solution uses the rear wheel steering system as an external redundant actuator after a steer-by-wire front wheel steering system failure. The two steering systems are independent of each other, avoiding common factor failures that the internal redundancy of the steer-by-wire front wheel steering system cannot handle, thereby preventing the vehicle from completely losing its steering function and improving driving safety.

[0113] Figure 11 This is a structural block diagram of a domain controller provided according to an embodiment of this application.

[0114] Typically, the domain controller 1100 includes: a main control module 1101, a CAN interface 1102, a hardwired input interface 1103, and a hardwired output interface 1104. The main control module 1101 is connected to the CAN interface 1102, the hardwired input interface 1103, and the hardwired output interface 1104, respectively.

[0115] The main control module 1101 typically includes a processor and memory. The processor may include one or more processing cores, such as a 4-core processor or an 8-core processor. The processor can be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). The processor may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the vehicle's display screen. In some embodiments, the processor may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning. The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, a non-transitory computer-readable storage medium in the memory is used to store at least one computer program, which is executed by a processor to implement the vehicle steering control method provided in this application.

[0116] The CAN interface 1102 may include a powertrain CAN interface, a motor CAN interface, and a diagnostic CAN interface. The powertrain CAN interface is used to communicate with the vehicle's powertrain module, the motor CAN interface is used to communicate with the vehicle's motor controller, and the diagnostic CAN interface is used to communicate with diagnostic equipment.

[0117] The hard-wired input interface 1103 is used to receive hard-wired control signals. The hard-wired output interface 1104 is used to send control commands to the vehicle's electronic control components, causing the vehicle's electronic control components to perform corresponding actions. The vehicle's electronic control components include a power management system, a motor controller, an on-board charger, and a body control system.

[0118] The main control module 1101 can communicate with the vehicle's powertrain module, motor controller and diagnostic equipment through the CAN interface 1102, and generate control commands based on the hard-wired control signals received by the hard-wired input interface 1103, so as to send the control commands to the vehicle's electronic control components through the hard-wired output interface 1104.

[0119] Those skilled in the art will understand that Figure 11 The structure shown does not constitute a limitation on the domain controller 1100 and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0120] In an exemplary embodiment, a vehicle is also provided, which includes the domain controller described in the above embodiments.

[0121] In an exemplary embodiment, a computer-readable storage medium is also provided, which stores at least one piece of program code that is loaded and executed by a processor to implement the vehicle steering control method in the above embodiments.

[0122] In an exemplary embodiment, a computer program product is also provided, which stores at least one piece of program code that is loaded and executed by a processor to implement the vehicle steering control method in the above embodiments.

[0123] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application, and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A vehicle steering control method, characterized in that, The method includes: When the steer-by-wire front wheel steering system malfunctions, obtain the steering wheel angle and vehicle speed; The rear wheel angle is determined based on the steering wheel angle and the vehicle speed; Based on the rear wheel angle, the vehicle steering is controlled by the rear wheel steering system.

2. The method according to claim 1, characterized in that, Determining the rear wheel steering angle based on the steering wheel angle and the vehicle speed includes: Based on the correspondence between vehicle speed and steering wheel angle threshold and the vehicle speed, the steering wheel angle threshold is determined; If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold and the steering wheel angle is negative, the rear wheel angle is determined based on the opposite of the steering wheel angle threshold; if the steering wheel angle is positive, the rear wheel angle is determined based on the steering wheel angle threshold. If the absolute value of the steering wheel angle is not greater than the steering wheel angle threshold, the rear wheel angle is determined based on the steering wheel angle.

3. The method according to claim 2, characterized in that, Determining the rear wheel angle based on the steering wheel angle includes: Determine the ratio of the steering wheel angle to the first transmission ratio; If the ratio is negative and the absolute value of the ratio is greater than the rear wheel steering angle threshold, the opposite of the rear wheel steering angle threshold is determined as the rear wheel steering angle; if the absolute value of the ratio is not greater than the rear wheel steering angle threshold, the ratio is determined as the rear wheel steering angle. If the ratio is positive and greater than the rear wheel steering angle threshold, the rear wheel steering angle threshold is determined as the rear wheel steering angle; if the ratio is not greater than the rear wheel steering angle threshold, the ratio is determined as the rear wheel steering angle.

4. The method according to claim 3, characterized in that, The method further includes: The rear wheel steering angle threshold is determined based on the correspondence between vehicle speed and rear wheel steering angle threshold and the vehicle speed.

5. The method according to claim 2, characterized in that, The method further includes: If the absolute value of the steering wheel angle is greater than the steering wheel angle threshold, a first control command is sent to the hand feel simulation system so that the hand feel simulation system outputs reverse torque based on the first control command.

6. The method according to claim 1, characterized in that, The rear wheel steering system includes: a rear wheel steering controller and a rear wheel steering actuator motor; The method of controlling vehicle steering via the rear wheel steering system based on the rear wheel steering angle includes: Based on the rear wheel angle, the target position and actual position of the rear wheel rack are determined by the rear wheel steering controller; a first position difference between the target position and the actual position of the rear wheel rack is determined; based on the first position difference, a second control command is generated and sent to the rear wheel steering actuator motor; The rear wheel steering actuator motor controls the vehicle steering based on the second control command.

7. A domain controller, characterized in that, The domain controller includes a processor and a memory, the memory storing at least one piece of program code, which is loaded and executed by the processor to implement the vehicle steering control method as described in any one of claims 1 to 6.

8. A vehicle, characterized in that, The vehicle includes the controller as described in claim 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor to implement the vehicle steering control method as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, The computer program product stores at least one piece of program code, which is loaded and executed by a processor to implement the vehicle steering control method as described in any one of claims 1 to 6.

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