Rear wheel steering control system of vehicle and vehicle

Abstract

The invention discloses a rear wheel steering control system of a vehicle and the vehicle, and relates to the technical field of vehicle control. The system comprises a domain controller and a rear wheel steering execution mechanism in communication connection with the domain controller. A domain controller for arbitrating a rear wheel steering control mode of the vehicle and determining a target rear wheel steering angle of the vehicle based on an arbitration result; the rear wheel steering executing mechanism is used for executing steering operation on rear wheels of the vehicle based on the target rear wheel steering angle; wherein the rear wheel steering control mode comprises a rear wheel steering control mode corresponding to power-on and power-off of the vehicle, a rear wheel steering control mode corresponding to crab running of the vehicle, a rear wheel steering control mode corresponding to intelligent driving of the vehicle, a rear wheel steering control mode corresponding to stable vehicle body posture of the vehicle and a basic rear wheel steering control mode. According to the invention, multiplexing of existing hardware resources is realized, the hardware cost is reduced, and the system layout is simplified.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a rear wheel steering control system of a vehicle and a vehicle. Background Art

[0002] With the development of new energy vehicles, demand for rear-wheel steering (RWS) is increasing in medium and large vehicles to improve low-speed agility and high-speed stability. Current passive RWS uses a mechanical connection to allow the rear-wheel steering mechanism to follow the front wheels, resulting in a fixed steering ratio and difficulty adapting to varying speeds. Active RWS, which achieves dynamic adjustment through independent control, has become the mainstream solution. However, active RWS requires a separate motor, controller, and sensors, increasing hardware costs and complicating system layout. Summary of the Invention

[0003] In response to the above technical problems, an embodiment of the present application provides a rear-wheel steering control system for a vehicle and a vehicle, which can reuse existing hardware resources, reduce hardware costs, and simplify system layout.

[0004] The technical solution of this application is achieved as follows:

[0005] In a first aspect, an embodiment of the present application provides a rear-wheel steering control system for a vehicle, comprising: a domain controller and a rear-wheel steering actuator communicatively connected to the domain controller;

[0006] The domain controller is configured to arbitrate a rear wheel steering control mode of the vehicle and determine a target rear wheel steering angle of the vehicle based on an arbitration result;

[0007] The rear wheel steering actuator is configured to perform a steering operation on the rear wheels of the vehicle based on the target rear wheel steering angle determined by the domain controller;

[0008] Among them, the rear-wheel steering control mode includes: the rear-wheel steering control mode corresponding to the vehicle's power on and off, the rear-wheel steering control mode corresponding to the vehicle's crab driving, the rear-wheel steering control mode corresponding to the vehicle's intelligent driving, the rear-wheel steering control mode corresponding to the vehicle's stable body posture and the basic rear-wheel steering control mode; the basic rear-wheel steering control mode is a mode that determines the vehicle's rear-wheel steering angle based on the vehicle's driving state and using a preset rear-wheel steering angle calculation model.

[0009] In some embodiments, the domain controller and the rear wheel steering actuator communicate based on a specific handshake mechanism;

[0010] The domain controller is further configured to: when determining that the rear-wheel steering actuator is in a standby handshake state, send a rear-wheel control request signal carrying the target rear-wheel steering angle to the rear-wheel steering actuator based on the specific handshake mechanism;

[0011] The rear-wheel steering actuator is also used to: based on the specific handshake mechanism, in response to the rear-wheel control request signal, switch the handshake state of the rear-wheel steering actuator from the standby handshake state to the activated handshake state, and then perform steering operations on the rear wheels of the vehicle based on the target rear-wheel steering angle.

[0012] In some embodiments, the rear wheel steering actuator is further used to:

[0013] Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller, based on the current rear wheel steering angle of the vehicle, the handshake state of the rear wheel steering actuator is switched from the activated handshake state to the standby handshake state.

[0014] In some embodiments, the rear wheel steering actuator is further used for at least one of the following:

[0015] Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller, when it is determined that the current rear wheel steering angle of the vehicle is zero, switching the handshake state of the rear wheel steering actuator from the active handshake state to the standby handshake state;

[0016] Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller, when it is determined that the current rear wheel steering angle of the vehicle is non-zero, the handshake state of the rear wheel steering actuator is switched from the activated handshake state to the neutral return state, and after the rear wheels of the vehicle are turned to the neutral position, the handshake state of the rear wheel steering actuator is switched from the neutral return state to the standby handshake state.

[0017] In some embodiments, the rear wheel steering actuator is further used to:

[0018] When a target fault is detected, the handshake state of the rear-wheel steering actuator is switched and the rear-wheel steering position of the vehicle is controlled based on the fault type of the target fault; the fault type includes a temporary fault type and a permanent fault type.

[0019] In some embodiments, the rear wheel steering actuator is further used for at least one of the following:

[0020] When it is determined that the fault type of the target fault is the temporary fault type, the handshake state of the rear-wheel steering actuator is switched from the activated handshake state to the neutral return state, and after the rear wheels of the vehicle are steered to the neutral position, the handshake state of the rear-wheel steering actuator is switched from the neutral return state to the temporary fault state; when it is determined that the target fault is recovered, the handshake state of the rear-wheel steering actuator is switched from the temporary fault state to the standby handshake state;

[0021] When it is determined that the fault type of the target fault is the permanent fault type, the handshake state of the rear wheel steering actuator is switched from the activated handshake state to the permanent fault state, and the rear wheels of the vehicle are locked at the current position of the rear wheels.

[0022] In some embodiments, the domain controller is further configured to: arbitrate the rear wheel steering control mode of the vehicle according to a preset rear wheel steering control mode priority;

[0023] The priorities of the rear-wheel steering control modes are as follows from high to low: the rear-wheel steering control mode corresponding to the vehicle's power on and off, the rear-wheel steering control mode corresponding to the vehicle's crab-like running, the rear-wheel steering control mode corresponding to the vehicle's intelligent driving, the rear-wheel steering control mode corresponding to the vehicle's stable body posture, and the basic rear-wheel steering control mode.

[0024] In some embodiments, the rear wheel steering actuator is further used to:

[0025] In response to a fault signal sent by the domain controller, when it is determined that the current speed of the vehicle is greater than a first threshold and the current rear wheel steering angle of the vehicle is greater than a second threshold, a follow-up steering operation is performed on the rear wheels of the vehicle; the follow-up steering operation indicates that the rear wheels of the vehicle follow the front wheels of the vehicle in steering.

[0026] In some embodiments, the rear wheel steering actuator is further used to:

[0027] During the follow-up steering operation for the rear wheels of the vehicle, if it is determined that the rear wheels have turned to a neutral position, the rear wheels are locked at the neutral position.

[0028] In a second aspect, an embodiment of the present application provides a vehicle, comprising the rear-wheel steering control system of the vehicle as described in the first aspect.

[0029] The rear-wheel steering control system and vehicle provided in embodiments of the present application utilize a domain controller and a rear-wheel steering actuator to communicate with each other, arbitrate the vehicle's rear-wheel steering control mode using the domain controller, determine the vehicle's target rear-wheel steering angle based on the arbitration result, and then utilize the rear-wheel steering actuator to perform steering operations on the vehicle's rear wheels based on the target rear-wheel steering angle determined by the domain controller. Thus, the existing domain controller centrally arbitrates the vehicle's rear-wheel steering multi-mode control logic and determines the target rear-wheel steering angle, while the rear-wheel steering actuator is only used to perform rear-wheel steering operations based on the target rear-wheel steering angle determined by the domain controller. Compared to the independent hardware design of traditional active rear-wheel steering control solutions, the embodiments of the present application achieve the reuse of existing hardware resources, thereby reducing hardware costs and simplifying system layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1 This is one of the structural schematic diagrams of a rear-wheel steering control system for a vehicle provided in an embodiment of the present application;

[0032] Figure 2 This is a second structural schematic diagram of a rear-wheel steering control system for a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] It should be noted that, in the description of the embodiments of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, in the description of the embodiments of the present application, "and / or" represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0035] In order to facilitate a clearer understanding of the various embodiments of the present application, some relevant technical knowledge is first introduced as follows.

[0036] In related technologies, rear-wheel steering control usually relies on multiple independent electronic control units (ECUs) to handle control logic in different scenarios, such as basic steering control, body stability control, and intelligent driving assistance. This distributed architecture has problems such as high system complexity, large communication delay, and low resource utilization, which is not conducive to the integrated development of vehicle functions.

[0037] In order to improve the defects of related technologies such as decentralized rear-wheel steering control, low functional integration and poor response efficiency, the embodiments of the present application provide a rear-wheel steering control system for a vehicle and a vehicle. By introducing a domain controller (DomainController), multiple rear-wheel steering control functions are concentrated in the domain control module, which works in conjunction with the rear-wheel steering actuator. It can not only realize intelligent arbitration and precise control of the rear-wheel steering angle, but also realize unified scheduling and efficient coordination of multiple control modes of the rear-wheel steering, thereby improving the driving stability, flexibility and functional safety of the entire vehicle.

[0038] The following is an illustrative introduction to the rear-wheel steering control system and the vehicle provided in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application.

[0039] Figure 1 This is one of the structural diagrams of a rear wheel steering control system of a vehicle provided in an embodiment of the present application, such as Figure 1 As shown, the system includes: a domain controller 110 and a rear wheel steering actuator 120 that is communicatively connected to the domain controller 110;

[0040] The domain controller 110 is configured to arbitrate a rear-wheel steering control mode of the vehicle and determine a target rear-wheel steering angle of the vehicle based on an arbitration result;

[0041] The rear-wheel steering actuator 120 is configured to perform a steering operation on the rear wheels of the vehicle based on the target rear-wheel steering angle determined by the domain controller 110;

[0042] Among them, the rear-wheel steering control mode includes: the rear-wheel steering control mode corresponding to the vehicle's power on and off, the rear-wheel steering control mode corresponding to the vehicle's crab driving, the rear-wheel steering control mode corresponding to the vehicle's intelligent driving, the rear-wheel steering control mode corresponding to the vehicle's stable body posture and the basic rear-wheel steering control mode; the basic rear-wheel steering control mode is a mode that determines the vehicle's rear-wheel steering angle based on the vehicle's driving state and using a preset rear-wheel steering angle calculation model.

[0043] It should be noted that domain controller 110 is an electronic control unit that integrates multiple control functions. It can integrate multiple subsystems such as front-wheel steering, braking, suspension, and rear-wheel steering to achieve centralized control of the vehicle chassis. As the central decision-making unit, domain controller 110 is responsible for coordinating information exchange and control logic between various subsystems, thereby improving overall response efficiency and functional safety.

[0044] It should be noted that the rear-wheel steering actuator 120 is a hardware device used to perform rear-wheel steering operations and can include components such as a motor, a reducer, a rack, and a position sensor. This actuator receives target steering angle commands from the domain controller 110 and, through closed-loop control, tracks the actual steering angle of the vehicle's rear wheels. Furthermore, the rear-wheel steering actuator 120 also includes functions such as fault diagnosis, redundant control, and handshake status management to ensure system safety and reliability under various operating conditions.

[0045] It should be noted that control mode arbitration refers to the process of deciding which control mode to ultimately adopt according to a preset strategy among multiple control requirements that may exist simultaneously.

[0046] In some embodiments, the domain controller 110 can receive input signals from the vehicle status module, the Electric Power Steering (EPS) system, and external advanced functional modules (such as the intelligent driving system, the vehicle stability control system, etc.), and make a comprehensive judgment based on the preset strategy to determine the rear-wheel steering control mode that should be currently adopted.

[0047] It should be noted that EPS is an electric power steering system used to control front-wheel steering. It detects the driver's steering input and converts it into electrical signals, which are transmitted to the domain controller 110. Based on this information, the domain controller 110 calculates the appropriate rear-wheel steering angle and transmits it to the rear-wheel steering actuator 120 via a signal bus. The vehicle status module collects and transmits parameters such as vehicle speed, wheel speed, acceleration, and yaw rate in real time. This data provides the domain controller 110 with important reference for determining the current vehicle driving condition and, in turn, deciding whether to activate a specific rear-wheel steering control mode. External advanced functional modules refer to functional systems with special requirements for rear-wheel steering, such as the Electronic Stability Control (ESC) system and the intelligent driving system. These systems send control requests to the domain controller 110 through a communication interface to influence the rear-wheel steering angle and direction, thereby meeting driving safety and maneuverability requirements under complex road conditions.

[0048] It is understandable that the domain controller 110 can not only improve the system's response speed and accuracy, but also enhance the vehicle's adaptability and stability in different driving scenarios by comprehensively processing multi-source input signals and selecting the optimal rear-wheel steering control mode based on the current vehicle state.

[0049] It should be noted that in the embodiment of the present application, the rear-wheel steering control mode may include a rear-wheel steering control mode corresponding to vehicle power on and off, a rear-wheel steering control mode corresponding to vehicle crab driving, a rear-wheel steering control mode corresponding to vehicle intelligent driving, a rear-wheel steering control mode corresponding to vehicle stable body posture, and a basic rear-wheel steering control mode. These modes correspond to different driving conditions, such as the return operation when the vehicle is started / shut down, low-speed oblique driving, body posture adjustment during high-speed driving, and automatic parking. Each control mode has its own specific application scenario. When multiple control requests appear at the same time, the domain controller 110 can arbitrate according to the preset strategy to ensure that key functions are responded to first.

[0050] It should be noted that the rear-wheel steering control mode corresponding to vehicle power on and off is used to return the rear wheels to the neutral position when the vehicle is started or shut down, ensuring that the vehicle is in a stable state before entering the next stage of operation. The rear-wheel steering control mode corresponding to the vehicle's crab-like operation allows the vehicle to move diagonally at low speeds, suitable for maneuvering in narrow spaces. The rear-wheel steering control mode corresponding to the vehicle's intelligent driving is requested by the intelligent driving system and is used to assist the vehicle in completing tasks such as automatic parking or high-speed cruising. The rear-wheel steering control mode corresponding to the vehicle's stable body posture is used to help stabilize the vehicle's posture by adjusting the rear-wheel steering angle in situations such as emergency obstacle avoidance or slippery roads. The basic rear-wheel steering control mode is the default control method. It is used in the absence of other high-priority control requirements. It is a conventional control mode that calculates the optimal rear-wheel steering angle based on the vehicle's driving status (such as vehicle speed, yaw rate, etc.) and using a preset rear-wheel steering angle calculation model.

[0051] In some embodiments, after receiving a request for any of the above control modes, the domain controller 110 may first check whether the activation conditions of the mode (such as vehicle speed, yaw angular velocity, etc.) are currently met. If the conditions are met, the priority relationship between the mode and other modes is further evaluated, and finally the control mode to be adopted is determined, and the corresponding target rear wheel steering angle is calculated.

[0052] It should be noted that rear-wheel steering is achieved by adjusting the rear wheel's deflection angle relative to the ground via a motor-driven rack movement. Specifically, the rear-wheel steering actuator 120 may include a closed-loop control system that converts the target rear-wheel steering angle into motor torque output, driving the steering motor, which ultimately shifts the rack to complete the rear wheel steering action. This entire process requires real-time response to ensure smooth and precise steering.

[0053] In some embodiments, the domain controller 110 can send the target rear-wheel steering angle to the rear-wheel steering actuator 120 through the signal bus. After receiving the target rear-wheel steering angle, the rear-wheel steering actuator 120 compares it with the current position of the rear wheel, calculates the required target rack position, and converts it into a motor control instruction. It controls the motor output torque through a pulse width modulation (PWM) waveform, thereby completing the rear-wheel steering action.

[0054] In some embodiments, the rear-wheel steering actuator 120 can also continuously feed back the actual rear-wheel steering angle to the domain controller 110 through the signal bus to make the next control decision, form a closed-loop control, and further improve the rear-wheel steering control accuracy.

[0055] It is understood that the rear-wheel steering control system for a vehicle provided in an embodiment of the present application, by communicatively connecting a domain controller and a rear-wheel steering actuator, utilizes the domain controller to arbitrate the vehicle's rear-wheel steering control mode, determines the vehicle's target rear-wheel steering angle based on the arbitration result, and then utilizes the rear-wheel steering actuator to perform steering operations on the vehicle's rear wheels based on the target rear-wheel steering angle determined by the domain controller. In this way, the existing domain controller centrally arbitrates the multi-mode control logic for the vehicle's rear-wheel steering and determines the target rear-wheel steering angle, while the rear-wheel steering actuator is only used to perform rear-wheel steering operations based on the target rear-wheel steering angle determined by the domain controller. Compared to the independent hardware design of traditional active rear-wheel steering control solutions, the embodiments of the present application achieve the reuse of existing hardware resources, thereby reducing hardware costs and simplifying system layout.

[0056] In some embodiments, the domain controller 110 and the rear wheel steering actuator 120 communicate based on a specific handshake mechanism;

[0057] The domain controller 110 is further configured to: when determining that the rear-wheel steering actuator 120 is in the standby handshake state, send a rear-wheel control request signal carrying the target rear-wheel steering angle to the rear-wheel steering actuator 120 based on the specific handshake mechanism;

[0058] The rear-wheel steering actuator 120 is also used to: based on the specific handshake mechanism, in response to the rear-wheel control request signal, switch the handshake state of the rear-wheel steering actuator 120 from the standby handshake state to the activated handshake state, and then perform steering operations on the rear wheels of the vehicle based on the target rear-wheel steering angle.

[0059] It should be noted that the specific handshake mechanism is a technical means for ensuring communication security and control priority between the domain controller 110 and the rear-wheel steering actuator 120. This mechanism manages the transfer of control authority by switching between handshake states (such as the standby handshake state and the active handshake state), preventing multiple control systems from simultaneously issuing conflicting commands to the rear-wheel steering actuator 120. The handshake mechanism can be implemented via a signal bus, such as a Controller Area Network (CAN) bus or a Local Interconnect Network (LIN) bus, supporting real-time communication and status feedback.

[0060] It should be noted that the handshake status refers to the control authority status between the rear-wheel steering actuator 120 and the domain controller 110. When in the active handshake state (Active), the rear-wheel steering actuator 120 is responding to control instructions from the domain controller; the standby handshake state (Ready) indicates that the rear-wheel steering actuator 120 is ready to receive new control requests but is not currently in a controlled state. Changes in the handshake status can be achieved through signal bus communication, ensuring the security and orderliness of system control.

[0061] It should be noted that when the domain controller 110 detects that the rear-wheel steering actuator 120 enters the Ready state, it indicates that it has completed the power-on self-test and there are no faults that affect the execution of the function. At this time, the domain controller 110 can initiate a handshake request (i.e., a rear-wheel control request signal) and encapsulate the target rear-wheel steering angle in the control request signal and send it together to start the rear-wheel steering action. When the rear-wheel steering actuator 120 receives the rear-wheel control request signal from the domain controller 110, if it is currently in the Ready state, it will switch its own state to the Active state, indicating that it is ready to accept subsequent control instructions. This process is accompanied by the switching of the internal state machine to ensure the orderliness of the control process.

[0062] In some embodiments, the handshake status may include: Ready handshake status, Active handshake status, Return status, Temporary Error status, Permanent Error status, etc. These statuses are sent to the domain controller 110 via a signal bus to facilitate the domain controller 110 to determine whether a control operation can be performed at the moment.

[0063] In some embodiments, the domain controller 110 can first read the handshake status of the rear-wheel steering actuator 120 via the signal bus. If the status is Ready, the domain controller 110 calculates the target rear-wheel steering angle based on the current vehicle operating conditions, packages the target rear-wheel steering angle into a standard protocol frame, and sends it to the rear-wheel steering actuator 120. This ensures that only systems with control authority can perform operations on the rear-wheel steering actuator 120, thereby improving system security and stability.

[0064] In some embodiments, after the rear-wheel steering actuator 120 receives the rear-wheel control request signal sent by the domain controller 110, it can first verify the validity of the signal, and after confirming that the verification is passed, it switches the handshake state from the Ready state to the Active state and prepares to execute the subsequent motor drive logic.

[0065] It can be understood that the rear-wheel steering actuator 120 has a handshake state management function, that is, by switching the handshake state with the domain controller 110, it is clear whether the two parties are currently in a communicative or controllable state, thereby ensuring the safe issuance and execution of control commands.

[0066] It can be understood that the embodiment of the present application can ensure that the communication between the domain controller and the rear-wheel steering actuator has a clear division of control authority by introducing a specific handshake mechanism, thereby preventing conflicts caused by concurrent control of multiple systems, and further improving the safety and reliability of vehicle control.

[0067] In some embodiments, the rear wheel steering actuator 120 is further used to:

[0068] Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller 110, based on the current rear wheel steering angle of the vehicle, the handshake state of the rear wheel steering actuator 120 is switched from the activated handshake state to the standby handshake state.

[0069] It should be noted that the rear-wheel control exit request signal is sent by the domain controller 110, indicating that the current demand for rear-wheel steering control has ended. This signal is a digital signal transmitted via the signal bus and can be represented as a Boolean value or a status code. When the domain controller 110 determines that the rear-wheel steering function is no longer required, it can proactively send this request signal to the rear-wheel steering actuator 120.

[0070] In this embodiment of the present application, after receiving the rear-wheel control exit request signal from the domain controller 110, the rear-wheel steering actuator 120 can switch its handshake state from the active handshake state to the standby handshake state based on the vehicle's current rear-wheel steering angle. That is, after the rear-wheel steering control task is completed, the system can switch the handshake state based on the current rear-wheel steering angle, thereby ensuring that the system enters a stable standby handshake state, preparing for subsequent control operations and improving the controllability and orderliness of system operation.

[0071] It can be understood that in the embodiment of the present application, the rear-wheel steering actuator can achieve a smooth transfer of control rights by dynamically adjusting the handshake state according to the current rear-wheel steering angle when receiving the rear-wheel control exit request signal sent by the domain controller, thereby preventing control conflicts and misoperation, and further improving the response efficiency and operational reliability of the rear-wheel steering system.

[0072] In some embodiments, the rear wheel steering actuator 120 is further used for at least one of the following:

[0073] Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller 110, when it is determined that the current rear wheel steering angle of the vehicle is zero, switching the handshake state of the rear wheel steering actuator 120 from the active handshake state to the standby handshake state;

[0074] Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller 110, when it is determined that the current rear wheel steering angle of the vehicle is non-zero, the handshake state of the rear wheel steering actuator 120 is switched from the activated handshake state to the neutral return state, and after the rear wheels of the vehicle are turned to the neutral position, the handshake state of the rear wheel steering actuator 120 is switched from the neutral return state to the standby handshake state.

[0075] It should be noted that when the rear-wheel steering actuator 120 receives a rear-wheel control exit request signal and detects that the current rear-wheel steering angle is zero, indicating that the rear wheels are already in the neutral position, the control exit process is completed without further operation. At this point, the rear-wheel steering actuator 120 switches the handshake state from the active handshake state to the standby handshake state, releasing control authority and entering a state where it awaits the next control request. This design avoids unnecessary mechanical movement, reduces energy consumption, and improves system response efficiency.

[0076] It should be noted that when the neutral return state is triggered, it indicates that the rear-wheel steering actuator 120 is performing the operation of returning the rear-wheel steering angle to zero. In this state, the rear-wheel steering actuator 120 no longer responds to rear-wheel steering angle commands from the domain controller 110, but instead gradually adjusts the rear-wheel steering angle to the neutral position according to preset logic. The neutral position generally refers to the state where the rear wheels are completely straight and non-deflected, that is, the rear-wheel steering angle is 0°.

[0077] In some embodiments, when the rear-wheel steering actuator 120 receives a rear-wheel control exit request signal and detects that the current rear-wheel steering angle is not zero, it first switches its handshake state from the active handshake state to the neutral return state, and then starts the internal algorithm to control the motor to drive the rack movement to gradually return the rear wheel to the neutral position. Once the rear wheel successfully returns to the neutral position, the rear-wheel steering actuator 120 switches the handshake state back to the standby handshake state, ready to accept the next round of control requests. The key to this process is the automatic execution mechanism of the neutral return, which ensures that the vehicle can maintain a good driving posture and handling stability even after exiting control. At the same time, this mechanism also provides a clear starting point for subsequent functional control, improving the predictability and safety of the system.

[0078] In some embodiments, when the domain controller 110 determines that it is no longer necessary to actively control the rear wheels (for example, function mode switching, emergency handling, or system sleep), it can send a rear wheel control exit request signal to the rear wheel steering actuator 120. After receiving the signal, the rear wheel steering actuator 120 determines the next action based on whether the current rear wheel steering angle is zero degrees. If the current rear wheel steering angle is zero, the handshake state jumps directly from the Active state to the Ready state; if it is not zero, it enters the Return state and executes the rear wheel return operation, and jumps to the Ready state again after the rear wheel return is completed. In this way, it can ensure that the control of the rear wheel steering system is safely returned to the default behavior of the rear wheel steering actuator 120 itself, thereby avoiding the risk of loss of control due to abnormality or failure of the domain controller 110, thereby improving the safety of the vehicle and the stability of the system.

[0079] It can be understood that the embodiments of the present application distinguish whether the current rear wheel steering angle is zero and adopt different handshake state switching strategies to ensure that the rear wheels can return to a safe position such as the middle position when the control is exited, avoiding the residual steering angle from affecting the next control action or driving safety, and further enhancing the stability and reliability of the system.

[0080] In some embodiments, the rear wheel steering actuator 120 is further used to:

[0081] When a target fault is detected, the handshake state of the rear-wheel steering actuator 120 is switched and the rear-wheel steering position of the vehicle is controlled based on the fault type of the target fault; the fault type includes a temporary fault type and a permanent fault type.

[0082] It should be noted that a target fault refers to an abnormal operating state of the system caused by signal anomalies, hardware failure, or software logic errors during system operation. This fault may include external signal loss, signal invalidity, signal verification errors, or internal hardware or software failures of the rear-wheel steering actuator 120 itself. Target faults can be divided into temporary faults (Temporary Error) and permanent faults (Permanent Error). The former automatically clears and re-enters the standby state after the conditions are restored, while the latter requires a power cycle to recover.

[0083] It should be noted that handshake state switching in this embodiment of the application refers to dynamically adjusting the control authority state between the rear-wheel steering actuator 120 and the domain controller 110 based on the type of target fault. When a target fault is detected, the rear-wheel steering actuator 120 can actively exit the current handshake state and enter the corresponding fault handling state to ensure system security and stability.

[0084] It should be noted that rear-wheel steering position control in this embodiment of the present application refers to controlling the actual steering angle position of the rear wheels after the handshake state switch is completed, causing them to return to the neutral position or maintain the current position, depending on the type of fault. For example, in the event of a temporary fault, the rear-wheel steering actuator 120 can enter the Return state and perform the rear-wheel return operation; in the event of a permanent fault, the rear-wheel steering actuator 120 can lock the rear wheels in the current position and wait for recovery after the next power-on.

[0085] It's understood that there's a direct data and logical relationship between the target fault and the handshake state. When the system detects a target fault, the rear-wheel steering actuator 120 determines whether to exit the current handshake state based on the fault type and switches to the appropriate processing state. For example, if a temporary fault (loss of signal) is detected, the rear-wheel steering actuator 120 will enter the Return state and attempt to return to the rear wheel. If a permanent fault (motor stall) is detected, the rear-wheel steering actuator 120 will enter the Permanent Error state and lock the rear wheels in their current position.

[0086] In some embodiments, target failures may include, but are not limited to:

[0087] Signal loss: The rear wheel steering actuator 120 fails to receive the rear wheel steering angle command or signal sent by the domain controller 110;

[0088] Invalid signal: The signal format received by the rear wheel steering actuator 120 is incorrect or exceeds the allowable range;

[0089] Verification failed: the signal received by the rear wheel steering actuator 120 fails to pass the data verification;

[0090] Internal fault: An error occurs in the internal hardware or software module of the rear wheel steering actuator 120.

[0091] It can be understood that in the embodiment of the present application, by switching the handshake state and controlling the rear wheel steering position when a target fault is detected, the risk of loss of control due to the fault can be effectively prevented, thereby ensuring the safety of the entire vehicle driving and further improving the robustness and reliability of the system.

[0092] In some embodiments, the rear wheel steering actuator 120 is further used for at least one of the following:

[0093] When it is determined that the fault type of the target fault is the temporary fault type, the handshake state of the rear-wheel steering actuator 120 is switched from the activated handshake state to the neutral return state, and after the rear wheels of the vehicle are steered to the neutral position, the handshake state of the rear-wheel steering actuator 120 is switched from the neutral return state to the temporary fault state; when it is determined that the target fault is recovered, the handshake state of the rear-wheel steering actuator 120 is switched from the temporary fault state to the standby handshake state;

[0094] When it is determined that the fault type of the target fault is the permanent fault type, the handshake state of the rear wheel steering actuator 120 is switched from the activated handshake state to the permanent fault state, and the rear wheels of the vehicle are locked at the current position of the rear wheels.

[0095] In this embodiment of the present application, when a temporary fault occurs, the handshake state jumps from the active handshake state to the neutral return state. At this point, the rear wheel steering actuator 120 no longer accepts control requests from the domain controller 110 and automatically steers the rear wheels to the neutral position to ensure driving safety. After the rear wheel return is completed, the handshake state further jumps to the temporary fault state, indicating that the fault is recoverable. If the cause of the temporary fault is resolved, the handshake state can jump back to the standby handshake state, and the system can resume normal operation.

[0096] It should be noted that the neutral return state refers to the intermediate state during which the rear-wheel steering actuator 120 automatically steers the rear wheels to the neutral position when encountering an abnormal situation. In this state, the rear-wheel steering actuator 120 no longer responds to external control commands and instead focuses on completing the rear-wheel return operation to ensure that the vehicle is in a relatively safe position.

[0097] For example, if the rear-wheel steering motor overheats and triggers a protection mechanism during high-speed driving, the rear-wheel steering actuator 120 will detect a temporary fault and enter the neutral return state. At this point, the rear-wheel steering actuator 120 automatically returns the rear wheels to the center position to ensure vehicle stability. Simultaneously, the domain controller 110 will no longer send control signals and will wait for the fault to resolve before reestablishing the handshake connection.

[0098] It should be noted that a permanent fault state refers to an unrecoverable fault state caused by hardware damage, irreversible software errors, or serious system conflicts. In this state, the rear-wheel steering actuator 120 will no longer respond to any control requests and will lock the rear wheels in their current position to prevent further safety hazards caused by continued execution of erroneous commands.

[0099] For example, if the main power supply circuit of the rear-wheel steering controller shorts and burns out during vehicle operation, the rear-wheel steering actuator 120 will be determined to have a permanent fault and immediately enter a permanent fault state. At this point, the rear-wheel steering actuator 120 will lock the rear wheels in their current position, halt all rear-wheel steering-related control logic, and may issue a warning message to the driver through the alarm module.

[0100] It can be understood that the embodiments of the present application can effectively ensure the safety of vehicle driving by adopting corresponding handshake state switching strategies according to different fault types, thereby avoiding improper steering control before the fault is resolved, and further improving the functional safety level of the entire vehicle and the user driving experience.

[0101] In some embodiments, the domain controller 110 is further configured to: arbitrate the rear wheel steering control mode of the vehicle according to a preset rear wheel steering control mode priority;

[0102] The priorities of the rear-wheel steering control modes are as follows from high to low: the rear-wheel steering control mode corresponding to the vehicle's power on and off, the rear-wheel steering control mode corresponding to the vehicle's crab-like running, the rear-wheel steering control mode corresponding to the vehicle's intelligent driving, the rear-wheel steering control mode corresponding to the vehicle's stable body posture, and the basic rear-wheel steering control mode.

[0103] It should be noted that rear-wheel steering control mode priority refers to a ranking mechanism based on the importance and urgency of multiple rear-wheel steering functions that may be triggered simultaneously. This mechanism ensures that when multiple tasks coexist, the most critical functions are executed first to avoid conflicts or waste of resources. For example, during vehicle startup or shutdown, the power-on and power-off reset function has the highest priority to ensure the vehicle remains in a safe state. In intelligent driving scenarios, intelligent driving control is activated only when there is no interference from higher-priority tasks.

[0104] It should be noted that the rear-wheel steering control mode corresponding to the vehicle's power on and off means that when the vehicle is started or shut down, the domain controller 110 controls the rear-wheel steering actuator 120 to adjust the rear wheel angle to the neutral position (i.e., zero degrees). The core goal of this mode is to ensure that the vehicle is in a standard and predictable position after each power on and off, thereby improving the safety and stability of the entire vehicle. This mode takes precedence over all other functions because regardless of whether other tasks are currently being performed, the power on and off process must ensure that the vehicle returns to its initial position to prevent directional deviation due to abnormal power outages.

[0105] It should be noted that the rear-wheel steering control mode for crab maneuvering is a special driving mode control logic, typically activated by the driver. In this mode, the front and rear wheels rotate in the same direction and angle, enabling diagonal maneuvering in tight spaces. Due to its high safety requirements, this mode takes precedence only over the rear-wheel steering control mode for powering on and off.

[0106] It should be noted that the rear-wheel steering control mode corresponding to vehicle intelligent driving is activated when the autonomous driving system takes over vehicle control. In this mode, domain controller 110, based on instructions from the intelligent driving system, precisely controls the rear wheel steering angle to meet the requirements of functions such as automatic parking and automatic lane changing. This mode is only activated when no higher-priority tasks are active, ensuring that the operation of the autonomous driving system is not interfered with by other non-critical functions.

[0107] It should be noted that the rear-wheel steering control mode for vehicle posture stabilization is primarily used to enhance vehicle stability at high speeds or in complex road conditions. For example, in the event of a skid or oversteer, the rear wheel steering angle is adjusted to correct the vehicle's posture. This mode provides auxiliary control during vehicle operation and has a lower priority than the rear-wheel steering control mode for powering on and off or crab-steering. However, it provides a higher priority than the basic rear-wheel steering control mode, ensuring that the vehicle maintains good dynamic balance under various operating conditions.

[0108] It's important to note that Basic rear-wheel steering control mode is the most fundamental implementation of rear-wheel steering. It relies primarily on the vehicle's model algorithm to determine the steering relationship between the rear and front wheels within different speed ranges. This mode is the default choice and provides the rear-wheel steering support required for daily driving, unless higher-level control logic is involved.

[0109] In some embodiments, when multiple control requests occur simultaneously, the domain controller 110 may arbitrate according to the preset rear-wheel steering control mode priority, select the highest priority mode as the current execution basis, and ensure that key functions are responded to first.

[0110] It can be understood that the embodiment of the present application can effectively coordinate conflicts between multiple control functions by setting clear rear-wheel steering control mode priorities, thereby ensuring that in any case, the most important or most urgent control needs can be responded to first, thereby improving the reliability and safety of the entire vehicle control.

[0111] In some embodiments, the rear wheel steering actuator 120 is further used to:

[0112] In response to the fault signal sent by the domain controller 110, when it is determined that the current speed of the vehicle is greater than a first threshold and the current rear wheel steering angle of the vehicle is greater than a second threshold, a follow-up steering operation is performed on the rear wheels of the vehicle; the follow-up steering operation indicates that the rear wheels of the vehicle follow the front wheels of the vehicle in steering.

[0113] It should be noted that the fault signal in the embodiments of the present application refers to a control signal issued by the domain controller 110 when a system anomaly is detected, which is used to notify the rear-wheel steering actuator 120 to enter a redundant or safe mode. This signal can be transmitted via bus communication and contains information such as the type of fault, severity, and whether it is recoverable. The generation of the fault signal may be caused by problems such as sensor failure, motor overheating, and communication interruption. When the rear-wheel steering actuator 120 receives this signal, it can switch to a backup control strategy according to the preset logic to ensure vehicle driving safety.

[0114] It should be noted that the first threshold is a set speed threshold, indicating that when the vehicle's operating speed exceeds this threshold, the rear-wheel steering actuator 120 will adopt a different control strategy. For example, the first threshold can be set to 60 km / h. Above this speed, the rear wheels will no longer perform counter-steering, but instead rotate in the same direction as the front wheels to improve high-speed stability. The setting of the first threshold can be determined based on factors such as the vehicle dynamics model, tire characteristics, and driving comfort.

[0115] It's important to note that the second threshold is a set rear-wheel steering angle threshold. When the current rear-wheel steering angle exceeds this value, the system deems it a significant abnormal steering behavior and requires additional safety mechanisms to be activated. For example, the second threshold could be set to 5°. If the current rear-wheel steering angle exceeds this value, it indicates a possible control anomaly or mechanical jam. At this point, the system will trigger redundant control logic to ensure the vehicle remains controllable.

[0116] It should be noted that follow-up steering operation refers to a control strategy in which the rear wheel steering angle automatically follows the changes in the front wheel steering angle under specific working conditions. Specifically, when the vehicle is traveling at high speed, the rear wheels steer in the same direction as the front wheels to improve vehicle stability; while at low speeds, the rear wheels steer in the opposite direction to reduce the turning radius. In an embodiment of the present application, when the domain controller 110 detects that it has failed, and the current vehicle speed is greater than a first threshold and the rear wheel steering angle is greater than a second threshold, the rear wheel steering actuator will switch to follow-up steering mode, that is, the rear wheels follow the front wheel steering at a fixed ratio until the rear wheels return to the neutral position, thereby avoiding vehicle loss of control due to failure of the main control.

[0117] For example, suppose a medium-to-large vehicle is traveling on a highway at 70 km / h. Domain controller 110 experiences a communication failure, preventing it from transmitting the target rear wheel steering angle. Because the vehicle speed exceeds a first threshold (e.g., 60 km / h) and the rear wheel steering angle is 6°, exceeding a second threshold (e.g., 5°), the rear-wheel steering actuator 120 receives a fault signal from domain controller 110 and initiates follow-up steering mode. At this point, the rear wheels follow the front wheels in a set ratio (e.g., 1:1) to maintain vehicle stability until the rear wheels return to neutral and the system reestablishes control or enters a safe shutdown state.

[0118] It can be understood that by dynamically determining whether to enable active steering based on the current vehicle speed and rear wheel angle when a domain controller fails, the present embodiment can maintain basic vehicle controllability without relying on master control signals. This effectively prevents rear wheel failure caused by control system failure, thereby improving vehicle driving safety and, in turn, enhancing user trust in and willingness to use the intelligent driving system.

[0119] In some embodiments, the rear wheel steering actuator 120 is further used to:

[0120] During the follow-up steering operation for the rear wheels of the vehicle, if it is determined that the rear wheels have turned to a neutral position, the rear wheels are locked at the neutral position.

[0121] It should be noted that the neutral position refers to the position where the rear wheels are aligned with the vehicle's forward direction and are not deflecting, typically corresponding to a zero-degree steering angle. This position serves as the vehicle's baseline during driving, helping to maintain vehicle stability and handling. When the rear wheels are in the neutral position, their impact on the vehicle's yaw rate and turning radius is minimal, facilitating subsequent control logic initialization and function switching.

[0122] In this embodiment of the present application, when the rear-wheel steering actuator 120 detects that the rear wheels have reached a neutral position while performing follow-up steering operations on the vehicle's rear wheels, it locks the rear wheels in that neutral position until an unlocking condition is met (e.g., the domain controller 110 recovers from a fault or the user manually releases the lock). This process not only improves the system's responsiveness but also enhances the smoothness and safety of function switching.

[0123] It can be understood that the rear-wheel steering actuator 120 supports redundant follow-up steering function, that is, in the event of a single-point failure of the domain controller 110, it can steer in the same direction as the front wheels according to a preset ratio until the rear-wheel steering passes the neutral position and is locked, thereby ensuring the basic driving safety of the vehicle.

[0124] In some embodiments, the rear-wheel steering actuator 120 may be integrated with a variety of protection mechanisms, such as motor temperature protection, stall protection, etc., to prevent system failure due to overheating or mechanical jamming.

[0125] It can be understood that in the embodiment of the present application, when the rear wheels are locked when they are steered to the neutral position, energy waste or potential safety hazards caused by continuous movement can be avoided, and the controllability and stability of the system in emergency situations can be improved.

[0126] It should be noted that current rear-wheel steering control schemes are divided into passive and active. In the passive scheme, the rear-wheel steering actuator is mechanically connected to the front-wheel steering actuator, causing the rear wheels to rotate in accordance with the rotation of the front wheels. This scheme has a single steering ratio coefficient for the rear and front wheels and cannot simultaneously meet high and low speed requirements, as high and low speeds require opposite steering directions for the rear wheels. In the active scheme, the rear-wheel steering system has a separate motor, controller, and control algorithm. The controller collects vehicle signals and calculates the optimal steering angle for the rear wheels under different operating conditions, thereby controlling the rear-wheel steering motor for active steering. The steering direction, ratio to the front-wheel steering, and rotation speed can all be adjusted. Therefore, the active scheme is the current mainstream new control scheme. Moreover, as vehicle functions increase, distributed control will increasingly shift to integrated control to reduce the number of vehicle modules. Therefore, embodiments of the present application provide a vehicle rear-wheel steering control system that, by moving the rear-wheel steering control function to a domain controller, achieves unified management and intelligent scheduling of multiple control modes. This can improve system response speed and functional integration, while also enhancing the vehicle's driving performance and safety under complex operating conditions.

[0127] For example, Figure 2 This is a second structural diagram of a rear wheel steering control system for a vehicle provided in an embodiment of the present application, as shown in FIG. Figure 2As shown, the system includes a domain controller 110, a rear-wheel steering actuator 120, an electric power steering system (EPS) 130, a vehicle status module 140, and an external system module 150. These five components are connected via a signal bus. Specifically, the EPS 130 receives steering input from the driver to control front-wheel steering. The vehicle status module 140 collects information such as vehicle speed, wheel speed, acceleration, and yaw rate, and transmits the vehicle status to the signal bus in real time. The external system module 150 is a high-level function that requires rear-wheel steering control, such as vehicle stability control and intelligent driving systems, and is used to transmit rear-wheel steering requirements. The domain controller 110 calculates the required rear-wheel steering angle based on the rear-wheel steering control signal and vehicle status signal sent by the EPS 130 using a rear-wheel steering control algorithm deployed in the domain controller 110 (equivalent to the preset rear-wheel steering angle calculation model mentioned above). The rear-wheel steering actuator 120 then executes the rear-wheel steering command from the domain controller 110.

[0128] It can be understood that the rear-wheel steering control system provided in the embodiment of the present application can move the control of the rear-wheel steering to the domain controller without changing the existing mature electric power steering system EPS and the vehicle status module. The rear-wheel steering actuator only needs to perform simple execution, thereby achieving the purpose of domain-controlled integrated control.

[0129] It should be noted that rear-wheel steering is a vehicle-level function, and the specific control method involves the functional division of labor between the domain controller and the rear-wheel steering actuator. Among them, the rear-wheel steering actuator can be used for rear-wheel steering motor control, motor temperature protection and stall protection, actuator-level fault diagnosis (including fault logic), and redundant follow-up steering. The domain controller can be used for rear-wheel steering angle control based on the rear-wheel steering angle calculation model, rear-wheel steering angle return control under vehicle power-on and power-off conditions, rear-wheel steering angle control in crab mode, rear-wheel steering angle control under vehicle body stability conditions, rear-wheel steering angle control under intelligent driving conditions, and function-level diagnosis (including fault logic).

[0130] It should be noted that the motor control function of the rear-wheel steering actuator is a control interface provided to the various functions of the domain controller. The domain controller sends the target rear-wheel steering angle to the rear-wheel steering actuator through the signal bus. The rear-wheel steering actuator itself is a rear-wheel steering rack displacement sensor, which can obtain the relationship between displacement and steering angle based on the mechanical position relationship. The rear-wheel steering actuator can obtain the current rear wheel steering angle value in real time based on the displacement value of the displacement sensor, and send the rear wheel steering angle to the signal bus. Since rear-wheel steering affects the safety of the entire vehicle, the embodiment of the present application designs a handshake mechanism, which is also implemented through signals. The rear-wheel steering actuator sends out a handshake state, and the domain controller sends out a request state. After the rear-wheel steering actuator completes the power-on self-test, if there is no internal fault that affects the rear-wheel steering execution, it enters the Ready state. After the domain controller determines that the rear-wheel steering actuator is in the Ready state, it can send out a rear-wheel control request signal Request. After receiving this command, the rear-wheel steering actuator can enter the Active state. In this state, the domain controller sends out the target rear-wheel steering angle in real time, and the rear-wheel steering actuator responds in real time, converting the received target rear-wheel steering angle into a target rack position value in the software, and then into a target motor torque, controlling the rear-wheel steering motor for execution, and finally achieving closed-loop control through the target rear-wheel steering angle and the actual rear-wheel steering angle.

[0131] In some embodiments, normal exit of rear-wheel steering control includes: when the domain controller determines that rear-wheel steering control is not required, it can actively switch the control request bit from Request (equivalent to the rear-wheel control request signal mentioned above) to No Request (equivalent to the rear-wheel control exit request signal mentioned above). After receiving the signal, the rear-wheel steering actuator no longer responds to the target rear-wheel steering angle sent by the domain controller. If the current rear-wheel steering angle is zero degrees, the handshake status bit jumps from the Active state to the Ready state. If the current rear-wheel steering angle is non-zero degrees, the handshake status bit jumps from the Active state to the Return state, and the rear-wheel return neutralization action is automatically performed. After the rear-wheel return neutralization is completed, the handshake status bit jumps from the Return state to the Ready state.

[0132] In some embodiments, the abnormal exit of the rear-wheel steering control includes: when the rear-wheel steering actuator is in the controlled state, if the external signal required for the control execution of the rear-wheel steering actuator is abnormal, the signal is lost, the signal is invalid, the signal verification is wrong, or the rear-wheel steering actuator itself has an internal fault, the rear-wheel steering actuator will be caused to actively exit the handshake. Depending on whether this fault is latched in the current power-on cycle, it is divided into a temporary fault (Temporary Error) and a permanent fault (Permanent Error). When a temporary fault occurs, the handshake status bit of the rear-wheel steering actuator jumps from the Active state to the Return state, and automatically performs the rear-wheel return position action. After the rear-wheel return is completed, the handshake status bit jumps from the Return state to the Temporary Error state. If the condition that caused the temporary fault is restored, the handshake status bit jumps from the Temporary Error state to the Ready state, and the handshake request from the domain controller can be accepted again to re-handshake. When a permanent fault occurs, the handshake status bit of the rear-wheel steering actuator jumps from the Active state to the Permanent Error state, and the rear-wheel steering actuator locks the rear wheels in the current position. This fault is latched and cannot be escaped during the current power-on cycle. It can only be recovered at the next power-on.

[0133] In some embodiments, the priority of the vehicle-level rear-wheel steering function deployed in the domain controller is defined as: rear-wheel steering control mode corresponding to vehicle power on and off > rear-wheel steering control mode corresponding to vehicle crab-steering > rear-wheel steering control mode corresponding to vehicle intelligent driving > rear-wheel steering control mode corresponding to vehicle stable body posture > basic rear-wheel steering control mode. When in the rear-wheel steering control mode corresponding to vehicle crab-steering, the rear-wheel steering control mode corresponding to vehicle intelligent driving, the rear-wheel steering control mode corresponding to vehicle stable body posture, and the basic rear-wheel steering control mode, the domain controller can provide real-time feedback of the current control mode on the bus. If it is not in these modes, it indicates that there is no control demand for rear-wheel steering, and this mode feedback is Reserved and not enabled.

[0134] In some embodiments, for the basic rear-wheel steering control mode, the domain controller logically determines whether rear-wheel steering is currently possible based on vehicle conditions and arbitrates between the vehicle-level rear-wheel steering functions deployed in the domain controller. Upon successful arbitration, the domain controller transitions the current rear-wheel steering mode to the basic rear-wheel steering control mode. The domain controller then runs a pre-defined rear-wheel steering angle calculation model, rotating in the opposite direction of the front wheels at low speeds and in the same direction at high speeds to determine the optimal rear-wheel steering angle in real time. The domain controller then controls the rear-wheel steering through the aforementioned angle control interface with the rear-wheel steering actuator. Furthermore, the domain controller assumes the responsibility of determining vehicle functional safety. Based on the current vehicle speed, lateral acceleration, and yaw rate, the domain controller determines the maximum steering angle and maximum speed limits for the rear-wheel steering output under the current operating conditions to ensure vehicle safety.

[0135] In some embodiments, the rear-wheel steering control modes corresponding to vehicle power on and off include a power-off return-to-center control mode and a power-on return-to-center control mode. In the power-off return-to-center control mode, the domain controller controls the rear wheels to return to the neutral position via the rear-wheel steering actuator's steering angle control interface. Upon successful return to center, the domain controller disconnects power to the rear-wheel steering actuator, and the domain controller then enters sleep mode. If the vehicle's surroundings cause the rear-wheel steering to become stuck during the return-to-center process, the rear-wheel steering actuator can detect this stall and proactively exit the handshake, entering a fault (Error) state. Upon receiving the fault status signaled by the rear-wheel steering actuator, the domain controller abandons the power-off return-to-center control, disconnects power to the rear-wheel steering actuator, and then enters sleep mode. If a permanent fault occurs in the rear-wheel steering actuator during the return-to-center process, the domain controller similarly abandons the power-off return-to-center control, disconnects power to the rear-wheel steering actuator, and then enters sleep mode. In the power-on return-to-center control mode, due to the power-off return-to-center function, the rear wheels are normally already in the neutral position upon power-on. After power-on, if the domain controller detects that the rear wheels are in the neutral position, power-on return control is not required. If power-off return control fails due to a fault in the previous power-on cycle, that is, the domain controller detects that the rear wheels are not in the neutral position during power-on, it will control the rear wheels to return to the neutral position through the rear wheel steering actuator's angle control interface. The fault handling is the same as that for power-off return control.

[0136] In some embodiments, the rear-wheel steering control mode corresponding to the vehicle's crab-like motion is a special mode that the driver needs to actively turn on and enter, and the domain controller is responsible for receiving the mode switch signal. When the domain controller receives the mode-on signal, it determines whether the vehicle speed is below the set safety threshold. If it is below the safety threshold, since the priority of this mode is only lower than the rear-wheel steering control mode corresponding to the vehicle's power on and off, under normal power-on conditions, the current rear-wheel steering mode can directly jump to the rear-wheel steering control mode corresponding to the vehicle's crab-like motion. When the vehicle speed is higher than the safety threshold, the current rear-wheel steering mode of the domain controller remains in the previous functional mode, the crab-like mode switch on the driver's control panel rebounds to off, and an error message pops up, indicating that this mode is not currently allowed to be turned on. When this function is turned on, the rear-wheel steering and front-wheel steering are in the same direction and angle, which can make the vehicle drive diagonally. After the domain controller determines that this function is turned on, it controls the rear wheels to rotate in the same direction and angle as the front wheels through the angle control interface of the rear-wheel steering actuator. When the user actively disables the rear-wheel steering control mode for crab-like driving, the domain controller switches the current rear-wheel steering mode to Reserved. The domain controller actively changes the control request bit from Request to NoRequest, waiting for the rear wheel to return and then re-uses the rear-wheel steering actuator's angle control interface for handshake. If the handshake is successful, the current rear-wheel steering mode switches to the basic rear-wheel steering control mode. If an abnormality in the rear-wheel steering actuator or domain controller causes the function to exit, the current rear-wheel steering mode switches to Reserved, the domain controller reports the integrated fault type, and simultaneously attempts to enter the basic rear-wheel steering control mode until a fault is encountered.

[0137] In some embodiments, for the rear-wheel steering control mode corresponding to vehicle posture stabilization, the rear-wheel steering supports control by the vehicle stability control system at high speeds to stabilize the vehicle posture. The ESC can establish a control relationship with the domain controller through a handshake mechanism. When the domain controller receives an ESC control request within the vehicle speed range required for ESC entry, it arbitrates between the vehicle-level rear-wheel steering functions deployed in the domain controller. After arbitration is successful, the domain controller switches the current rear-wheel steering mode to the rear-wheel steering control mode corresponding to vehicle posture stabilization. The ESC sends the requested rear wheel angle to the rear-wheel steering actuator through the rear-wheel steering actuator's angle control interface, subject to its own functional safety constraints. After the ESC's rear-wheel steering control request is completed, the handshake with the domain controller is gracefully terminated. The domain controller's current rear-wheel steering mode switches to Reserved. The domain controller actively changes the control request bit from Request to No Request, waiting for the rear wheel to return and then re-handshaking using the rear-wheel steering actuator's angle control interface. If the handshake is successful, the current rear-wheel steering mode switches to the basic rear-wheel steering control mode. When the rear-wheel steering actuator or domain controller is abnormal and causes the function to exit, the current rear-wheel steering mode jumps to Reserved, and the domain controller reports the integrated fault type. At the same time, the domain controller attempts to enter the basic rear-wheel steering control mode until a fault is encountered.

[0138] In some embodiments, for the rear-wheel steering control mode corresponding to vehicle intelligent driving, the rear-wheel steering supports the angle control in response to driving and parking intelligent driving, which can reduce the parking steering radius and improve the stability of the entire vehicle during driving. The intelligent driving module and the domain controller establish a control relationship through a signal handshake mechanism. When the domain controller receives a control request from the intelligent driving module within the speed range for entering intelligent driving, it arbitrates between the vehicle-level rear-wheel steering functions deployed in the domain controller. After the arbitration is carried out through this mode, the current rear-wheel steering mode jumps to the rear-wheel steering control mode corresponding to the vehicle intelligent driving, and the rear-wheel steering angle required by the vehicle intelligent driving module is sent to the intelligent driving module through the angle control interface of the rear-wheel steering actuator after being limited by its own functional safety conditions. After the intelligent driving module completes its rear-wheel steering control request, it exits the handshake with the domain controller normally. The domain controller's current rear-wheel steering mode jumps to Re served. The domain controller actively changes the control request bit from Request to No Request, waits for the rear wheel to return, and then re-uses the rear-wheel steering actuator's angle control interface for a handshake. If the handshake is successful, the current rear-wheel steering mode jumps to the basic rear-wheel steering control mode. If an abnormality in the rear-wheel steering actuator or domain controller causes the function to exit, the current rear-wheel steering mode jumps to Reserved, the domain controller reports the integrated fault type, and simultaneously attempts to enter the basic rear-wheel steering control mode until a fault is encountered.

[0139] In some embodiments, the domain controller can collect fault signals sent out by the rear-wheel steering actuator, and process them together with the fault signals determined by itself to form a total alarm signal, which is sent to the alarm display module of the entire vehicle.

[0140] In some embodiments, when the vehicle speed is higher than a first set threshold (equivalent to the first threshold mentioned above) and the current rear wheel steering angle is greater than a second set threshold (equivalent to the second threshold mentioned above), if there is a single point failure in the domain controller, the rear wheel steering actuator may perform redundant control after receiving a fault signal from the domain controller, and respond to the front wheel steering angle by steering in the same direction as the front wheels at a fixed ratio until the rear wheels pass through the neutral position, then lock the rear wheels in the neutral position and wait for the domain controller to recover.

[0141] It can be understood that the rear-wheel steering control system provided in the embodiment of the present application meets multiple functional requirements with one rear-wheel angle control interface, simplifies the rear-wheel angle control to the greatest extent, and proposes a redundant follow-up steering function of the rear-wheel steering actuator, thereby improving the reliability and safety of the system.

[0142] An embodiment of the present application also provides a vehicle, which includes the rear-wheel steering control system of the vehicle of any one of the above embodiments.

[0143] It should be noted that in this embodiment, the vehicle described is a smart car equipped with rear-wheel steering, particularly suitable for medium-to-large vehicles with long wheelbases and high requirements for maneuverability and driving stability. Such vehicles are equipped with a domain controller to achieve integrated control of multiple subsystems.

[0144] It's important to note that the rear-wheel steering control system, as part of the vehicle's chassis control system, centralizes functions previously performed by independent ECUs into a domain controller, thereby reducing the number of modules in the vehicle and improving system integration and communication efficiency. By moving the rear-wheel steering control logic to the domain controller, it enables more flexible collaboration with other advanced driver assistance systems and body electronics systems.

[0145] In the embodiments of this application, by integrating the rear-wheel steering control system into a domain-based architecture, the integration level of the vehicle control system can be improved, hardware complexity can be reduced, and the compatibility of the rear-wheel steering function with intelligent driving, vehicle stability control, and other systems can be enhanced. This allows for dynamic optimization of the rear-wheel steering angle, thereby reducing the turning radius at low speeds and improving driving stability at high speeds, significantly improving the vehicle's handling performance and driving experience.

[0146] It should be noted that other components of the vehicle in the embodiment of the present application, such as the specific structure of the body and wheels and the connecting and fastening components, can adopt various technical solutions known to ordinary technicians in this field now and in the future, and will not be described in detail here.

[0147] The embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network elements. Some or all of the modules may be selected based on actual needs to achieve the objectives of the embodiments. Persons of ordinary skill in the art will be able to understand and implement the embodiments without inventive effort.

[0148] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the embodiments of the present application may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the embodiments of the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0149] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0150] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0151] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0152] The above description is merely an optional embodiment of the present application and is not intended to limit the scope of protection of the present application.

Claims

1. A rear wheel steering control system for a vehicle, characterized in that: include: A domain controller and a rear wheel steering actuator communicatively connected to the domain controller; The domain controller is configured to arbitrate a rear wheel steering control mode of the vehicle and determine a target rear wheel steering angle of the vehicle based on an arbitration result; The rear wheel steering actuator is configured to perform a steering operation on the rear wheels of the vehicle based on the target rear wheel steering angle determined by the domain controller; Among them, the rear-wheel steering control mode includes: the rear-wheel steering control mode corresponding to the vehicle's power on and off, the rear-wheel steering control mode corresponding to the vehicle's crab driving, the rear-wheel steering control mode corresponding to the vehicle's intelligent driving, the rear-wheel steering control mode corresponding to the vehicle's stable body posture and the basic rear-wheel steering control mode; the basic rear-wheel steering control mode is a mode that determines the vehicle's rear-wheel steering angle based on the vehicle's driving state and using a preset rear-wheel steering angle calculation model.

2. The rear wheel steering control system of a vehicle according to claim 1, characterized in that: The domain controller and the rear wheel steering actuator communicate based on a specific handshake mechanism; The domain controller is further configured to: when determining that the rear-wheel steering actuator is in a standby handshake state, send a rear-wheel control request signal carrying the target rear-wheel steering angle to the rear-wheel steering actuator based on the specific handshake mechanism; The rear-wheel steering actuator is also used to: based on the specific handshake mechanism, in response to the rear-wheel control request signal, switch the handshake state of the rear-wheel steering actuator from the standby handshake state to the activated handshake state, and then perform steering operations on the rear wheels of the vehicle based on the target rear-wheel steering angle.

3. The rear wheel steering control system of a vehicle according to claim 2, characterized in that: The rear wheel steering actuator is also used for: Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller, based on the current rear wheel steering angle of the vehicle, the handshake state of the rear wheel steering actuator is switched from the activated handshake state to the standby handshake state.

4. The rear wheel steering control system of a vehicle according to claim 3, characterized in that: The rear wheel steering actuator is also used for at least one of the following: Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller, when it is determined that the current rear wheel steering angle of the vehicle is zero, switching the handshake state of the rear wheel steering actuator from the active handshake state to the standby handshake state; Based on the specific handshake mechanism, in response to the rear wheel control exit request signal sent by the domain controller, when it is determined that the current rear wheel steering angle of the vehicle is non-zero, the handshake state of the rear wheel steering actuator is switched from the activated handshake state to the neutral return state, and after the rear wheels of the vehicle are turned to the neutral position, the handshake state of the rear wheel steering actuator is switched from the neutral return state to the standby handshake state.

5. The rear wheel steering control system of a vehicle according to any one of claims 2 to 4, characterized in that: The rear wheel steering actuator is also used for: When a target fault is detected, switching the handshake state of the rear-wheel steering actuator based on the fault type of the target fault and controlling the rear-wheel steering position of the vehicle; The fault types include temporary fault types and permanent fault types.

6. The rear wheel steering control system of a vehicle according to claim 5, characterized in that: The rear wheel steering actuator is also used for at least one of the following: When it is determined that the fault type of the target fault is the temporary fault type, the handshake state of the rear-wheel steering actuator is switched from the activated handshake state to the neutral return state, and after the rear wheels of the vehicle are steered to the neutral position, the handshake state of the rear-wheel steering actuator is switched from the neutral return state to the temporary fault state; when it is determined that the target fault is recovered, the handshake state of the rear-wheel steering actuator is switched from the temporary fault state to the standby handshake state; When it is determined that the fault type of the target fault is the permanent fault type, the handshake state of the rear wheel steering actuator is switched from the activated handshake state to the permanent fault state, and the rear wheels of the vehicle are locked at the current position of the rear wheels.

7. The rear wheel steering control system of a vehicle according to any one of claims 1 to 4, characterized in that: The domain controller is further configured to: arbitrate the rear wheel steering control mode of the vehicle according to a preset rear wheel steering control mode priority; The priorities of the rear-wheel steering control modes are as follows from high to low: the rear-wheel steering control mode corresponding to the vehicle's power on and off, the rear-wheel steering control mode corresponding to the vehicle's crab-like running, the rear-wheel steering control mode corresponding to the vehicle's intelligent driving, the rear-wheel steering control mode corresponding to the vehicle's stable body posture, and the basic rear-wheel steering control mode.

8. The rear wheel steering control system of a vehicle according to any one of claims 1 to 4, characterized in that: The rear wheel steering actuator is also used for: In response to a fault signal sent by the domain controller, when it is determined that the current speed of the vehicle is greater than a first threshold and the current rear wheel steering angle of the vehicle is greater than a second threshold, a follow-up steering operation is performed on the rear wheels of the vehicle; the follow-up steering operation indicates that the rear wheels of the vehicle follow the front wheels of the vehicle in steering.

9. The rear wheel steering control system of a vehicle according to claim 8, characterized in that: The rear wheel steering actuator is also used for: During the follow-up steering operation for the rear wheels of the vehicle, if it is determined that the rear wheels have turned to a neutral position, the rear wheels are locked at the neutral position.

10. A vehicle, characterized in that: The vehicle includes the rear-wheel steering control system for a vehicle according to any one of claims 1 to 9.

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