Vehicle steering control method and device, computer equipment and vehicle

Abstract

The invention discloses a vehicle steering control method and device, computer equipment and a vehicle, and belongs to the field of vehicle control. The method comprises the steps that under the condition that front wheels of a vehicle steer, steering parameters of the vehicle are collected; determining a dynamic control parameter of the vehicle based on the steering parameter; solving a dynamic model of the vehicle based on the dynamic control parameters to obtain target rear wheel turning angles suitable for a high-speed working condition and a low-speed working condition respectively; setting a vehicle speed interval according to the target rear wheel rotation angle, and controlling rear wheel steering according to the interval of the current vehicle speed in the vehicle driving process. According to the method, dynamic response characteristics of the vehicle at different speeds are fused, physical quantities such as the dynamic yaw velocity and the change rate of the dynamic yaw velocity are adopted as control targets, and compared with a traditional static model, the method has higher responsiveness and adaptability, the vehicle state can be reflected more truly, fine control over the rear wheel steering angle is achieved, and the method is suitable for large-scale popularization and application. Therefore, the requirements of low-speed maneuverability and high-speed stability are met simultaneously.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle control, and in particular relates to a vehicle steering control method, device, computer equipment and vehicle. Background Art

[0002] With the development of intelligent driving technology, vehicle chassis control systems are gradually evolving from traditional open-loop control to more sophisticated model predictive control. Rear-wheel steering (RWS), a key technology for improving vehicle handling and stability under various operating conditions, has garnered widespread attention.

[0003] In related technologies, rear-wheel steering control mostly relies on the vehicle dynamics model. According to input conditions such as the vehicle's current speed, front wheel steering angle, and geometric parameters, the corresponding control quantity is calculated to achieve steering control of the vehicle.

[0004] However, the control results obtained by solving the parameters as the target under different vehicle speeds and path curvatures may deviate from the true steady state, and the steady-state characteristics of the vehicle often do not meet the driver's control expectations. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a vehicle steering control method, device, computer equipment and vehicle to balance the flexibility and stability of the rear wheel steering process under different driving conditions.

[0006] In a first aspect, the present invention provides a vehicle steering control method, the method comprising:

[0007] When the front wheels of the vehicle are turned, the steering parameters of the vehicle are collected;

[0008] Determining dynamic control parameters of the vehicle based on the steering parameters, the dynamic control parameters including a dynamic sideslip angle of the center of mass, a dynamic yaw rate, and a dynamic yaw rate change rate;

[0009] Solving a vehicle dynamics model based on the dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed operating conditions, respectively;

[0010] The vehicle speed range is set according to the target rear wheel turning angle, and the rear wheel steering is controlled according to the current vehicle speed range during vehicle driving.

[0011] The vehicle steering control method provided by the present invention collects vehicle steering parameters when the vehicle's front wheels are steering, and determines the vehicle's dynamic control parameters based on the steering parameters. The dynamic center of mass sideslip angle, dynamic yaw rate, and dynamic yaw rate change rate are used as control targets. Compared with traditional static models, the method has stronger responsiveness and adaptability and can more realistically reflect the vehicle state. The vehicle's dynamic model is solved based on the dynamic control parameters to obtain target rear wheel steering angles suitable for high-speed and low-speed conditions, respectively. The target rear wheel steering angle is partitioned and integrated through a strategy to avoid inconsistent vehicle responses due to sudden changes in the rear wheel steering angle. The vehicle speed range is set according to the target rear wheel steering angle, and the rear wheel steering is controlled according to the current speed range during vehicle driving, thereby achieving dynamic adaptation of the rear wheel steering angle of the vehicle in different speed ranges, improving flexibility at low speeds and stability at high speeds, thereby enhancing the lateral control performance and ride comfort of the entire vehicle. The method can also adjust the model parameters and control strategies based on the attributes or specifications of different vehicles, adapt to different vehicle parameters and platforms, and has strong scalability.

[0012] According to one embodiment of the present invention, determining the dynamic control parameters of the vehicle based on the steering parameters includes:

[0013] Based on the steering parameters and according to a dynamic model of the vehicle, determining a quasi-static yaw rate and a quasi-static initial center of mass sideslip angle;

[0014] generating a dynamic initial yaw rate and a dynamic initial center-of-mass sideslip angle based on the quasi-static yaw rate and the quasi-static initial center-of-mass sideslip angle;

[0015] Correcting the dynamic initial yaw rate and the dynamic initial center of mass sideslip angle according to control strategies under high-speed and low-speed conditions, respectively, to obtain a dynamic center of mass sideslip angle and a dynamic yaw rate;

[0016] Combined with the vehicle's tire cornering force model, the dynamic center of mass slip angle and dynamic yaw rate are calculated to obtain the dynamic yaw rate change rate.

[0017] In the above embodiment, by introducing a solution strategy for dynamic control parameters, based on the current front wheel steering state of the vehicle, the yaw angular velocity, center of mass sideslip angle, and its rate of change, which can reflect the dynamic response characteristics of the vehicle, are calculated to more accurately drive the control of the rear wheel steering angle, ensure that the vehicle has good steering response and driving stability at different vehicle speeds and operating conditions, and achieve more flexible and stable vehicle handling performance.

[0018] In a second aspect, the present invention provides a steering control device for a vehicle, the device comprising:

[0019] A detection module, used to collect the steering parameters of the vehicle when the front wheels of the vehicle are turned;

[0020] a calculation module, configured to determine dynamic control parameters of the vehicle based on the steering parameters, the dynamic control parameters including a dynamic sideslip angle of the center of mass, a dynamic yaw rate, and a dynamic yaw rate change rate;

[0021] The calculation module is further configured to solve a dynamic model of the vehicle based on the dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed operating conditions, respectively;

[0022] The control module is used to set the vehicle speed range according to the target rear wheel turning angle, and control the rear wheel steering according to the current vehicle speed range during vehicle driving.

[0023] The vehicle steering control device provided by the present invention collects the vehicle's steering parameters when the vehicle's front wheels are steering, and determines the vehicle's dynamic control parameters based on the steering parameters. The dynamic center of mass sideslip angle, dynamic yaw rate, and dynamic yaw rate change rate are used as control targets. Compared with traditional static models, the device has stronger responsiveness and adaptability and can more realistically reflect the vehicle state. The vehicle's dynamic model is solved based on the dynamic control parameters to obtain target rear wheel steering angles suitable for high-speed and low-speed conditions, respectively. The target rear wheel steering angle is partitioned and integrated through a strategy to avoid inconsistent vehicle responses due to sudden changes in the rear wheel steering angle. The vehicle speed range is set according to the target rear wheel steering angle, and the rear wheel steering is controlled according to the current speed range during vehicle driving, thereby achieving dynamic adaptation of the vehicle's rear wheel steering angle in different speed ranges, improving flexibility at low speeds and stability at high speeds, thereby improving the lateral control performance and ride comfort of the entire vehicle. The device can also adjust the model parameters and control strategies based on the properties or specifications of different vehicles, adapt to different vehicle parameters and platforms, and has strong scalability.

[0024] In a third aspect, the present invention provides a vehicle, which is used to execute and implement the vehicle steering control method as described in the first aspect.

[0025] In a fourth aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the vehicle steering control method as described in the first aspect above is implemented.

[0026] In a fifth aspect, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the vehicle steering control method as described in the first aspect above.

[0027] In a sixth aspect, the present invention provides a chip comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a computer program or instruction to implement the vehicle steering control method as described in the first aspect above.

[0028] In a seventh aspect, the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the vehicle steering control method as described in the first aspect above.

[0029] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0031] Figure 1 Schematic diagram of an application scenario of a vehicle steering control method provided in some embodiments of the present invention;

[0032] Figure 2 is a flow chart of a vehicle steering control method provided in other embodiments of the present invention;

[0033] Figure 3 is a schematic structural diagram of a vehicle steering control device provided in some embodiments of the present invention;

[0034] Figure 4 It is a schematic diagram of the structure of a computer device provided in some embodiments of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification and application of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having," as well as any variations thereof, in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," etc., in the specification and claims of the present invention and the accompanying drawings are used to distinguish between different objects, rather than to describe a specific order or a primary-secondary relationship.

[0037] References to "embodiments" in this disclosure mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] The term "and / or" in this disclosure simply describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this disclosure generally indicates that the related objects are in an "or" relationship.

[0040] The term "multiple" used in the present invention refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0041] In related technologies, rear-wheel steering control methods typically use the center of mass slip angle or yaw rate as the control target. In some solutions, the target center of mass slip angle is set to zero to approximate steady-state characteristics. However, the center of mass slip angle is difficult to perceive directly, and its changes do not provide obvious feedback to the driver's subjective experience. In addition, the control results brought about by using this parameter as the target at different vehicle speeds and path curvatures may deviate from the true steady state. In order to improve the naturalness and controllability of the control effect and to be closer to the driver's actual control intention, a model control method is urgently needed that is dominated by the target yaw rate and its change rate, and is combined with the vehicle dynamic model to perform adaptive calculation of the rear wheel angle, so as to achieve balanced control of the vehicle's stability and flexibility over the entire speed range.

[0042] In view of this, an embodiment of the present invention provides a vehicle steering control method, which aims to construct an adaptive rear-wheel steering control method based on dynamic control targets. By integrating the dynamic response characteristics of the vehicle at different speeds and adopting physical quantities such as dynamic yaw angular velocity and its rate of change as control targets, the method has stronger responsiveness and adaptability than traditional static models, can more realistically reflect the vehicle state, and achieve fine control of the rear wheel angle to simultaneously meet the requirements of low-speed maneuverability and high-speed stability.

[0043] On this basis, the invention scheme designed a control interval mechanism based on vehicle speed division. By setting the transition speed interval and weighted fusion of the target rear wheel angles at different speeds, it avoided the discontinuity and mutation in the control switching, achieved smooth output of the rear wheel angle, and thus completed the flexible transition of the steering control, ensuring driving comfort and safety.

[0044] The vehicle steering control method of the embodiment of the present invention performs control solution based on a universal vehicle dynamics model. The model has strong adaptability and can be applied to different vehicle models and steering strategies, and has good scalability and practical value.

[0045] It should be noted that the vehicles mentioned in the embodiments of the present invention include but are not limited to fuel vehicles, plug-in hybrid vehicles or new energy vehicles, etc., and the present invention does not make specific limitations on this.

[0046] The vehicle steering control method and the like provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0047] The vehicle steering control method can be applied to a controller. The controller can be a dedicated vehicle tailgate controller, a microcontroller unit (MCU), or a vehicle control unit (VCU). The following describes the vehicle steering control method provided by an embodiment of the present invention, using the controller as an example.

[0048] Figure 1 FIG. 1 is a flow chart of a vehicle steering control method provided in some embodiments of the present invention. Figure 1 As shown, the vehicle steering control method includes: steps 110 to 140.

[0049] Step 110: When the front wheels of the vehicle are turned, the steering parameters of the vehicle are collected.

[0050] Front-wheel steering refers to the process of turning a vehicle's front wheels, controlled by the driver or the autonomous driving system. Correspondingly, rear-wheel steering refers to the rotation angle of the rear wheels relative to the vehicle's longitudinal axis, used to adjust the vehicle's trajectory and improve handling.

[0051] Steering parameters are key parameters used to describe the current vehicle steering state, including but not limited to vehicle speed, front wheel angle, and other information. These parameters can be used to calculate dynamic control targets.

[0052] The controller first detects the vehicle's current steering parameters and collects data including but not limited to the vehicle's current front wheel angle, vehicle speed, etc. as input basis for subsequent dynamic control calculations.

[0053] For example, the controller can obtain real-time front wheel angle, vehicle longitudinal speed, body acceleration data collected by the acceleration sensor through the vehicle CAN (Controller Area Network) bus, or collect comprehensive vehicle motion information through the IMU (Inertial Measurement Unit).

[0054] Step 120 : Determine dynamic control parameters of the vehicle based on the steering parameters. The dynamic control parameters include a dynamic sideslip angle of the center of mass, a dynamic yaw rate, and a dynamic yaw rate change rate.

[0055] Dynamic control parameters are key control targets obtained through dynamic calculation based on the vehicle's driving state. They include dynamic sideslip angle of the center of mass, dynamic yaw rate, and dynamic yaw rate change rate, and are used to reflect the vehicle's current and short-term dynamic response requirements.

[0056] After detecting the steering parameters, the controller calculates the dynamic slip angle, dynamic yaw rate, and yaw rate change rate in real time based on these parameters to reflect the current vehicle dynamic response. These parameters are used in subsequent dynamic control calculations and are therefore collectively referred to as dynamic control parameters.

[0057] For example, the calculation of dynamic control parameters can be based on a two-degree-of-freedom vehicle model, a Kalman filter estimation method that integrates wheel speed sensor data and front wheel angle, etc.

[0058] Step 130 : Solve the vehicle's dynamics model based on the dynamic control parameters to obtain target rear wheel steering angles suitable for high-speed and low-speed conditions, respectively.

[0059] A dynamics model is a mathematical model used to describe the dynamic behavior of a vehicle under different control inputs and environmental conditions. Common models include two-degree-of-freedom models, which cover mechanical relationships such as center of mass motion, lateral force, and moment of inertia.

[0060] High-speed conditions refer to conditions where the vehicle's speed exceeds a preset threshold, during which vehicle stability control takes precedence over maneuverability control. In high-speed conditions, the target rear wheel steering angle prioritizes suppressing yaw rate changes, enhancing vehicle posture stability, and preventing sideslip and oversteer. This threshold can be determined based on vehicle specifications and test data.

[0061] Low-speed operation refers to conditions where the vehicle's speed falls below a preset threshold, during which vehicle agility control takes precedence over stability control. In these conditions, the rear wheels can steer in coordination with the front wheels, improving maneuverability on narrow roads or when making slow U-turns. This threshold can be determined based on vehicle specifications and test data.

[0062] Vehicle control requirements vary significantly across speed ranges. Low-speed maneuverability is emphasized, while high-speed maneuvers prioritize lateral stability. To accommodate this shift, smooth transitions between speeds are essential, with the ability to adjust target control variables based on the vehicle's dynamic response. This ensures that the vehicle's steady-state characteristics better align with the driver's control expectations and the vehicle's inherent dynamic characteristics.

[0063] Therefore, based on the calculated dynamic control parameters of the vehicle, the controller substitutes the dynamic control parameters into the vehicle's two-degree-of-freedom lateral dynamics model, performs analytical calculations within the framework of the vehicle's two-degree-of-freedom model, and outputs the target rear wheel steering angle applicable to high-speed conditions and the target rear wheel steering angle applicable to low-speed conditions, respectively.

[0064] Step 140: Set a vehicle speed range according to the target rear wheel turning angle, and control the rear wheel steering according to the current vehicle speed range during vehicle driving.

[0065] According to the target rear wheel steering angles applicable to high-speed and low-speed conditions respectively, the controller can divide the vehicle speed range into a low-speed range, a high-speed range and a transition range based on the difference in the target rear wheel steering angles and the vehicle speed characteristic curve, so as to match different rear-wheel steering control strategies.

[0066] In high-speed and low-speed ranges, the controller can directly use the corresponding target rear wheel steering angles to control the vehicle's rear wheel steering. In the transition range, the controller can use a weighted strategy to integrate the target rear wheel steering angles of high-speed and low-speed conditions to achieve a smooth transition in rear wheel steering angle output.

[0067] The vehicle steering control method provided by an embodiment of the present invention collects vehicle steering parameters when the vehicle's front wheels are steering, and determines the vehicle's dynamic control parameters based on the steering parameters. The method uses the dynamic center of mass sideslip angle, dynamic yaw rate, and dynamic yaw rate change rate as control targets. Compared with traditional static models, the method has stronger responsiveness and adaptability and can more realistically reflect the vehicle state. The method solves the vehicle's dynamic model based on the dynamic control parameters to obtain target rear wheel steering angles suitable for high-speed and low-speed conditions, respectively. A partitioned control and fusion strategy for the target rear wheel steering angles avoids inconsistent vehicle responses caused by sudden changes in the rear wheel steering angles. Speed ​​ranges are set according to the target rear wheel steering angles, and rear wheel steering is controlled based on the current speed range during vehicle driving. This achieves dynamic adaptation of the rear wheel steering angles in different speed ranges, improving flexibility at low speeds and stability at high speeds, thereby enhancing the vehicle's lateral control performance and ride comfort. The method can also adjust model parameters and control strategies based on the attributes or specifications of different vehicles, adapting to different vehicle parameters and platforms, and possessing strong scalability.

[0068] Due to the presence of certain lags and inertia in the vehicle response process, the target value calculated only by the quasi-static model may not effectively reflect the actual driving state. Therefore, a dynamic response modeling method needs to be introduced to more realistically approximate the current vehicle dynamic characteristics.

[0069] To this end, in some embodiments, dynamic control parameters of the vehicle are determined based on steering parameters, including: determining a quasi-static yaw rate and a quasi-static initial center of mass sideslip angle based on the steering parameters and a dynamic model of the vehicle; generating a dynamic initial yaw rate and a dynamic initial center of mass sideslip angle based on the quasi-static yaw rate and the quasi-static initial center of mass sideslip angle; correcting the initial yaw rate and the initial center of mass sideslip angle according to control strategies under high-speed and low-speed conditions, respectively, to obtain a dynamic center of mass sideslip angle and a dynamic yaw rate; and calculating based on the dynamic center of mass sideslip angle and the dynamic yaw rate in combination with a tire cornering force model of the vehicle to obtain a dynamic yaw rate change rate.

[0070] Among them, the controller first determines the vehicle's quasi-static yaw rate and quasi-static initial center of mass sideslip angle based on the collected steering parameters such as vehicle speed and front wheel angle, combined with the vehicle's structural properties and dynamic model, to characterize the vehicle's steady-state steering response under current conditions.

[0071] To further consider the dynamic characteristics of the vehicle during steering, the controller solves the vehicle's initial yaw rate and initial center of mass sideslip angle under dynamic conditions based on the quasi-static yaw rate and the quasi-static initial center of mass sideslip angle, namely the dynamic initial yaw rate and the dynamic initial center of mass sideslip angle.

[0072] According to the control targets corresponding to different vehicle speeds, the above initial values ​​are modified according to the low-speed and high-speed strategies respectively to obtain the dynamic center of mass sideslip angle and dynamic yaw rate that can reflect the expected response state of the vehicle.

[0073] Based on the above calculation results, the controller changes factors such as the wheelbase, the distance from the front and rear axles to the center of mass, the vehicle's moment of inertia, or the tire curve used in the calculation process, and adjusts the final dynamic target yaw angle and dynamic target center of mass sideslip angle according to the control goals of improving vehicle flexibility at low speeds and improving vehicle stability at high speeds.

[0074] For example, the controller can increase the weight of the initial center of mass sideslip angle at low speeds to enhance low-speed flexibility; at high speeds, it can give a higher weight to the initial yaw rate to enhance stability when driving at high speeds.

[0075] The dynamic yaw rate change rate can be calculated by solving for the vehicle's lateral acceleration and angular acceleration based on the vehicle's two-degree-of-freedom model, thereby deriving the required rate of change. Specifically, the controller uses the dynamic slip angle and dynamic yaw rate as inputs into the tire cornering force model. Combined with the current vehicle state, the dynamic yaw rate change rate is calculated, serving as a core indicator for subsequent dynamic control calculations. For example, the tire cornering force model can be a linear cornering force model or a modified linear cornering force model.

[0076] In the above embodiment, by introducing a solution strategy for dynamic control parameters, based on the current front wheel steering state of the vehicle, the yaw angular velocity, center of mass sideslip angle, and its rate of change, which can reflect the dynamic response characteristics of the vehicle, are calculated to more accurately drive the control of the rear wheel steering angle, ensure that the vehicle has good steering response and driving stability at different vehicle speeds and operating conditions, and achieve more flexible and stable vehicle handling performance.

[0077] In some embodiments, a dynamic initial yaw rate and a dynamic initial center of mass sideslip angle are generated based on the quasi-static yaw rate and the quasi-static initial center of mass sideslip angle, including: obtaining a dynamic yaw rate and a dynamic center of mass sideslip angle by introducing a dynamic response into the quasi-static yaw rate and the quasi-static center of mass sideslip angle; wherein the dynamic response compensation is used to characterize changes in vehicle dynamic characteristics.

[0078] Among them, quasi-static refers to the response characteristics of the vehicle in a steady state or approximately steady state, ignoring the impact of high-speed dynamic changes, and is suitable for calculating the initial target state.

[0079] The controller can model the vehicle's yaw motion state based on the vehicle's dynamic model and current steering parameters to obtain the yaw angular velocity and sideslip angle under quasi-static conditions; on this basis, the dynamic response is introduced to correct the above state quantities to obtain the yaw angular velocity and sideslip angle under dynamic conditions.

[0080] Dynamic response refers to the response characteristics of a vehicle when the controlled variables change over time under non-steady-state conditions. It is used to describe dynamic behaviors such as rapid steering or lane changes. Accordingly, dynamic response compensation is a preset coefficient that characterizes the dynamic response characteristics of the vehicle during steering, and is used to dynamically correct the quasi-static yaw rate and quasi-static center of mass sideslip angle. For example, dynamic response compensation can be determined based on preset compensation parameters to improve the control accuracy of the vehicle under non-steady-state driving conditions. By introducing dynamic response, the actual physical inertia and hysteresis behavior of the vehicle can be reflected, so that the calculated dynamic state parameters are more consistent with the actual response of the vehicle, which helps to improve the subsequent control accuracy.

[0081] For example, the controller models the vehicle as a two-degree-of-freedom model, using the current vehicle speed and front wheel angle as input parameters. Based on this model, it calculates the quasi-static yaw rate and sideslip angle. By introducing dynamic response correction factors, such as those based on the vehicle's moment of inertia, cornering stiffness, and yaw acceleration trends, the controller can modify the quasi-static parameters to obtain dynamic state values.

[0082] Alternatively, the controller can also represent the vehicle's response characteristics to inputs through a first-order lag system or a state-space filter model, thereby dynamically correcting the quasi-static parameters to obtain the dynamic yaw rate and dynamic center of mass sideslip angle.

[0083] Exemplarily, the controller calculates the vehicle's quasi-static target yaw rate and quasi-static target center-of-mass sideslip angle according to the dynamic model based on external inputs such as vehicle speed and front wheel steering angle. The controller then adds a dynamic response component based on the quasi-static target yaw rate and quasi-static target center-of-mass sideslip angle to calculate the vehicle's dynamic target yaw rate and dynamic target center-of-mass sideslip angle using the following formula:

[0084]

[0085] in, is the dynamic yaw rate, β dyn (s) is the dynamic center of mass sideslip angle, is the static yaw rate, β stat (s) is the static center of mass sideslip angle, T d is the dynamic response time constant, ω0 is the eigenfrequency, and D is the damping factor; T d, ω0 and D are calculated based on vehicle speed, vehicle weight, distance from the front and rear axles to the center of mass, front and rear tire cornering stiffness and vehicle moment of inertia.

[0086] In the above embodiment, by introducing the dynamic response modeling method, the current dynamic state of the vehicle can be more accurately characterized, thereby improving the timeliness and accuracy of subsequent control instructions; compared with the traditional quasi-static model calculation method, this solution can effectively adapt to the state changes of the vehicle under different speeds and steering conditions, thereby improving the handling performance and control robustness of the entire vehicle.

[0087] In some embodiments, a dynamic model of the vehicle is solved using dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed conditions, respectively, including: establishing a two-degree-of-freedom model of the vehicle; the two-degree-of-freedom model reflects the vehicle's lateral force balance relationship and the torque balance relationship around the center of mass; based on the two-degree-of-freedom model, the dynamic target yaw rate, the dynamic target center of mass sideslip angle, and the target yaw rate change rate are substituted into the solution to obtain the target rear wheel steering angle under high-speed conditions; the target rear wheel steering angle under high-speed conditions is converted to obtain the target rear wheel steering angle under low-speed conditions.

[0088] Among them, the vehicle's two-degree-of-freedom model is a classic vehicle lateral dynamics model, which includes two degrees of freedom: lateral displacement and yaw angle, and is used to calculate dynamic indicators such as yaw angular velocity and sideslip angle.

[0089] The controller constructs a two-degree-of-freedom model of the vehicle, which takes into account the balance of the vehicle's lateral force and the balance of the torque around the center of mass. The dynamic control parameters (including dynamic yaw rate, dynamic center of mass sideslip angle and yaw rate change rate) are substituted into the model, and the target rear wheel steering angle under high-speed conditions is obtained by solving it.

[0090] Subsequently, the controller corrects the high-speed target rear wheel steering angle based on the steering demand characteristics of the vehicle at low speed to obtain a target rear wheel steering angle suitable for the low-speed state.

[0091] For example, the controller converts the target rear wheel steering angle under high-speed conditions into equivalent front wheel steering, or uses trajectory tracking methods to convert it, to obtain the target rear wheel steering angle under low-speed conditions, so as to meet the high flexibility requirements under low-speed conditions.

[0092] In the above embodiment, by separately solving the target rear wheel steering angles at high and low speeds, more precise rear wheel control can be achieved under different vehicle speed conditions, thereby improving the dynamic performance of the entire vehicle. The separate calculation and conversion fusion of the high and low speed target angles help to build a unified rear wheel steering angle control framework and simplify the design of the transition interval control strategy. Among them, the application of the two-degree-of-freedom model takes into account both calculation accuracy and real-time performance, so that the controller has good real-time responsiveness under actual road conditions.

[0093] Among them, in some embodiments, based on a two-degree-of-freedom model, the dynamic target yaw rate, the dynamic target center-of-mass slip angle and the target yaw rate change rate are respectively substituted into the solution to obtain the target rear wheel turning angle under high-speed conditions, including: determining the vehicle's lateral stiffness parameters; the lateral stiffness parameters include the front wheel lateral stiffness and the rear wheel lateral stiffness; the dynamic target yaw rate, the dynamic target center-of-mass slip angle and the target yaw rate change rate are used as target values, and the target values ​​and the lateral stiffness parameters are substituted into the two-degree-of-freedom model to solve the rear wheel turning angle to obtain the target rear wheel turning angle under high-speed conditions.

[0094] Among them, the cornering stiffness parameter represents the lateral force generated by the tire at a unit slip angle, mainly including the front wheel cornering stiffness and the rear wheel cornering stiffness, and is used to describe the lateral response characteristics of the tire.

[0095] The tire cornering force model refers to a mathematical model that describes the lateral force generated by the tire under certain slip angle conditions. It is used to calculate parameters such as the vehicle's yaw response and center of mass slip angle.

[0096] The controller first obtains vehicle structural parameters and tire characteristic data to determine the cornering stiffness of the front and rear wheels. It then combines the currently detected dynamic target yaw rate, dynamic target center of mass slip angle, and target yaw rate change rate, and substitutes these target values ​​and cornering stiffness parameters into the vehicle's two-degree-of-freedom model. By solving these two degrees of freedom, the controller can determine the rear wheel steering angle that meets the dynamic performance requirements.

[0097] For example, the controller establishes a two-degree-of-freedom model of the actual vehicle based on the actually measured vehicle speed, front wheel steering angle, and tire characteristic curve using the Newtonian dynamics principle as follows:

[0098]

[0099]

[0100] Among them, m is the mass of the vehicle, V is the speed of the center of mass, is the rate of change of yaw angular velocity, is the rate of change of the center of mass sideslip angle, β is the center of mass sideslip angle, δ f is the front wheel turning angle, δ r is the rear wheel turning angle, C f is the front axle cornering stiffness, C r is the rear axle cornering stiffness, l f is the distance from the front axle to the center of mass, l r is the distance from the rear axle to the center of mass, J z is the vehicle's moment of inertia.

[0101] The controller can obtain the front wheel cornering stiffness Cf and the rear wheel cornering stiffness Cr through experiments or estimation methods, and based on the above-mentioned vehicle two-degree-of-freedom model formula, use dynamic control parameters such as the target yaw angular velocity as constraints, and solve the system of equations to solve the rear wheel cornering angle when the target conditions are met, thereby inferring the rear wheel steering angle.

[0102] In this embodiment, by incorporating front and rear wheel cornering stiffness parameters, which reflect the vehicle's tire response characteristics, and combining them with dynamic control parameters as target inputs, the target rear wheel angle can be accurately calculated under high-speed conditions, providing a theoretical basis for subsequent rear-wheel steering control. Compared to methods that solely calculate rear wheel angles using static or simplified models, this solution better ensures vehicle lateral stability and path tracking capabilities during high-speed driving, thereby improving overall vehicle handling and safety.

[0103] The response requirements for rear-wheel steering vary under different vehicle speed conditions: high-speed conditions prioritize stability, while low-speed conditions emphasize maneuverability and flexibility. Due to the accuracy of low-speed tire characteristic curves, to improve the controllability and visibility of low-speed agility control, the control of low-speed rear-wheel steering angle can be visualized as a proportional relationship between vehicle speed and front-wheel steering angle.

[0104] To this end, in some embodiments, the target rear wheel steering angle under high-speed conditions is converted to obtain the target rear wheel steering angle under low-speed conditions, including: establishing a proportional mapping relationship between vehicle speed, front wheel steering angle and rear wheel steering angle based on the vehicle speed characteristic curve; and converting the target rear wheel steering angle under high-speed conditions according to the proportional mapping relationship to obtain the target rear wheel steering angle under low-speed conditions.

[0105] The vehicle speed characteristic curve refers to a function curve that describes how vehicle control parameters change with vehicle speed, such as the relationship between rear wheel steering angle or control gain and vehicle speed.

[0106] After calculating the target rear wheel steering angle for high-speed operation, the controller must further convert this angle into a control target suitable for low-speed operation. To achieve this conversion, the controller establishes a proportional mapping relationship between vehicle speed, front wheel steering angle, and rear wheel steering angle based on the vehicle speed characteristic curve. The controller then adjusts the target value for high-speed operation based on this proportional relationship, thereby obtaining a target rear wheel steering angle suitable for low-speed operation.

[0107] For example, the controller can establish a set of vehicle speed characteristic curves based on simulation, experimental, or empirical data. These curves describe the mapping between the front and rear wheel angles at different speeds. Typically, as vehicle speed decreases, the absolute value of the rear wheel angle increases to improve maneuverability and turning radius control, and the mapping relationship will reflect this nonlinear trend.

[0108] In the above embodiment, by establishing a proportional mapping relationship based on the vehicle speed characteristics, the rear wheel steering angle under high-speed conditions is accurately converted to the target angle under low-speed conditions. This not only improves the adaptability of the control strategy, but also makes the functional goals of the rear-wheel steering at different vehicle speeds more targeted: ensuring vehicle stability during high-speed driving, enhancing the vehicle's steering flexibility during low-speed operation, improving the vehicle's handling performance while reducing the driving burden.

[0109] In some embodiments, establishing a two-degree-of-freedom model of a vehicle includes: obtaining a vehicle operation curve obtained from a test; the vehicle operation curve includes at least a vehicle speed characteristic curve, a front wheel turning angle curve, and a tire characteristic curve; and constructing a two-degree-of-freedom model of the vehicle based on the vehicle operation curve and dynamic control parameters.

[0110] The controller collects and organizes vehicle operation data from actual tests or simulations to obtain vehicle operation curves for modeling. The vehicle operation curve is a multi-parameter joint variation curve that reflects the actual operating conditions of the vehicle, including a vehicle speed characteristic curve, a front wheel steering angle curve, and a tire characteristic curve. The front wheel steering angle curve represents the change of the front wheel steering angle over time or other state variables (such as vehicle speed) and is used to simulate or analyze driving input characteristics. The tire characteristic curve is a curve used to characterize the relationship between physical quantities such as tire lateral force, sideslip angle, and cornering stiffness, and is used for tire modeling.

[0111] Based on the above curves and the determined dynamic control parameters (dynamic yaw rate, dynamic center of mass sideslip angle, etc.), a two-degree-of-freedom model of the vehicle is constructed.

[0112] For example, during the specific construction process, the controller can use experimental data for modeling, such as collecting response data under different vehicle speeds and front wheel angle inputs from a test platform or actual vehicle tests; or, it can be modeled by fitting the tire side slip characteristics; or, it can also determine the center of mass parameters and geometric parameters, such as vehicle mass, center of mass position, wheelbase, track width, moment of inertia, etc., and derive the lateral force balance and torque balance equations to form a complete two-degree-of-freedom motion equation.

[0113] In the above embodiment, the two-degree-of-freedom model constructed based on the vehicle's actual operating curve can more accurately reflect the vehicle's behavior under lateral dynamic control, providing an accurate dynamic basis for subsequent rear wheel steering angle calculation. This model is not only suitable for stability control under high-speed conditions, but also has adaptability to low-speed conditions, significantly improving the reliability, applicability, and accuracy of the control strategy.

[0114] In some embodiments, a vehicle speed range is set according to a target rear wheel turning angle, and the rear wheel steering of the vehicle is controlled in different vehicle speed ranges, including: setting a vehicle speed range according to a target rear wheel turning angle; the vehicle speed stage includes at least a low-speed range, a high-speed range and a transition range; detecting the current speed of the vehicle, and determining the speed range in which the vehicle is currently located based on the current speed; when the vehicle is currently in a low-speed range, controlling the rear wheel steering of the vehicle according to the rear wheel turning angle corresponding to the low-speed range; when the vehicle is currently in a high-speed range, controlling the rear wheel steering of the vehicle according to the rear wheel turning angle corresponding to the high-speed range; when the vehicle is currently in a transition range, performing weight allocation according to the current vehicle speed, and fusing the target rear wheel turning angles under high-speed and low-speed conditions to obtain a rear wheel turning angle for smooth transition.

[0115] The transition interval refers to the speed interval in which the vehicle transitions from a low-speed state to a high-speed state or vice versa, and is used to achieve smooth switching of control strategies.

[0116] Smooth transition refers to the continuity and stability of control variables or control strategies during changes, avoiding sudden changes or oscillations.

[0117] The controller establishes control logic associated with vehicle speed based on the target rear wheel steering angle results obtained under high-speed and low-speed conditions respectively, divides the vehicle speed range into a low-speed range, a high-speed range and a transition range, and determines the speed range in which the vehicle is located based on its current real-time speed value.

[0118] For example, a speed less than V1 (e.g., 30 km / h) is defined as a low-speed range, a speed greater than V2 (e.g., 70 km / h) is defined as a high-speed range, and the transition range is defined between the two. The controller can read the output of the on-board speed sensor to determine in real time which range the current vehicle speed belongs to.

[0119] Based on the control strategy in different intervals, the controller determines the actual applied rear wheel steering angle.

[0120] When the vehicle is currently in a low-speed range, the controller controls the steering of the vehicle's rear wheels according to the rear wheel turning angle corresponding to the low-speed range.

[0121] When the vehicle is currently in a high-speed section, the controller controls the steering of the vehicle's rear wheels according to the rear wheel turning angle corresponding to the high-speed section.

[0122] When the vehicle is in the transition zone, the controller assigns weights based on the current vehicle speed and fuses the target rear-wheel steering angles for high-speed and low-speed conditions to produce a smooth transition rear-wheel steering angle. For example, the controller can set a speed-dependent weighting factor α and fuse the high-speed and low-speed target rear-wheel steering angles through linear interpolation to obtain the final target rear-wheel steering angle. The controller then sends this fused rear-wheel steering angle command to the rear-wheel steering actuator to control the vehicle's rear-wheel steering for a smooth transition.

[0123] Among them, the division of vehicle speed ranges and weight factors can be customized according to different vehicle models and control requirements, and have good scalability.

[0124] In the above embodiment, by improving steering flexibility and ease of operation when driving at low speeds, enhancing the vehicle's yaw stability and response consistency when driving at high speeds, and achieving smooth connection between the two control strategies in the transition zone, sudden changes in vehicle response or jumps in control logic are avoided, thereby improving driving comfort and safety.

[0125] In some embodiments, when the vehicle is currently in a transition zone, weights are allocated based on the current vehicle speed, and the target rear wheel steering angles under high-speed conditions and low-speed conditions are fused to obtain a rear wheel steering angle for a smooth transition, including: when the vehicle is in the transition zone, based on the current vehicle speed, respectively determining the weight factors corresponding to the high-speed condition and the low-speed condition; based on the weight factors corresponding to the high-speed condition and the low-speed condition, weighted fusion of the target rear wheel steering angles under the high-speed condition and the low-speed condition is performed to obtain a rear wheel steering angle for a smooth transition.

[0126] Among them, the weight factor is the coefficient used when performing weighted fusion between multiple control targets, which is used to dynamically adjust the target contribution ratio according to factors such as the current vehicle speed.

[0127] After detecting that the vehicle is currently in the transition speed range, the controller calculates the weight factors of low-speed and high-speed operating conditions based on the current vehicle speed, and uses this to weight the target rear wheel steering angles under the two conditions to generate a fused rear wheel steering angle command.

[0128] For example, weight factors can be set separately for high-speed and low-speed conditions, and then integrated through linear interpolation, weighted averaging, etc. For example, the high-speed condition corresponds to weight factor α, and the low-speed condition corresponds to weight factor β. Then, the rear wheel steering angle used for smooth transition = weight factor α * rear wheel steering angle corresponding to the high-speed condition + weight factor β * rear wheel steering angle corresponding to the low-speed condition, and so on.

[0129] For example, the controller may set a fusion buffer or a derivative limiter to avoid frequent switching or excessive response.

[0130] In the above embodiment, a weight distribution mechanism based on vehicle speed is used to achieve dynamic fusion between high-speed and low-speed target rear wheel angles, thereby avoiding steering jitter or instability caused by sudden changes in control strategy when the vehicle enters the transition zone, improving the steering continuity and response smoothness of the entire vehicle, and being able to adapt to the comprehensive requirements of dynamic stability and comfort under different vehicle models and driving conditions.

[0131] In some embodiments, based on the current vehicle speed, the weight factors corresponding to the high-speed working condition and the low-speed working condition are determined respectively, including: obtaining the attribute information of the vehicle; determining the control strategy in the transition interval based on the attribute information, the control strategy including the flexibility strategy and the stability strategy; under the determined control strategy, adjusting the initial weight factor to obtain the weight factors corresponding to the high-speed working condition and the low-speed working condition.

[0132] Vehicle attribute information includes, but is not limited to, vehicle model and vehicle body parameters. Body parameters are used to describe the vehicle's physical characteristics and structural parameters, including but not limited to vehicle mass, front and rear wheel load distribution, wheelbase, track width, vehicle steering response sensitivity, or suspension stiffness.

[0133] The control strategy refers to the policy rules that determine how to set the rear wheel angle or other control variables under the conditions of specific vehicle attribute information, and usually relies on dynamic models and objective function design.

[0134] Control strategies include flexibility and stability. The flexibility strategy aims to improve low-speed maneuverability and responsiveness, and is suitable for narrow roads or low-speed cornering scenarios. The stability strategy aims to improve the vehicle's stability and anti-skid capability at high speeds, and is suitable for scenarios such as high-speed cruising and emergency obstacle avoidance.

[0135] For example, if the vehicle is a sports vehicle, the goal during steering is to improve flexibility, or flexibility is the main focus. Therefore, the control strategy is a flexibility strategy, and the control method in the medium-speed section or transition zone is similar to or the same as the control method in the high-speed section.

[0136] For example, if the vehicle is a commercial vehicle, the goal during steering is to improve stability, or stability is the main focus. Therefore, the control strategy is a stability strategy, and the control method in the medium-speed section or transition range is similar to or the same as the control method in the low-speed section.

[0137] Therefore, based on the determined control strategy, the controller can adjust the initial weight factor to obtain the weight factors corresponding to the high-speed operating condition and the low-speed operating condition respectively.

[0138] For example, the weight factors corresponding to the high-speed working condition and the low-speed working condition are the initial weights. When the control strategy is the flexibility strategy, the controller can assign a higher fusion weight to the high-speed target rear wheel angle, such as the controller increases the weight factor corresponding to the high-speed working condition, and lowers or keeps the weight factor corresponding to the low-speed working condition unchanged; or, when the control strategy is the stability strategy, the controller can assign a higher fusion weight to the low-speed target rear wheel angle, such as the controller increases the weight factor corresponding to the low-speed working condition, and lowers or keeps the weight factor corresponding to the high-speed working condition unchanged, and so on.

[0139] The initial weights can be obtained based on linear interpolation, logical lookup tables, or neural network prediction, etc. The adjustment of the fusion weight factors can achieve smooth weight changes through functional relationships.

[0140] In the above embodiment, by introducing vehicle attribute information and selecting different control strategies based on actual needs, the fusion ratio of high-speed and low-speed target rear wheel angles can be set more reasonably. In combination with different control objectives (such as handling flexibility or stability), different fusion weights are assigned to the target rear wheel angles under high-speed conditions and low-speed conditions, thereby achieving adaptive optimization adjustment of the rear wheel angle in the transition range. Compared with static weight setting or linear interpolation methods, it can more finely balance handling flexibility and stability, thereby improving the vehicle's handling performance, response consistency and driving comfort.

[0141] Figure 2 FIG. 1 is a flow chart of the steering control of a vehicle provided in other embodiments of the present invention. Figure 2 As shown, the method includes steps 1 to 8. Among them:

[0142] Step 1: Based on the vehicle speed and front wheel angle external inputs, the vehicle's quasi-static target yaw rate and quasi-static target sideslip angle are calculated according to the dynamic model;

[0143] Step 2: Based on the quasi-static target yaw rate and the quasi-static target sideslip angle, a dynamic response step is added to calculate the vehicle's dynamic target yaw rate and the vehicle's dynamic target sideslip angle.

[0144] Step 3: Based on the above calculation results, factors such as wheelbase, distance from the front and rear axles to the center of mass, vehicle moment of inertia, or tire curve used in the calculation are changed. The final dynamic target yaw angle and dynamic target sideslip angle are adjusted to achieve the control objectives of improving vehicle agility at low speeds and improving vehicle stability at high speeds.

[0145] Step 4: Based on the target yaw rate and target sideslip angle calculated above, calculate the target yaw rate change rate using the front and rear axle tire formulas.

[0146] Step 5: Based on the actual measured vehicle speed, front wheel angle, and tire characteristic curve, a two-degree-of-freedom model of the actual vehicle is established using the Newtonian dynamics principle;

[0147] Step 6: The real-time cornering stiffness of the front and rear axles is calculated using the two-degree-of-freedom model from step 5. Based on the target yaw rate calculated from step 3 and the target yaw rate change rate calculated from step 4, as well as the current actual front wheel angle and center-of-mass speed, the target rear wheel angle is calculated using the vehicle's two-degree-of-freedom model.

[0148] Step 7: Based on the results of Step 6, due to the accuracy of the low-speed tire characteristic curve, in order to improve the controllability of low-speed flexibility control and enhance the explicitness of the function, the control of the low-speed rear wheel angle can be visualized as a proportional relationship between vehicle speed and front wheel angle. Based on this proportional relationship, the target rear wheel angle for the low-speed operating condition is obtained.

[0149] Step 8: Based on the rear wheel steering angle of the high-speed condition obtained in step 6 and the rear wheel steering angle of the low-speed condition obtained in step 7, plan the vehicle speed range for angle transition, and perform weighting processing based on the vehicle speed factor according to the change in vehicle speed to perform a smooth transition between high and low speed angle control. For details, please refer to the calibration results.

[0150] The vehicle steering control method provided by the present invention reversely calculates the target rear wheel angle based on the target yaw rate, and the calculation of the target yaw rate is based on variable vehicle parameters (including vehicle wheelbase, vehicle moment of inertia, tire characteristic curve, etc.). The target yaw rate change rate and target center of mass sideslip angle are calculated based on the variable vehicle parameters. The control target in the algorithm can be flexibly adjusted according to the ideal control result, thereby improving the flexibility of control. In addition, the driver's in-the-loop experience perception is enhanced during the development process, thereby improving the accuracy of control.

[0151] Compared to traditional approaches, the present invention, based on model-based control, uses the target yaw rate as the primary vehicle control target when calculating the rear wheel steering angle. This control target clearly reflects the driver-perceived yaw rate gain (yaw rate change rate / front wheel steering angle), enabling a more accurate determination of the vehicle's overall steady-state characteristics. Furthermore, the control method, which is based on various adjustable parameters within the target yaw rate (including vehicle wheelbase, vehicle moment of inertia, and tire characteristic curves), creates a control target that approximates a true steady-state vehicle, avoiding the potential for non-perfectly steady-state vehicle control results associated with using a zero target slip angle. This model-based control, based on the target yaw rate change rate, improves the controllability of the control process and the accuracy of the control results, resulting in a more natural control effect without creating peculiar vehicle perception. Model-based control visualizes low-speed control as a proportional relationship, leveraging the characteristics of model-based control to enhance the explicitness and accuracy of low-speed control. Furthermore, a transition algorithm between high and low speed control is designed based on this, enhancing the continuity of rear-wheel steering control across the entire speed range. The rear-wheel steering control system based on this control method can comprehensively improve the flexibility of low-speed vehicles under steady-state conditions and reduce the turning radius; improve the stability of high-speed vehicles and make lane changes smoother; and the medium-speed section can be flexibly configured according to the characteristics of the vehicle model release, either to improve flexibility or stability, ultimately changing the driving characteristics of steady-state vehicles at all speeds.

[0152] The vehicle steering control method provided in the embodiment of the present invention can be executed by a vehicle steering control device. In the embodiment of the present invention, the vehicle steering control device is used as an example to illustrate the vehicle steering control method.

[0153] An embodiment of the present invention further provides a vehicle steering control device, which is applied to a computer device, such as a controller or a control system.

[0154] Figure 3 Schematic diagram of the structure of the computer equipment provided in some embodiments of the present invention. Figure 3 As shown, the vehicle steering control device includes a detection module 301, a calculation module 302 and a control module 303.

[0155] The detection module 301 is used to collect the steering parameters of the vehicle when the front wheels of the vehicle are turned;

[0156] a calculation module 302 for determining dynamic control parameters of the vehicle based on the steering parameters, the dynamic control parameters including a dynamic sideslip angle of the center of mass, a dynamic yaw rate, and a dynamic yaw rate change rate;

[0157] The calculation module 302 is further configured to solve the vehicle dynamics model based on the dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed operating conditions, respectively;

[0158] The control module 303 is used to set a vehicle speed range according to the target rear wheel steering angle, and control the rear wheel steering according to the current vehicle speed range during vehicle driving.

[0159] According to an embodiment of the present invention, a vehicle steering control device provides a vehicle steering control method. By collecting vehicle steering parameters when the vehicle's front wheels are steering, the device determines the vehicle's dynamic control parameters based on the steering parameters. The device uses the dynamic center of mass sideslip angle, dynamic yaw rate, and dynamic yaw rate change rate as control targets. This device exhibits greater responsiveness and adaptability than traditional static models and can more realistically reflect the vehicle's state. The device solves the vehicle's dynamic model based on the dynamic control parameters to obtain target rear wheel steering angles suitable for high-speed and low-speed conditions, respectively. A partitioned control and fusion strategy for the target rear wheel steering angles avoids inconsistent vehicle responses caused by sudden changes in the rear wheel steering angles. Speed ​​ranges are set according to the target rear wheel steering angles, and rear wheel steering is controlled based on the current speed range during vehicle travel. This achieves dynamic adaptation of the rear wheel steering angles in different speed ranges, improving flexibility at low speeds and stability at high speeds, enhancing the vehicle's lateral control performance and ride comfort. Furthermore, the device can adjust model parameters and control strategies based on the attributes or specifications of different vehicles, adapting to different vehicle parameters and platforms and demonstrating strong scalability.

[0160] According to one embodiment of the present invention, the calculation module is further used to determine the quasi-static yaw rate and the quasi-static initial center of mass sideslip angle based on the steering parameters and the dynamic model of the vehicle; generate the dynamic initial yaw rate and the dynamic initial center of mass sideslip angle based on the quasi-static yaw rate and the quasi-static initial center of mass sideslip angle; correct the initial yaw rate and the initial center of mass sideslip angle according to the control strategies under high-speed and low-speed conditions, respectively, to obtain the dynamic center of mass sideslip angle and the dynamic yaw rate; and calculate based on the dynamic center of mass sideslip angle and the dynamic yaw rate in combination with the tire cornering force model of the vehicle to obtain the dynamic yaw rate change rate.

[0161] According to one embodiment of the present invention, the calculation module is further used to obtain the dynamic yaw rate and the dynamic center of mass sideslip angle by introducing dynamic response compensation into the quasi-static yaw rate and the quasi-static center of mass sideslip angle; wherein the dynamic response compensation is a preset coefficient that characterizes the dynamic response characteristics of the vehicle during steering, and is used to dynamically correct the quasi-static yaw rate and the quasi-static center of mass sideslip angle.

[0162] According to one embodiment of the present invention, the calculation module is also used to establish a two-degree-of-freedom model of the vehicle; the two-degree-of-freedom model reflects the vehicle's lateral force balance relationship and the torque balance relationship around the center of mass; based on the two-degree-of-freedom model, the dynamic target yaw angular velocity, the dynamic target center of mass sideslip angle and the target yaw angular velocity change rate are respectively substituted into the solution to obtain the target rear wheel turning angle under high-speed conditions; the target rear wheel turning angle under high-speed conditions is converted to obtain the target rear wheel turning angle under low-speed conditions.

[0163] According to one embodiment of the present invention, the calculation module is also used to determine the vehicle's cornering stiffness parameters; the cornering stiffness parameters include the front wheel cornering stiffness and the rear wheel cornering stiffness; the dynamic target yaw rate, the dynamic target center of mass sideslip angle and the target yaw rate change rate are used as target values, and the target values ​​and the cornering stiffness parameters are substituted into the two-degree-of-freedom model to solve the rear wheel turning angle to obtain the target rear wheel turning angle under high-speed conditions.

[0164] According to one embodiment of the present invention, the calculation module is also used to establish a proportional mapping relationship between the vehicle speed, the front wheel steering angle and the rear wheel steering angle based on the vehicle speed characteristic curve; according to the proportional mapping relationship, the target rear wheel steering angle under the high-speed working condition is converted to obtain the target rear wheel steering angle under the low-speed working condition.

[0165] According to one embodiment of the present invention, the calculation module is also used to obtain the vehicle operation curve obtained by testing; the vehicle operation curve includes at least a vehicle speed characteristic curve, a front wheel turning angle curve and a tire characteristic curve; based on the vehicle operation curve and dynamic control parameters, a two-degree-of-freedom model of the vehicle is constructed.

[0166] According to one embodiment of the present invention, the control module is also used to set the vehicle speed range according to the target rear wheel turning angle; the vehicle speed stage includes at least a low-speed range, a high-speed range and a transition range; the current speed of the vehicle is detected, and the speed range in which the vehicle is currently located is determined based on the current speed; when the vehicle is currently in the low-speed range, the rear wheel steering of the vehicle is controlled according to the rear wheel turning angle corresponding to the low-speed range; when the vehicle is currently in the high-speed range, the rear wheel steering of the vehicle is controlled according to the rear wheel turning angle corresponding to the high-speed range; when the vehicle is currently in the transition range, weights are allocated according to the current vehicle speed, and the target rear wheel turning angles under high-speed and low-speed conditions are merged to obtain a rear wheel turning angle for smooth transition.

[0167] According to one embodiment of the present invention, the control module is also used to determine the weight factors corresponding to the high-speed working condition and the low-speed working condition respectively based on the current vehicle speed when the vehicle is in the transition zone; based on the weight factors corresponding to the high-speed working condition and the low-speed working condition respectively, the target rear wheel steering angles under the high-speed working condition and the low-speed working condition are weightedly fused to obtain the rear wheel steering angle for smooth transition.

[0168] According to one embodiment of the present invention, the control module is also used to obtain attribute information of the vehicle; determine the control strategy in the transition interval based on the attribute information, the control strategy includes a flexibility strategy and a stability strategy; under the determined control strategy, adjust the initial weight factor to obtain the weight factors corresponding to the high-speed working condition and the low-speed working condition respectively.

[0169] The steering control device of the vehicle in the embodiment of the present invention can be a computer device, or a component in the computer device, such as an integrated circuit or a chip. The computer device can be a controller. For example, the computer device can be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle computer device, a mobile Internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook or a personal digital assistant (PDA), etc. It can also be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), an ATM or a self-service machine, etc., and the embodiment of the present invention does not specifically limit it.

[0170] An embodiment of the present invention further provides a vehicle, which is used to execute and implement the above-mentioned vehicle steering control method.

[0171] An embodiment of the present invention further provides a vehicle, the vehicle comprising: Figure 3 The steering controls of the vehicle are shown.

[0172] The vehicle steering control device in the embodiment of the present invention may be a device having an operating system. The operating system may be a Microsoft (Windows) operating system, an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present invention.

[0173] The vehicle steering control device provided by the embodiment of the present invention can implement each process implemented by each method embodiment, and to avoid repetition, it will not be described here.

[0174] Figure 4 Schematic diagram of the structure of a computer device provided in some embodiments of the present invention. Figure 4As shown, an embodiment of the present invention further provides a computer device 400, including a processor 401, a memory 402, and a computer program stored in the memory 402 and executable on the processor 401. When the program is executed by the processor 401, the various processes of the above-mentioned method embodiments are implemented, and the same technical effects can be achieved. To avoid repetition, they will not be described here.

[0175] It should be noted that the computer devices in the embodiments of the present invention include the mobile computer devices and non-mobile computer devices mentioned above.

[0176] An embodiment of the present invention also provides a non-transitory computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the various processes of the above-mentioned vehicle steering control method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0177] The processor is the processor in the computer device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0178] An embodiment of the present invention further provides a computer program product, comprising a computer program, which implements the above-mentioned vehicle steering control method when executed by a processor.

[0179] The processor is the processor in the computer device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0180] An embodiment of the present invention further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned vehicle steering control method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0181] It should be understood that the chip mentioned in the embodiment of the present invention can also be called a system-on-chip, a system-on-chip, a chip system, or a system-on-chip chip, etc.

[0182] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0183] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the relevant technology can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a number of instructions for enabling a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0184] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

[0185] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0186] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0187] Unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0188] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, "the method includes steps (a) and (b)" indicates that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, "the method may further include step (c)" indicates that step (c) may be added to the method in any order, for example, the method may include steps (a), (b), and (c), or may include steps (a), (c), and (b), or may include steps (c), (a), and (b), etc.

[0189] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A vehicle steering control method, characterized in that: The method comprises: When the front wheels of the vehicle are turned, the steering parameters of the vehicle are collected; Determining dynamic control parameters of the vehicle based on the steering parameters, the dynamic control parameters including a dynamic sideslip angle of the center of mass, a dynamic yaw rate, and a dynamic yaw rate change rate; Solving a vehicle dynamics model based on the dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed operating conditions, respectively; The vehicle speed range is set according to the target rear wheel turning angle, and the rear wheel steering is controlled according to the current vehicle speed range during vehicle driving.

2. The method according to claim 1, characterized in that The determining of the dynamic control parameters of the vehicle based on the steering parameters includes: Based on the steering parameters and according to a dynamic model of the vehicle, determining a quasi-static yaw rate and a quasi-static initial center of mass sideslip angle; generating a dynamic initial yaw rate and a dynamic initial center-of-mass sideslip angle based on the quasi-static yaw rate and the quasi-static initial center-of-mass sideslip angle; Correcting the dynamic initial yaw rate and the dynamic initial center of mass sideslip angle according to control strategies under high-speed and low-speed conditions, respectively, to obtain a dynamic center of mass sideslip angle and a dynamic yaw rate; Combined with the vehicle's tire cornering force model, the dynamic center of mass slip angle and dynamic yaw rate are calculated to obtain the dynamic yaw rate change rate.

3. The method according to claim 2, characterized in that Generating a dynamic initial yaw rate and a dynamic initial center-of-mass sideslip angle based on the quasi-static yaw rate and the quasi-static initial center-of-mass sideslip angle includes: By introducing dynamic response compensation into the quasi-static yaw rate and the quasi-static center-of-mass sideslip angle, a dynamic initial yaw rate and a dynamic initial center-of-mass sideslip angle are obtained; The dynamic response compensation is a preset coefficient that characterizes the dynamic response characteristics of the vehicle during steering, and is used to dynamically correct the quasi-static yaw rate and the quasi-static sideslip angle of the center of mass.

4. The method according to claim 1, wherein Solving the vehicle dynamics model based on the dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed operating conditions, respectively, includes: Establishing a two-degree-of-freedom model of the vehicle; the two-degree-of-freedom model reflects the vehicle's lateral force balance relationship and the moment balance relationship around the center of mass; Based on the two-degree-of-freedom model, the dynamic target yaw rate, the dynamic target sideslip angle of the center of mass, and the target yaw rate change rate are substituted into the solution to obtain the target rear wheel turning angle under high-speed conditions; The target rear wheel steering angle under high-speed conditions is converted to obtain the target rear wheel steering angle under low-speed conditions.

5. The method according to claim 4, characterized in that Based on the two-degree-of-freedom model, the dynamic target yaw rate, the dynamic target center-of-mass sideslip angle, and the target yaw rate change rate are substituted into the solution to obtain the target rear wheel turning angle under high-speed conditions, including: Determining cornering stiffness parameters of the vehicle; the cornering stiffness parameters include front wheel cornering stiffness and rear wheel cornering stiffness; The dynamic target yaw rate, dynamic target center of mass sideslip angle, and target yaw rate change rate are used as target values. These target values ​​and cornering stiffness parameters are substituted into a two-degree-of-freedom model to solve for the rear wheel steering angle and obtain the target rear wheel steering angle under high-speed conditions.

6. The method according to claim 4, characterized in that The converting the target rear wheel steering angle under the high-speed working condition to obtain the target rear wheel steering angle under the low-speed working condition includes: Based on the vehicle speed characteristic curve, a proportional mapping relationship between vehicle speed, front wheel steering angle and rear wheel steering angle is established; According to the proportional mapping relationship, the target rear wheel steering angle under high-speed working condition is converted to obtain the target rear wheel steering angle under low-speed working condition.

7. The method according to any one of claims 4 to 6, characterized in that The two-degree-of-freedom model of the vehicle is established, comprising: Obtaining a vehicle operation curve obtained from the test; the vehicle operation curve includes at least a vehicle speed characteristic curve, a front wheel angle curve, and a tire characteristic curve; Based on the vehicle operation curve and dynamic control parameters, a two-degree-of-freedom model of the vehicle is constructed.

8. The method according to claim 1, characterized in that The step of setting a vehicle speed range according to the target rear wheel steering angle and controlling the rear wheel steering of the vehicle in different vehicle speed ranges includes: Setting a vehicle speed range according to the target rear wheel turning angle; the vehicle speed stage includes at least a low speed range, a high speed range and a transition range; detecting a current speed of the vehicle, and determining a current speed range of the vehicle based on the current speed; When the vehicle is currently in a low-speed range, the rear wheel steering of the vehicle is controlled according to the rear wheel steering angle corresponding to the low-speed range; When the vehicle is currently in a high-speed zone, the rear wheel steering of the vehicle is controlled according to the rear wheel steering angle corresponding to the high-speed zone; When the vehicle is currently in the transition zone, weights are allocated according to the current vehicle speed, and the target rear wheel steering angles under high-speed and low-speed conditions are integrated to obtain the rear wheel steering angle for smooth transition.

9. The method according to claim 8, characterized in that When the vehicle is currently in the transition zone, weight distribution is performed according to the current vehicle speed, and the target rear wheel steering angles under high-speed and low-speed conditions are integrated to obtain the rear wheel steering angle for smooth transition, including: When the vehicle is in the transition zone, the weight factors corresponding to the high-speed and low-speed conditions are determined based on the current vehicle speed; Based on the corresponding weight factors of high-speed and low-speed conditions, the target rear wheel steering angles under high-speed and low-speed conditions are weightedly fused to obtain the rear wheel steering angle for smooth transition.

10. The method according to claim 9, characterized in that Determining the weight factors corresponding to the high-speed operating condition and the low-speed operating condition based on the current vehicle speed includes: Get the vehicle's attribute information; Determining a control strategy in a transition interval based on the attribute information, wherein the control strategy includes a flexibility strategy and a stability strategy; Under the determined control strategy, the initial weight factors are adjusted to obtain the weight factors corresponding to the high-speed working condition and the low-speed working condition respectively.

11. A vehicle steering control device, characterized in that: The device comprises: A detection module, used to collect the steering parameters of the vehicle when the front wheels of the vehicle are turned; a calculation module, configured to determine dynamic control parameters of the vehicle based on the steering parameters, the dynamic control parameters including a dynamic sideslip angle of the center of mass, a dynamic yaw rate, and a dynamic yaw rate change rate; The calculation module is further configured to solve a dynamic model of the vehicle based on the dynamic control parameters to obtain target rear wheel steering angles applicable to high-speed and low-speed operating conditions, respectively; The control module is used to set the vehicle speed range according to the target rear wheel turning angle, and control the rear wheel steering according to the current vehicle speed range during vehicle driving.

12. A vehicle, characterized in that: The vehicle is used to execute and implement the vehicle steering control method according to any one of claims 1 to 10.

13. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the vehicle steering control method according to any one of claims 1 to 10 is implemented.

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