A steering control method and device of a vehicle, a vehicle and an electronic device

Abstract

This invention relates to a vehicle steering control method, device, vehicle, and electronic equipment, belonging to the field of vehicle technology, and aims to improve the accuracy of vehicle steering control. The method includes: determining the steering stage of the vehicle based on the operating parameters of the steering wheel; wherein the operating parameters include: steering wheel angle and steering wheel torque; the steering stage is any one of the calibrated steering stages; the calibrated steering stages include: a stationary stage, a starting stage, a steady-state stage, and a return-to-center stage; determining the parameter values ​​of the controller tuning parameters of the steering controller based on the steering stage; determining the target control current of the steering drive motor based on the parameter values; and controlling the operation of the steering drive motor based on the target control current to adjust the vehicle's direction of travel. This invention divides the steering stage into multiple stages, enabling fine-grained control of multiple stages to reduce the error between the vehicle's direction of travel and the expected direction of travel, thereby improving the accuracy of vehicle steering control.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically to a vehicle steering control method, device, vehicle, and electronic equipment. Background Technology

[0002] As the automotive industry rapidly evolves towards intelligent and electric vehicles, the steering system, as a core component for vehicle handling and safety, is also undergoing continuous iteration. Electric Power Steering (EPS), with its significant advantages such as energy efficiency, compact structure, and flexible control, has gradually replaced traditional hydraulic power steering systems, becoming the mainstream configuration for modern vehicle steering systems. The EPS system uses a torque sensor to sense the driver's steering intention, the Electronic Control Unit (ECU) calculates the required assistance, and then drives the motor to output auxiliary torque, effectively reducing driver workload. Simultaneously, it adapts to steering feel adjustments at different vehicle speeds, significantly improving the fundamental performance of the steering system.

[0003] However, existing EPS systems still have significant limitations in the accuracy of vehicle steering control, especially in complex driving scenarios. Current EPS systems mostly use fixed control parameters or simple adaptive strategies, which are difficult to dynamically match the changing steering requirements in complex scenarios. As a result, steering control cannot meet the higher standards of precise handling required by intelligent driving, thus hindering the improvement of overall vehicle handling performance. Summary of the Invention

[0004] This invention provides a method, apparatus, vehicle, and electronic equipment for steering control of a vehicle, aimed at improving the accuracy of vehicle steering control.

[0005] In a first aspect, this application provides a vehicle steering control method, comprising: determining the steering stage of the vehicle based on the operating parameters of the steering wheel in the vehicle; wherein the operating parameters include: steering wheel angle and steering wheel torque; the steering stage is any one of the calibrated steering stages; the calibrated steering stages include: stationary stage, starting stage, steady-state stage and return-to-center stage; determining the parameter values ​​of the controller tuning parameters of the steering controller based on the steering stage; determining the target control current of the steering drive motor based on the parameter values; and controlling the steering drive motor to operate based on the target control current to adjust the vehicle's running direction.

[0006] Based on the aforementioned technical methods, by monitoring the steering wheel's operating parameters, multiple steering stages with clear physical meaning can be identified. For each stage, the system matches corresponding controller tuning parameters, which precisely match the dynamic characteristics of each steering stage and the driver's steering intentions. Furthermore, by combining these parameter values, the target control current of the steering drive motor can be calculated more accurately, ultimately achieving precise control of the vehicle's direction of travel through this target control current.

[0007] Furthermore, the calibration steering phase also includes: a first transition phase from the stationary phase to the startup phase, a second transition phase from the startup phase to the steady-state phase, and a third transition phase from the steady-state phase to the homing phase.

[0008] Based on the aforementioned technical means, further dividing the vehicle's steering phase into transition phases can achieve a more comprehensive and detailed differentiation of the steering process, thereby ensuring that the parameter values ​​of the controller tuning parameters transition smoothly during phase switching, avoiding fluctuations in steering feel caused by sudden parameter changes, further improving the continuity and accuracy of steering control, and better matching the driver's operating intentions at different steering phases.

[0009] Furthermore, based on the steering phase, the parameter values ​​of the steering controller tuning parameters are determined, including: determining the parameter values ​​based on a preset dataset and the steering phase; wherein, the preset dataset includes the parameter values ​​of the controller tuning parameters corresponding to the stationary phase, the start-up phase, the steady-state phase, and the return-to-center phase.

[0010] Based on the above technical means, by pre-setting the dataset and steering stage, the parameter values ​​can be determined to better match the dynamic characteristics and control requirements of each steering stage, thereby significantly improving the accuracy and adaptability of the parameter values.

[0011] Furthermore, based on the preset dataset and the turning stage, parameter values ​​are determined, including: when the turning stage is a first transition stage, a second transition stage, or a third transition stage, determining the transition start stage and the transition end stage corresponding to the turning stage; determining a first parameter value and a second parameter value, wherein the first parameter value is the parameter value of the controller tuning parameter corresponding to the transition start stage; the second parameter value is the parameter value of the controller tuning parameter corresponding to the transition end stage; and determining the parameter value based on the first parameter value, the second parameter value, and the theoretical transition duration and the already transitioned duration of the turning stage.

[0012] Based on the aforementioned technical means, the first and second parameter values ​​are determined according to the transition start and end stages corresponding to the steering phase. Then, combined with the theoretical transition time and the already transitioned time, dynamic calculations are performed to achieve smooth, continuous, and precise dynamic adjustment of parameter values ​​from the transition start stage to the transition end stage. This not only retains the characteristics of the core parameters of the transition start and end stages (such as the stability of the start stage and the responsiveness of the end stage), but also eliminates the parameter abruptness of steering phase switching through gradient changes in the time dimension. This ensures that steering control remains synchronized with the driver's operating intentions throughout the transition process, significantly improving the continuity of steering feel and the smoothness of the driving experience.

[0013] Furthermore, based on the operating parameters of the steering wheel in the vehicle, the steering stage of the vehicle is determined, including: monitoring the end times of the stationary stage, the starting stage, and the steady-state stage based on the operating parameters; determining the steering stage of the vehicle within the first time period after the end time of the stationary stage as the first transition stage; determining the steering stage of the vehicle within the second time period after the end time of the starting stage as the second transition stage; and determining the steering stage of the vehicle within the third time period after the end time of the steady-state stage as the third transition stage.

[0014] Based on the aforementioned technical means, by clearly defining the transition phases (first to third transition phases) after the static phase, the startup phase, and the steady-state phase, and their durations, it is possible to achieve seamless connection and refined division of the turning phase.

[0015] Furthermore, the steering controller is a PID controller; the controller tuning parameters include: integral time; the vehicle steering control method also includes: when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold, the parameter value of the integral time is corrected to infinity.

[0016] Based on the above technical means, by correcting the integral time to infinity (i.e. pausing the accumulation of integral terms) when the duty cycle of the steering drive motor is greater than or equal to the preset duty cycle threshold, the integral saturation phenomenon can be effectively avoided, thereby accurately matching the output boundary of the steering drive motor, ensuring the stability of steering control under high load conditions, reducing unnecessary integral residues from interfering with subsequent adjustments, and improving the control accuracy and reliability of the steering system under extreme conditions.

[0017] Furthermore, the steering controller is a composite controller of PID control and feedforward control; the controller tuning parameters also include: proportional coefficient, derivative coefficient and feedforward gain coefficient; the target control current of the steering drive motor is determined based on the parameter values, including: determining the feedforward compensation current based on the steering wheel torque and the feedforward gain coefficient; and determining the target control current based on the feedforward compensation current, proportional coefficient, integral time and derivative coefficient.

[0018] Based on the aforementioned technical methods, the feedforward compensation current, which can respond to the driver's steering intentions in advance, is determined by using steering wheel torque and feedforward gain coefficient. By combining feedforward control and PID control, both the timeliness of steering response and the stability of control are improved, effectively optimizing steering feel and driving safety.

[0019] Secondly, this application provides a vehicle steering control device, comprising: a determining module and a controlling module; the determining module is used to determine the steering stage of the vehicle based on the operating parameters of the steering wheel in the vehicle; wherein the operating parameters include: steering wheel angle and steering wheel torque; the steering stage is any one of the calibrated steering stages; the calibrated steering stages include: stationary stage, starting stage, steady-state stage and return-to-center stage; based on the steering stage, the module determines the parameter values ​​of the controller tuning parameters of the steering controller; based on the parameter values, the module determines the target control current of the steering drive motor; the controlling module is used to control the operation of the steering drive motor based on the target control current to adjust the driving direction of the vehicle.

[0020] Furthermore, the calibration steering phase also includes: a first transition phase from the stationary phase to the startup phase, a second transition phase from the startup phase to the steady-state phase, and a third transition phase from the steady-state phase to the homing phase.

[0021] Furthermore, the determination module is specifically used to determine parameter values ​​based on a preset dataset and the turning stage; wherein, the preset dataset includes the parameter values ​​of the controller tuning parameters corresponding to the stationary stage, the start-up stage, the steady-state stage, and the return-to-center stage.

[0022] Furthermore, the determination module is specifically used to determine the transition start stage and transition end stage corresponding to the steering stage when the steering stage is a first transition stage, a second transition stage, or a third transition stage; determine the first parameter value and the second parameter value, wherein the first parameter value is the parameter value of the controller tuning parameter corresponding to the transition start stage; the second parameter value is the parameter value of the controller tuning parameter corresponding to the transition end stage; and determine the parameter value based on the first parameter value, the second parameter value, and the theoretical transition time and the already transitioned time of the steering stage.

[0023] Furthermore, the determination module is specifically used to monitor the end times of the stationary phase, the start-up phase, and the steady-state phase based on operating parameters; determine the first transition phase as the steering phase of the vehicle within the first time period after the end time of the stationary phase; determine the second transition phase as the steering phase of the vehicle within the second time period after the end time of the start-up phase; and determine the third transition phase as the steering phase of the vehicle within the third time period after the end time of the steady-state phase.

[0024] Furthermore, the steering controller is a PID controller; the controller tuning parameters include: integral time; the vehicle steering control device also includes: a correction module; the correction module is used to correct the parameter value of the integral time to infinity when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold.

[0025] Furthermore, the steering controller is a composite controller of PID control and feedforward control; the controller tuning parameters also include: proportional coefficient, derivative coefficient and feedforward gain coefficient; the determination module is specifically used to determine the feedforward compensation current based on the steering wheel torque and the feedforward gain coefficient; and to determine the target control current based on the feedforward compensation current, proportional coefficient, integral time and derivative coefficient.

[0026] Thirdly, this application provides a vehicle that includes: the steering control device of the vehicle described in the second aspect.

[0027] Fourthly, this application provides an electronic device comprising: a processor and a memory; the memory storing processor-executable instructions. When the processor is configured to execute the instructions, the electronic device causes the method described in the first aspect to be implemented.

[0028] Fifthly, this application provides a computer-readable storage medium storing computer program instructions that, when executed by a processor, implement the method described in the first aspect.

[0029] In a sixth aspect, this application provides a computer program product including computer program instructions that, when executed by a processor, implement the method described in the first aspect.

[0030] It should be noted that the technical effects of any of the implementation methods in aspects two through six can be found in the technical effects of the corresponding implementation methods in aspect one, and will not be repeated here.

[0031] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0032] Figure 1 A block diagram of a vehicle steering control system provided by the present invention;

[0033] Figure 2 A block diagram of a steering controller provided by the present invention;

[0034] Figure 3 A flowchart of a vehicle steering control method provided by the present invention;

[0035] Figure 4A control principle diagram of a steering controller provided by the present invention;

[0036] Figure 5 A flowchart of yet another vehicle steering control method provided by the present invention;

[0037] Figure 6 A flowchart of yet another vehicle steering control method provided by the present invention;

[0038] Figure 7 A control principle diagram of a vehicle steering control system provided by the present invention;

[0039] Figure 8 A flowchart of yet another vehicle steering control method provided by the present invention;

[0040] Figure 9 A flowchart of yet another vehicle steering control method provided by the present invention;

[0041] Figure 10 A schematic diagram of a vehicle steering control device provided by the present invention;

[0042] Figure 11 This is a structural diagram of an electronic device provided by the present invention. Detailed Implementation

[0043] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0044] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0045] The steering control method for the vehicle provided in this application will be described in detail below with reference to the accompanying drawings.

[0046] In some embodiments, the vehicle steering control method provided in this application can be applied to a vehicle steering control system, such as... Figure 1As shown, the vehicle's steering control system includes: a steering wheel 101, a data acquisition device 102, a steering controller 103, a steering drive motor 104, and a steering actuator 105. The steering controller 103 is communicatively connected to the data acquisition device 102 and the steering drive motor 104.

[0047] As a feasible implementation method, the acquisition device 102 is used to acquire the operating parameters of the steering wheel 101 and send them to the steering controller 103.

[0048] The operating parameters include: steering wheel angle and steering wheel torque.

[0049] For example, the acquisition device 102 may include an angle sensor and a torque sensor. The angle sensor may be a high-precision encoder or a Hall sensor; the torque sensor may be a torsion bar torque sensor.

[0050] As a feasible implementation method, the steering controller 103 is used to determine the steering stage of the vehicle based on the operating parameters of the steering wheel in the vehicle; based on the steering stage, determine the parameter value of the controller tuning parameter of the steering controller; based on the parameter value, determine the target control current of the steering drive motor; and control the steering drive motor 104 to operate based on the target control current to adjust the driving direction of the vehicle.

[0051] The steering phase can be any one of the calibration steering phases; the calibration steering phase includes: stationary phase, starting phase, steady state phase and return-to-center phase.

[0052] As a feasible implementation method, such as Figure 2 As shown, the steering controller 103 includes: a steering phase identification module, a controller tuning parameter determination module, a feedforward control compensation module, an integral freeze module, and a negative integral acceleration exit module.

[0053] The steering phase identification module determines the steering phase (stationary phase, starting phase, steady-state phase, and return-to-center phase). The controller tuning parameter determination module determines the parameter values ​​of the controller tuning parameters based on the steering phase and the control characteristics of each steering phase (stationary phase: suppressing jitter and enhancing damping; starting phase: fast response and reducing delay; steady-state phase: smooth output and anti-interference; return-to-center phase: accelerating exit from saturation and suppressing overshoot). The parameter values ​​are corrected based on the integral freeze module (i.e., when the duty cycle of the steering drive motor is greater than or equal to the preset duty cycle threshold, the integral time is corrected to infinity) and the negative integral acceleration exit module (i.e., the integral term in the return-to-center phase is negative). The reference control current is determined based on the corrected parameter values. The feedforward compensation current is determined based on the feedforward control compensation module. Furthermore, the target control current is determined based on the reference control current and the feedforward compensation current.

[0054] For example, the steering controller 103 can be a PID controller or a composite controller combining PID control and feedforward control. Whether it is a PID controller or a composite controller, its hardware carrier can be any control device or apparatus capable of incorporating PUD control algorithms and feedforward control algorithms, such as an ECU, a dedicated microcontroller, or a vehicle controller; this application embodiment does not limit this.

[0055] It should be understood that when the steering controller is a PID controller, the controller tuning parameters include: proportional coefficient, integral time, and derivative coefficient; when the steering controller is a composite controller of PID control and feedforward control, the controller tuning parameters include: proportional coefficient, integral time, derivative coefficient, and feedforward gain coefficient.

[0056] As a feasible implementation method, the steering drive motor 104 generates a corresponding amount of assist torque under the action of the target control current, so as to drive the steering actuator 105 to operate, thereby adjusting the driving direction of the vehicle.

[0057] For example, the steering drive motor 104 can be a permanent magnet synchronous motor.

[0058] As a feasible implementation method, the steering actuator 105 may include: a worm gear reduction mechanism and a rack and pinion mechanism.

[0059] For example, the worm gear reducer is used to receive the assist torque output by the steering drive motor 104, and amplify the torque and reduce the speed. For instance, through the meshing transmission of the worm gear and worm, the high-speed, low-torque of the motor is converted into low-speed, high-torque, improving the load capacity of the steering system. At the same time, its own reverse self-locking characteristic is used to prevent road impact forces from being transmitted in reverse to the steering drive motor during vehicle operation, ensuring steering stability.

[0060] The rack and pinion mechanism is used to receive low-speed, high-torque transmission from the worm gear reducer. Through the connection between the rack and the steering wheel tie rod, the rotational motion output by the worm gear reducer is converted into the linear reciprocating motion of the rack, which in turn pulls the steering wheel to produce deflection and adjust the vehicle's direction of travel.

[0061] It should be noted that the system architecture described in the embodiments of this application is for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and does not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of system architecture, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0062] The vehicle steering control method described in this application can be applied to the steering controller in a vehicle's steering control system, such as... Figure 3As shown, the vehicle steering control method includes the following steps:

[0063] S301. Determine the steering stage of the vehicle based on the operating parameters of the steering wheel in the vehicle.

[0064] The operating parameters include: steering wheel angle and steering wheel torque.

[0065] Steering wheel angle is used to represent the angular value and direction of rotation of the steering wheel around its axis of rotation, starting from its initial neutral position (usually the position when the vehicle is traveling in a straight line). For example, when the steering wheel angle is greater than zero, the direction of rotation is clockwise; when the steering wheel angle is less than zero, the direction of rotation is counterclockwise.

[0066] Steering wheel torque indicates the magnitude and direction of the steering torque applied by the driver through their hands on the steering wheel rim. For example, when the steering wheel torque is greater than zero, a clockwise steering torque is applied; when the steering wheel torque is less than zero, a counterclockwise steering torque is applied.

[0067] In some embodiments, the steering wheel rotation angular velocity is determined based on the steering wheel angle; the steering wheel hand torque is determined based on the steering wheel hand torque rate of change; and the current steering stage of the vehicle is determined in real time based on one or more of the steering wheel angle, rotation angular velocity, steering wheel hand torque, and steering wheel hand torque rate of change.

[0068] As a feasible implementation method, the steering wheel angle and steering wheel torque can be collected according to a preset sampling period, and the collected data can be filtered. The preset sampling period can be 2ms.

[0069] For example, based on the steering wheel angle, the rotational angular velocity is calculated using the center difference method, while a second-order Butterworth low-pass filter with a cutoff frequency of a preset threshold is used to suppress noise. The preset frequency threshold can be 5Hz.

[0070] For example, the rotational angular velocity can satisfy the following formula:

[0071] ;

[0072] in, Used to indicate rotational angular velocity; Used to represent the steering wheel angle in the (k+1)th sampling period; Used to represent the steering wheel angle in the (k-1)th sampling period; Used to represent the time of a sampling period.

[0073] For example, based on the steering wheel torque, the rate of change of the steering wheel torque can be calculated after median filtering.

[0074] For example, the rate of change of steering wheel torque can satisfy the following formula:

[0075] ;

[0076] in, Used to represent the difference in steering wheel torque between two consecutive sampling periods; Used to represent the time of a sampling period.

[0077] In some embodiments, the steering phase is any one of the calibrated steering phases.

[0078] The steering phase refers to the different operational stages a vehicle is in from the initiation of a steering intention to the completion of the steering action and the restoration of the target driving state.

[0079] The calibration steering phase is used to represent a predefined set of standardized phases covering typical steering scenarios in order to achieve accurate calibration of the controller tuning parameters.

[0080] As a feasible implementation method, the calibration steering phase includes: the stationary phase, the startup phase, the steady-state phase, and the return-to-center phase.

[0081] The stationary phase is used to indicate that the vehicle is traveling in a straight line, the user has no intention to steer, and the steering wheel is not turned.

[0082] The initiation phase is used to indicate the stage when the driver begins to apply steering operation, and the steering wheel angle and steering wheel torque begin to change from the initial state (close to zero value) (i.e. the initiation phase of the steering action).

[0083] The steady-state phase is used to indicate the phase in which the steering operation continues and the steering wheel angle, angular velocity, and hand torque remain within a stable range (with small fluctuations) (i.e., the continuous phase of the steering action).

[0084] The return-to-center phase is used to indicate the stage where the driver reduces or cancels the steering operation, and the steering wheel returns from the current angle to the initial neutral position (straight driving position) (i.e., the end of the steering action).

[0085] For example, for each calibrated steering stage, corresponding preset conditions can be set based on one or more of the following parameters: steering wheel angle, angular velocity of rotation, steering wheel torque, and rate of change of torque. When the real-time monitored parameters meet the preset conditions of a certain stage, it can be determined that the vehicle is currently in that steering stage.

[0086] S302. Based on the steering phase, determine the parameter values ​​of the controller tuning parameters of the steering controller.

[0087] As a feasible implementation method, controller tuning parameters are used to represent the set of key parameters that need to be determined through debugging in order to enable the steering controller to achieve the expected control performance (such as response speed, stability, control accuracy, etc.).

[0088] For example, when the steering controller is a PID controller, the controller tuning parameters may include: proportional coefficient, integral time, and derivative coefficient; when the steering controller is a composite controller of PID control and feedforward control, the controller tuning parameters may include: proportional coefficient, integral time, derivative coefficient, and feedforward gain coefficient.

[0089] It should be understood that the specific configuration of the controller tuning parameters needs to be flexibly adjusted according to the type of steering controller, and the above example is only a common case.

[0090] The proportional coefficient is used to represent the instantaneous response ratio of the controller output to the input deviation signal; the integral time is used to represent the speed at which the steering controller eliminates the cumulative effect of the input deviation signal; the derivative coefficient is used to represent the steering controller's sensitivity to predicting the changing trend of the input deviation signal; and the feedforward gain coefficient is used to represent the steering controller's strength of advance compensation for known interference signals.

[0091] As a feasible approach, each vehicle can be individually calibrated to predetermine the correspondence between each steering stage and the specific values ​​of the controller tuning parameters.

[0092] For example, before the vehicle leaves the factory, bench tests or real vehicle tests can be conducted to match verified optimal proportional coefficients, integral times, and other parameter values ​​for the stationary phase, startup phase, steady-state phase, and return-to-center phase, respectively, forming a fixed parameter mapping table.

[0093] Specifically, the parameter configuration logic for different steering stages is closely related to the characteristics of the steering stage.

[0094] The main characteristic of the stationary phase is that the steering controller is in standby or responding to minor disturbances. The control objective is to prevent false power assist or motor jitter caused by sensor noise or minor disturbances. Therefore, a strategy of low proportional gain, disabling integral action, and enhancing differential damping is required to improve the stability of the steering control system.

[0095] The initial launch phase demands extremely high responsiveness, requiring rapid establishment of power assist to reduce the steering torque applied by the driver. Slow control response will result in a noticeable delay in the power assist. Therefore, the steering controller should be configured with high proportional gain, short integral time, and moderate derivative gain to achieve rapid tracking and minimal overshoot.

[0096] In the steady-state phase, the control output needs to be stable and have strong anti-interference capabilities to avoid power assist fluctuations caused by uneven road surfaces or motor noise. Therefore, a moderate proportional gain, a longer integral time, and a lower derivative gain are adopted to enhance the robustness and steady-state accuracy of the steering control system.

[0097] The key to the homing phase is to prevent rebound or overshoot caused by the accumulation of integral terms. To this end, an innovative negative integral term mechanism is proposed. In this phase, the integral term is negatively or in reversely integrated to accelerate the steering control system out of saturation and improve the homing response speed and smoothness.

[0098] In addition, when the steering controller determines that the current state does not belong to any preset stage, it will continue to maintain the stage identification state of the previous cycle and apply the corresponding controller tuning parameter values ​​to ensure the continuity of control.

[0099] For example, the parameter values ​​of the controller tuning parameters corresponding to each steering stage can be shown in Table 1.

[0100] Table 1 Steering Stage - Parameter Values

[0101]

[0102] It should be understood that the low, medium, and high values ​​in the table above only represent the range of specific values. The range of parameter values ​​needs to be adjusted according to different vehicle models, and the actual parameter values ​​need to be obtained by calibration on the actual vehicle according to each steering stage.

[0103] As another feasible approach, the actual values ​​of controller tuning parameters corresponding to each stage of the vehicle's historical steering process can be collected to construct a training sample set. The control model can then be trained using this sample set, enabling the control model to autonomously output the corresponding controller tuning parameter values ​​based on the real-time identified steering stage.

[0104] For example, a neural network model can be used, with historical steering stage data as input and the optimal controller tuning parameters for the corresponding stage as output, to achieve dynamic generation of parameters based on the steering stage.

[0105] It should be understood that setting different controller tuning parameters for different steering stages allows for refined processing of different steering stages, enabling the steering controller to dynamically adjust its operating characteristics according to the core requirements of each steering stage. This avoids problems such as delayed response or insufficient stability that may occur when a single parameter is adapted to all stages.

[0106] S303. Determine the target control current of the steering drive motor based on parameter values.

[0107] Among them, the target control current is used to represent the reference value of the command current that the steering drive motor needs to receive in order to output a value that matches the user's current steering intention. It is the core command signal that connects the controller parameters and the actual operation of the motor.

[0108] As a feasible approach, the preset correspondence between the parameter values ​​of the controller tuning parameters and the target control current is determined through experiments.

[0109] In an exemplary embodiment, during bench or vehicle testing, motor current data that can meet the optimal steering effect can be recorded for typical parameter values ​​(such as specific proportional coefficients and integral time combinations) at different steering stages, forming a "parameter value-target control current" mapping table; in actual applications, the corresponding target control current can be directly retrieved from the table based on the current parameter value.

[0110] As another feasible implementation method, when the steering controller is a PID controller, the target control current is determined by the PID control algorithm.

[0111] Among them, the PID control algorithm is used to represent a closed-loop control algorithm that calculates based on the proportional, integral, and derivative characteristics of the input deviation to generate control quantities to adjust the system output.

[0112] In an exemplary embodiment, a reference current is input, the deviation between the reference current and the actual current is determined, the control quantity is calculated using the formula "proportional term (deviation × proportional coefficient) + integral term (cumulative deviation × 1 / integral time) + derivative term (rate of change of deviation × derivative coefficient)", and then the control quantity is converted into the corresponding target control current.

[0113] As another feasible implementation method, when the steering controller is a composite controller of PID control and feedforward control, the reference control current is determined based on the PID control algorithm; the feedforward compensation current is determined based on the feedforward control algorithm; and the sum of the reference control current and the feedforward compensation current is used as the target control current.

[0114] Among them, the feedforward compensation algorithm is used to represent an open-loop control algorithm that calculates the compensation amount in advance to offset system lag or disturbance based on the known inputs of the steering controller (such as steering wheel angle, vehicle speed, etc.) and the preset vehicle dynamics model (such as steering transmission ratio, tire characteristics).

[0115] In an exemplary embodiment, based on the current steering wheel angle and vehicle speed, the feedforward compensation current corresponding to the ideal compensation torque is calculated through the feedforward gain coefficient, and then the reference control current output by the PID control algorithm is superimposed to obtain the final target control current, so as to improve the timeliness of steering response.

[0116] For example, such as Figure 4As shown, based on the error between the input and output of the steering controller, the reference control current is determined by "proportional term (deviation × proportional coefficient) + integral term (deviation accumulation × 1 / integral time) + derivative term (deviation change rate × derivative coefficient)". Then, the feedforward compensation current is determined based on the feedforward control algorithm. The sum of the reference control current and the feedforward compensation current is used as the target control current.

[0117] It should be understood that if the target control current deviates too much from the actual demand, it may lead to insufficient steering assist (too low current) or steering overshoot (too high current). Therefore, in the process of determining the target control current based on parameter values, it is usually necessary to add logic such as current limiting and dynamic compensation to ensure that the motor operates safely and conforms to the actual steering scenario.

[0118] S304. The steering drive motor is controlled based on the target control current to adjust the vehicle's direction of travel.

[0119] In an exemplary embodiment, once the vehicle's steering phase is determined, the target control current is calculated, and the steering drive motor receives the target control current command and outputs the corresponding torque. This torque is transmitted to the wheels through the steering transmission mechanism (such as gears or tie rods), pushing the wheels to deflect to the target angle, thereby enabling the vehicle to smoothly transition from a straight-line driving state to a steering state.

[0120] It should be understood that if the actual output current of the motor deviates from the target control current (e.g., due to a decrease in current caused by line losses), it may result in insufficient wheel deflection angle, affecting steering response. Therefore, in actual control, a current feedback closed loop is usually added (e.g., by monitoring the motor current in real time through a current sensor) to dynamically correct the deviation, ensuring that the motor always outputs torque as expected, thus guaranteeing the accuracy and stability of vehicle steering.

[0121] By monitoring the steering wheel's operating parameters, multiple steering stages with clear physical meaning can be identified. For each stage, the system matches corresponding controller tuning parameters, which precisely match the dynamic characteristics of each steering stage and the driver's steering intentions. Based on this, the target control current of the steering drive motor can be calculated more accurately using these parameter values, ultimately achieving precise control of the vehicle's direction of travel.

[0122] In some embodiments, the process of determining the stationary phase can be as follows: based on the steering wheel angle, determine the steering wheel rotation angular velocity; if the rotation angular velocity and steering wheel hand torque meet the first preset condition, determine that the steering phase in which the vehicle is in is the stationary phase.

[0123] The first preset condition includes: the absolute value of the rotational angular velocity is less than or equal to the first preset angular velocity threshold, and the absolute value of the steering wheel torque is less than or equal to the first preset torque threshold.

[0124] The first preset angular velocity threshold is used to represent the maximum angular velocity at which the steering wheel rotates almost imperceptibly. For example, the first preset angular velocity threshold can be... .

[0125] The first preset torque threshold is used to represent the maximum value of the steering wheel hand torque when no effective steering intention is formed. For example, the first preset torque threshold can be 0.5 Nm.

[0126] In an exemplary embodiment, to avoid misjudgment caused by instantaneous signal fluctuations, a time-dimensional determination condition can be added. For example, if the rotational angular velocity and steering wheel torque meet a first preset condition and the duration is greater than or equal to a preset time threshold, the steering phase of the vehicle is determined to be a stationary phase.

[0127] The preset time threshold is used to represent the minimum duration required for the static phase of the symptom determination. For example, the preset time threshold can be 10 sampling periods.

[0128] For example, the first preset condition can satisfy the following formula:

[0129] and ;

[0130] in, Used to indicate rotational angular velocity; Used to indicate the torque applied to the steering wheel.

[0131] It should be understood that, from a physical perspective, based on sensor noise levels and human operating characteristics, when the rotational angular velocity is less than the first preset angular velocity threshold, the range of steering wheel movement exceeds the range that the human eye can perceive (almost no visible movement); and when the hand torque is less than the first preset torque threshold, its force is far lower than the force exerted by the driver actively steering, and is more due to the inertia of natural hand contact or the interference of vehicle vibration transmission. Therefore, it can be determined that there is no effective steering intention, which meets the core characteristics of the stationary stage.

[0132] In some embodiments, the determination process for the start-up phase can be as follows: if the absolute value of the rate of change of steering wheel torque is greater than or equal to a first preset torque change threshold, the steering phase in which the vehicle is located is determined to be the start-up phase.

[0133] The first preset torque change threshold is used to represent the minimum rate of change of the steering wheel torque at which the driver begins to actively apply steering input. For example, the first preset torque change threshold can be 5 Nm / s.

[0134] As a feasible implementation method, the judgment condition in the startup phase can satisfy the following formula:

[0135] ;

[0136] in, Used to represent the difference between steering wheel torque in two consecutive sampling periods; Used to indicate the duration of a sampling period.

[0137] As a feasible implementation method, assuming a sampling period of 2ms, the judgment condition in the startup phase can also satisfy the following formula:

[0138] ;

[0139] in, Used to represent the steering wheel torque during the kth sampling period; Used to represent the steering wheel torque during the (k-1)th sampling period.

[0140] It should be understood that judging by the rate of change of steering wheel torque has high sensitivity and can complete the stage switching within 3 sampling cycles after the driver first applies torque. The response speed is better than traditional fuzzy control methods based on vehicle speed or steering angle. Once the starting stage is identified, the steering controller will immediately switch to the parameter value of the highly responsive controller tuning parameter and activate the differential feedforward compensation mechanism to quickly match the driver's steering intention.

[0141] In some embodiments, when the vehicle has left the stationary phase and the starting phase, the steady-state phase determination process can be as follows: based on the steering wheel angle, determine the steering wheel rotation angular velocity; if the rotation angular velocity and steering wheel hand torque meet the second preset condition, determine that the steering phase in which the vehicle is located is the steady-state phase.

[0142] The second preset condition includes: the absolute value of the rotational angular velocity is less than or equal to the second preset angular velocity threshold, the absolute value of the steering wheel torque is greater than or equal to the second preset torque threshold, and the absolute value of the rate of change of the steering wheel torque is less than or equal to the second preset torque change threshold.

[0143] The second preset angular velocity threshold is used to represent the maximum rotational angular velocity when the steering action enters a stable and continuous state. For example, the second preset angular velocity threshold can be... .

[0144] The second preset torque threshold is used to represent the minimum steering wheel torque required to continuously apply an effective steering operation. For example, the second preset torque threshold can be... .

[0145] The second preset torque variation threshold is used to represent the critical value for the stability of the hand torque during the steady-state phase. For example, the second preset torque variation threshold can be... .

[0146] For example, the second preset condition can satisfy the following formula:

[0147] and and ;

[0148] in, Used to indicate rotational angular velocity; Used to indicate steering wheel torque; Used to indicate the rate of change of steering wheel torque.

[0149] It should be understood that the steady-state phase is the core interval that lasts the longest during normal steering. Its judgment logic must meet three conditions simultaneously: first, the angular velocity is sufficiently smooth (to avoid sharp turns); second, the hand torque maintains effective strength (to ensure the steering intention continues); and third, the rate of torque change is stable (to eliminate sudden changes in force). At the same time, this phase must ensure that the direction of the hand torque is consistent with the direction of the angular velocity (such as both being positive when turning clockwise), thereby achieving smooth control output and strong anti-interference ability, adapting to the stability requirements of the vehicle during continuous steering.

[0150] In some embodiments, the process of determining the return-to-center stage can be as follows: when the direction of the steering wheel torque is opposite to the direction of steering wheel rotation, the steering stage in which the vehicle is in is determined to be the return-to-center stage.

[0151] As a feasible implementation method, the return-to-center phase typically includes scenarios where the driver releases the steering wheel (relying on the steering control system's own return-to-center force) or actively reverses the steering wheel.

[0152] For example, the judgment condition for the return-to-normal phase can satisfy the following formula:

[0153] ;

[0154] in, Used to indicate rotational angular velocity; Used to indicate the torque applied to the steering wheel.

[0155] It should be understood that the characteristic that the direction of the steering wheel torque is opposite to the direction of steering wheel rotation directly reflects the driver's intention to decelerate or return to center. For example, when the steering wheel is turned in the forward direction (positive angle), if the driver applies negative torque, it indicates that they wish to reduce the steering angle or return the steering wheel to the center position. This criterion has a clear physical meaning and can effectively reduce the risk of misjudgment, especially applicable to automatic return-to-center control and steering wheel return-to-center scenarios at high speeds. Once the steering control system recognizes the return-to-center phase, the steering controller immediately activates the negative integral mechanism (quickly eliminating accumulated deviation) and maintains a high differential gain to enhance the damping effect, ensuring that the steering wheel returns to the center position smoothly and accurately.

[0156] It should be noted that when the steering controller determines that the vehicle's current state does not belong to any recognition stage, it retains the parameter values ​​from the previous sampling cycle and continues to operate. Furthermore, each steering stage uses a mutually exclusive judgment method, with the priority order being: starting stage > returning to center stage > stationary stage > steady-state stage. For example, even if the rotational angular velocity is low, as long as a high rate of change in steering wheel torque is detected, it is still preferentially identified as the starting stage; similarly, if the direction of steering wheel torque is opposite to the direction of steering wheel rotation, even if the rotational angular velocity is low, it is preferentially identified as the returning to center stage.

[0157] In some embodiments, a preset dataset can be calibrated experimentally to determine the parameter values ​​of the controller tuning parameters.

[0158] As a feasible implementation method, the above step S202 can be specifically implemented as follows: based on the preset dataset and the steering stage, determine the parameter values ​​of the controller tuning parameters.

[0159] The preset dataset includes the parameter values ​​of the controller tuning parameters corresponding to the static phase, startup phase, steady-state phase, and homing phase.

[0160] As a feasible implementation method, the preset dataset can be calibrated through whole vehicle experiments. For specific implementation methods, please refer to the fixed parameter mapping table mentioned above.

[0161] For example, the controller tuning parameters may include: proportional coefficient, integral time, derivative coefficient and feedforward gain coefficient. Table 2 below is a preset dataset provided in this application.

[0162] Table 2 Preset Dataset

[0163]

[0164] By pre-setting datasets and steering stages, the parameter values ​​can be determined to better match the dynamic characteristics and control requirements of each steering stage, thereby significantly improving the accuracy and adaptability of the parameter values.

[0165] In some embodiments, the calibration steering phase further includes: a first transition phase from the stationary phase to the startup phase, a second transition phase from the startup phase to the steady-state phase, and a third transition phase from the steady-state phase to the homing phase.

[0166] As a feasible approach, the transition phase can be determined by the end time of each transition phase.

[0167] As a feasible implementation method, when the calibration steering phase consists of a first transition phase from the stationary phase to the startup phase, a second transition phase from the startup phase to the steady-state phase, or a third transition phase from the steady-state phase to the return-to-center phase, combined with... Figure 3 ,like Figure 5 As shown, step S301 above can be specifically implemented as follows:

[0168] S501. Based on operating parameters, monitor the end times of the static phase, startup phase, and steady-state phase.

[0169] As a feasible implementation method, the end time of the stationary phase is determined when the absolute value of the rotational angular velocity is greater than a first preset angular velocity threshold and the absolute value of the steering wheel torque is greater than a first preset torque threshold.

[0170] The end time of the start-up phase is determined when the absolute value of the rate of change of steering wheel torque is less than the second preset torque change threshold and the rotational angular velocity tends to stabilize.

[0171] The end of the steady-state phase is determined when the direction of the steering wheel hand torque is opposite to the direction of steering wheel rotation, or when the absolute value of the hand torque is less than the second preset torque threshold.

[0172] It should be understood that the operating parameters are directly related to the end time of the turning phase. Changes in the operating parameters are the core triggering condition for phase switching. When the key parameters representing the current phase no longer meet the preset conditions and the parameter characteristics of transitioning to the next turning phase appear, it corresponds to the end time of the current turning phase.

[0173] S502. The first transition phase is the turning phase that the vehicle is in during the first time period after the end of the stationary phase is determined.

[0174] The first duration is used to indicate the buffer time for the steering controller to switch from static control logic to dynamic control logic after the static phase ends. The purpose is to avoid steering fluctuations caused by overly abrupt parameter switching.

[0175] It should be understood that the first duration can be set based on the driver's historical driving habits. For example, for drivers who are used to turning the steering wheel slowly, the first duration can be set to 0.5 seconds; for drivers who are more agile, it can be shortened to 0.2 seconds.

[0176] S503. The second transition phase is the steering phase that the vehicle is in during the second time period after the end time of the start-up phase is determined.

[0177] The second duration is used to indicate the smooth transition time of the steering controller from high-response control parameters to steady-state control parameters after the start-up phase ends, preventing sudden changes in steering feel due to abrupt parameter changes.

[0178] S504. The third transition phase is the steering phase that the vehicle is in during the third time period after the end of the steady-state phase.

[0179] The third duration is used to indicate the preparation time for the steering controller to transition from steady-state control logic to homing control logic after the steady-state phase ends, in preparation for the parameter activation in the subsequent homing phase.

[0180] It should be understood that the first, second, and third durations can be determined by actual vehicle calibration to establish basic values, and then dynamically adjusted in combination with the steering system stiffness of different models and driver operation data to ensure a consistent steering experience in each transition phase.

[0181] Further dividing the vehicle's steering phase into transition phases allows for a more comprehensive and detailed differentiation of the steering process, ensuring a smooth transition of the controller's tuning parameters during phase switching. This avoids fluctuations in steering feel caused by sudden parameter changes, further improving the continuity and precision of steering control and better aligning with the driver's operational intentions at different steering phases.

[0182] In some embodiments, to prevent abrupt changes in the parameter values ​​of the controller tuning parameters, a transition phase is set between the two steering phases. The parameter values ​​of the transition phase are determined by the parameter values ​​of the transition start phase and the transition end phase, so that the controller tuning parameters can smoothly transition from the parameter values ​​of the transition start phase to the parameter values ​​of the transition end phase.

[0183] As a feasible implementation method, combined with Figure 3 ,like Figure 6 As shown, step S302 above can also be implemented as the following steps:

[0184] S601. When the turning phase is the first transition phase, the second transition phase, or the third transition phase, determine the transition start phase and the transition end phase corresponding to the turning phase.

[0185] It should be understood that when the turning phase is the first transition phase, the transition start phase is the stationary phase, and the transition end phase is the starting phase.

[0186] When the turning phase is the second transition phase, the starting point of the transition is the initiation phase, and the ending point of the transition is the steady-state phase.

[0187] When the turning phase is the third transition phase, the starting point of the transition is the steady state phase, and the ending point of the transition is the return-to-normal phase.

[0188] S602. Determine the values ​​of the first parameter and the second parameter.

[0189] The first parameter value is the parameter value of the controller tuning parameter corresponding to the transition start stage; the second parameter value is the parameter value of the controller tuning parameter corresponding to the transition end stage.

[0190] Specifically, the value of the first parameter is determined based on the transition start stage and the preset dataset.

[0191] The second parameter value is determined based on the transition endpoint stage and the preset dataset.

[0192] S603. Determine the parameter values ​​based on the first parameter value, the second parameter value, and the theoretical transition time and the already transitioned time of the turning phase.

[0193] Specifically, when the turning phase is the first transition phase, the corresponding theoretical transition time can be the first time mentioned above; when the turning phase is the second transition phase, the corresponding theoretical transition time can be the second time mentioned above; and when the turning phase is the third transition phase, the corresponding theoretical transition time can be the third transition time mentioned above.

[0194] The transition duration is used to indicate the cumulative number of sampling periods from the expiration start stage to the current sampling period.

[0195] As a feasible approach, at the boundary of the steering phase switching, in order to avoid abrupt changes in the controller tuning parameters (such as a sudden change from the stationary phase parameters to the starting phase parameters), the parameter values ​​need to be subjected to short-time linear interpolation or weighted transition processing. By ensuring the continuous change of parameter values, the smoothness of the driving process can be effectively improved.

[0196] In an exemplary embodiment, short-time linear interpolation can be performed by first calculating the total error between the first parameter value (the parameter at the start of the transition phase) and the second parameter value (the parameter at the end of the transition phase), and then distributing this error evenly over the total number of sampling periods in the transition phase, so that the parameter value changes only by a corresponding proportion of the error in each sampling period. In this way, the controller tuning parameters can smoothly and continuously transition from the first parameter value to the second parameter value, avoiding sudden changes in steering feel due to parameter jumps.

[0197] For example, taking the turning phase as the first transition phase, assuming the first duration is 50ms (25 sampling periods), the parameter values ​​corresponding to the first transition phase can satisfy the following formula:

[0198] ;

[0199] ;

[0200] ;

[0201] in, Used to represent the scaling factor corresponding to the nth sampling period in the first transition phase; The scaling factor used to represent the static phase; The proportional coefficient used to represent the start-up phase; n is used to represent the transition time; Used to represent the integration time corresponding to the nth sampling period in the first transition phase; Used to represent the integration time during the stationary phase; Used to represent the integration time during the startup phase; Used to represent the scaling factor corresponding to the nth sampling period in the first transition phase; The scaling factor used to represent the static phase; A proportional coefficient used to represent the start-up phase.

[0202] Based on the transition start and end points of the steering phase, the first and second parameter values ​​are determined. Then, combined with the theoretical transition time and the actual transition time, dynamic calculations are performed to achieve smooth, continuous, and precise dynamic adjustment of parameter values ​​from the transition start to the transition end. This retains the characteristics of the core parameters of the transition start and end points (such as the stability of the start point and the responsiveness of the end point), while eliminating parameter abrupt changes during steering phase switching through gradient changes in the time dimension. This ensures that steering control remains synchronized with the driver's operating intentions throughout the transition process, significantly improving the continuity of steering feel and the smoothness of the driving experience.

[0203] In some embodiments, the integral term is used to eliminate steady-state error in traditional PID control. However, in scenarios with high loads such as when the PWM is close to its upper limit or when the actuator is limited, integral saturation is likely to occur. That is, the error persists and causes the integral term to accumulate continuously. Once the control system conditions change, it will cause severe overshoot or oscillation.

[0204] As a feasible implementation method, the vehicle steering control method provided in this application further includes: when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold, correcting the parameter value of the integral time to infinity.

[0205] The preset duty cycle threshold is used to represent the maximum duty cycle at which the steering drive motor's output capability approaches its limit. For example, the preset duty cycle threshold can be 95%.

[0206] For example, such as Figure 7 As shown, after receiving the vehicle speed and steering wheel torque from the data acquisition device, a reference current is calculated based on a preset power assist characteristic curve. Simultaneously, the PWM control module monitors the duty cycle of the steering drive motor in real time and dynamically adjusts the integral time parameter based on the duty cycle status (when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold, the integral time parameter value is corrected to infinity; when the duty cycle of the steering drive motor is less than the preset duty cycle threshold, the integral time is determined normally based on a preset dataset). The PID controller uses the reference current as the target benchmark, and performs calculations based on the real-time monitored actual current of the steering drive motor, the current integral time, the proportional coefficient, and the derivative coefficient to ultimately determine the target control current. Then, the steering drive motor is regulated according to this target control current to achieve precise steering assist control.

[0207] The preset power steering characteristic curve can be used to represent the correspondence between the pre-calibrated vehicle speed, steering wheel torque, and reference current.

[0208] It should be understood that when the duty cycle of the steering drive motor reaches or exceeds a preset threshold (such as 95%), the steering controller determines that the steering drive motor is close to its output limit (and cannot further increase torque output). At this time, by forcibly setting the integral time to infinity, the accumulation of the integral term can be paused, avoiding the "integral saturation" problem caused by the continuous accumulation of integrals when the output capacity of the steering drive motor is saturated. This prevents excessive overshoot or oscillation when the output capacity of the steering drive motor recovers, thus ensuring the stability of the steering control system.

[0209] For example, when the duty cycle of the steering drive motor is less than a preset duty cycle threshold, the integral term in the PID control is integrated normally, and the integral term can satisfy the following formula:

[0210] ;

[0211] in, Used to represent the integral term of the steering controller in the nth adoption cycle; Used to represent the integral term of the steering controller in the (n-1)th sampling period; Used to indicate integration time; This is used to represent the error value between the target control current and the actual current value corresponding to the nth adoption cycle.

[0212] As another feasible implementation method, when the turning phase is the homing phase, the integral gain is set to a negative value or a negative sign is added when accumulating integrals. This mechanism can quickly offset the memory of the previous positive integral, allowing the system to recover to the equilibrium point more quickly and reducing the number of homing oscillations.

[0213] For example, by adding a negative sign when accumulating integrals, the negative integral term can satisfy the following formula:

[0214] ;

[0215] in, Used for negative integral terms; Used to represent integral gain, it is the reciprocal of the integration time; This is used to represent the error value between the reference current and the actual current at each moment.

[0216] By correcting the integral time to infinity (i.e. pausing the accumulation of integral terms) when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold, integral saturation can be effectively avoided. This allows for precise matching of the output boundary of the steering drive motor, ensuring the stability of steering control under high load conditions. At the same time, it reduces unnecessary integral residue from interfering with subsequent adjustments, improving the control accuracy and reliability of the steering system under extreme conditions.

[0217] In some embodiments, after determining the parameter value, combined with Figure 3 ,like Figure 8 As shown, step S303 above can be specifically implemented as follows:

[0218] S801. Determine the feedforward compensation current based on the steering wheel hand torque and the feedforward gain coefficient.

[0219] As a feasible implementation method, the feedforward compensation current can be determined based on the following: determining the second derivative of the steering wheel torque; and determining the feedforward compensation current based on the product of the second derivative and the feedforward gain coefficient. The feedforward gain coefficient can be determined using a preset dataset and the steering phase.

[0220] For example, the second derivative can satisfy the following formula:

[0221] ;

[0222] in, Used to indicate steering wheel torque; Used to indicate the duration of a sampling period; Used to represent the steering wheel torque during the kth sampling period; Used to represent the steering wheel torque during the (k-1)th sampling period; Used to represent the steering wheel torque during the (k-2)th sampling period.

[0223] It should be understood that the second derivative of the steering wheel torque reflects the changing trend of the driver's steering force (such as acceleration). Based on this, the feedforward compensation current is calculated with the feedforward gain coefficient, which can predict changes in the driver's steering intention in advance, reduce the response lag of the steering control system, and especially in dynamic scenarios such as steering start or sharp turns, it can quickly compensate for changes in steering wheel torque, improve steering responsiveness and smoothness.

[0224] S802. Determine the target control current based on the feedforward compensation current, proportional coefficient, integral time, and derivative coefficient.

[0225] As a feasible approach, the target control current is obtained by superimposing the feedforward compensation current with the control quantity output by the PID controller (the reference control current calculated based on the proportional coefficient, integral time, derivative coefficient, and deviation signal).

[0226] For example, the target control current can satisfy the following formula:

[0227] ;

[0228] in, Used to represent the reference control current; Used to represent feedforward compensation current.

[0229] Specifically, the reference control current can satisfy the following formula:

[0230] ;

[0231] in, Used to represent reference current ( ) and actual current ( ) difference; Used to represent the proportionality coefficient; Used to indicate integration time; Used to represent differential coefficients.

[0232] Furthermore, the target control current can also satisfy the following formula:

[0233] ;

[0234] By using steering wheel torque and feedforward gain coefficient, the feedforward compensation current that can respond to the driver's steering intentions in advance is determined. By combining feedforward control with PID control, both the timeliness of steering response and the stability of control are improved, effectively optimizing steering feel and driving safety.

[0235] In some embodiments, such as Figure 9 As shown, the vehicle steering control method can also be implemented as follows:

[0236] S901, obtain steering wheel angle and steering wheel torque.

[0237] S902. Based on the steering wheel angle and steering wheel torque, determine the steering wheel rotation angular velocity and the rate of change of steering wheel torque.

[0238] S903. The steering stage of the vehicle is determined based on the steering wheel angle, steering wheel torque, steering wheel rotation angular velocity, and the rate of change of steering wheel torque.

[0239] S904. Determine the parameter values ​​of the controller tuning parameters based on the steering phase and the preset dataset.

[0240] The controller tuning parameters include: proportional gain, integral time, derivative gain, and feedforward gain.

[0241] S905. When the duty cycle of the steering drive motor is greater than or equal to the preset duty cycle, the integral time is corrected to infinity.

[0242] S906. Determine the target control current based on the parameter values ​​of the controller tuning parameters.

[0243] The vehicle steering control method provided in this application uses real-time collected steering wheel angle and steering wheel torque as inputs. By calculating the rate of change of steering wheel torque and combining it with preset conditions, the steering stage of the vehicle is identified, accurately determining whether the vehicle is currently in a stationary, starting, steady-state, or return-to-center stage. Furthermore, based on the current steering stage, the corresponding controller tuning parameters are dynamically called. An integral term freezing mechanism (i.e., when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold, the integral time is corrected to infinity) and a negative integral strategy (the integral term corresponding to the return-to-center stage is negative) are introduced during the control process to prevent integral saturation. Simultaneously, a feedforward compensation current is superimposed under rapid dynamic conditions to improve response speed. Finally, the PID output (reference control current) after smoothing transition processing is superimposed with the feedforward term (feedforward compensation current) to generate the target control current, driving the steering drive motor to achieve precise power assist. The process adopts a closed-loop real-time control architecture with clear logic and timing between modules, and has good feasibility and engineering stability, ensuring high-performance steering assist control even in complex and ever-changing driving scenarios.

[0244] The foregoing mainly describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the vehicle steering control device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Experts may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0245] like Figure 10 As shown, the vehicle steering control device 1000 includes: a determining module 1001 and a control module 1002; the determining module 1001 is used to determine the steering stage of the vehicle based on the operating parameters of the steering wheel in the vehicle; wherein, the operating parameters include: steering wheel angle and steering wheel torque; the steering stage is any one of the calibrated steering stages; the calibrated steering stages include: stationary stage, starting stage, steady-state stage and return-to-center stage; based on the steering stage, the parameter values ​​of the controller tuning parameters of the steering controller are determined; based on the parameter values, the target control current of the steering drive motor is determined; the control module 1002 is used to control the operation of the steering drive motor based on the target control current to adjust the running direction of the vehicle.

[0246] Furthermore, the calibration steering phase also includes: a first transition phase from the stationary phase to the startup phase, a second transition phase from the startup phase to the steady-state phase, and a third transition phase from the steady-state phase to the homing phase.

[0247] Furthermore, the determining module 1001 is specifically used to determine parameter values ​​based on a preset dataset and the turning stage; wherein, the preset dataset includes the parameter values ​​of the controller tuning parameters corresponding to the stationary stage, the start-up stage, the steady-state stage, and the return-to-center stage.

[0248] Furthermore, the determining module 1001 is specifically used to determine the transition start stage and transition end stage corresponding to the turning stage when the turning stage is a first transition stage, a second transition stage, or a third transition stage; determine the first parameter value and the second parameter value, wherein the first parameter value is the parameter value of the controller tuning parameter corresponding to the transition start stage; the second parameter value is the parameter value of the controller tuning parameter corresponding to the transition end stage; and determine the parameter value based on the first parameter value, the second parameter value, and the theoretical transition time and the already transitioned time of the turning stage.

[0249] Furthermore, the determination module 1001 is specifically used to monitor the end times of the stationary phase, the start-up phase, and the steady-state phase based on operating parameters; determine the first transition phase as the steering phase in which the vehicle is located within a first time period after the end time of the stationary phase; determine the second transition phase as the steering phase in which the vehicle is located within a second time period after the end time of the start-up phase; and determine the third transition phase as the steering phase in which the vehicle is located within a third time period after the end time of the steady-state phase.

[0250] Furthermore, the steering controller is a PID controller; the controller tuning parameters include: integral time; the vehicle steering control device 1000 also includes: correction module 1003; the correction module 1003 is used to correct the parameter value of integral time to infinity when the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold.

[0251] Furthermore, the steering controller is a composite controller of PID control and feedforward control; the controller tuning parameters also include: proportional coefficient, derivative coefficient and feedforward gain coefficient; the determination module 1001 is specifically used to determine the feedforward compensation current based on the steering wheel torque and the feedforward gain coefficient; and to determine the target control current based on the feedforward compensation current, proportional coefficient, integral time and derivative coefficient.

[0252] like Figure 11 As shown, the electronic device 1100 includes, but is not limited to, a processor 1101 and a memory 1102.

[0253] The memory 1102 described above is used to store the executable instructions of the processor 1101. It is understood that the processor 1101 is configured to execute instructions to implement the vehicle steering control method in the above embodiments.

[0254] It should be noted that those skilled in the art will understand that Figure 11 The electronic device structure shown does not constitute a limitation on electronic device 1100; electronic device 1100 may include, but is not limited to, other electronic devices. Figure 11 This may indicate more or fewer components, or combinations of certain components, or different component arrangements.

[0255] Processor 1101 is the control center of electronic device 1100. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs and / or modules stored in memory 1102, and by calling data stored in memory 1102, it performs various functions and processes data of electronic device 1100, thereby providing overall monitoring of electronic device 1100. Processor 1101 may include one or more processing units. Optionally, processor 1101 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into processor 1101.

[0256] The memory 1102 can be used to store software programs and various data. The memory 1102 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, processing unit, etc.), etc. Furthermore, the memory 1102 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0257] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1102 including instructions, which can be executed by a processor 1101 of an electronic device 1100 to implement the vehicle steering control method in the above embodiments.

[0258] In actual implementation, Figure 10 The functions of the determination module 1001, control module 1002, and correction module 1003 can all be provided by... Figure 11 The processor 1101 calls the computer program stored in the memory 1102 to implement the process. The specific execution process can be found in the method section of the previous embodiment, and will not be repeated here.

[0259] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0260] In an exemplary embodiment, this application also provides a computer program product including one or more instructions, which can be executed by the processor 1101 of the electronic device 1100 to complete the vehicle steering control method in the above embodiments.

[0261] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0262] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0263] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0264] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the classified units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0265] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0266] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, essentially, or the part that contributes to the prior art, or a complete or partial classification of the technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0267] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A steering control method of a vehicle, characterized by, The vehicle steering control method includes: Based on the operating parameters of the steering wheel in the vehicle, the steering stage of the vehicle is determined; wherein, the operating parameters include: steering wheel angle and steering wheel torque; the steering stage is any one of the calibrated steering stages; the calibrated steering stages include: stationary stage, starting stage, steady-state stage, and return-to-center stage; Based on the steering phase, determine the parameter values ​​of the controller tuning parameters of the steering controller; The target control current of the steering drive motor is determined based on the parameter values; The steering drive motor is controlled based on the target control current to adjust the vehicle's direction of travel.

2. The steering control method of a vehicle according to claim 1, characterized by The calibration steering phase further includes: a first transition phase from the stationary phase to the startup phase, a second transition phase from the startup phase to the steady-state phase, and a third transition phase from the steady-state phase to the homing phase.

3. The steering control method of a vehicle according to claim 2, characterized by The step of determining the controller tuning parameters of the steering controller based on the steering phase includes: The parameter values ​​are determined based on the preset dataset and the turning phase; The preset dataset includes the parameter values ​​of the controller tuning parameters corresponding to the static phase, the startup phase, the steady-state phase, and the homing phase, respectively.

4. The vehicle steering control method according to claim 3, characterized in that, The process of determining the parameter values ​​based on the preset dataset and the turning phase includes: When the turning phase is the first transition phase, the second transition phase, or the third transition phase, determine the transition start phase and the transition end phase corresponding to the turning phase; Determine a first parameter value and a second parameter value, wherein the first parameter value is the parameter value of the controller tuning parameter corresponding to the transition start stage; and the second parameter value is the parameter value of the controller tuning parameter corresponding to the transition end stage. The parameter value is determined based on the first parameter value, the second parameter value, and the theoretical transition time and the already transitioned time of the turning phase.

5. The vehicle steering control method according to claim 2, characterized in that, Determining the steering stage of the vehicle based on the operating parameters of the steering wheel includes: Based on the operating parameters, monitor the end times of the static phase, the startup phase, and the steady-state phase; The first transition phase refers to the steering phase in which the vehicle is within a first time period after the end of the stationary phase is determined. The steering phase in which the vehicle is within a second time period after the end time of the start-up phase is determined is the second transition phase; The steering phase of the vehicle within the third time period after the end of the steady-state phase is determined is the third transition phase.

6. The vehicle steering control method according to any one of claims 1-5, characterized in that, The steering controller is a PID controller; The controller tuning parameters include: integral time; the vehicle steering control method further includes: If the duty cycle of the steering drive motor is greater than or equal to a preset duty cycle threshold, the parameter value of the integral time is corrected to infinity.

7. The vehicle steering control method according to claim 6, characterized in that, The steering controller is a composite controller of PID control and feedforward control; The controller tuning parameters also include: proportional coefficient, derivative coefficient, and feedforward gain coefficient; determining the target control current of the steering drive motor based on the parameter values ​​includes: The feedforward compensation current is determined based on the steering wheel torque and the feedforward gain coefficient. The target control current is determined based on the feedforward compensation current, the proportional coefficient, the integral time, and the derivative coefficient.

8. A vehicle steering control device, characterized in that, The vehicle's steering control device includes: a determination module and a control module; The determining module is used to determine the steering stage of the vehicle based on the operating parameters of the steering wheel in the vehicle; wherein the operating parameters include: steering wheel angle and steering wheel torque; the steering stage is any one of the calibrated steering stages; the calibrated steering stages include: stationary stage, starting stage, steady-state stage and return-to-center stage; based on the steering stage, the module determines the parameter values ​​of the controller tuning parameters of the steering controller; and based on the parameter values, the module determines the target control current of the steering drive motor. The control module is used to control the operation of the steering drive motor based on the target control current, so as to adjust the running direction of the vehicle.

9. A vehicle, characterized in that, include: The vehicle steering control device as described in claim 8.

10. An electronic device, characterized in that, include: Processor and memory; The memory stores instructions that the processor can execute; When the processor is configured to execute the instructions, it causes the electronics to implement the vehicle steering control method as described in any one of claims 1-7.

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