Vehicle control method, electronic equipment and storage medium

Abstract

The invention provides a vehicle control method, electronic equipment and a storage medium. The method comprises the following steps: acquiring driving state parameters of a vehicle; determining a current road surface type according to the driving state parameters; determining a target value of a wheel turning angle according to the current road surface type and the driving state parameters; and controlling the vehicle according to the target value of the wheel turning angle. The wheel turning angle is controlled according to the current road surface type, so that the lateral control effect of the vehicle is more stable, and it can be guaranteed that the lateral control effect of the vehicle is better in any environment.

Description

Technical Field

[0001] This application relates to the field of vehicle lateral control technology, specifically to a vehicle control method, electronic device, and storage medium. Background Technology

[0002] The steer-by-wire system eliminates the mechanical connection between the steering wheel and the front wheels, and uses electrical signals controlled via the CAN bus (Controller Area Network). This allows the steering system's gear ratio to change according to the driver's intentions and the vehicle's driving characteristics, and also makes the change of gear ratio no longer limited by the mechanical structure.

[0003] However, the control effect of steer-by-wire can be affected by external factors, thus impacting vehicle safety. These factors include road surface adhesion conditions and crosswinds. Existing active steering controllers suppress the influence of these interference factors by selecting a higher gain. However, these interference factors only exist under specific conditions and are absent in most situations. Furthermore, active steering controllers cannot flexibly adjust their control strategies according to changes in the external environment, leading to system chattering and affecting vehicle control, preventing them from achieving optimal control performance.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] This application provides a vehicle control method, electronic device, and storage medium that controls the wheel steering angle according to the current road surface type, thereby making the lateral control effect of the vehicle more stable and ensuring better lateral control effect of the vehicle in any environment.

[0006] In a first aspect, embodiments of this application provide a vehicle control method, including: Obtain the vehicle's driving status parameters; The current road surface type is determined based on the driving status parameters; The target value of the wheel angle is determined based on the current road surface type and the driving state parameters; The vehicle is controlled based on the target value of the wheel rotation angle.

[0007] According to the technical solution provided in the embodiments of this application, optionally, determining the current road surface type based on the driving state parameters includes: The average wheel speed of the left wheel and the average wheel speed of the right wheel of the vehicle are determined based on the driving state parameters. Calculate the difference between the average wheel speed of the left wheel and the average wheel speed of the right wheel; Calculate the ratio of the difference to the average wheel speed of the left and right wheels, where the average wheel speed of the left and right wheels is the average of the average wheel speed of the left wheel and the average wheel speed of the right wheel; The current road surface type is determined based on the ratio. According to the technical solution provided in the embodiments of this application, optionally, determining the current road surface type based on the ratio includes: If the ratio is greater than a first threshold and the duration of the ratio being greater than the first threshold is greater than the duration threshold, then the road surface type is determined to be the first type. The first type of road surface is a split road surface where the adhesion coefficient of the left side of the road surface is lower than the adhesion coefficient of the right side of the road surface. If the ratio is less than the second threshold and the duration of the ratio being less than the second threshold is greater than the duration threshold, then the road surface type is determined to be the second type. The second type of road surface is a split road surface where the adhesion coefficient of the left side of the road surface is higher than the adhesion coefficient of the right side of the road surface. If the ratio is greater than or equal to the second threshold and less than or equal to the first threshold, and the duration is greater than the duration threshold, then the road surface type is determined to be the third type, and the third type of road surface is a non-split road surface. According to the technical solution provided in the embodiments of this application, optionally, the target value of the wheel steering angle includes the target value of the front wheel steering angle, and the step of determining the target value of the wheel steering angle based on the current road surface type and the driving state parameters includes: The vehicle's motion conditions are determined based on the driving state parameters, including braking conditions, non-braking conditions, non-acceleration conditions, and acceleration conditions. The feedforward compensation value of the front wheel steering angle is determined based on the described motion conditions and the current road surface type, and the feedback compensation value of the front wheel steering angle is determined based on the vehicle's ideal yaw rate and actual yaw rate. The sum of the feedforward compensation value and the feedback compensation value of the front wheel angle is determined as the comprehensive compensation value of the front wheel angle. The target value of the front wheel steering angle is determined based on the ideal value of the front wheel steering angle and the comprehensive compensation value. According to the technical solution provided in the embodiments of this application, optionally, determining the feedforward compensation value of the front wheel steering angle based on the motion conditions and the current road surface type includes: When the motion condition is a non-acceleration condition or a non-braking condition, the feedforward compensation value of the front wheel steering angle is determined by the first calculation formula; When the motion condition is an acceleration condition, if the road surface type is the first type, the feedforward compensation value of the front wheel angle is determined to be the smaller of the reference value and 0; if the road surface type is the second type, the feedforward compensation value of the front wheel angle is determined to be the larger of the reference value and 0; if the road surface type is the third type, the feedforward compensation value of the front wheel angle is determined by the first calculation formula. When the motion condition is braking condition, if the road surface type is the first type, the feedforward compensation value of the front wheel angle is determined to be the larger of the reference value and 0; if the road surface type is the second type, the feedforward compensation value of the front wheel angle is determined to be the smaller of the reference value and 0; if the road surface type is the third type, the feedforward compensation value of the front wheel angle is determined by the first calculation formula. The reference value is determined based on the wheel torque, the distance from the front axle to the center of gravity, and the front wheel lateral stiffness. According to the technical solution provided in the embodiments of this application, optionally, the first calculation formula is:

[0008] Where k represents time. Indicates the calibration coefficient. This represents the feedforward compensation value of the front wheel steering angle at time k. express Feedforward compensation value of the front wheel steering angle at time , initial time This is the calibration value. According to the technical solution provided in the embodiments of this application, optionally, the target value of the wheel rotation angle includes the target value of the front wheel rotation angle and the target value of the rear wheel rotation angle; the step of controlling the vehicle based on the target value of the wheel rotation angle includes: The first weight of the front wheel steering angle and the second weight of the rear wheel steering angle are determined based on the current road surface type. The final value of the front wheel angle is determined based on the first weight and the target value of the front wheel angle, and the final value of the rear wheel angle is determined based on the second weight and the target value of the rear wheel angle. The steering angles of the front and rear wheels of the vehicle are controlled separately based on the final values ​​of the front wheel steering angle and the rear wheel steering angle.

[0009] According to the technical solution provided in the embodiments of this application, optionally, the target value of the wheel steering angle includes the target value of the rear wheel steering angle, and the step of determining the target value of the wheel steering angle based on the current road surface type and the driving state parameters includes: The feedback value of the rear wheel steering angle is determined based on the actual yaw rate and the ideal yaw rate in the driving state parameters. The feedforward value of the rear wheel steering angle is determined based on the driving state parameters and the ideal two-degree-of-freedom reference model. The target value of the rear wheel steering angle is determined based on the feedback value of the rear wheel steering angle and the feedforward value of the rear wheel steering angle.

[0010] Secondly, embodiments of this application also provide a vehicle control device, including: The acquisition module is used to acquire the vehicle's driving status parameters; The road surface type determination module is used to determine the current road surface type based on the driving status parameters. The target angle value determination module is used to determine the target value of the wheel angle based on the current road surface type and the driving state parameters. The control module is used to control the vehicle according to the target value of the wheel rotation angle.

[0011] Thirdly, embodiments of this application also provide an electronic device, the electronic device comprising: Processor and memory; The processor executes the steps of the vehicle control method as described in any embodiment by calling programs or instructions stored in the memory.

[0012] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a program or instructions that cause a computer to perform the steps of the vehicle control method as described in any embodiment.

[0013] In summary, this application proposes a vehicle control method that determines the target value of the vehicle's wheel angle based on the current road surface type and driving state parameters, and then controls the wheel angle based on the target value. This achieves the goal of ensuring the vehicle's lateral control effect in any driving environment, making the vehicle's lateral control effect more stable. Attached Figure Description

[0014] Figure 1 This is a flowchart of a vehicle control method provided in an embodiment of this application; Figure 2 This is a schematic diagram of an ideal two-degree-of-freedom model provided in an embodiment of this application; Figure 3 This is a flowchart of another vehicle control method provided in an embodiment of this application; Figure 4 This is a schematic diagram of control logic provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0015] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a flowchart illustrating a vehicle control method provided in an embodiment of this application. This method is applicable to vehicles that control wheel angles using drive-by-wire technology. See also... Figure 1 The vehicle control method specifically includes the following steps: S110. Obtain the vehicle's driving status parameters.

[0018] Among these, vehicle driving status parameters can be obtained through onboard sensors. These parameters include, but are not limited to: steering wheel angle, vehicle speed, wheel speed, yaw angle, yaw rate, and lateral acceleration.

[0019] S120. Determine the current road surface type based on the driving status parameters.

[0020] If a vehicle is traveling on a road with two sides facing each other, the different road conditions on either side will result in different levels of traction on the wheels, causing a difference in wheel speed. Based on this principle, the current road surface type can be determined.

[0021] Specifically, determining the current road surface type based on the driving state parameters includes: Based on the driving state parameters, determine the average wheel speed of the left and right wheels of the vehicle over a period of time (the length of which can be flexibly set); calculate the difference between the average wheel speed of the left and right wheels; calculate the ratio of this difference to the average wheel speed of the left and right wheels, where the average wheel speed is the average of the average wheel speeds of the left and right wheels; determine the current road surface type based on this ratio. It is understood that the left wheel further includes the left front wheel and the left rear wheel, and the right wheel further includes the right front wheel and the right rear wheel.

[0022] For example, the ratio is determined by the following calculation formula:

[0023] in, This indicates the ratio. This indicates the average wheel speed of the left wheel. This indicates the average wheel speed of the right-hand wheel. This represents the average wheel speed of the left and right wheels, that is, the average of the average wheel speed of the left wheel and the average wheel speed of the right wheel.

[0024] The wheel speeds of the four wheels can be obtained using wheel speed sensors. In some implementations, to improve the accuracy of wheel speed determination, abnormal fluctuations in wheel speed can be dynamically corrected by combining the vehicle's lateral acceleration and yaw rate, thereby improving the accuracy of wheel speed determination.

[0025] Furthermore, determining the current road surface type based on the ratio includes: If the ratio is greater than a first threshold and the duration of the ratio being greater than the first threshold is greater than the duration threshold, then the road surface type is determined to be the first type. The first type of road surface is a split road surface where the adhesion coefficient of the left side of the road surface is lower than that of the right side of the road surface.

[0026] If the ratio is less than the second threshold and the duration of the ratio being less than the second threshold is greater than the duration threshold, then the road surface type is determined to be the second type. The second type of road surface is a split road surface where the adhesion coefficient of the left side of the road surface is higher than that of the right side of the road surface.

[0027] If the ratio is greater than or equal to the second threshold and less than or equal to the first threshold, and the duration is greater than the duration threshold, then the road surface type is determined to be the third type, and the third type of road surface is a non-split road surface.

[0028] S130. Determine the target value of the wheel angle based on the current road surface type and the driving state parameters.

[0029] Active front-wheel steering control allows the vehicle to steer more flexibly, improving steering sensitivity and accuracy. In sharp turns or emergency avoidance situations, it can help the driver better control the vehicle, improving driving stability and safety.

[0030] The target value for wheel steering angle includes the target value for front wheel steering angle. Correspondingly, determining the target value for wheel steering angle based on the current road surface type and driving state parameters includes: determining the vehicle's motion condition based on the driving state parameters. The motion condition includes braking, non-braking, non-acceleration, and acceleration conditions. Specifically, the driving state parameters may include accelerator pedal signals and brake pedal signals. If the accelerator pedal signal value is less than a third threshold, the vehicle's motion condition is determined to be non-acceleration; if the accelerator pedal signal value is greater than or equal to the third threshold, the vehicle's motion condition is determined to be acceleration. If the brake pedal signal value is less than a fourth threshold, the vehicle's motion condition is determined to be non-braking; if the brake pedal signal value is greater than or equal to the fourth threshold, the vehicle's motion condition is determined to be braking. The third and fourth thresholds can be specific values ​​set based on experience.

[0031] The feedforward compensation value of the front wheel steering angle is determined based on the driving conditions and the current road surface type, and the feedback compensation value of the front wheel steering angle is determined based on the vehicle's ideal yaw rate and actual yaw rate; the sum of the feedforward compensation value and the feedback compensation value of the front wheel steering angle is determined as the comprehensive compensation value of the front wheel steering angle; the target value of the front wheel steering angle is determined based on the ideal value of the front wheel steering angle and the comprehensive compensation value (specifically, the sum of the ideal value of the front wheel steering angle and the comprehensive compensation value is determined as the target value).

[0032] The ideal front wheel steering angle = steering wheel angle ÷ gear ratio. The gear ratio can be dynamically changed. For example, at higher speeds, a large gear ratio is used, meaning the steering wheel is turned much, but the front wheels rotate at a smaller angle to ensure steering stability at high speeds. At lower speeds, a small gear ratio is used, meaning the steering wheel is turned slightly, controlling the front wheels to rotate at a relatively larger angle to ensure agility at low speeds. Specifically, the variable gear ratio for steer-by-wire (i.e., the dynamically changing gear ratio) can be based on a constant yaw rate gain, a constant lateral acceleration gain, or a combination of a constant yaw rate gain for low-to-medium speed ranges and a constant lateral acceleration gain for high-speed ranges, or it can be calculated in segments. The yaw rate gain is derived from an ideal two-degree-of-freedom model, and the lateral acceleration gain is the ratio of lateral acceleration to the steering wheel angle.

[0033] The feedback compensation value for determining the front wheel steering angle based on the vehicle's ideal yaw rate and actual yaw rate includes: With the error between the ideal yaw rate and the actual yaw rate being zero as the control objective, a PID (Proportional-Integral-Derivative) control algorithm is used for control. Specifically, the feedback compensation value for the front wheel steering angle can be obtained using the following formula:

[0034] in, This represents the feedback compensation value for the front wheel steering angle. This represents the proportional coefficient used to adjust the front wheel steering angle. This represents the integral coefficient used to adjust the front wheel steering angle. Indicates the regulatory cycle. This represents the error between the ideal yaw rate and the actual yaw rate at time k. This represents the error between the ideal yaw rate and the actual yaw rate at time k-1. The PID control algorithm is the most classic and commonly used closed-loop control algorithm. Its core logic is to compare the deviation between the "target value" (i.e., the expected value, which in this embodiment refers to the ideal yaw rate) and the "actual value" (which in this embodiment refers to the actual yaw rate), combining the three functions of "instant response," "cumulative correction," and "trend prediction," to output a control signal (in this embodiment, the signal controlling the front wheel steering angle) to quickly and stably eliminate the deviation, ultimately allowing the controlled object to accurately follow the target value.

[0035] The ideal yaw rate can be determined using an ideal two-degree-of-freedom reference model. Specifically, using an ideal two-degree-of-freedom model of a car (see reference...) Figure 2 The diagram shown is a schematic of an ideal two-degree-of-freedom model. Using this as a reference model, the following assumptions are made: The effect of the suspension is ignored; only the lateral displacement and yaw angle of the vehicle are considered, while longitudinal motion, pitch, and roll degrees of freedom are ignored. The changes in tire characteristics and the tire self-centering torque caused by load variations in the left and right wheels are ignored, simplifying to a single-wheel model, i.e., a single-rail model. The effects of driving and braking on the vehicle are ignored, as are air resistance effects. The influence of the steering system is ignored; the ideal front wheel steering angle is directly used as input. The sideslip and yaw angles are assumed to be small, and approximate values ​​are taken for trigonometric functions. The vehicle's forward speed along the x-axis is considered constant, i.e., the vehicle has no longitudinal acceleration; the tire side-clamping force is assumed to be linearly related to the sideslip angle. The calculation of the resultant force of external forces along the y-axis and the torque around the center of mass in the ideal two-degree-of-freedom model is given in the following formula:

[0036]

[0037] In the formula, m is the vehicle mass. For longitudinal vehicle speed, It is lateral acceleration. This is the actual yaw rate. This indicates the lateral force exerted by the front tires. This indicates the lateral force exerted by the rear tire. Let be the moment of inertia about the Z-axis. The yaw rate represents the actual yaw acceleration; a and b are the distances from the front axle to the center of mass and the rear axle to the center of mass, respectively, and L = a + b, where L represents the vehicle wheelbase.

[0038] The relationship between the lateral force and the slip angle of the front and rear tires is as follows:

[0039]

[0040] Indicates the front wheel slip angle. Indicates the rear wheel slip angle. This represents the ideal value for the front wheel steering angle. and These are the front wheel lateral stiffness and the rear wheel lateral stiffness, respectively. This refers to the lateral vehicle speed.

[0041] The steady-state yaw rate gain of a vehicle in steady state for:

[0042] In the formula, K is the steering gain, and Furthermore, considering the impact of road surface adhesion conditions on vehicles, and Therefore, the ideal yaw rate for:

[0043] In the formula, Where is the road surface adhesion coefficient, L is the vehicle wheelbase, K is the steering gain, and g is the gravitational acceleration. For a symbolic function, if If it is greater than 0, then =1, if If less than 0, then =-1, if If it equals 0, then =0.

[0044] In some implementations, determining the feedforward compensation value for the front wheel steering angle based on the driving conditions and the current road surface type includes: When the motion condition is a non-acceleration condition or a non-braking condition, the feedforward compensation value of the front wheel steering angle is determined by the first calculation formula; when the motion condition is an acceleration condition, if the road surface type is type 1, the feedforward compensation value of the front wheel steering angle is determined to be the smaller of the reference value and 0; if the road surface type is type 2, the feedforward compensation value of the front wheel steering angle is determined to be the larger of the reference value and 0; if the road surface type is type 3, the feedforward compensation value of the front wheel steering angle is determined by the first calculation formula.

[0045] When the motion condition is braking, if the road surface type is type 1, the feedforward compensation value of the front wheel steering angle is determined to be the larger of the reference value and 0. If the road surface type is type 2, the feedforward compensation value of the front wheel steering angle is determined to be the smaller of the reference value and 0. If the road surface type is type 3, the feedforward compensation value of the front wheel steering angle is determined by the first calculation formula.

[0046] The reference value is determined based on the wheel torque, the distance from the front axle to the center of gravity, and the front wheel lateral stiffness.

[0047] For example, the reference value is determined by the following calculation formula:

[0048] in, This refers to the reference value. This represents the sum of the torques on the four wheels of the vehicle. Indicates the distance from the front axle to the center of gravity. This indicates the front wheel lateral stiffness (by default, the lateral stiffness of the left front wheel is the same as that of the right front wheel).

[0049] The torque of each of the four wheels can be determined using the following formulas:

[0050]

[0051]

[0052]

[0053] in, This indicates the torque on the left front wheel. This indicates the torque on the left rear wheel. This indicates the torque on the right front wheel. This indicates the torque on the right rear wheel. This indicates the longitudinal acceleration of the left front wheel. This indicates the longitudinal acceleration of the left rear wheel. This indicates the longitudinal acceleration of the right front wheel. This indicates the longitudinal acceleration of the right rear wheel. This represents the vehicle's moment of inertia about the y-axis. The x-axis points towards the front of the vehicle, with its positive direction aligned with the vehicle's centerline. The y-axis is perpendicular to the x-axis, with its positive direction pointing to the left. The positive direction of the z-axis is vertically upward. B represents the track width (by default, the track widths of the front and rear axles are equal). This indicates the effective radius of the tires (by default, the effective radii of the tires on all four wheels are equal).

[0054] Furthermore, the longitudinal acceleration of each wheel is determined by the following formula:

[0055]

[0056]

[0057]

[0058] in, This indicates the wheel speed of the left front wheel. This indicates the wheel speed of the left rear wheel. This indicates the wheel speed of the right front wheel. This indicates the wheel speed of the right rear wheel. Indicates the vehicle's yaw angle.

[0059] The first calculation formula is:

[0060] Where k represents time. Indicates the calibration coefficient. This represents the feedforward compensation value of the front wheel steering angle at time k. express Feedforward compensation value of the front wheel steering angle at time , initial time This is the calibration value.

[0061] Active rear-wheel steering control dynamically adjusts the rear wheel steering angle to achieve reverse steering in low-speed scenarios (such as parking and U-turns in narrow roads) to reduce the turning radius and improve agility. At high speeds, it enhances vehicle stability through fine-tuning in the same direction, suppressing sideslip and yaw, and optimizing lane-changing and cornering safety. Its dynamic steering ratio adjustment function improves handling precision, reduces the risk of understeer or oversteer, and works in conjunction with systems such as ESP (Electronic Stability Program) and ABS (Anti-lock Braking System) to enhance vehicle attitude control under extreme conditions. By reducing tire wear due to sideslip, it extends tire life and has potential for energy savings, making it one of the core technologies for enhancing driving experience and safety in luxury and high-performance vehicles. Active rear-wheel steering control consists of two parts: feedforward and feedback.

[0062] In some embodiments, the target value of the wheel steering angle includes a target value of the rear wheel steering angle, and determining the target value of the wheel steering angle based on the current road surface type and the driving state parameters includes: The feedback value of the rear wheel steering angle is determined based on the actual yaw rate and the ideal yaw rate in the driving state parameters; the feedforward value of the rear wheel steering angle is determined based on the driving state parameters and the ideal two-degree-of-freedom reference model; and the target value of the rear wheel steering angle is determined based on the feedback value and the feedforward value of the rear wheel steering angle.

[0063] Specifically, with the error between the ideal yaw rate and the actual yaw rate being zero as the control objective, a PID strategy is employed for control to obtain the feedback value of the rear wheel steering angle:

[0064] in, This is the feedback value for the rear wheel steering angle. This represents the proportional coefficient for rear wheel control. This represents the integral coefficient for rear wheel control. Indicates the regulatory cycle. This represents the error between the ideal yaw rate and the actual yaw rate at time k. This represents the error between the ideal yaw rate and the actual yaw rate at time k-1. The ideal yaw rate can be determined using an ideal two-degree-of-freedom reference model.

[0065] The determination of the feedforward value of the rear wheel steering angle based on the driving state parameters and the ideal two-degree-of-freedom reference model includes: calculating the steering gain with the vehicle's center of gravity sideslip angle at zero as the control objective. The product of the steering gain and the front wheel steering angle is determined as the feedforward value for the rear wheel steering angle, specifically:

[0066]

[0067] in, L represents steering gain, a and b are the distances from the front axle to the center of gravity and the rear axle to the center of gravity, respectively, and L = a + b, where L represents the vehicle wheelbase. and These are longitudinal speed and lateral speed, respectively. m For the quality of the vehicle, This represents the feedforward value of the rear wheel steering angle. This represents the ideal value for the front wheel steering angle. This indicates the front wheel lateral stiffness (by default, the lateral stiffness of the left front wheel is the same as that of the right front wheel). This indicates the rear wheel lateral stiffness (by default, the lateral stiffness of the left rear wheel is the same as that of the right rear wheel).

[0068] S140. Control the vehicle according to the target value of the wheel rotation angle.

[0069] In some implementations, steering control of the front wheels can be performed based solely on the target value of the front wheel steering angle. In other implementations, steering control of the rear wheels can be performed based solely on the target value of the rear wheel steering angle. In still other implementations, combined control of the front and rear wheels can be performed based on both the target values ​​of the front and rear wheel steering angles, i.e., controlling both the front and rear wheel steering angles simultaneously.

[0070] For example, the target values ​​for wheel angles include target values ​​for front wheel angles and rear wheel angles; controlling the vehicle based on the target values ​​for wheel angles includes: A first weight for the front wheel steering angle and a second weight for the rear wheel steering angle are determined based on the current road surface type. The final value of the front wheel steering angle is determined based on the first weight and the target value of the front wheel steering angle, and the final value of the rear wheel steering angle is determined based on the second weight and the target value of the rear wheel steering angle. For example, the sum of the first weight and the second weight is 1, the product of the first weight and the target value of the front wheel steering angle is the final value of the front wheel steering angle, and the product of the second weight and the target value of the rear wheel steering angle is the final value of the rear wheel steering angle. Steering angle control is then applied to the front and rear wheels of the vehicle based on the final values ​​of the front and rear wheel steering angles respectively.

[0071] For example, if the road surface type is a split road, the first weight is determined to be greater than the second weight (e.g., the first weight is 0.95 and the second weight is 0.05). If the road surface type is a non-split road, the first weight is determined to be less than the second weight (e.g., the first weight is 0.05 and the second weight is 0.95). This is because when the vehicle enters a split road, the front axle first deviates from its trajectory. The active front wheel steering control can correct the vehicle's yaw motion while also influencing the lateral speed to help correct the trajectory deviation, reducing the need for driver steering wheel intervention. Therefore, if the road surface type is a split road, the first weight is determined to be greater than the second weight, allowing the active front wheel steering to fully function, correcting the vehicle's trajectory, reducing the degree of driver intervention, and improving the driver's driving experience.

[0072] When a vehicle enters a non-parallel road surface, the rear axle has greater lateral stiffness, resulting in stronger vehicle control. While the front axle's lateral slip angle is easily affected by rapid steering wheel changes and exhibits transient fluctuations, the rear axle's lateral slip angle is only related to the overall vehicle attitude and is less affected by steering wheel dynamics. Therefore, active rear-wheel steering control offers better boundary stability and can decouple driver input at the actuator level, achieving seamless engagement. Compared to active front-wheel steering control, it offers a greater advantage in improving stability. Therefore, if the road surface is non-parallel, the first weight should be less than the second weight to allow the active rear-wheel steering angle to fully exert its effect and improve vehicle driving stability.

[0073] In summary, by leveraging the respective advantages of active front-wheel steering control and active rear-wheel steering control, integrating them, and selecting weighting factors to adjust the degree of intervention in their control, the goal of ensuring vehicle driving stability can be achieved.

[0074] Optionally, to better utilize the advantages of active front-wheel steering and active rear-wheel steering, the fusion control method can also be selected to use an ideal yaw rate. and actual yaw rate The error is the control target, that is... Design corresponding control strategies, such as selecting weighting factors. When the road surface is a split road surface, the weight of the active front wheel steering angle feedback control is increased, i.e. When the road surface is not a split road surface, the weight of the active rear wheel steering angle feedback control is increased, i.e. .

[0075] The vehicle control method provided in this application embodiment can effectively correct the vehicle trajectory deviation phenomenon when the vehicle is on a split road surface, and reduce the driver's steering wheel angle intervention. For braking and acceleration conditions on split roads, the system can greatly reduce the vehicle's lateral deviation and prevent vehicle instability through dynamic compensation of the front wheel angle. When the road surface is identified as a non-split road surface, the intervention of the rear wheel steering system can improve the dynamic boundary stability of the vehicle and enhance the handling stability under extreme conditions by adjusting the rear wheel steering angle in real time.

[0076] Based on the above embodiments, refer to as follows Figure 3 The flowchart of a vehicle control method shown includes the following steps: 310. Acquire steering wheel angle, accelerator / brake pedal signals, yaw angle, yaw rate, and lateral acceleration signals based on vehicle sensors. 320. Acquire the ideal yaw rate based on the vehicle dynamics model. 330. Identify the split road surface based on vehicle state parameter estimation and acquire the split road surface identification marker. 340. Acquire the active front wheel feedforward additional front wheel angle based on the steer-by-wire actuator, road surface adhesion conditions, and braking or acceleration signals. 350. Acquire the additional yaw torque required for active front wheel or active rear wheel feedback based on the ideal yaw rate and the actual yaw rate. 360. Perform fusion control to improve vehicle stability and trajectory correction based on the road surface adhesion conditions and the additional yaw torque.

[0077] For reference Figure 4The diagram illustrates a control logic, including: determining the steering wheel angle and vehicle speed using a driver model; determining the ideal front wheel angle using a transmission ratio module; determining the ideal yaw rate using a reference model; and outputting a compensated front wheel angle based on the deviation between the ideal and actual yaw rates and a road surface identification flag (a flag indicating the road surface type; for example, if the road surface type is a split road and the adhesion coefficient of the left side is lower than that of the right side, the flag is less than 0; if the road surface type is a split road and the adhesion coefficient of the left side is higher than that of the right side, the flag is greater than 0; if the road surface type is a non-split road, the flag is equal to 0). The active rear wheel controller outputs the rear wheel angle based on the deviation between the ideal and actual yaw rates and the road surface identification flag. Wheel speed and yaw angle are determined using a vehicle model, and the road surface identification flag is determined through vehicle state estimation. The fusion module makes decisions on the involvement of the front wheel steering angle and the rear wheel steering angle, and controls the vehicle's steering through the steer-by-wire execution module.

[0078] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. For example... Figure 5 As shown, the electronic device 500 includes one or more processors 501 and memory 502.

[0079] The processor 501 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 500 to perform desired functions.

[0080] The memory 502 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 501 may execute the program instructions to implement the vehicle control method of any embodiment of this application described above and / or other desired functions. Various contents such as initial extrinsic parameters and thresholds may also be stored in the computer-readable storage medium.

[0081] In one example, the electronic device 500 may further include an input device 503 and an output device 504, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown). The input device 503 may include, for example, a keyboard, a mouse, etc. The output device 504 may output various information to the outside, including warning messages, braking force, etc. The output device 504 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0082] Of course, for the sake of simplicity, Figure 5 Only some of the components of the electronic device 500 relevant to this application are shown in this illustration; components such as buses, input / output interfaces, etc., are omitted. In addition, the electronic device 500 may include any other suitable components depending on the specific application.

[0083] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps of the vehicle control method provided in any embodiment of this application.

[0084] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0085] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the vehicle control method provided in any embodiment of this application.

[0086] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0087] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0088] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0089] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A vehicle control method, characterized in that, include: Obtain the vehicle's driving status parameters; The current road surface type is determined based on the driving status parameters; The target value of the wheel angle is determined based on the current road surface type and the driving state parameters; The vehicle is controlled based on the target value of the wheel rotation angle.

2. The method according to claim 1, characterized in that, Determining the current road surface type based on the driving status parameters includes: The average wheel speed of the left wheel and the average wheel speed of the right wheel of the vehicle are determined based on the driving state parameters. Calculate the difference between the average wheel speed of the left wheel and the average wheel speed of the right wheel; Calculate the ratio of the difference to the average wheel speed of the left and right wheels, where the average wheel speed of the left and right wheels is the average of the average wheel speed of the left wheel and the average wheel speed of the right wheel; The current road surface type is determined based on the ratio.

3. The method according to claim 2, characterized in that, Determining the current road surface type based on the ratio includes: If the ratio is greater than a first threshold and the duration of the ratio being greater than the first threshold is greater than the duration threshold, then the road surface type is determined to be the first type. The first type of road surface is a split road surface where the adhesion coefficient of the left side of the road surface is lower than the adhesion coefficient of the right side of the road surface. If the ratio is less than the second threshold and the duration of the ratio being less than the second threshold is greater than the duration threshold, then the road surface type is determined to be the second type. The second type of road surface is a split road surface where the adhesion coefficient of the left side of the road surface is higher than the adhesion coefficient of the right side of the road surface. If the ratio is greater than or equal to the second threshold and less than or equal to the first threshold, and the duration is greater than the duration threshold, then the road surface type is determined to be the third type, and the third type of road surface is a non-split road surface.

4. The method according to claim 1, characterized in that, The target value of the wheel steering angle includes the target value of the front wheel steering angle. Determining the target value of the wheel steering angle based on the current road surface type and the driving state parameters includes: The vehicle's motion conditions are determined based on the driving state parameters, including braking conditions, non-braking conditions, non-acceleration conditions, and acceleration conditions. The feedforward compensation value of the front wheel steering angle is determined based on the described motion conditions and the current road surface type, and the feedback compensation value of the front wheel steering angle is determined based on the vehicle's ideal yaw rate and actual yaw rate. The sum of the feedforward compensation value and the feedback compensation value of the front wheel angle is determined as the comprehensive compensation value of the front wheel angle. The target value of the front wheel steering angle is determined based on the ideal value of the front wheel steering angle and the comprehensive compensation value.

5. The method according to claim 4, characterized in that, The step of determining the feedforward compensation value of the front wheel steering angle based on the driving conditions and the current road surface type includes: When the motion condition is a non-acceleration condition or a non-braking condition, the feedforward compensation value of the front wheel steering angle is determined by the first calculation formula; When the motion condition is an acceleration condition, if the road surface type is the first type, the feedforward compensation value of the front wheel angle is determined to be the smaller of the reference value and 0; if the road surface type is the second type, the feedforward compensation value of the front wheel angle is determined to be the larger of the reference value and 0; if the road surface type is the third type, the feedforward compensation value of the front wheel angle is determined by the first calculation formula. When the motion condition is braking condition, if the road surface type is the first type, the feedforward compensation value of the front wheel angle is determined to be the larger of the reference value and 0; if the road surface type is the second type, the feedforward compensation value of the front wheel angle is determined to be the smaller of the reference value and 0; if the road surface type is the third type, the feedforward compensation value of the front wheel angle is determined by the first calculation formula. The reference value is determined based on the wheel torque, the distance from the front axle to the center of gravity, and the front wheel lateral stiffness.

6. The method according to claim 5, characterized in that, The first calculation formula is: Where k represents time. Indicates the calibration coefficient. This represents the feedforward compensation value of the front wheel steering angle at time k. express Feedforward compensation value of the front wheel steering angle at time , initial time This is the calibration value.

7. The method according to claim 1, characterized in that, The target values ​​for wheel angles include the target values ​​for the front wheel angles and the rear wheel angles; controlling the vehicle based on the target values ​​for wheel angles includes: The first weight of the front wheel steering angle and the second weight of the rear wheel steering angle are determined based on the current road surface type. The final value of the front wheel angle is determined based on the first weight and the target value of the front wheel angle, and the final value of the rear wheel angle is determined based on the second weight and the target value of the rear wheel angle. The steering angles of the front and rear wheels of the vehicle are controlled separately based on the final values ​​of the front wheel steering angle and the rear wheel steering angle.

8. The method according to claim 1, characterized in that, The target value of the wheel steering angle includes the target value of the rear wheel steering angle. Determining the target value of the wheel steering angle based on the current road surface type and the driving state parameters includes: The feedback value of the rear wheel steering angle is determined based on the actual yaw rate and the ideal yaw rate in the driving state parameters. The feedforward value of the rear wheel steering angle is determined based on the driving state parameters and the ideal two-degree-of-freedom reference model. The target value of the rear wheel steering angle is determined based on the feedback value of the rear wheel steering angle and the feedforward value of the rear wheel steering angle.

9. An electronic device, characterized in that, The electronic device includes: Processor and memory; The processor executes the steps of the vehicle control method as described in any one of claims 1 to 8 by calling programs or instructions stored in the memory.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that cause a computer to perform the steps of the vehicle control method as described in any one of claims 1 to 8.

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