Vehicle lateral movement control method, device, vehicle, and computer-readable storage medium

Abstract

This application relates to the field of vehicle control technology, specifically to a vehicle lateral movement control method, device, vehicle, and computer-readable storage medium. The control method includes: acquiring vehicle operating status information and driving scenario information; determining a target lateral movement speed based on the driving scenario information; determining a first target steering angle and a first target rotational speed for each motor based on the target lateral movement speed; optimizing the first target steering angle and first target rotational speed based on the operating status information during lateral movement to obtain a second target steering angle and a second target rotational speed; correcting the second target rotational speed based on the real-time tire forces of the four wheels to obtain a third target rotational speed; correcting the third target rotational speed based on the vehicle's yaw rate to obtain a fourth target rotational speed; and controlling the steering actuator and each drive system to perform lateral movement based on the second target steering angle and the fourth target rotational speed, thereby improving the stability and reliability of lateral movement control.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, such as a method, apparatus, vehicle, and computer-readable storage medium for controlling vehicle lateral movement. Background Technology

[0002] Distributed drive vehicles, with their extremely high degrees of dynamic freedom and precise torque vector control capabilities, have become an important vehicle for achieving advanced autonomous driving and complex maneuvers. Among these, lateral movement control is crucial for improving vehicle flexibility in scenarios such as dense urban traffic, narrow road maneuvers, and automated parking.

[0003] Among the related technologies, a lateral movement control based on matching the slip ratios of the driving wheel and the driven wheel is disclosed. By controlling the matching of the slip ratios of the front and rear wheels, the longitudinal adhesion components cancel each other out and the lateral adhesion components are superimposed, thereby reducing longitudinal offset and yaw to a certain extent.

[0004] In implementing the above technical solution, at least the following problems exist: This scheme relies on yaw rate and longitudinal motion data as feedback signals. During lateral movement, the vehicle is prone to undetected sideslip or accumulated longitudinal position drift, resulting in insufficient control precision and affecting the stability and safety of lateral movement control.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a method, apparatus, vehicle, and computer-readable storage medium for controlling vehicle lateral movement, thereby improving the accuracy of lateral movement control and the stability and safety of the lateral movement process.

[0008] In some embodiments, a method for controlling lateral movement of a vehicle is provided. The vehicle includes a four-wheel independent drive system and a steering actuator. The control method includes: acquiring vehicle operating status information and driving scenario information, and determining a target lateral movement speed based on the driving scenario information; determining a first target steering angle and a first target rotational speed of each drive system based on the target lateral movement speed; optimizing the first target steering angle and the first target rotational speed based on the operating status information during lateral movement of the vehicle to obtain a second target steering angle and a second target rotational speed; correcting the second target rotational speed based on the real-time tire forces of the four wheels to obtain a third target rotational speed; and correcting the third target rotational speed based on the yaw rate of the vehicle to obtain a fourth target rotational speed; and controlling the steering actuator and each drive system to perform lateral movement based on the second target steering angle and the fourth target rotational speed.

[0009] The vehicle lateral movement control method disclosed herein is applied to vehicles with four independent drive systems and steering actuators, enabling independent control of the wheels. The target lateral movement speed is determined by acquiring vehicle operating status information and driving scenario information. Based on the target lateral movement speed, a first target steering angle and a first target speed for each drive system are determined. This feedforward initial setting based on the target lateral movement speed quickly establishes a control benchmark, resulting in faster control response, no significant lag during the lateral movement initiation phase, and more stable initial posture. A second target steering angle and a second target speed are obtained based on operating status optimization. Real-time status feedback is introduced to perform closed-loop optimization of the initial targets, eliminating deviations caused by feedforward setting errors, road surface interference, and load changes, thus improving control accuracy. Based on tire force and yaw rate, the target speed is dynamically corrected for tire adhesion and vehicle posture, respectively, providing layered compensation for errors from different sources. This suppresses both tire slippage and vehicle yaw, significantly improving stability. Through coupling based on multi-dimensional state information, the target steering angle and target speed for lateral movement control are dynamically adjusted, improving the stability and reliability of lateral movement control.

[0010] Optionally, determining the first target steering angle based on the target lateral vehicle speed includes: obtaining an initial target steering angle through nonlinear mapping based on the target lateral vehicle speed; obtaining the vertical load of each wheel; determining a first correction coefficient based on the vertical load distribution ratio of each wheel; and correcting the initial target steering angle using the first correction coefficient to obtain the first target steering angle.

[0011] In this embodiment, the initial target steering angle is corrected according to the vertical load distribution ratio to obtain the first target steering angle. This prevents the tires on the heavily loaded side from prematurely entering the nonlinear region or saturating due to excessive steering angle, thereby improving the stability and tire life during lateral movement.

[0012] Optionally, determining the first target speed of each drive system based on the target lateral vehicle speed includes: obtaining the initial target speed of each drive system through a kinematic model based on the target lateral vehicle speed and the first target steering angle; obtaining the vertical load of each wheel and determining a second correction coefficient according to the vertical load distribution ratio of each wheel; and correcting the initial target speed using the second correction coefficient to obtain the first target speed.

[0013] In this embodiment, the initial target rotational speed is corrected according to the vertical load distribution ratio to obtain the first target rotational speed. This compensates for the driving force required to compensate for load differences, preventing slippage of lightly loaded wheels or insufficient driving force of heavily loaded wheels. Distributing the rotational speed according to the load ratio, i.e., distributing the driving torque, ensures that the longitudinal force of each wheel is proportional to the vertical load, improving adhesion utilization.

[0014] Optionally, based on the operating status feedback information, the first target steering angle is optimized to obtain the second target steering angle, including: acquiring the vertical load of each wheel and the longitudinal acceleration of the vehicle; calculating the vehicle body center of gravity offset and inertial displacement trend value through a load-acceleration coupling model based on the vertical load of each wheel; determining the feedforward control quantity according to the vehicle body center of gravity offset and inertial displacement trend value; acquiring the vehicle's longitudinal displacement deviation, using a PID control algorithm, and calculating the front wheel steering angle correction quantity based on the longitudinal displacement deviation; and superimposing the first target steering angle, the feedforward control quantity, and the front wheel steering angle correction quantity to obtain the second target steering angle.

[0015] In this embodiment, the feedforward control quantity is calculated using a load-acceleration coupling model, and combined with longitudinal displacement deviation PID feedback to obtain the second target steering angle. Longitudinal acceleration causes load transfer, thereby changing tire sideslip characteristics; inertia causes the vehicle body to lurch forward and backward. Feedforward control adjusts the steering angle in advance based on model prediction, while feedback control eliminates residual errors. The combination of the two significantly improves response speed and steady-state accuracy. In this way, by compensating for load transfer and inertial displacement trends in advance and reducing feedback lag, the goal of "zero longitudinal displacement" is achieved.

[0016] Optionally, a PID control algorithm is used to calculate the front wheel steering angle correction based on the longitudinal displacement deviation, including: the calculation formula used is: ; where δ dx d is the front wheel steering angle correction amount. xerr K represents the longitudinal displacement deviation value. p K is the proportionality coefficient. i K is the integral coefficient. d Here, K is the differential coefficient; where K is determined based on the longitudinal displacement deviation, longitudinal acceleration, and the load difference between the left and right wheels, respectively. p K i and K d .

[0017] In this embodiment, the PID parameters are dynamically adjusted based on the longitudinal displacement deviation, longitudinal acceleration, and the load difference between the left and right wheels. When the deviation is large, the proportional term is increased for rapid correction; when the acceleration is large, the integral term is increased to eliminate continuous drift; when the load difference is large, the derivative term is increased to predict the lateral slip trend. By adapting to different operating conditions, overshoot or slow response is avoided.

[0018] Optionally, based on the operating status feedback information, the first target rotational speed is optimized to obtain the second target rotational speed, including: calculating the slip ratio limitation factor K using a weighted multiplication model. w According to the slip ratio limiting factor K w The first target speed of each drive system is optimized to obtain the second target speed of each drive system.

[0019] In this embodiment, a weighted multiplicative model is used to calculate the slip ratio constraint factor K. w This optimizes the first target speed. Excessive slip ratio leads to rapid tire wear, while insufficient slip ratio results in inadequate lateral force. (Through K...) w The target slip ratio is adjusted to ensure the tire always operates in the low-wear zone. This minimizes tire wear as the control objective, coupling vehicle speed deviation, road grip, and optimal slip ratio to achieve synergistic optimization of lateral movement capability and tire life.

[0020] Alternatively, the weighted multiplication model is: Among them, K v,i K μ,i K γ,i The coefficients for the optimal slip ratio correction are α, β, and γ, which are weighting coefficients and α+β+γ=1. i is the wheel number, i=1~4, corresponding to the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively.

[0021] Optionally, based on the real-time tire forces of the four wheels, the second target speed is corrected to obtain the third target speed, including: obtaining the lateral tire forces of each wheel, which are respectively F y1 F y2、 F y3、 F y4 F y1 For the lateral tire force of the left front wheel, F y2 For the lateral tire force of the right front wheel, F y3 For the lateral tire force of the left rear wheel, F y4 The lateral tire force on the right rear wheel is calculated; the overall deviation of the lateral force is calculated. Based on the numerical range of the lateral force deviation, determine the wheel and speed correction amount that need to be corrected; superimpose the speed correction amount with the second target speed to generate the third target speed.

[0022] Optionally, the wheels requiring correction are determined based on the numerical range of the overall lateral force deviation, including: when 0 <F y_delta When the first deviation force threshold is reached, the corrected rotational speed of the right front wheel is determined; when F y_delta When the deviation force threshold is greater than or equal to the first deviation force threshold, determine the corrected rotational speed of the left front wheel; when the second deviation force threshold is reached... <F y_delta When <0N, determine the corrected right rear wheel speed; when F y_delta When the deviation force threshold is less than or equal to the second deviation force threshold, the corrected left rear wheel speed is determined.

[0023] In this embodiment, the correction amount for the wheels and their rotational speed is determined based on the overall deviation of the lateral forces. The lateral force deviation reflects an imbalance in the lateral forces between the front and rear axles, which can lead to yaw or sideslip. By correcting the wheel rotational speed, an additional yaw moment can be generated, quickly balancing the vehicle's attitude. This actively suppresses body roll and yaw tendencies, improving stability under complex road conditions.

[0024] Optionally, based on the vehicle's yaw rate, the third target rotational speed is corrected to obtain the fourth target rotational speed, including: obtaining the vehicle's actual yaw rate γ. act When |γ act |>γ max Incremental PID control is used, with the change in yaw rate error as the control input, to calculate the increment Δn of the yaw correction speed. yaw (t); The increments of the yaw correction speed are accumulated to obtain the yaw correction speed value n for the current cycle. yaw (t); Based on the direction of the yaw rate, the yaw correction speed value is applied to the corresponding side wheel, and the fourth target speed is obtained by superimposing the yaw correction speed value on the third target speed.

[0025] Optionally, based on the direction of the yaw rate, a yaw correction speed value is applied to the corresponding side wheel, and a fourth target speed is obtained by superimposing the yaw correction speed value on the third target speed, including: when γ act When the value is greater than 0, the yaw correction speed n will be adjusted. yaw (t) is applied to the right wheel, where the fourth target rotational speed n of the right front wheel is... 4,fr =n 3,fr +n yaw (t), n 3,fr The third target speed for the right front wheel; the fourth target speed for the right rear wheel, n. 4,rr =n 3,rr n yaw (t), n 3,rr The third target speed is the speed of the right rear wheel; the fourth target speeds of the left front wheel and left rear wheel remain unchanged at their respective third target speeds; when γ act When <0, the yaw correction speed value nyaw (t) is applied to the left wheel, where the fourth target rotational speed n of the left front wheel is... 4,fl =n 3,fl +n yaw (t), n 3,fl The third target speed for the left front wheel; the fourth target speed for the left rear wheel, n. 4,rl =n 3,rl n yaw (t), n 3,rl The third target speed is the speed of the left rear wheel; the fourth target speeds of the right front wheel and the right rear wheel remain unchanged at their respective third target speeds.

[0026] In this embodiment, an incremental PID controller outputs a yaw correction speed value for the yaw rate. This yaw correction speed value is applied to the corresponding wheel. A fourth target speed is obtained by superimposing the yaw correction speed value on top of a third target speed. When the vehicle exhibits unwanted spin, increasing the speed of one front wheel while simultaneously decreasing the speed of the rear wheel on the same side generates a counter-yaw torque without causing longitudinal force imbalance. Incremental PID control avoids integral saturation, resulting in a smoother response. Furthermore, by rapidly suppressing yaw rates exceeding the allowable range and utilizing the differential force between the front and rear wheels to generate an anti-yaw torque, a "zero yaw" target is achieved.

[0027] Optionally, the control method further includes: increasing the proportional coefficient of the incremental PID control when the yaw rate error is greater than a first angular velocity threshold; decreasing the proportional coefficient of the incremental PID control when the yaw rate error is less than a second angular velocity threshold; adjusting the integral coefficient of the incremental PID control to a preset integral coefficient value and setting an integral upper limit when the duration of the yaw rate error is greater than or equal to a preset time threshold; adjusting the derivative coefficient of the incremental PID control to a first coefficient value when the rate of change of the yaw rate error is greater than a first change threshold; and adjusting the derivative coefficient of the incremental PID control to a second coefficient value when the rate of change of the yaw rate error is less than the first change threshold, wherein the first coefficient value is greater than the second coefficient value.

[0028] In this embodiment, the PID parameters are dynamically adjusted based on the magnitude, duration, and rate of change of the yaw rate error. This ensures a rapid response when the deviation is large and avoids overshoot when the deviation is small; the integral term intervenes only during sustained deviations to prevent integral saturation; and the derivative term predicts trends based on the rate of change to improve anti-interference capability. Specific thresholds and coefficients can be calibrated on a real vehicle to ensure stable convergence under various yaw disturbances.

[0029] Optionally, the control method further includes: acquiring the road surface type; and correcting the parameters of the incremental PID control according to the road surface type; wherein the parameters include proportional coefficient, integral coefficient, and derivative coefficient.

[0030] In this embodiment, the weights of the PID parameters are adjusted according to the road surface type. Wheel speed fluctuation frequency can effectively distinguish between asphalt roads, cement roads, and gravel roads. Fuzzy control rules can be designed based on experience to achieve adaptive parameter tuning, enhancing adaptability to different road surfaces. For example, on bumpy roads, increasing the derivative term suppresses high-frequency fluctuations, while on slippery roads, increasing the proportional term improves response.

[0031] Optionally, the control method further includes: during the lateral movement of the vehicle, assigning weights to feedforward control and feedback control quantities according to the movement stage of the lateral movement, wherein the feedforward control quantity is pre-calculated based on the target lateral movement speed and load distribution, and the feedback control quantity is calculated in real time based on the operating status information; wherein the operating stage includes the lateral movement start stage, the lateral movement stage, and the lateral movement deceleration stage.

[0032] In this embodiment, the feedforward-feedback weights are dynamically allocated according to the motion phase. During lateral movement, the vehicle accelerates from a standstill, and feedforward prediction can prevent initial yaw. During deceleration, inertia can easily cause reverse yaw, and enhanced feedback can correct this in a timely manner. In this way, by rapidly establishing attitude with feedforward as the main force in the initial stage of start-up, balancing feedforward and feedback in the stabilization stage, and suppressing rebound with feedback as the main force in the deceleration stage, the lateral movement process is made smoother and safer.

[0033] In some embodiments, a vehicle lateral movement control device is provided, including a processor and a memory storing program instructions, the processor being configured to execute the vehicle lateral movement control method described in any of the above embodiments when executing the program instructions.

[0034] In some embodiments, a vehicle is provided, including: a vehicle body; and a vehicle lateral movement control device as described in any of the above embodiments, disposed on the vehicle body.

[0035] In some embodiments, a computer-readable storage medium is provided storing program instructions that, when executed, cause a computer to perform the vehicle lateral movement control method as described in any of the above embodiments.

[0036] The vehicle lateral movement control method, apparatus, vehicle, and computer-readable storage medium provided in this disclosure can achieve the following technical effects: The vehicle lateral movement control method disclosed herein is applied to distributed drive vehicles, specifically vehicles with four independent drive systems and steering actuators, enabling independent control of the wheels. Relying on the motors in the four independent drive systems, a four-wheel independent and real-time linked speed control system is constructed. Each of the four motors can independently respond to control commands, precisely controlling the speed or torque of each wheel in real time. Based on the lateral movement dynamics and differences in road surface adhesion coefficients, the speed of each motor is differentiated, balancing power output and speed matching accuracy. Simultaneously, a collaborative control strategy can quickly compensate for single-wheel speed deviations, ensuring that the speeds of all four wheels always closely match the real-time changes in the lateral movement trajectory and vehicle posture. This collaborative mode offers higher control freedom and adaptability; minor anomalies in a single motor can be compensated for by dynamic adjustment of the speeds of the other three motors, further enhancing the stability and reliability of lateral movement control. It fundamentally avoids problems such as unilateral power excess, speed imbalance leading to vehicle deviation, and motion stuttering inherent in existing technologies, representing a technological breakthrough distinct from traditional drive control. This allows for full utilization of the independent control of the distributed four motors during lateral movement control.

[0037] By combining multimodal environmental perception with surround-view vision and millimeter-wave radar, and replacing single-signal feedback with three-dimensional feedback signals of yaw rate, center of gravity sideslip angle, and longitudinal displacement deviation, the steering angle and speed are corrected and adjusted. Specifically, based on the driver's operating intention and scene information, a target lateral speed is set, and based on the target lateral speed, a first target steering angle and a first target speed for the four motors are set. On this basis, a second target steering angle and a second target speed for the four motors are optimized by combining yaw rate, center of gravity sideslip angle, and longitudinal displacement deviation using parameter self-tuning fuzzy PID correction, thereby achieving conflict-free multi-target response and solving the problems of single control target, low control accuracy, and instability in existing patents.

[0038] This disclosure provides a dynamic setting method for tire wear minimization slip ratio limits during lateral movement control of distributed electric vehicles. It couples the tire wear minimization objective with a slip ratio limiting factor, integrating multi-dimensional parameters such as motor speed, lateral movement speed, and road adhesion coefficient. This overcomes the limitations of traditional lateral movement control that only focuses on motion performance, proposing a weighted multiplicative model for calculating the limiting factor. This achieves synergistic optimization of lateral movement function and tire wear, addressing the technical challenge of excessively rapid tire wear during lateral movement in distributed electric vehicles. Specifically, it introduces a slip ratio limiting factor K based on minimizing tire wear. w By calculating K in real time w The target slip ratio output by the lateral control algorithm is corrected to obtain the actual executed slip ratio; K w It is necessary to couple key parameters such as the real-time speed of the motor, the lateral movement speed of the vehicle, and the road surface adhesion coefficient to minimize tire wear while ensuring the lateral movement function is realized.

[0039] Based on the real-time tire force of the four wheels, the real-time vertical load of the four wheels, and the multi-parameter active correction model of the adhesion limit of each wheel, it can quickly suppress longitudinal offset and yaw phenomena in complex scenarios such as uneven road surface adhesion, split road surface, joint road surface, and dynamic changes in the load of the four wheels, thus solving the problems of low control accuracy and slow response of the existing centralized dual-motor architecture.

[0040] Specifically, for scenarios with uneven four-wheel adhesion, a target speed correction coefficient for each wheel is determined based on the vertical load distribution ratio of the four wheels. The deviation between the actual tire force and the feedforward target tire force is compared in real time. Combined with vehicle posture feedback data, the target speeds of the four motors are dynamically adjusted to compensate for control deviations caused by load transfer and differences in road adhesion, thereby improving response speed. Based on a tire force and speed matching algorithm, the feedback-corrected target tire force is converted into real-time target speeds for each motor. The speed control parameters are dynamically adjusted according to the deviation between the actual tire force and the target value, achieving rapid response and tracking of motor speeds.

[0041] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0042] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein: Figure 1 This is a schematic diagram of the four-wheel independent drive system and steering actuator of the vehicle provided in the embodiments of this disclosure; Figure 2 This is a schematic flowchart of a vehicle lateral movement control method provided in one embodiment of the present disclosure; Figure 3 This is a schematic diagram of a seven-degree-of-freedom model of lateral movement of a vehicle provided in an embodiment of this disclosure; Figure 4 This is a schematic flowchart of a vehicle lateral movement control method provided in another embodiment of this disclosure; Figure 5 This is a schematic diagram of a vehicle lateral movement control device provided in one embodiment of the present disclosure.

[0043] Component markings in the attached diagram: 10 Front left wheel; 20 Front right wheel; 30 Rear left wheel; 40 Rear right wheel; 11. Front left wheel motor; 21. Front right wheel motor; 31. Rear left wheel motor; 41. Rear right wheel motor; 50 Front axle steering mechanism; 60 Rear axle steering mechanism. Detailed Implementation

[0044] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0045] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0046] Unless otherwise stated, the term "multiple" means two or more.

[0047] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0048] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0049] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0050] In some embodiments, a distributed drive vehicle is provided, combined with Figure 1 The diagram shows the vehicle's four-wheel independent drive system and steering actuator. The four-wheel independent drive system includes: a left front wheel motor 11, a right front wheel motor 21, a left rear wheel motor 31, and a right rear wheel motor 41. These four motors drive the left front wheel 10, right front wheel 20, left rear wheel 30, and right rear wheel 40 respectively, and can independently output torque and speed. The steering actuator includes a front axle steering mechanism 50 and a rear axle steering mechanism 60. The left front wheel 10 and right front wheel 20 are steered via the front axle steering mechanism 50, while the left rear wheel 30 and right rear wheel 40 are steered via the rear axle steering mechanism 60. The front axle steering mechanism 50 and the rear axle steering mechanism 60 are each equipped with a steering motor and a steering transmission mechanism, allowing independent control of the steering angle of the front and rear axles.

[0051] The vehicle also includes a central controller, four motor controllers, four steering actuators, an inertial measurement unit (IMU), an environmental perception system, and a GPS (Global Positioning System) / INS (Inertial Navigation System) integrated navigation system. The environmental perception system includes surround-view cameras and millimeter-wave radar.

[0052] Optionally, before performing lateral control, a system initialization and preparation phase is performed, including system power-on self-test and starting environmental perception and status monitoring.

[0053] The system power-on self-test includes a central controller power-on self-test to confirm normal communication with the four motor controllers, four steering actuators, IMU, environmental perception system, and GPS / INS. It also loads calibration parameters: lateral speed threshold (e.g., 5 km / h); yaw rate limit (e.g., ±3 deg / s); longitudinal displacement deviation limit (e.g., ±5 cm); weighting coefficients α, β, and γ of the slip ratio limitation factor Kw; and initial PID control values, such as setting the initial PID control value to: K... p =0.8, K i =0.15, K d =0.08; Set the control period, for example, set it to 10ms, which can be adjusted according to the hardware capabilities.

[0054] The system initiates environmental perception and status monitoring, including: activating surround-view cameras and millimeter-wave radar to collect real-time data on the position, speed, and trajectory of obstacles around the vehicle; distances between vehicles and obstacles in the side lanes; and collecting yaw rate, longitudinal acceleration, and lateral acceleration via IMU. Wheel speed sensors collect the actual rotational speeds of all four wheels. Steering angle sensors collect the actual steering angles of the front and rear axles.

[0055] In some embodiments, combined with Figure 2 As shown, a method for controlling vehicle lateral movement is provided. The vehicle includes a four-wheel independent drive system and a steering actuator. The control method includes: S201: Obtain vehicle operating status information and driving scenario information, and determine the target lateral movement speed based on the driving scenario information.

[0056] The operating status information includes, but is not limited to: current vehicle speed, acceleration, rotational speed of the four motors, wheel steering angle, yaw rate, and center of gravity sideslip angle.

[0057] Driving scenario information includes obstacle trajectories, road surface adhesion conditions, and other driving scenario information.

[0058] Before determining the target lateral movement speed, the process also includes: determining whether the lateral movement conditions are met. Specifically, these include: speed conditions: the current vehicle speed is less than or equal to a speed threshold, for example, a speed threshold of 5 km / h; safety conditions: the intelligent driving system reports "no vehicles / obstacles in the side lane" and there is no collision warning signal; and vehicle status conditions: all wheel speeds are at zero or extremely low speeds.

[0059] If all the above conditions are met, the "lateral movement enable flag" is set, and the lateral movement control mode is entered; otherwise, it exits and maintains normal driving control. By sensing the vehicle's operating status and surrounding environmental information, it determines whether the lateral movement conditions are met and initiates lateral movement control, ensuring that lateral movement mode is only entered when it is absolutely safe and the vehicle's condition permits, preventing dangerous operations and improving safety.

[0060] Determining the target lateral movement speed based on driving scenario information includes: obtaining the driver's target lateral movement speed v. target It can be obtained through driving commands; the safe speed limit value v is determined based on intelligent driving scenario information. limit and road speed limit v μ The target lateral movement speed is: v y0 =min(v target v limit v μ ).

[0061] Among them, the safe speed limit value v is determined based on intelligent driving scenario information. limit and road speed limit v μ The safe speed limit v is obtained by looking up a table based on the distance to obstacles in the driving scenario. limit For example, if the obstacle is more than 5 meters away, refer to the table to determine the safe speed limit v. limit =0.8 m / s. And, based on the road surface adhesion coefficient μ, the road speed limit v is obtained from a table. μ It should be noted that the mapping tables between obstacle distance and safe speed limit, and between road surface adhesion coefficient and road surface speed limit, can be pre-set in the controller after vehicle calibration. The specific contents of these mapping tables will not be shown or explained in detail here. By comprehensively considering driver intent, obstacle distance, and road surface adhesion, a safe and reasonable lateral movement speed target is determined, avoiding loss of control due to excessive speed requests from the driver or skidding due to slippery road surfaces; thus achieving adaptive speed limiting and improving safety.

[0062] S202, based on the target lateral speed, determine the first target steering angle and the first target speed of each drive system respectively.

[0063] Optionally, determining the first target steering angle based on the target lateral speed includes: obtaining the initial target steering angle δ based on the target lateral speed through a nonlinear mapping. tm(m=1~2, corresponding to the front and rear axle steering angles); obtain the vertical load of each wheel, and determine the first correction coefficient according to the vertical load distribution ratio of each wheel; use the first correction coefficient to correct the initial target steering angle, and obtain the first target steering angle δ based on the principle of large load and small steering angle. 1m (m=1~2, corresponding to the front and rear axle steering angles).

[0064] In this embodiment, the required steering angle for each axle is initially determined based on the target lateral speed, and then corrected using vertical load information to make the steering angle distribution more consistent with the current load distribution. The principle of large load and small steering angle can prevent the tires on the heavily loaded side from saturating prematurely due to excessive steering angle, thereby improving lateral stability and providing a reference value for subsequent closed-loop correction.

[0065] Specifically, the target lateral movement speed v y0 relative to the initial target rotation angle δ tm The relationship between them is nonlinear, and its physical essence is that at a given lateral speed, the wheels need to deflect at a certain angle to generate sufficient lateral force to drive the vehicle laterally. This nonlinear mapping relationship can be established in advance through vehicle dynamics simulation or real-vehicle calibration to establish the target lateral speed v. y0 relative to the initial target rotation angle δ tm The mapping relationship is not shown in detail here.

[0066] Furthermore, the principle of large load and small steering angle is adopted for vertical load correction. The physical basis for this is that, under the same lateral acceleration requirement, a wheel with a larger vertical load needs a smaller steering angle to generate the required lateral force. Conversely, if a lightly loaded wheel has an excessively large steering angle, it is prone to entering the nonlinear region or saturation, leading to sideslip.

[0067] The process involves obtaining the vertical load of each wheel and determining the first correction factor based on the vertical load distribution ratio of each wheel. This includes calculating the vertical load of each wheel, as well as calculating the total front axle load and the total rear axle load separately. The total front axle load is equal to the sum of the vertical loads of the left and right front wheels, and the total rear axle load is equal to the sum of the vertical loads of the left and right rear wheels. The first correction factor for the front axle vertical load is equal to the ratio of the total front axle load to the nominal front axle load, and the first correction factor for the rear axle vertical load is equal to the ratio of the total rear axle load to the nominal rear axle load. The nominal front axle load and nominal rear axle load can be preset and calibrated according to the vehicle type.

[0068] Optionally, determining the first target speed of each drive system based on the target lateral vehicle speed includes: obtaining the initial target speed of each drive system through a kinematic model based on the target lateral vehicle speed and the first target steering angle; obtaining the vertical load of each wheel and determining a second correction coefficient according to the vertical load distribution ratio of each wheel; and correcting the initial target speed using the second correction coefficient to obtain the first target speed.

[0069] In this embodiment, the speed of each motor is initially allocated based on the target lateral speed and steering angle, and differentiated compensation is performed using vertical load. The principle of high load and high speed can compensate for the greater driving force required by the heavy-duty wheels, achieve initial coordination of the four wheel speeds, and avoid single-wheel slippage or insufficient driving force due to load differences.

[0070] Specifically, the target lateral movement speed v y0 With the initial target rotational speed n of the wheel t,i There is a positive correlation between them. Since the wheel speeds of the four wheels are not exactly the same during lateral movement, the initial target rotational speed of each wheel is calculated based on the kinematic model. The kinematic model is: n t,i = ; where n t,i For the initial target rotational speed, δ i δ is the steering angle corresponding to the wheel. 11 δ is the front axle steering angle. 12 Let cos(δ) be the rear axle steering angle. i ) is the cosine of the steering angle, cos(δ) 11 )=cos(δ 12 ), R w v is the effective rolling radius of the wheel. y0 Let i = 1, 2, 3, 4, representing the target lateral movement speed. Preferably, based on the actual scene identified by the visual algorithm, such as obstacle distance and road surface type, an upper limit can be set on the initial target speed output by the kinematic model. The minimum value between the speed limit and the kinematic model output value is taken as the final initial target speed of the wheels. For example, if the distance to the lateral obstacle is less than 1m, the speed limit is within 100rpm; if the road surface is slippery, i.e., the road surface adhesion coefficient is less than 0.5, the speed limit is within 80rpm.

[0071] Furthermore, the principle of differentiated correction based on vertical load is that higher load means higher rotational speed. The physical basis is that, under the same lateral speed requirement, wheels with higher vertical loads need greater driving force, i.e., higher rotational speed, to generate the required longitudinal force to balance the longitudinal force components of the front and rear axles, while also providing sufficient lateral force. The greater the load, the greater the ground adhesion, and the greater the permissible driving force. Therefore, appropriately increasing the rotational speed can fully utilize the adhesion and prevent wheel slippage under light load.

[0072] The formula for determining the second correction factor based on the vertical load distribution ratio of each wheel is as follows: ; where k n,i F is the second correction factor; zi For the real-time vertical load of each wheel; F z,nomThe nominal load of the wheel can be pre-calibrated; β is an exponent, ranging from 0.2 to 0.5, calculated theoretically or calibrated on a real vehicle. The larger the β, the more significant the load effect. i = 1 to 4, corresponding to the left front wheel / right front wheel / left rear wheel / right rear wheel.

[0073] Thus, the first target rotational speed n 1,i =n t,i ×k n,i n t,i For the initial target rotational speed, k n,i This is the second correction factor.

[0074] S203, during the lateral movement of the vehicle, based on the operating status information, the first target steering angle and the first target speed are optimized respectively to obtain the second target steering angle and the second target speed.

[0075] The vehicle's yaw rate, sideslip angle, and longitudinal displacement deviation are acquired as feedback parameters for multi-objective control. Replacing traditional single-signal feedback, this allows the controller to simultaneously sense the vehicle's rotational trend, sideslip trend, and forward / backward drift, providing necessary information for decoupled control.

[0076] Optionally, based on the operating status feedback information, the first target steering angle is optimized to obtain the second target steering angle, including: acquiring the vertical load of each wheel and the longitudinal acceleration of the vehicle; calculating the vehicle center of gravity offset and inertial displacement trend value through a load-acceleration coupling model based on the vertical load of each wheel; determining the feedforward control quantity based on the vehicle center of gravity offset and inertial displacement trend value; acquiring the longitudinal displacement deviation of the vehicle, using a PID control algorithm, and calculating the front wheel steering angle correction quantity based on the longitudinal displacement deviation; and superimposing the first target steering angle, the feedforward control quantity, and the front wheel steering angle correction quantity to obtain the second target steering angle.

[0077] In this embodiment, based on load transfer and acceleration prediction of inertial displacement trends, angle compensation is provided in advance to reduce feedback control lag, thereby offsetting impending longitudinal displacement or yaw, improving response speed, and avoiding overshoot or oscillation caused by corrections after longitudinal displacement deviations have occurred. The front wheel angle is dynamically adjusted according to the actual longitudinal displacement deviation to bring the vehicle's longitudinal position back to zero. The proportional term quickly eliminates the current deviation, the integral term eliminates long-term accumulated errors, and the derivative term predicts trends to prevent overshoot; parameter adaptation ensures control quality under different operating conditions. The feedforward and feedback corrections are superimposed to form the final target angle command, achieving the "zero longitudinal displacement" target and preventing the vehicle from lurching forward or backward during lateral movement.

[0078] It should be noted that the load-acceleration coupling model is common knowledge and a conventional technique in the field of vehicle dynamics. Therefore, this disclosure will not provide a specific explanation of the model.

[0079] Specifically, based on the vertical load of each wheel, the load-acceleration coupling model is used to calculate the vehicle's center of gravity offset and inertial displacement trend. This includes: estimating the lateral and longitudinal offset of the vehicle's center of gravity based on the differences in the distribution of vertical loads on the four wheels, which affects the lateral force distribution and yaw tendency during lateral movement; and predicting the longitudinal displacement trend over a future period based on longitudinal acceleration, and applying compensation in advance.

[0080] Specifically, the vertical loads on the four wheels are acquired in real time, namely F. z,fl F z,fr F z,rl F z,rr .

[0081] The steps for calculating the lateral centroid offset include: Calculate the load difference between the left and right sides of the front axle: ΔF z,f =F z,fl F z,fr ; Calculate the load difference between the left and right sides of the rear axle: ΔF z,r =F z,rl F z,rr ; Calculate the lateral load difference of the entire vehicle: ΔF z,lat =ΔF z,f +ΔF z,r ; Calculate the lateral offset of the center of gravity relative to the vehicle's centerline: ,in, y cg This represents the lateral center of gravity shift, where T is the track width and the distance between the centers of the left and right wheels. Simplified estimation: When the left front wheel is 10% heavier than the right front wheel, the center of gravity can be considered to have shifted a certain distance to the left. y cg ≈0.05×T.

[0082] The steps for calculating the longitudinal centroid offset include: Calculate the load difference between the left and right sides of the front axle: ΔF z,f =F z,fl F z,fr ; Calculate the load difference between the left and right sides of the rear axle: ΔF z,r =F z,rl F z,rr ; Calculate the lateral load difference of the entire vehicle: ΔF z,lat =ΔF z,f +ΔF z,r ; Calculate the longitudinal center of gravity offset relative to the vehicle's centerline: ,in, xcg L represents the longitudinal center of gravity offset, and L is the wheelbase, which refers to the distance between the center line of the front axle and the center line of the rear axle of the vehicle.

[0083] Based on the prediction of longitudinal displacement trend over a future period using longitudinal acceleration and velocity, the longitudinal displacement increment ΔS is calculated using the following formula. x,pred , , where v x Given the current longitudinal velocity, it should be close to 0 during lateral movement, a x Δt represents the longitudinal acceleration, and Δt represents the prediction time window.

[0084] The feedforward control quantity is determined based on the vehicle's center of gravity offset and inertial displacement trend value; that is, the feedforward control quantity δ. fedfwd It consists of two independent linear superpositions, which respectively address lateral load imbalance and longitudinal inertial tendency, with a feedforward control variable δ. fedfwd The calculation formula is: δ fedfwd =δ fedfwd,lat +δ fedfwd,lon ; where δ fedfwd,lat δ is used to counteract the undesirable yaw moment caused by the lateral shift of the center of gravity. fedfwd,lon Used to counteract the tendency of inertial displacement caused by longitudinal acceleration.

[0085] Specifically, when the vehicle load is unevenly distributed, the vehicle's center of gravity will deviate from the vehicle's longitudinal centerline, resulting in a lateral center of gravity offset Δy. cg During lateral movement, the resultant force of the lateral forces acting on the four wheels from the ground is located at the vehicle's geometric center, while the vehicle's center of rotation is located at the center of gravity. When the center of gravity does not coincide with the geometric center, the resultant force of the lateral forces from the four wheels generates an undesirable yaw moment relative to the center of gravity. This moment causes the vehicle to yaw in the direction of the center of gravity shift. Specifically: Δy cg A positive value indicates that the center of gravity shifts to the right, meaning the vehicle tends to yaw to the right, requiring a leftward correction of the steering angle to counteract this. Δy cg A negative value indicates that the center of gravity is shifted to the left, meaning the vehicle tends to yaw to the left, requiring a rightward correction of the steering angle to counteract this.

[0086] To proactively suppress the undesirable yaw moment before it develops, the controller pre-applies a counter-steering angle compensation, causing the tire lateral force to generate a counter-yaw moment to counteract the undesirable yaw moment caused by the center of gravity shift. Based on the linearization assumption, the steering angle compensation is proportional to the lateral shift of the center of gravity: δ fedfwd,lat =K lat ×Δy cg In the formula, δ fedfwd,lat This is the lateral center of gravity offset feedforward, i.e., the steering angle compensation; K lat Δy is the feedforward scaling factor for the lateral center of gravity offset;cg This represents the lateral offset of the center of gravity.

[0087] Among them, the lateral centroid offset feedforward amount δ fedfwd,lat This is a pre-defined steering angle compensation amount based on the yaw tendency caused by the lateral shift of the vehicle's center of gravity. When the vehicle's center of gravity shifts laterally, an undesirable yaw moment is generated during the lateral movement. Specifically, when the center of gravity shifts to the left, the vehicle tends to yaw to the left, requiring a rightward correction of the front wheel steering angle to counteract this tendency. The purpose of the lateral center of gravity shift feedforward is to apply a corrective steering angle before the yaw actually occurs, thus avoiding lag compensation relying on feedback control after the yaw has occurred. The larger the lateral center of gravity shift, the greater the required steering angle compensation; the two are directly proportional.

[0088] Lateral center of gravity offset feedforward proportional coefficient K lat This is the proportionality coefficient that converts lateral center of gravity offset (mm) into feedforward steering angle (deg). This coefficient reflects the inherent characteristics of the vehicle, indicating how much steering angle compensation is required per unit lateral center of gravity offset. It is related to parameters such as vehicle track width, suspension stiffness, and tire lateral stiffness. A wider track width or greater suspension stiffness results in a smaller yaw tendency for the same center of gravity offset, and thus a smaller required steering angle compensation. Therefore, K... lat The value can be reduced accordingly. Unit: deg / mm. Calibration method: Calibrate through actual vehicle testing or high-precision vehicle dynamics simulation, such as CarSim. The initial reference value can be set to 0.05~0.15 deg / mm.

[0089] Lateral centroid offset Δy cg It is the lateral offset of the vehicle's actual center of gravity relative to the vehicle's longitudinal centerline. Lateral center of gravity offset Δy cg Calculated based on the lateral distribution differences of the vertical load on the four wheels. Unit: mm.

[0090] Specifically, if the vehicle is subjected to a longitudinal acceleration a during lateral movement... x For example, due to road slope causing slippage, changes in road resistance causing deceleration, or fluctuations in drive system output causing acceleration, according to Newton's first law, the vehicle will exhibit a tendency for longitudinal inertial displacement. If this tendency is not suppressed before the displacement actually occurs, the vehicle will experience longitudinal position drift, deviating from the intended lateral trajectory.

[0091] To proactively counteract the inertial tendency before longitudinal displacement occurs, the controller pre-applies a steering angle compensation, causing the wheel driving force to decompose into a longitudinal component to counteract the inertial force. Specifically, when a positive longitudinal displacement is predicted, the front wheel steering angle is increased, causing the driving force to generate a rearward longitudinal component, counteracting the forward lurching inertial tendency; when a negative longitudinal displacement is predicted, the front wheel steering angle is decreased, causing the driving force to generate a forward longitudinal component, counteracting the backward slipping inertial tendency. Based on the kinematic prediction model, the feedforward steering angle compensation is proportional to the predicted longitudinal displacement increment: δ fedfwd,lon =K lon ×ΔS x,pred In the formula, δ fedfwd,lon This is the feedforward amount for the inertial displacement trend, i.e., the feedforward rotation angle compensation amount; K lon ΔS is the feedforward proportional coefficient for the inertial displacement trend; x,pred To predict the longitudinal displacement increment.

[0092] Where, δ fedfwd,lon This is a pre-defined feedforward steering angle compensation amount based on the predicted longitudinal displacement trend caused by longitudinal acceleration. When the vehicle experiences longitudinal acceleration, it will generate an inertial displacement trend. δ fedfwd,lon Its function is to apply a corrective rotation angle before the actual longitudinal displacement occurs, actively counteracting the longitudinal drift caused by inertia, rather than waiting for the displacement to occur before making feedback corrections. The larger the predicted longitudinal displacement increment, the larger the required rotation angle compensation; the two are directly proportional.

[0093] K lon This is a proportionality coefficient that converts the predicted longitudinal displacement increment (mm) into a feedforward steering angle (deg). This coefficient reflects the vehicle's characteristic of "how much steering angle compensation is needed per unit predicted longitudinal displacement," and is related to parameters such as vehicle wheelbase, tire longitudinal stiffness, and braking / driving capability. The longer the wheelbase or the greater the tire longitudinal stiffness, the less steering angle compensation is needed for the same longitudinal displacement trend; conversely, the more sensitive the system is to longitudinal displacement, the greater the coefficient needs to be to improve the feedforward compensation strength. Unit: deg / mm. Calibration method: Through real vehicle testing or simulation calibration, the value range can be set to 0.1~0.3 deg / mm.

[0094] ΔS x,pred This predicts the increase in longitudinal displacement of a vehicle over a future time window, based on its current longitudinal acceleration and longitudinal velocity. A positive value indicates a predicted forward lurch, while a negative value indicates a predicted backward lurch. Unit: mm.

[0095] Optionally, a PID control algorithm is used to calculate the front wheel steering angle correction based on the longitudinal displacement deviation, including: the calculation formula used is: ; where δ dx d is the front wheel steering angle correction amount. xerrK represents the longitudinal displacement deviation value. p K is the proportionality coefficient. i K is the integral coefficient. d Here, K is the differential coefficient; where K is determined based on the longitudinal displacement deviation, longitudinal acceleration, and the load difference between the left and right wheels, respectively. p K i and K d .

[0096] In this embodiment, after obtaining the first target steering angle δ 1m Subsequently, to eliminate the longitudinal displacement deviation and yaw rate generated during lateral movement, a multi-dimensional feedback signal is needed for secondary optimization. This scheme employs a dual correction structure of load-acceleration coupled feedforward and longitudinal displacement deviation PID feedback, and calculates the feedforward control quantity δ. fedfwd and front wheel steering angle correction δ dx Superimposed on the first target steering angle δ 1m The second target turning angle δ is obtained from the above. 2m (m=1~2, corresponding to the front and rear axle steering angles), i.e., δ 2m =δ 1m +δ dx +δ fedfwd .

[0097] K is determined based on the longitudinal displacement deviation, longitudinal acceleration, and load difference between the left and right wheels. p K i and K d ,include: proportionality coefficient K p The adaptive adjustment steps include: setting an initial value K. p0 =0.8, its core function is to quickly offset the current longitudinal deviation (±5cm level). When | When |>3cm, K p Automatically increases by 15% to improve response speed, i.e., K p =K p0 ×1.15; when | When |<1cm, K p Reduce by 20%. This prevents overshoot, i.e., Kp = K. p0 ×0.8. In other cases, the proportionality coefficient Kp remains constant. p0 Unchanged. Amplitude limit: K p ∈[0.4, 1.2].

[0098] Integral coefficient K i The adaptive adjustment steps include: setting an initial value K. i0 =0.15, used to eliminate long-term accumulated errors. When the longitudinal acceleration a x Continuously greater than 0.05 m / s 2 At that time, Ki Increase by 10% to enhance the ability to resist inertial interference, i.e., K i =K i0 ×1.1; When the longitudinal acceleration a x Below 0.02m / s 2 At that time, K i Set the integral coefficient to zero to avoid excessive correction due to integral saturation. In other cases, the integral coefficient K... i Keep K i0 Unchanged. Output limit for integral term: maximum integral contribution not exceeding ±5. ° .

[0099] Differential coefficient K d The adaptive adjustment steps include: setting an initial value K. d0 =0.08, used to predict the trend of deviation changes. For example, if the load change rate exceeds 1% / ms, it indicates that the deviation will increase. When the load difference between the left and right wheels exceeds 5%, K... d Increase by 25% to proactively suppress offset caused by unilateral loads, i.e., K d =K d0 ×1.25; When the load difference between the left and right wheels is less than 2%, Kd decreases by 30%, reducing sensitivity to small fluctuations, i.e., K d =K d0 ×0.7. Integral coefficient K in other cases. d Keep K d0 Unchanged. Amplitude limit: K d ∈[0.05, 0.2].

[0100] If there are three consecutive control cycles, for example, each control cycle is 10ms, then after 3 × 10ms = 30ms, | If it is still greater than 1cm, then: K p Increase the value by 10% from the current value, but not exceeding the upper limit. Alternatively, appropriately increase the weight of the load-acceleration coupling model, i.e., increase the feedforward coefficient K. lon K lat This adjustment continues until the deviation is eliminated or the lateral movement ends, improving long-term control stability until the lateral movement operation is completed and the longitudinal displacement of the vehicle body remains stable at the target zero position.

[0101] Optionally, based on the operating status feedback information, the first target rotational speed is optimized to obtain the second target rotational speed, including: calculating the slip ratio limitation factor K using a weighted multiplication model. w According to the slip ratio limiting factor K w For each drive system, the first target speed n 1,i Optimization was performed to obtain the second target speed n for each drive system. 2,i n 2,i =n 1,i +Kw , i = 1, 2, 3, 4.

[0102] In this embodiment, the slip ratio limiting factor K is calculated. w Quantify the tire wear risk under current operating conditions, slip ratio limiting factor K w Between 0.1 and 1, avoid K w Too low a value will cause the lateral movement function to fail, while too high a value will fail to limit wear. By weighted and fused the effects of motor speed, lateral movement speed, and road surface adhesion coefficient on wear, this system achieves, for the first time, synergistic optimization of tire life and lateral movement function. By modifying the target slip ratio, it reduces the target slip ratio under high-wear conditions, protecting the tires. It actively reduces the slip ratio on wet or slippery surfaces or during high-speed lateral movement, preventing excessive slippage and abnormal wear. Thus, the optimized second target speed implements wear optimization into the speed command of each wheel, achieving wear suppression.

[0103] Alternatively, the weighted multiplication model is: Among them, K v,i K μ,i K γ,i The coefficients are the optimal slip ratio correction coefficients, α, β, and γ are the weighting coefficients, which are calibrated by orthogonal experiments and satisfy α+β+γ=1; i is the wheel number, i=1~4, corresponding to the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively.

[0104] In this embodiment, the lateral speed deviation sub-coefficient is obtained based on the lateral speed deviation calibration threshold. .

[0105] Road surface adhesion coefficient sub-coefficient Where μ is the current road surface adhesion coefficient, μ ref The reference adhesion coefficient.

[0106] Optimal slip ratio modifier coefficient , where γ opt For the optimal slip ratio, γ tar The target slip ratio is calculated for the system.

[0107] S204, based on the real-time tire force of the four wheels, corrects the second target speed to obtain the third target speed.

[0108] Optionally, based on the real-time tire forces of the four wheels, the second target speed is corrected to obtain the third target speed, including: obtaining the lateral tire forces of each wheel, respectively. ; Calculate the overall deviation of lateral force Based on the numerical range of the overall deviation of the lateral force, determine the wheel and speed correction amount n that needs to be corrected. cor,i; Compare the speed correction amount with the second target speed n 2,i Superimpose the values ​​to generate the third target rotational speed n. 3,i n 3,i =n 2,i +n cor,i , i = 1, 2, 3, 4.

[0109] In this embodiment, after obtaining the second target rotational speed, in order to cope with the vehicle body posture imbalance caused by complex working conditions, such as split road surfaces, single-sided bumps, and load transfer, it is necessary to introduce active correction based on real-time tire forces of all four wheels. Here, the tire force disclosed herein is the result of the combined effect of the vehicle's tire elastic deformation and road friction, referring to a three-dimensional force vector between the tire and the ground, including the longitudinal force F. x lateral force F y and vertical force F z Specifically, the tire force F of each wheel can be calculated online based on the magic formula or the Dugoff tire model. x F y and F z The specific calculation process of the magic formula or Dugoff tire model is common knowledge and will not be explained in detail here.

[0110] In this embodiment, by analyzing the imbalance of lateral tire forces of each wheel, the yaw trend of the vehicle body is predicted, and the rotational speed of specific wheels is actively adjusted to generate additional yaw torque, thereby quickly suppressing unexpected attitude changes.

[0111] By estimating tire forces in real time, the actual longitudinal and lateral forces of each wheel are obtained as a basis for correction. Online estimation is performed using the Magic Formula or Dugoff tire model, requiring no additional sensors, resulting in low cost and acceptable accuracy. By calculating the comprehensive deviation of lateral forces, the vehicle's attitude imbalance trend is judged based on the difference in lateral forces between the front and rear axles, and the wheels requiring correction are identified. When the left and right lateral forces are unbalanced, yaw or sideslip can be suppressed in advance through fine-tuning of the engine speed, providing proactive prevention rather than reactive correction. The correction amount caused by the lateral force deviation is added to the engine speed command to generate a third target engine speed, achieving a closed loop of tire force-engine speed, enabling the vehicle to maintain straight lateral movement even on complex road surfaces.

[0112] Specifically, the system obtains the wheel speed of each wheel, steering wheel angle, vehicle yaw rate, lateral acceleration, longitudinal acceleration, and vertical load on each wheel. Based on the Magic Formula tire force estimation algorithm model, it outputs the actual lateral and longitudinal force values ​​of the four tires. Combined with... Figure 3 As shown, , , , These are the longitudinal tire forces of each wheel. For the lateral tire force of each wheel, , For front and rear steering angles, The rear axle track. The yaw rate is angular velocity. The moment of inertia of the entire vehicle. These represent longitudinal and lateral accelerations, respectively. The Magic Formula tire force estimation algorithm model is pre-installed in the system.

[0113] Calculate the combined lateral force deviation of the front and rear axles, the lateral force deviation of the left and right wheels of the front axle, and the lateral force deviation of the left and right wheels of the rear axle respectively.

[0114] The formula for calculating the combined deviation of lateral forces between the front and rear axles is: F y_delta A positive value indicates that the sum of the lateral forces on the front axle is greater than that on the rear axle. Viewed from above, the vehicle appears to rotate counter-clockwise. (F) y_delta A negative value indicates that the sum of the lateral forces on the rear axle is greater than that on the front axle, and from the perspective of looking above the vehicle, the vehicle has a clockwise rotation tendency.

[0115] The formula for calculating the lateral force deviation between the left and right wheels of the front axle is: F f_delta = F f_delta A positive value indicates that the lateral force on the left front wheel is greater than that on the right front wheel, and the vehicle tends to sway to the left.

[0116] The formula for calculating the lateral force deviation between the left and right rear axle wheels is: F r_delta = F r_delta A positive value indicates that the lateral force on the left rear wheel is greater than that on the right rear wheel, and the vehicle tends to sway to the left.

[0117] In this embodiment, F is mainly used when correcting the rotational speed. y_delta This is because it directly reflects the imbalance of the vehicle's yaw moment.

[0118] Optionally, the wheels requiring correction are determined based on the numerical range of the overall lateral force deviation, including: when 0 <F y_delta When the first deviation force threshold is reached, the corrected rotational speed of the right front wheel is determined; when F y_delta When the deviation force threshold is greater than or equal to the first deviation force threshold, determine the corrected rotational speed of the left front wheel; when the second deviation force threshold is reached... <F y_delta When <0N, determine the corrected right rear wheel speed; when F y_delta When the deviation force threshold is less than or equal to the second deviation force threshold, the corrected left rear wheel speed is determined.

[0119] In this embodiment, the corrected wheel and the correction amount are determined based on the overall deviation of the lateral force, F y_delta Different wheels need to be adjusted in different ranges to generate a reverse yaw moment.

[0120] Specifically, the first deviation force threshold is 50N, and the second deviation force threshold is -50N.

[0121] When 0 <F y_delta When the torque is less than 50N, that is, the lateral force on the front axle is slightly greater than that on the rear axle, with a slight counterclockwise trend, the target wheel for correction is determined to be the right front wheel. The speed of the right front wheel is increased to generate a clockwise torque.

[0122] When F y_delta When the torque is ≥50N, that is, the lateral force on the front axle is significantly greater than that on the rear axle, and there is a strong counterclockwise trend, the target wheel for correction is determined to be the left front wheel. The speed of the left front wheel is increased to generate a clockwise torque.

[0123] When -50N <F y_delta When the torque is less than 0 N, that is, the lateral force on the rear axle is slightly greater than that on the front axle, with a slight clockwise tendency, the target wheel is determined to be the right rear wheel. The speed of the right rear wheel is increased to generate a counterclockwise torque.

[0124] When F y_delta When the torque is ≤ -50N, that is, the lateral force of the rear axle is significantly greater than that of the front axle, with a stronger clockwise tendency, the target wheel for correction is determined to be the left rear wheel. The speed of the left rear wheel is increased to generate a counterclockwise torque.

[0125] Optionally, the magnitude of the correction depends on F. y_delta The magnitude of deviation from the threshold. When |F y_delta When |>50N, let the deviation amplitude ΔF=|F y_delta |-50N;When|F y_delta When |≤50N, let the deviation amplitude ΔF=|F y_delta |

[0126] Determine the speed correction amount n based on the numerical range of the lateral force comprehensive deviation. cor,i The steps include: constructing the deviation magnitude ΔF and the speed correction amount n cor,i The mapping relationship is detailed in Table 1; based on the actual deviation range, the corresponding speed correction amount n is determined by looking up the table. cor,i The deviation magnitude ΔF is proportional to the speed correction amount. cor,i Directly proportional.

[0127]

[0128] S205, based on the vehicle's yaw rate, corrects the third target speed to obtain the fourth target speed.

[0129] Optionally, based on the vehicle's yaw rate, the third target rotational speed is corrected to obtain the fourth target rotational speed, including: obtaining the vehicle's actual yaw rate γ. act When |γ act |>γ maxIncremental PID control is used, with the change in yaw rate error as the control input, to calculate the increment Δn of the yaw correction speed. yaw (t); The increments of the yaw correction speed are accumulated to obtain the yaw correction speed value n for the current cycle. yaw (t); Based on the direction of the yaw rate, the yaw correction speed value is applied to the corresponding side wheel, and the fourth target speed is obtained by superimposing the yaw correction speed value on the third target speed.

[0130] In this embodiment, during the vehicle's lateral movement, although the yaw tendency has been suppressed through feedforward-feedback steering angle control and tire force correction, unpredictable disturbances such as sudden road surface changes and crosswinds may still cause yaw velocities exceeding the allowable range. Therefore, a closed-loop correction based on yaw rate is needed. By adjusting the speed difference between the left and right wheels, an additional yaw torque is generated, quickly controlling the yaw rate within the allowable range, for example, ±3° / s. This solution employs incremental PID control, using the change in yaw rate error as the proportional term input to achieve fast response and yaw correction without integral saturation.

[0131] Specifically, the actual yaw rate γ of the vehicle is obtained. act and the target yaw rate γ ref =0, meaning no rotation is required during lateral movement. The error in yaw rate e γ (t)=γ act γ ref =γ act The change in yaw rate error Δe γ (t)=e γ (t) e γ (t 1) The error difference between two adjacent control cycles; activation threshold γ max For example, 3° / s, when |γ act |>γ max Time-based activation correction; exit threshold γ min For example, 1° / s, when |γ act ∣<γ min The correction stops when the error occurs, and the previous correction value is latched. The increment is no longer accumulated, but the latched value can still be output until the deviation is completely eliminated.

[0132] An incremental PID control law is used to output the increment Δn of the yaw correction speed. yaw (t), instead of directly outputting the correction value. The incremental PID control formula is as follows: Δn yaw (t)=Kp×Δe γ (t)+Ki×eγ (t)+Kd×[Δe γ (t) Δe γ (t 1)];wherein: Δe γ (t) represents the difference between the current cycle error and the previous cycle error; Δe γ (t 1) is the difference between the error of the previous cycle and the error of the cycle before that; Kp, Ki, and Kd are the proportional coefficient, integral coefficient, and differential coefficient, respectively.

[0133] The increment Δn of the yaw correction speed yaw (t) is added to the correction value of the previous cycle to obtain the yaw correction speed value of the current cycle: n yaw (t)=n yaw (t-1)+Δn yaw (t), where n yaw (0) = 0, where t is the number of periods.

[0134] Optionally, based on the direction of the yaw rate, a yaw correction speed value is applied to the corresponding side wheel, and a fourth target speed is obtained by superimposing the yaw correction speed value on the third target speed, including: when γ act When the value is greater than 0, the yaw correction speed n will be adjusted. yaw (t) is applied to the right wheel, where the fourth target rotational speed n of the right front wheel is... 4,fr =n 3,fr +n yaw (t), n 3,fr The third target speed for the right front wheel; the fourth target speed for the right rear wheel, n. 4,rr =n 3,rr n yaw (t), n 3,rr The third target speed is the speed of the right rear wheel; the fourth target speeds of the left front wheel and left rear wheel remain unchanged at their respective third target speeds. In this way, increasing the speed of the right front wheel generates forward driving force, while decreasing the speed of the right rear wheel generates backward driving force, and both produce a clockwise torque about the center of gravity.

[0135] When γ act When <0, the yaw correction speed value n yaw (t) is applied to the left wheel, where the fourth target rotational speed n of the left front wheel is... 4,fl =n 3,fl +n yaw (t), n 3,fl The third target speed for the left front wheel; the fourth target speed for the left rear wheel, n. 4,rl =n 3,rl nyaw (t), n 3,rl The third target speed is the speed of the left rear wheel; the fourth target speeds of the right front wheel and the right rear wheel remain unchanged at their respective third target speeds.

[0136] Furthermore, to improve control safety and stability, the single yaw correction speed value n yaw The absolute value of (t) shall not exceed 50 rpm. The corrected fourth target speed for each wheel must not exceed the maximum safe speed of the motor. And, Δn yaw The absolute value of (t) does not exceed 10 rpm / 10ms.

[0137] Optionally, the control method further includes: adjusting the parameters in the incremental PID control, specifically including: For incremental PID control, the proportional coefficient adjustment is as follows: When the yaw rate error is greater than the first angular velocity threshold, the proportional coefficient of the incremental PID control is increased; when the yaw rate error is less than the second angular velocity threshold, the proportional coefficient of the incremental PID control is decreased. For example, when the yaw rate deviation is |e γ When (t)|>0.3° / s, the proportional coefficient is set to Kp=1.2 to quickly suppress the deviation; When the yaw rate deviation is |e γ When (t)∣<0.1° / s, the proportional coefficient is set to Kp=0.6 to avoid overshoot; When the yaw rate deviation is 0.1° / s ≤ |e γ When (t)∣≤0.3° / s, the proportionality coefficient is determined by linear interpolation.

[0138] For incremental PID control, the integral coefficient adjustment is as follows: When the duration of the yaw rate error is greater than or equal to the preset time threshold, the integral coefficient of the incremental PID control is adjusted to the preset value of the integral coefficient, and the upper limit of the integral is set.

[0139] For example, the integral term is activated only when the duration of the yaw rate deviation exceeds 20ms, and the integral coefficient is set to Ki=0.2 to eliminate long-term static deviations; and the upper limit of the integral term output is set to 5rpm to prevent integral saturation from causing excessive accumulation of control quantity.

[0140] For example, when the absolute value of the yaw rate deviation is less than 0.05° / s and lasts for more than 30ms, the integral term output is cleared to zero.

[0141] For incremental PID control, the adjustment of the derivative coefficient: When the rate of change of yaw rate error is greater than the first threshold, the derivative coefficient of the incremental PID control is adjusted to the first coefficient value; when the rate of change of yaw rate error is less than the first threshold, the derivative coefficient of the incremental PID control is adjusted to the second coefficient value, and the first coefficient value is greater than the second coefficient value.

[0142] For example, the rate of change of yaw rate deviation is calculated in real time; when the rate of change of deviation is greater than 10° / s, the differential coefficient is set to Kd=0.3 to predict the trend of deviation expansion and apply suppression in advance; when the rate of change of deviation is less than 5° / s, the differential coefficient is set to Kd=0.1 to reduce the sensitivity to small fluctuations; when the rate of change of deviation is between 5° / s and 10° / s, the differential coefficient is determined by linear interpolation.

[0143] Optionally, the control method further includes: acquiring the road surface type; and correcting the parameters of the incremental PID control according to the road surface type; wherein the parameters include proportional coefficient, integral coefficient, and derivative coefficient.

[0144] In this embodiment, the road surface types include high-adhesion roads, bumpy roads, and slippery roads. For high-adhesion roads, the parameters of the incremental PID control remain unchanged. For bumpy and slippery roads, the parameters of the incremental PID control are modified to improve the stability of the vehicle during lateral movement.

[0145] Optionally, the road surface type is determined, including: acquiring wheel speed signals from four wheels within each control cycle, calculating the slip ratio of each wheel speed relative to the vehicle reference speed; and calculating the wheel speed variation coefficient within the sliding window of each wheel speed. The wheel speed variation coefficient is calculated as: (Standard deviation of wheel speed / Mean wheel speed) × 100%. The wheel speed variation coefficient is a commonly used indicator for evaluating the intensity of wheel speed fluctuations. The window duration ranges from 500ms to 1000ms. Simultaneously, a Fast Fourier Transform is performed on the wheel speed signals to extract the dominant frequency of the fluctuations.

[0146] A road surface is considered bumpy if the wheel speed variation coefficient of any wheel is >3% and the dominant frequency of fluctuation is >15Hz for more than 200ms. A wet road surface is defined as one where the slip ratio increases rapidly (e.g., slip ratio change rate >0.02 / ms) but the vehicle's longitudinal acceleration does not increase significantly, and the estimated road adhesion coefficient is less than 0.5. A dry, smooth road surface, i.e., a high-adhesion road surface, is defined as one where the wheel speed variation coefficients of all four wheels are <1% and the dominant frequency of fluctuation is <5Hz.

[0147] Optionally, the parameters of the incremental PID control are modified, including: Under bumpy road conditions, the differential term's ability to suppress high-frequency disturbances is enhanced, while the integral term's over-response to instantaneous fluctuations is reduced. Specifically, the current value of the differential coefficient Kd is increased by 30% to enhance the suppression of yaw fluctuations caused by road bumps, effectively buffering the yaw caused by road excitation. The integral coefficient Ki is decreased by 20% to reduce the integral term's over-response to instantaneous fluctuations and prevent control variable oscillations. The proportional coefficient Kp remains unchanged.

[0148] Under slippery road conditions, the proportional coefficient Kp is appropriately increased to improve response speed, while the upper limit of the integral coefficient Ki is limited to prevent integral saturation. Specifically, the proportional coefficient Kp is increased by 15%~20% to improve the system's response speed to yaw deviation and quickly respond to attitude changes caused by a decrease in the adhesion coefficient. The integral coefficient Ki is decreased by 30% or the upper limit of the integral is limited to prevent the integral term from accumulating continuously on low-adhesion surfaces, leading to integral saturation. The differential coefficient Kd remains unchanged.

[0149] It should be noted that in this embodiment, the parameters of the aforementioned incremental PID controller are adaptively calibrated based on the scenario. As described earlier, the PID parameters are adjusted according to the magnitude and rate of change of the yaw rate error. This embodiment adds an external correction dimension based on road surface type. Both can act simultaneously, taking the most conservative result or superimposing them according to priority.

[0150] For example: First, calculate the basic values ​​of Kp, Ki, and Kd according to the adjustment rules of yaw rate; then, make a second correction to the above basic values ​​according to the road surface type, such as Kd × 1.3; finally, output the corrected parameters for incremental PID control law calculation.

[0151] Optionally, it also includes a tire stability margin monitoring mechanism: calculating the tire stability margin index using the following formula: Among them, F xi F is the longitudinal tire force of the i-th wheel. yi F is the lateral tire force of the i-th wheel. zi Let μ be the vertical load on the i-th wheel. i Let η be the road adhesion coefficient of the i-th wheel; when η i When the torque is less than a preset margin threshold, the driving torque of that wheel is reduced by fine-tuning the rotational speed. Where F... xi F yi F zi All values ​​were calculated online based on the Magic Formula or Dugoff tire model, as mentioned above. The preset margin threshold ranged from 0.15 to 0.35.

[0152] In this embodiment, during the vehicle's lateral movement, due to changes in road surface adhesion conditions and load transfer, some wheels may approach their adhesion limit, meaning the tire force approaches the maximum adhesion that the road surface can provide. When the tire enters the adhesion saturation zone, its lateral force characteristics change drastically, easily leading to sideslip or loss of control. Therefore, it is necessary to monitor the tire stability margin of each wheel in real time and actively reduce the driving torque of that wheel when the margin is insufficient, i.e., reduce the target speed, so that the tire always maintains a stable slipping state and ensures lateral movement safety.

[0153] For the i-th wheel (i=1,2,3,4 corresponding to the front left, front right, rear left, and rear right respectively), the tire stability margin index η is defined. i for ,in, μ is the total adhesion force currently acting on the tire. i F zi The maximum adhesion that the road surface can provide; ratio This represents the current adhesion utilization rate, with a value ranging from [0,1]. η i Indicates the remaining adhesion margin. η i The larger the value, the further the tire is from saturation; η i The smaller the value of η, the closer the tire is to its traction limit. i When the torque is less than a preset margin threshold, the driving torque of the wheel needs to be reduced to decrease the total tire adhesion and bring the tire back to the stable slip zone. Since motor torque is approximately proportional to speed in a steady state, torque reduction can be achieved by lowering the target speed of the wheel.

[0154] Furthermore, when η i Less than the preset margin threshold η th At that time, determine the speed optimization amount Δn i,stab = K stab ×Δη i ×n target,i Where: Δη i =η th η i K stab This is a proportionality coefficient, ranging from 0.2 to 0.5, and can be calibrated; n target,i The target speed of the wheel at present, for example, the third target speed n. 3,i The negative sign indicates a decrease in rotational speed.

[0155] The correction amount from stability margin monitoring is superimposed on the existing target speed. Since this correction may be activated simultaneously with tire force correction and yaw correction, a priority setting is required. Stability margin correction has the highest priority: when η... i <η thWhen this happens, the wheel speed is forcibly reduced to compensate for other corrections that require increased speed. For example, if yaw correction requires an increase in the speed of a certain wheel, and that wheel has insufficient margin, the increase in speed is limited or even reduced. If η i ≥η th If the margin is sufficient, the speed optimization amount is 0, and other corrections will proceed normally.

[0156] The preset margin threshold ranges from 0.15 to 0.35, and the specific values ​​include, but are not limited to, 0.15, 0.2, 0.25, and 0.35.

[0157] S206, based on the second target steering angle and the fourth target rotational speed, controls the steering actuator and each drive system to perform lateral movement.

[0158] Optionally, the control method further includes: during the lateral movement of the vehicle, assigning weights to feedforward control and feedback control quantities according to the movement stage of the lateral movement, wherein the feedforward control quantity is pre-calculated based on the target lateral movement speed and load distribution, and the feedback control quantity is calculated in real time based on the operating status information; wherein the operating stage includes the lateral movement start stage, the lateral movement stage, and the lateral movement deceleration stage.

[0159] In this embodiment, during vehicle lateral movement control, feedforward control and feedback control each have their advantages: feedforward has a fast response but relies on model accuracy; feedback has strong anti-interference capabilities but suffers from lag. To achieve optimal control performance at different stages of motion, the weights of feedforward and feedback need to be dynamically allocated. Specifically, in the initial startup phase, feedforward is dominant to quickly establish lateral movement and avoid initial yaw and response delay. In the stable movement phase, feedforward and feedback are balanced, maintaining response speed while using feedback to eliminate model errors and disturbances. At the end of deceleration, feedback is dominant to suppress yaw rebound caused by inertia and ensure a smooth stop.

[0160] In this context, the feedforward control quantity refers to the control command pre-calculated based on the target value and the vehicle model, which does not rely on real-time deviation feedback and is determined before the control command is issued. For example, in this disclosure, the feedforward control quantity includes: a first target steering angle δ. 1m First target rotational speed n 1,i Feedforward control quantity δ fedfwd The second target rotational speed n obtained by correcting for slip ratio constraint factor 2,i .

[0161] Feedback control quantity refers to a correction command calculated based on the deviation between the operating state measured by real-time sensors and the target value, relying on real-time feedback signals. For example, in this disclosure, the feedback control quantity includes: front wheel steering angle correction δ. dx Speed ​​correction amount n cor,i Yaw correction speed value n yaw (t), speed optimization amount Δni,stab。

[0162] Based on the time progression and speed changes of lateral movement, the lateral movement process is divided into three stages: the lateral movement initiation stage, the lateral movement stage, and the lateral movement deceleration stage. The initial initiation stage refers to 0-500ms after the lateral movement command is issued; the lateral movement stage refers to 500ms later, before the vehicle speed begins to decelerate; and the lateral movement deceleration stage refers to the stage after receiving a deceleration command or when the target position is about to be reached.

[0163] For example, in the initial stage of lateral movement startup, a feedforward weight W is set. ff 70%, feedback weight W fb The feedforward weight is 30%; during the steady-state shift phase, the feedforward weight W is... ff Reduced to 50%, feedback weight W fb Increase to 50%; during the deceleration phase at the end of the lateral movement, increase the feedforward weight W. ff Reduced to 30%, feedback weight W fb The weighting is increased to 70%. However, the specific weighting value for each stage is not limited to this and can be specifically calibrated based on the actual vehicle.

[0164] Among them, the feedforward weight W ff With feedback weight W fb Satisfy W ff +W fb =1. During implementation, the feedforward control quantity, as a reference command, participates fully in the final output, while the feedback control quantity is calculated according to W. fb The proportion participates in the correction, thereby realizing the feedforward weight W. ff =1 W fb The equivalent allocation. For example, taking the steering angle: δ 2m =δ 1m +δ fedfwd +W fb ×δ dx , where δ 2m The second target steering angle; the feedforward component includes: δ 1m and δ fedfwd δ 1m The first target steering angle, δ fedfwd The feedforward control variable is δ; the feedback variable is δ. dx， δ dx This is the front wheel steering angle correction amount. This ensures that the vehicle always moves towards the target lateral speed, and also allows for adjustment of the feedback correction intensity according to the stage of motion.

[0165] In some embodiments, combined with Figure 4 As shown, a method for controlling vehicle lateral movement is provided. The vehicle includes a four-wheel independent drive system and a steering actuator. The control method includes: S401 acquires vehicle operating status information and driving scenario information, and determines the target lateral movement speed based on the driving scenario information.

[0166] S402, based on the target lateral speed, determine the first target steering angle and the first target speed of each drive system respectively.

[0167] S403, during the lateral movement of the vehicle, based on the operating status information, the first target steering angle and the first target speed are optimized respectively to obtain the second target steering angle and the second target speed.

[0168] S404, based on the real-time tire force of the four wheels, corrects the second target speed to obtain the third target speed.

[0169] S405, based on the vehicle's yaw rate, corrects the third target speed to obtain the fourth target speed.

[0170] S406 controls the steering actuator and each drive system to perform lateral movement based on the second target steering angle and the fourth target rotational speed.

[0171] S407: When the intelligent driving system sends the vehicle's current position to the expected position, it controls the lateral movement parking control.

[0172] When the intelligent driving system sends the vehicle's current location to the expected location, the algorithm controls the vehicle to stop. The front and rear axle steering angles maintain the current actual steering angles, and the torque of the four distributed electric drives is controlled to return to 0 at the same time. Once the actual torque and speed of the distributed electric drives have all returned to 0, the front and rear axle steering angles are controlled to return to 0°.

[0173] In some embodiments, combined with Figure 5 As shown, a vehicle lateral movement control device is provided, including a processor 500 and a memory 501. Optionally, the device 500 may further include a communication interface 502 and a bus 503. The processor 500, communication interface 502, and memory 501 can communicate with each other via the bus 503. The communication interface 502 can be used for information transmission. The processor 500 can call logical instructions in the memory 501 to execute the vehicle lateral movement control method of the above embodiment.

[0174] Furthermore, the logic instructions in the aforementioned memory 501 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0175] The memory 501, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 500 executes functional applications and data processing by running the program instructions / modules stored in the memory 501, thereby implementing the vehicle lateral movement control method in the above embodiments.

[0176] The memory 501 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function. The data storage area may store data created based on the use of the terminal device. Furthermore, the memory 501 may include high-speed random access memory and may also include non-volatile memory.

[0177] In some embodiments, a vehicle is provided, including: a vehicle body; and a vehicle lateral movement control device as described in any of the above embodiments, disposed on the vehicle body.

[0178] In some embodiments, a computer-readable storage medium is provided storing program instructions that, when executed, cause a computer to perform the vehicle lateral movement control method as described in any of the above embodiments.

[0179] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, such as a USB flash drive, external hard drive, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, etc., and other media capable of storing program code.

[0180] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0181] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0182] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling the lateral movement of a vehicle, characterized in that, The vehicle includes a four-wheel independent drive system and steering actuators, and the control methods include: Acquire vehicle operating status information and driving scenario information, and determine the target lateral movement speed based on the driving scenario information; Based on the target lateral speed, determine the first target steering angle and the first target speed of each drive system respectively; During the lateral movement of the vehicle, based on the operating status information, the first target steering angle and the first target speed are optimized respectively to obtain the second target steering angle and the second target speed; Based on the real-time tire force of the four wheels, the second target speed is corrected to obtain the third target speed; and based on the yaw rate of the vehicle, the third target speed is corrected to obtain the fourth target speed. Based on the second target steering angle and the fourth target rotational speed, the steering actuator and each drive system are controlled to perform lateral movement.

2. The vehicle lateral movement control method according to claim 1, characterized in that, The step of determining the first target steering angle based on the target lateral speed includes: The initial target turning angle is obtained through nonlinear mapping based on the target lateral speed. Obtain the vertical load of each wheel, and determine the first correction factor based on the vertical load distribution ratio of each wheel. The initial target turning angle is corrected using the first correction factor to obtain the first target turning angle.

3. The vehicle lateral movement control method according to claim 1, characterized in that, The step of determining the first target speed of each drive system based on the target lateral vehicle speed includes: Based on the target lateral speed and the first target steering angle, the initial target rotational speed of each drive system is obtained through a kinematic model; Obtain the vertical load of each wheel, and determine the second correction factor based on the vertical load distribution ratio of each wheel; The initial target speed is corrected using a second correction factor to obtain the first target speed.

4. The vehicle lateral movement control method according to claim 1, characterized in that, Based on operational status feedback information, the first target steering angle is optimized to obtain the second target steering angle, including: Obtain the vertical load on each wheel and the longitudinal acceleration of the vehicle; Based on the vertical load of each wheel, the offset of the vehicle's center of gravity and the trend value of inertial displacement are calculated using a load-acceleration coupling model. The feedforward control quantity is determined based on the vehicle body center of gravity offset and inertial displacement trend value; The longitudinal displacement deviation of the vehicle is obtained, and the front wheel steering angle correction is calculated based on the longitudinal displacement deviation using a PID control algorithm. The second target steering angle is obtained by superimposing the first target steering angle, the feedforward control quantity, and the front wheel steering angle correction quantity.

5. The vehicle lateral movement control method according to claim 4, characterized in that, The PID control algorithm is used to calculate the front wheel steering angle correction based on the longitudinal displacement deviation, including: The calculation formula used is: ; Where, δ dx d is the front wheel steering angle correction amount. xerr K represents the longitudinal displacement deviation value. p K is the proportionality coefficient. i K is the integral coefficient. d These are the differential coefficients; K is determined based on the longitudinal displacement deviation, longitudinal acceleration, and load difference between the left and right wheels. p K i and K d .

6. The vehicle lateral movement control method according to any one of claims 1 to 5, characterized in that, Based on the operational status feedback information, the first target speed is optimized to obtain the second target speed, including: The slip ratio constraint factor K was calculated using a weighted multiplication model. w ; According to the slip ratio limiting factor K w The first target speed of each drive system is optimized to obtain the second target speed of each drive system.

7. The vehicle lateral movement control method according to claim 6, characterized in that, The weighted multiplication model is as follows: ; Among them, K v,i K is the coefficient for the lateral speed deviation. μ,i K is a sub-coefficient of road surface adhesion coefficient. γ,i The coefficients for the optimal slip ratio correction are α, β, and γ, which are weighting coefficients and α+β+γ=1. i is the wheel number, i=1~4, corresponding to the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively.

8. The vehicle lateral movement control method according to any one of claims 1 to 5, characterized in that, Based on the real-time tire forces of the four wheels, the second target speed is corrected to obtain the third target speed, including: Obtain the lateral tire force of each wheel, which is F. y1 F y2、 F y3、 F y4 F y1 For the lateral tire force of the left front wheel, F y2 For the lateral tire force of the right front wheel, F y3 For the lateral tire force of the left rear wheel, F y4 The lateral force on the right rear wheel; Calculate the overall deviation of lateral force ; Based on the numerical range of the overall deviation of the lateral force, determine the wheel and speed correction amount that needs to be corrected; The speed correction amount is superimposed on the second target speed to generate the third target speed.

9. The vehicle lateral movement control method according to claim 8, characterized in that, Based on the numerical range of the overall deviation of lateral force, determine the wheels that need correction, including: When 0 <F y_delta When the first deviation force threshold is reached, determine the corrected rotational speed of the right front wheel; When F y_delta When the deviation force threshold is greater than or equal to the first deviation force threshold, determine the speed of the left front wheel to be corrected; When the second deviation force threshold <F y_delta When <0N, determine the corrected right rear wheel speed; When F y_delta When the deviation force threshold is less than or equal to the second deviation force threshold, the corrected left rear wheel speed is determined.

10. The vehicle lateral movement control method according to any one of claims 1 to 5, characterized in that, Based on the vehicle's yaw rate, the third target speed is corrected to obtain the fourth target speed, which includes: Obtain the vehicle's actual yaw rate γ act ; When |γ act |>γ max Incremental PID control is used, with the change in yaw rate error as the control input, to calculate the increment Δn of the yaw correction speed. yaw (t); The increments of the yaw correction speed are summed to obtain the yaw correction speed value n for the current cycle. yaw (t); Based on the direction of the yaw rate, the yaw correction speed value is applied to the corresponding side wheel. The fourth target speed is obtained by superimposing the yaw correction speed value on the third target speed.

11. The vehicle lateral movement control method according to claim 10, characterized in that, Based on the direction of the yaw rate, a yaw correction speed value is applied to the corresponding side wheel. The fourth target speed is obtained by superimposing the yaw correction speed value on top of the third target speed, including: When γ act When the value is greater than 0, the yaw correction speed n will be adjusted. yaw (t) is applied to the right wheel, where the fourth target rotational speed n of the right front wheel is... 4,fr =n 3,fr +n yaw (t), n 3,fr The third target speed for the right front wheel; the fourth target speed for the right rear wheel, n. 4,rr =n 3,rr n yaw (t), n 3,rr The third target speed is the speed of the right rear wheel; the fourth target speeds of the left front wheel and the left rear wheel remain unchanged at their respective third target speeds. When γ act When <0, the yaw correction speed value n yaw (t) is applied to the left wheel, where the fourth target rotational speed n of the left front wheel is... 4,fl =n 3,fl +n yaw (t), n 3,fl The third target speed for the left front wheel; the fourth target speed for the left rear wheel, n. 4,rl =n 3,rl n yaw (t), n 3,rl The third target speed is the speed of the left rear wheel; the fourth target speeds of the right front wheel and the right rear wheel remain unchanged at their respective third target speeds.

12. The vehicle lateral movement control method according to claim 10, characterized in that, The parameters of incremental PID control include proportional coefficient, integral coefficient, and derivative coefficient. The control method also includes: When the yaw rate error is greater than the first angular velocity threshold, increase the proportional coefficient of the incremental PID control. When the yaw rate error is less than the second angular velocity threshold, reduce the proportional coefficient of the incremental PID control. When the duration of the yaw rate error is greater than or equal to the preset time threshold, the integral coefficient of the incremental PID control is adjusted to the preset value of the integral coefficient, and the upper limit of the integral is set. When the rate of change of yaw rate error is greater than the first change threshold, adjust the derivative coefficient of the incremental PID control to the first coefficient value. When the rate of change of yaw rate error is less than the first change threshold, the derivative coefficient of the incremental PID control is adjusted to the second coefficient value, and the first coefficient value is greater than the second coefficient value.

13. The vehicle lateral movement control method according to claim 10, characterized in that, Also includes: Get the road surface type; The parameters of the incremental PID control are modified according to the road surface type; these parameters include the proportional coefficient, integral coefficient, and derivative coefficient.

14. The vehicle lateral movement control method according to any one of claims 1 to 5, characterized in that, Also includes: During the lateral movement of the vehicle, the weights of the feedforward control quantity and the feedback control quantity are allocated according to the movement stage of the lateral movement. The feedforward control quantity is pre-calculated based on the target lateral speed and load distribution, while the feedback control quantity is calculated in real time based on the operating status information. The operation phase includes the lateral movement start-up phase, the lateral movement phase, and the lateral movement deceleration phase.

15. A vehicle lateral movement control device, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute the vehicle lateral movement control method as described in any one of claims 1 to 14 when executing the program instructions.

16. A vehicle, characterized in that, include: Vehicle body; The vehicle lateral movement control device as described in claim 15 is disposed on the vehicle body.

17. A computer-readable storage medium storing program instructions, characterized in that, When the program instructions are executed, they cause the computer to perform the vehicle lateral movement control method as described in any one of claims 1 to 14.

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