Vehicle wheel rotation angle adjusting method, vehicle and storage medium

Abstract

The embodiment of the invention provides a wheel turning angle adjusting method of a vehicle, the vehicle and a storage medium, and relates to the technical field of vehicles. The method comprises the steps that in response to the condition that state information of a vehicle meets a preset condition, a rear wheel steering system auxiliary control function of the vehicle is started; when the auxiliary control function of the rear wheel steering system is in the starting state, the first weight of the rear wheel steering system, the second weight of the electronic stability control system and an operation strategy are determined based on the yaw velocity deviation of the vehicle; a rear wheel steering system and an electronic stability control system are operated according to the operation strategy, and in the operation process, the target rear wheel steering angle of the vehicle is determined based on the wheel slip rate and the first weight of the vehicle; a rear wheel steering angle of the vehicle is adjusted to the target rear wheel steering angle based on the execution constraint. The technical problems that in the prior art, braking intervention only depends on ESC, the yaw moment compensation capacity is limited, and energy loss is high are solved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of vehicles, in particular to a wheel steering angle adjustment method of a vehicle, a vehicle and a storage medium. BACKGROUND

[0002] In the field of vehicle dynamics control, the intelligent evolution of steering, braking and driving systems has made it not only limited to executing user instructions, but also derived active control functions such as Anti-lock Braking System (ABS), Electronic Stability Control (ESC) and Traction Control System (TCS), which significantly improve driving safety and performance. The above functions effectively control the longitudinal and lateral dynamics of the vehicle by precisely adjusting braking force, torque, etc.

[0003] However, current lateral control mainly relies on the braking intervention of ESC, so there are problems of limited yaw moment compensation ability and high energy loss, especially in extreme conditions.

[0004] There is currently no good solution to the above problems. SUMMARY

[0005] Embodiments of the present application provide a wheel steering angle adjustment method of a vehicle, a vehicle and a storage medium to at least solve the technical problem in the related art that only relying on braking intervention of ESC results in limited yaw moment compensation ability and high energy loss.

[0006] According to an aspect of embodiments of the present application, a wheel steering angle adjustment method of a vehicle is provided, comprising: in response to state information of the vehicle satisfying a preset condition, starting an auxiliary control function of a rear wheel steering system of the vehicle, wherein the state information is used to reflect a driving attribute of the vehicle; when the auxiliary control function of the rear wheel steering system is in a started state, determining a first weight of the rear wheel steering system, a second weight of an electronic stability control system and a running strategy based on a yaw rate deviation of the vehicle, wherein the running strategy is used to adjust the intervention degree of the rear wheel steering system and the electronic stability control system on the yaw rate deviation of the vehicle; running the rear wheel steering system and the electronic stability control system according to the running strategy, and in the running process, determining a target rear wheel steering angle of the vehicle based on a wheel slip ratio of the vehicle and the first weight; adjusting the rear wheel steering angle of the vehicle to the target rear wheel steering angle based on execution constraints, wherein the execution constraints are used to limit the adjustment range of the rear wheel steering angle.

[0007] Further, the method further comprises: obtaining initial state information of the vehicle; performing noise reduction processing on the initial state information to obtain first state information; eliminating invalid data in the first state information to obtain state information, wherein the state information comprises wheel speed, steering wheel angle and yaw rate.

[0008] Further, the method further comprises: determining vehicle speed based on the wheel speed; determining a yaw rate gradient based on the yaw rate; in response to the vehicle speed being greater than a first threshold value, the steering wheel angle being less than a second threshold value, and the yaw rate gradient being greater than or equal to a third threshold value, determining that the state information satisfies a preset condition.

[0009] Further, based on the yaw rate deviation of the vehicle, determining the first weight of the rear wheel steering system, the second weight of the electronic stability control system and the running strategy comprises: in response to the absolute value of the yaw rate deviation being less than or equal to a third threshold value, determining the first weight, the second weight and a first running strategy, wherein the first weight is a first numerical value, the second weight is a second numerical value, the first numerical value is greater than the second numerical value, and the first running strategy is used to independently run the rear wheel steering system.

[0010] Further, based on the yaw rate deviation of the vehicle, determining the first weight of the rear wheel steering system, the second weight of the electronic stability control system and the running strategy further comprises: in response to the absolute value being greater than the third threshold value and less than or equal to a fourth threshold value, determining the first weight, the second weight and a second running strategy, wherein the first weight is greater than the second weight, the first weight is less than the first numerical value, the second weight is greater than the second numerical value, the second running strategy is used to control the rear wheel steering system to output yaw moment and control the electronic stability control system to assist in suppressing the yaw rate deviation; in response to the absolute value being greater than the fourth threshold value, determining the first weight, the second weight and a third running strategy, wherein the first weight is less than the second weight, the first weight is less than the first numerical value, the second weight is greater than the second numerical value, and the third running strategy is used to control the electronic stability control system to output yaw moment and control the rear wheel steering system to assist in suppressing the yaw rate deviation.

[0011] Further, based on the yaw rate deviation of the vehicle, determining the first weight of the rear wheel steering system, the second weight of the electronic stability control system and the running strategy further comprises: in response to the absolute value being less than a fifth threshold value and the steering wheel angle being less than a sixth threshold value, exiting the running of the rear wheel steering system and the electronic stability control system, wherein the fifth threshold value is less than the third threshold value.

[0012] Further, based on the wheel slip ratio of the vehicle and the first weight, determining a target rear wheel steering angle of the vehicle comprises: determining the wheel slip ratio based on the wheel speed and the vehicle speed; determining the target rear wheel steering angle based on the yaw rate deviation, the wheel slip ratio and the first weight.

[0013] Furthermore, adjusting the rear wheel angle of the vehicle to the target rear wheel angle based on the execution constraints includes: generating control commands based on the execution constraints, the rear wheel angle, and the target rear wheel angle; and controlling the execution motor to adjust the output of the execution motor through the first feedback control of the position loop and the second feedback control of the speed loop according to the control commands, until the rear wheel angle is adjusted to the target rear wheel angle.

[0014] According to another aspect of the embodiments of this application, a vehicle wheel angle adjustment device is also provided, comprising: an activation module, configured to activate the rear wheel steering system auxiliary control function of the vehicle in response to the vehicle's state information satisfying preset conditions, wherein the state information is used to reflect the vehicle's driving attributes; a determination module, configured to determine a first weight of the rear wheel steering system, a second weight of the electronic stability control system, and an operating strategy based on the vehicle's yaw rate deviation when the rear wheel steering system auxiliary control function is activated, wherein the operating strategy is used to adjust the degree of intervention of the rear wheel steering system and the electronic stability control system on the vehicle's yaw rate deviation; an operating module, configured to operate the rear wheel steering system and the electronic stability control system according to the operating strategy, and determine the target rear wheel angle of the vehicle based on the vehicle's wheel slip ratio and the first weight during operation; and an adjustment module, configured to adjust the vehicle's rear wheel angle to the target rear wheel angle based on execution constraints, wherein the execution constraints are used to limit the adjustment range of the rear wheel angle.

[0015] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0016] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0017] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0018] In this embodiment, the rear-wheel steering system auxiliary control function is activated in response to the vehicle's state information meeting preset conditions. The state information reflects the vehicle's driving attributes. With the rear-wheel steering system auxiliary control function activated, a first weight for the rear-wheel steering system, a second weight for the electronic stability control system, and an operating strategy are determined based on the vehicle's yaw rate deviation. The operating strategy adjusts the degree of intervention of the rear-wheel steering system and the electronic stability control system on the vehicle's yaw rate deviation. The rear-wheel steering system and the electronic stability control system are operated according to the operating strategy. During operation, the target rear-wheel steering angle is determined based on the vehicle's wheel slip ratio and the first weight. The rear-wheel steering angle is adjusted to the target rear-wheel steering angle based on execution constraints, which limit the adjustment range of the rear-wheel steering angle. This achieves the goal of precise control of the vehicle's lateral dynamics based on RWS and ESC, thereby realizing efficient compensation of yaw moment and reducing energy loss. This solves the technical problems in related technologies where relying solely on ESC braking intervention results in limited yaw moment compensation capability and high energy loss. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a flowchart of a method for adjusting the wheel angle of a vehicle according to one embodiment of this application;

[0021] Figure 2 This is a flowchart of the lateral control of the rear wheel steering system according to one embodiment of this application;

[0022] Figure 3 This is a schematic diagram of test data according to one embodiment of this application;

[0023] Figure 4 This is a structural block diagram of a vehicle wheel angle adjustment device according to one embodiment of this application. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application 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 so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] According to an embodiment of this application, a method embodiment for adjusting the wheel angle of a vehicle is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0027] This embodiment provides a method for adjusting the wheel angle of a vehicle. Figure 1 This is a flowchart of a vehicle wheel angle adjustment method according to one embodiment of this application, such as... Figure 1 As shown, the process includes the following steps:

[0028] Step S11: In response to the vehicle's status information meeting preset conditions, the rear wheel steering system auxiliary control function of the vehicle is activated, wherein the status information is used to reflect the vehicle's driving attributes.

[0029] In this embodiment of the application, the vehicle status information refers to data collected in real time that reflects the vehicle's driving attributes, such as wheel speed, steering wheel angle, yaw rate, etc.

[0030] The preset conditions are used to determine whether to activate the rear-wheel steering system auxiliary control function, based on vehicle status information, such as a yaw rate gradient ≥ 8 degrees per second squared (° / s). 2 If the vehicle speed is greater than 10 km / h (kph), it means that the status information meets the preset conditions and the rear wheel steering system auxiliary control function of the vehicle can be activated.

[0031] As can be seen, in this application, when the real-time status information of the vehicle meets the preset conditions of the system, the rear-wheel steering system auxiliary control function will be activated. The timing of the activation of the rear-wheel steering system auxiliary control function ensures that the system can respond quickly in emergency or complex road conditions requiring additional lateral control, thereby improving vehicle stability and safety.

[0032] Therefore, this application avoids unnecessary system intervention by accurately identifying and responding to the vehicle's needs under specific operating conditions, while ensuring that the rear wheel steering system can be activated in a timely manner when lateral dynamic control is required, thereby improving control efficiency.

[0033] Step S12: With the rear wheel steering system auxiliary control function in the active state, based on the vehicle's yaw rate deviation, determine the first weight of the rear wheel steering system, the second weight of the electronic stability control system, and the operating strategy. The operating strategy is used to adjust the degree of intervention of the rear wheel steering system and the electronic stability control system on the vehicle's yaw rate deviation.

[0034] In this embodiment of the application, the yaw rate deviation refers to the difference between the actual yaw rate of the vehicle and the target or expected yaw rate.

[0035] The first weight is the relative importance or contribution of the rear wheel steering system (RWS) to lateral control, and the second weight is the relative importance or contribution of the electronic stability control system to lateral control.

[0036] The operating strategy is a method to dynamically adjust the intervention levels of RWS and ESC based on the vehicle's current state and control objectives. For example, the operating strategy is used to determine which system plays a dominant role under the current operating conditions, and how the two systems work together to optimize yaw rate tracking and control.

[0037] As can be seen, this application dynamically allocates the corresponding control weights of RWS and ESC based on the magnitude of the yaw rate deviation and formulates corresponding operating strategies. Therefore, this application proposes a lateral control strategy that coordinates RWS and ESC by introducing RWS. Specifically, by intelligently adjusting the control weights and operating strategies of the two systems, the characteristics of each system are effectively utilized to achieve more efficient and precise lateral dynamic control. At the same time, it reduces the risk of overuse of a single system and improves the flexibility and adaptability of the overall control strategy.

[0038] Step S13: Operate the rear wheel steering system and electronic stability control system according to the operating strategy, and determine the target rear wheel steering angle of the vehicle based on the vehicle's wheel slip ratio and first weight during operation.

[0039] In this embodiment of the application, wheel slip ratio refers to the degree of difference between the actual wheel speed and the vehicle speed.

[0040] The target rear wheel steering angle refers to the steering angle that the rear wheels need to achieve in order to realize the expected yaw rate tracking performance.

[0041] As can be seen, in this application, the RWS and ESC will be controlled to start running according to the aforementioned determined operating strategy. During the operation, the current wheel slip ratio and the weight coefficient of RWS will be comprehensively considered to calculate the target rear wheel steering angle, so as to ensure optimal tracking of yaw rate.

[0042] Therefore, by accurately calculating the target rear wheel steering angle, this application enables the system to adjust the rear wheel steering more precisely based on the vehicle's real-time status and yaw rate deviation, thereby enhancing the vehicle's lateral stability under complex road conditions and reducing the occurrence of oversteer or understeer.

[0043] Step S14: Adjust the rear wheel angle of the vehicle to the target rear wheel angle based on the execution constraints, wherein the execution constraints are used to limit the adjustment range of the rear wheel angle.

[0044] In this embodiment of the application, the execution constraint refers to the limiting conditions set on the adjustment range and rate of the rear wheel steering angle to ensure the safe and efficient operation of the system.

[0045] As can be seen, in this application, during the process of the actuator adjusting the rear wheel angle to achieve the target rear wheel angle, the output of the actuator (such as a motor) is limited based on the execution constraints, such as the rear wheel angle amplitude limit (±5°) and the rate of change limit (≤50° / s), thereby ensuring that the steering adjustment is both rapid and does not exceed the limits of safety or mechanical performance.

[0046] Therefore, by implementing execution constraints, this application enables the system to safely and smoothly adjust the rear wheel angle, avoiding vehicle dynamic instability caused by over-adjustment, while reducing wear on mechanical parts and improving the service life and reliability of the steering system.

[0047] In summary, this application proposes a coordinated control strategy for the rear-wheel steering (RWS) and electronic stability control (ESC). During strategy operation, the control weights of RWS and ESC are dynamically adjusted based on the vehicle's yaw rate deviation, enabling the two systems to work collaboratively. This optimizes yaw rate tracking performance and achieves efficient yaw moment compensation. Furthermore, during strategy operation, this application calculates the target rear wheel angle in real time by combining wheel slip ratio and the first weight, allowing RWS to respond more accurately to vehicle dynamics and reducing the risk of oversteer or understeer. During steering execution, execution constraints are followed to ensure that RWS adjusts the vehicle's rear wheel angle quickly and safely, avoiding vehicle instability and mechanical wear that may be caused by excessive operation. Moreover, compared to single braking intervention, this collaborative control strategy effectively reduces the frequency of active ESC control, thus reducing energy consumption.

[0048] The above steps of this application, in response to the vehicle's state information meeting preset conditions, activate the rear-wheel steering system auxiliary control function, where the state information reflects the vehicle's driving attributes. With the rear-wheel steering system auxiliary control function activated, based on the vehicle's yaw rate deviation, determine the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and an operating strategy. The operating strategy adjusts the degree of intervention of the rear-wheel steering system and the electronic stability control system on the vehicle's yaw rate deviation. The rear-wheel steering system and the electronic stability control system operate according to the operating strategy, and during operation, based on the vehicle's wheel slip ratio and the first weight, determine the vehicle's target rear-wheel steering angle. Based on execution constraints, the vehicle's rear-wheel steering angle is adjusted to the target rear-wheel steering angle, where the execution constraints limit the adjustment range of the rear-wheel steering angle. Thus, the goal of precisely controlling the vehicle's lateral dynamics based on RWS and ESC is achieved, thereby realizing efficient compensation of yaw moment and reducing energy loss. This solves the technical problems of related technologies that rely solely on ESC braking intervention, resulting in limited yaw moment compensation capability and high energy loss.

[0049] Optionally, the method may further include the following execution steps:

[0050] Step S100: Obtain the initial state information of the vehicle.

[0051] Step S101: Perform noise reduction processing on the initial state information to obtain the first state information.

[0052] Step S102: Remove invalid data from the first state information to obtain state information, which includes wheel speed, steering wheel angle and yaw rate.

[0053] In this embodiment of the application, the initial state information of the vehicle will also be obtained, such as the initial four-wheel wheel speeds collected by the wheel speed sensor, the initial steering wheel angle collected by the steering wheel angle sensor, and the initial yaw rate collected by the yaw rate sensor, etc., to reflect the current operating state of the vehicle.

[0054] Then, the initial state information is denoised to obtain the first state information. The denoising process refers to using signal processing techniques (such as Kalman filtering) to remove or reduce random noise in the signal, thereby improving the signal purity and signal-to-noise ratio.

[0055] As can be seen, after collecting the initial state information of the vehicle, noise reduction algorithms such as Kalman filtering are used to preprocess the initial state information, eliminate noise introduced by sensors or environmental factors, and obtain purer state data, namely the first state information, thereby ensuring that subsequent decisions are based on more reliable data.

[0056] Finally, invalid data in the first state information is removed to obtain the state information. Invalid data refers to data that is outside the normal operating range or is considered abnormal, such as erroneous readings caused by sensor malfunctions, or data points where wheel speed changes exceed the 20% threshold.

[0057] As can be seen, after noise reduction, invalid data in the first state information will be further identified and removed, and only valid data will be retained to obtain the final state information, providing a precise basis for subsequent control decisions.

[0058] Therefore, by preprocessing the data collected by the sensors to remove noise and invalid data, clean and reliable status information is obtained. This provides high-quality data support for the lateral dynamic control strategy of RWS and ESC working together.

[0059] Optionally, the method may further include the following execution steps:

[0060] Step S103: Determine the vehicle speed based on the wheel speed.

[0061] Step S104: Determine the yaw rate gradient based on the yaw rate.

[0062] Step S105: In response to the vehicle speed being greater than the first threshold, the steering wheel angle being less than the second threshold, and the yaw rate gradient being greater than or equal to the third threshold, it is determined that the state information meets the preset conditions.

[0063] In this embodiment of the application, wheel speed refers to the speed at which each wheel rotates when the vehicle is in motion, which is usually monitored in real time by a wheel speed sensor.

[0064] Vehicle speed refers to the actual forward speed of the vehicle, which is calculated by comprehensively analyzing the speeds of the four wheels.

[0065] Yaw rate refers to the rotational speed of a vehicle around its vertical axis when it turns or changes direction. It is usually measured by a yaw rate sensor mounted on the vehicle chassis.

[0066] The yaw rate gradient, or the rate of change of yaw rate over time, is a key indicator describing the stability of a vehicle's yaw motion and is used to determine whether a lateral dynamic control strategy needs to be activated. It is obtained by differentiating the yaw rate.

[0067] For example, after obtaining the wheel speeds from the four-wheel speed sensors, mathematical models or algorithms, such as average wheel speed calculation and maximum speed wheel speed determination, can be used to comprehensively analyze and calculate the vehicle's current actual driving speed, i.e., the vehicle speed. Simultaneously, the yaw rate data obtained from the yaw rate sensor will be processed by differentiation to calculate the rate of change of the yaw rate, i.e., the yaw rate gradient.

[0068] Then, the relationship between vehicle speed and the first threshold, the relationship between steering wheel angle and the second threshold, and the relationship between yaw rate gradient and the third threshold are determined. If the steering wheel angle is less than the second threshold, and the yaw rate gradient is greater than or equal to the third threshold, the state information is determined to meet the preset conditions.

[0069] For example, if the vehicle speed is >10 kph, the steering wheel angle is <10 degrees (°), and the yaw rate gradient is ≥8° / s 2 If the status information meets the preset conditions, the rear wheel steering system auxiliary control function of the vehicle will be activated.

[0070] Therefore, by judging the relationship between the state information and the corresponding threshold, the control strategy is ensured to be activated in a timely manner when the vehicle is in a potentially unstable state but has not entered a severely out-of-control state, avoiding unnecessary control intervention, while ensuring a rapid response when needed, thus improving the pertinence and effectiveness of the control strategy.

[0071] Optionally, in step S12, determining the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the vehicle's yaw rate deviation may include the following execution steps:

[0072] Step S121: In response to the absolute value of the yaw rate deviation being less than or equal to a third threshold, a first weight, a second weight, and a first operating strategy are determined, wherein the first weight is a first value, the second weight is a second value, the first value is greater than the second value, and the first operating strategy is used to independently operate the rear wheel steering system.

[0073] In this embodiment, the yaw rate deviation refers to the difference between the actual yaw rate of the vehicle and the target yaw rate, and is used to evaluate the lateral dynamic stability of the vehicle.

[0074] The first weight refers to the relative control effort undertaken by the rear wheel steering system (RWS) in controlling the yaw rate deviation. For example, the first value is 1.

[0075] The second weight refers to the relative control effort undertaken by the Electronic Stability Control (ESC) system in controlling the yaw rate deviation. For example, the second value is 0.

[0076] The third threshold is a critical value used to determine whether the vehicle's yaw rate deviation is within a range that can be independently controlled by the rear-wheel steering system. For example, the third threshold is 5° / s.

[0077] The first operating strategy is used to independently operate the rear-wheel steering system. Specifically, it is a vehicle lateral dynamic control strategy under low yaw rate deviation conditions, focusing on independent control of the rear-wheel steering system to reduce energy consumption and improve response speed. In other words, the first operating strategy is used during the initial response phase (e.g., 0-40ms), prioritizing rapid compensation of yaw deviation with rear-wheel steering.

[0078] It can be seen that when determining the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the vehicle's yaw rate deviation, the first weight, second weight, and operating strategy can be determined according to the absolute value of the yaw rate deviation. Specifically, if the absolute value of the yaw rate deviation is less than or equal to a third threshold, the first weight is determined to be 1, the second weight to be 0, and the first operating strategy is determined, meaning the rear-wheel steering system assumes the primary control responsibility, while the electronic stability control system is in an auxiliary state. By independently operating the rear-wheel steering system, the yaw rate deviation can be compensated in a fast and low-energy manner.

[0079] Therefore, since the rear-wheel steering (RWS) system responds faster than the electronic stability control (ESC) system, independent operation of the RWS can quickly correct slight yaw rate deviations, improving the vehicle's lateral dynamic response. Compared to frequent ESC braking intervention, independent RWS operation reduces energy loss, especially under low deviation conditions, avoiding unnecessary braking energy conversion and mechanical wear. Furthermore, by reducing the frequency of ESC braking intervention, it reduces potential steering wheel backlash during braking, improving driving comfort and safety.

[0080] Optionally, in step S12, determining the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the vehicle's yaw rate deviation may further include the following execution steps:

[0081] Step S122: In response to the absolute value being greater than the third threshold and less than or equal to the fourth threshold, determine the first weight, the second weight, and the second operating strategy, wherein the first weight is greater than the second weight, the first weight is less than the first value, the second weight is greater than the second value, and the second operating strategy is used to control the output yaw moment of the rear wheel steering system and to control the electronic stability control system to assist in suppressing the yaw rate deviation.

[0082] Step S123: In response to the absolute value being greater than the fourth threshold, determine the first weight, the second weight, and the third operating strategy, wherein the first weight is less than the second weight, the first weight is less than the first value, the second weight is greater than the second value, and the third operating strategy is used to control the output yaw moment of the electronic stability control system and to control the rear wheel steering system to assist in suppressing the yaw rate deviation.

[0083] In this embodiment, the fourth threshold is a critical value used to define a vehicle as being in a state of high yaw rate deviation. For example, the fourth threshold is 15° / s.

[0084] The second operating strategy is used to control the output yaw moment of the rear wheel steering system and to control the electronic stability control system to assist in suppressing yaw rate deviation. That is, the second operating strategy is a control strategy in which RWS and ESC work together when the vehicle yaw rate deviation is between the third and fourth thresholds, with RWS as the main force and ESC as the auxiliary force, to jointly suppress yaw rate deviation.

[0085] The third operating strategy is used to control the output yaw moment of the electronic stability control system and to control the rear wheel steering system to assist in suppressing yaw rate deviation. That is, when the vehicle yaw rate deviation exceeds the fourth threshold, the third operating strategy is a high-performance control strategy with ESC as the main control means and RWS as an auxiliary means.

[0086] It can be seen that if the absolute value of the yaw rate deviation is greater than the third threshold and less than or equal to the fourth threshold, then the first weight is determined to be, for example, 0.7, the second weight is determined to be, for example, 0.3, and the second operating strategy is determined. That is, RWS still assumes the main control responsibility, while ESC intervenes as an auxiliary control means. The yaw torque is output by RWS, and ESC helps to suppress the yaw deviation, forming a composite control scheme.

[0087] Therefore, under moderate deviation conditions, the coordinated control of RWS and ESC provides greater yaw moment compensation compared to single-system control, improving the system's ability to control the vehicle's lateral dynamics. Furthermore, the dynamically allocated weights allow the system to flexibly adjust control methods according to the degree of deviation, achieving a more refined control strategy and optimizing the vehicle's lateral dynamic response.

[0088] If the absolute value of the yaw rate deviation is greater than the fourth threshold, then the first weight is determined to be, for example, 0.4, the second weight is determined to be, for example, 0.6, and the third operating strategy is determined, that is, ESC assumes the main control responsibility and generates yaw moment through rapid and high-intensity braking intervention, while RWS assists in improving vehicle stability under the guidance of ESC.

[0089] Therefore, under extreme conditions, this application utilizes ESC's rapid braking to quickly generate the required yaw moment, effectively suppressing oversteer or understeer and improving vehicle control in emergency situations. Simultaneously, RWS (Road Stability Management) enhances stability. Thus, through the rational division of labor between ESC and RWS, the system can quickly stabilize the vehicle's lateral dynamics under high deviation conditions, reducing the risk of loss of control and enhancing driving safety. Furthermore, under high deviation conditions, the rapid response of the automatic control strategy reduces the need for emergency corrections by the driver, improving both the driving experience and safety.

[0090] For example, the second and third operating strategies are operating strategies during the dynamic compensation phase (e.g., 40ms-80ms). If the deviation does not converge, ESC braking intervention is initiated to form a compound yaw moment.

[0091] Optionally, in step S12, determining the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the vehicle's yaw rate deviation may further include the following execution steps:

[0092] Step S124: In response to the absolute value being less than the fifth threshold and the steering wheel angle being less than the sixth threshold, the operation of the rear wheel steering system and the electronic stability control system is discontinued, wherein the fifth threshold is less than the third threshold.

[0093] In this embodiment, the fifth threshold is used to determine whether the vehicle's yaw rate deviation is within a sufficiently small range to safely disengage the active control of the rear-wheel steering system and the electronic stability control system. For example, the fifth threshold is 2° / s. Since the fifth threshold is less than the third threshold, the deviation within the range of the fifth threshold can be naturally adjusted by the vehicle's own mechanical characteristics and driver operation.

[0094] The sixth threshold is used to determine whether the steering wheel angle is at a slight angle, indicating that the driver is gently correcting the vehicle's trajectory without the need for additional active control system intervention. For example, the sixth threshold is 5°.

[0095] Disabling the rear-wheel steering system and electronic stability control system means stopping the active control functions of RWS and ESC, allowing the vehicle to return to a normal passive control state, with the driver directly controlling the vehicle.

[0096] It can be seen that if the absolute value of the yaw rate deviation is less than the fifth threshold and the steering wheel angle is less than the sixth threshold, it indicates that the vehicle has returned to a relatively stable driving state, and the driver is making slight steering wheel corrections without significant yaw or steering abnormalities. In this case, the system will disengage the rear-wheel steering system and electronic stability control system, allowing the vehicle to continue driving without active control, thereby saving energy and reducing unnecessary load on the control system.

[0097] Therefore, when the vehicle's state becomes stable, disengaging the active control strategy can effectively reduce energy consumption, improve the vehicle's energy efficiency ratio, reduce the burden on the rear-wheel steering system and electronic stability control system, avoid unnecessary system intervention, extend the system's service life, and reduce maintenance costs.

[0098] Optionally, in step S13, determining the target rear wheel steering angle of the vehicle based on the vehicle's wheel slip ratio and a first weight may include the following steps:

[0099] Step S131: Determine the wheel slip ratio based on the wheel speed and vehicle speed.

[0100] Step S132: Determine the target rear wheel steering angle based on the yaw rate deviation, wheel slip ratio, and the first weight.

[0101] In this embodiment of the application, when determining the target rear wheel steering angle of the vehicle based on the vehicle's wheel slip ratio and a first weight, the wheel slip ratio can be determined based on the wheel speed and the vehicle speed. For example, the wheel slip ratio λ i It can be calculated using the following formula.

[0102]

[0103] Among them, V x V represents the vehicle speed. wheel Let λ be the wheel speed, i be the wheel number in the vehicle, and λ be the wheel speed. i This refers to the slip ratio of each wheel.

[0104] Then, based on the yaw rate deviation, wheel slip ratio, and a first weight, the target rear wheel steering angle is determined. For example, the target rear wheel steering angle δ RWS It can be calculated using the following formula.

[0105]

[0106] Among them, K p and K dK is the gain of the proportional-integral-derivative controller (PID). p For proportional gain, K d ω is the differential gain. RWS Δγ is the weighting coefficient corresponding to RWS, i.e., the first weight. Δγ is the yaw rate deviation.

[0107] As can be seen, based on the current yaw rate deviation, wheel slip ratio, and the first weight set for the rear-wheel steering system, the optimal target rear wheel steering angle is calculated using a preset mathematical model or algorithm (such as Model Predictive Control (MPC)). This target rear wheel steering angle aims to minimize the yaw rate deviation while taking into account the influence of wheel slip ratio, ensuring effective vehicle lateral stability control under different road conditions.

[0108] This allows for the precise calculation of the target rear wheel steering angle to suit the current vehicle condition, improving the accuracy of active lateral stability control. Furthermore, by considering the slip ratio and a given initial weight, the system can optimize resource utilization, ensuring that the rear wheel steering action maximizes the correction effect on yaw rate deviation.

[0109] Optionally, in step S14, adjusting the rear wheel steering angle of the vehicle to the target rear wheel steering angle based on the execution constraints may include the following execution steps:

[0110] Step S141: Generate control commands based on execution constraints, rear wheel steering angle, and target rear wheel steering angle.

[0111] Step S142: According to the control command, the actuator motor is controlled to adjust the output of the actuator motor through the first feedback control of the position loop and the second feedback control of the speed loop until the rear wheel angle is adjusted to the target rear wheel angle.

[0112] In this embodiment, when adjusting the rear wheel steering angle of the vehicle to the target rear wheel steering angle based on execution constraints, control commands can be generated based on the execution constraints, the rear wheel steering angle, and the target rear wheel steering angle. The execution constraints are the safety and physical limitations that the system must adhere to when operating the rear wheel steering, typically including steering angle limits and rate of change limits. Steering angle limits ensure that the rear wheel steering angle does not exceed design limits (e.g., ±5°), while rate of change limits the speed of steering angle change (e.g., ≤50° / s), avoiding sudden and severe steering impacts on the vehicle.

[0113] Control commands are command signals used to instruct actuators (such as motors) on how to adjust the rear wheel angle to achieve a target rear wheel angle.

[0114] It can be seen that the system takes into account the execution constraints, namely the limits on the amplitude and rate of change of the rear wheel angle. At the same time, it combines the current rear wheel angle with the target rear wheel angle to be achieved, and generates specific control commands through internal algorithms. This ensures that, under the premise of meeting safety and physical constraints, it guides the actuator motor to smoothly and stably adjust the rear wheel angle to the target value.

[0115] Then, according to the control commands, the actuator motor is controlled through a first feedback control in the position loop and a second feedback control in the speed loop to adjust the output of the actuator motor until the rear wheel angle is adjusted to the target rear wheel angle. The position loop is a closed-loop control system used to control the actuator motor's angular position to precisely match the target value, providing the first feedback control. The speed loop is another closed-loop control system specifically used to control the actuator motor's speed, ensuring a fast and stable motor response, providing the second feedback control.

[0116] As can be seen, after receiving the control command generated in the previous step, the actuator motor dynamically adjusts its output through a dual-loop feedback control mechanism consisting of a position loop and a speed loop to adjust the rear wheel angle. Specifically, the position loop monitors and adjusts the position error of the rear wheel angle, while the speed loop focuses on the motor speed, ensuring rapid response while avoiding overload. Thus, through this dual-loop feedback mechanism, the rear wheel steering system can efficiently and accurately adjust the rear wheel angle to the target rear wheel angle while adhering to the execution constraints.

[0117] In summary, this application achieves coordinated control of rear-wheel steering and ESC based on vehicle dynamics models and multimodal decision-making, and optimizes yaw rate tracking performance through a feedforward-feedback composite control architecture. Specifically, the control architecture of this application includes the following parts.

[0118] 1. Signal layer, used to fuse information on four-wheel speed, steering wheel angle, and yaw rate.

[0119] 2. The decision-making layer, including the function triggering module, detects a lateral acceleration gradient. When the vehicle speed is greater than 10 kph, the cooperative control mode is activated. The control mode switching module dynamically allocates the intervention weights of rear wheel steering and braking torque based on the slip ratio difference (Δλ) and yaw rate deviation (Δγ).

[0120] 3. The execution layer includes a rear wheel steering angle calculation module, which optimizes the target steering angle in real time based on model predictive control (MPC), and an execution constraint module, which imposes amplitude limits (±5°) and rate of change limits (≤50° / s) on the rear wheel steering angle.

[0121] The specific control phase execution strategy is as follows: In the initial response phase (0-40ms), rear-wheel steering is prioritized to quickly compensate for yaw deviation. In the dynamic compensation phase (40-80ms), if the deviation does not converge, ESC braking intervention is initiated to generate a compound yaw moment. In the exit phase, when Δγ < 2° / s and the steering wheel correction amount < 5°, control is gradually disengaged.

[0122] Figure 2 This is a flowchart of the lateral control of the rear wheel steering system according to one embodiment of this application, such as... Figure 2 As shown, the process includes the following steps S1 to S4.

[0123] S1: Multi-source signal acquisition and preprocessing.

[0124] The system collects data on wheel speeds, steering wheel angle, yaw rate, and longitudinal / lateral acceleration from the Inertial Measurement Unit (IMU). Noise is then eliminated using Kalman filtering, and invalid signals (such as wheel speed abrupt changes exceeding a 20% threshold) are removed.

[0125] S2: Function trigger condition.

[0126] Based on whether the current vehicle speed is >10 kph, whether the steering wheel angle is <10°, and whether the yaw rate gradient is ≥8° / s 2 Determine whether to activate the lateral active control function.

[0127] S3: Dynamic calculation of rear wheel steering angle.

[0128] Calculate slip ratio Among them, V x V represents the vehicle speed. wheel This refers to wheel speed.

[0129] The control weights are dynamically allocated based on the yaw rate deviation Δγ, including the following three allocation methods.

[0130] (1) RWS condition only: |Δγ|≤5° / s

[0131] Weighting: ω RWS =1, ω ESC =0

[0132] Function: The rear wheel steering independently compensates for yaw deviation and avoids brake energy consumption.

[0133] (2) RWS dominance condition: 5° / s < |Δγ| ≤ 15° / s

[0134] Weighting: ω RWS =0.7w, ω ESC =0.3

[0135] Function: Rear-wheel steering provides the main yaw moment, and ESC helps suppress residual deviation.

[0136] (3) ESC dominant condition: |Δγ|>15° / s

[0137] Weighting: ω RWS =0.4, ω ESC =0.6

[0138] Function: ESC generates yaw moment quickly through single-sided braking, while RWS assists in improving stability.

[0139] The specific weight values ​​and the threshold values ​​corresponding to the yaw rate deviation mentioned above can be adjusted according to the actual situation, and are not restricted here.

[0140] Calculate the rear wheel steering angle and optimize the target rear wheel steering angle in real time based on model predictive control (MPC). Specifically, the target rear wheel steering angle... Among them, K p and K d For PID gain, λ i Let ω be the slip ratio of each wheel. RWS These are the weighting coefficients.

[0141] The constraint applies an amplitude limit (±5°) and a rate of change limit (≤50° / s) to the rear wheel steering angle.

[0142] S4: Actuator output and closed-loop verification.

[0143] After obtaining the target rear wheel angle, the actuator motor executes the corresponding target angle through the feedback control of the position loop and speed loop, and then jumps to S2 again.

[0144] In summary, this application can solve the problems of insufficient yaw torque and actuator conflict under extreme conditions caused by single braking force intervention, significantly improving lateral compensation capability. Furthermore, the steer-by-wire-based rear-wheel steering system of this application has a faster response speed, making the vehicle's dynamic control more sensitive. In addition, reducing active braking system intervention during the process effectively reduces wear and tear and improves the user experience.

[0145] Figure 3 This is a schematic diagram of test data according to one embodiment of this application, such as... Figure 3As shown, this application reduces the yaw rate tracking error by 40%-60% (compared to the traditional single ESC control strategy), improves the yaw rate suppression capability on open roads by 50%, and reduces steering wheel correction by 30%. Furthermore, this application reduces the braking intervention frequency by 70%, extending the life of the braking system. Therefore, this invention, by introducing a rear-wheel steering system (RWS) and combining it with the high-frequency response characteristics (<20ms) of steer-by-wire technology, proposes a lateral control strategy in conjunction with ESC, overcoming the physical limitations of single braking intervention while reducing energy consumption and mechanical wear.

[0146] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation portals are provided for users to choose to authorize or refuse.

[0147] According to an embodiment of this application, an apparatus embodiment for a method of adjusting the wheel angle of a vehicle is provided. It should be noted that the apparatus can be used to perform the above-described method of adjusting the wheel angle of a vehicle.

[0148] Figure 4 This is a structural block diagram of a vehicle wheel angle adjustment device according to one embodiment of this application, such as... Figure 4 As shown, a vehicle wheel angle adjustment device 400 is used as an example. This device includes: an activation module 401, used to activate the rear wheel steering system auxiliary control function of the vehicle in response to the vehicle's state information meeting preset conditions, wherein the state information is used to reflect the vehicle's driving attributes; a determination module 402, used to determine the first weight of the rear wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the vehicle's yaw rate deviation when the rear wheel steering system auxiliary control function is activated, wherein the operating strategy is used to adjust the degree of intervention of the rear wheel steering system and the electronic stability control system on the vehicle's yaw rate deviation; an operation module 403, used to operate the rear wheel steering system and the electronic stability control system according to the operating strategy, and during operation, to determine the target rear wheel angle of the vehicle based on the vehicle's wheel slip ratio and the first weight; and an adjustment module 404, used to adjust the vehicle's rear wheel angle to the target rear wheel angle based on execution constraints, wherein the execution constraints are used to limit the adjustment range of the rear wheel angle.

[0149] Embodiments of this application also provide a vehicle, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods described in various embodiments of this application when it runs.

[0150] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0151] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0152] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0153] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0154] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0155] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0156] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several 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 methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0157] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for adjusting the wheel angle of a vehicle, characterized in that, The method includes: In response to the vehicle's status information meeting preset conditions, the rear-wheel steering system auxiliary control function of the vehicle is activated, wherein the status information is used to reflect the vehicle's driving attributes; With the rear wheel steering system auxiliary control function in the active state, based on the vehicle's yaw rate deviation, a first weight of the rear wheel steering system, a second weight of the electronic stability control system, and an operating strategy are determined, wherein the operating strategy is used to adjust the degree of intervention of the rear wheel steering system and the electronic stability control system on the vehicle's yaw rate deviation. The rear-wheel steering system and the electronic stability control system are operated according to the operating strategy, and during operation, the target rear wheel steering angle of the vehicle is determined based on the vehicle's wheel slip ratio and the first weight. The rear wheel steering angle of the vehicle is adjusted to the target rear wheel steering angle based on execution constraints, wherein the execution constraints are used to limit the adjustment range of the rear wheel steering angle.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the initial state information of the vehicle; The initial state information is denoised to obtain the first state information; Invalid data in the first state information is removed to obtain the state information, which includes wheel speed, steering wheel angle and yaw rate.

3. The method according to claim 2, characterized in that, The method further includes: The vehicle speed is determined based on the wheel speed. The yaw rate gradient is determined based on the yaw rate. In response to the vehicle speed being greater than a first threshold, the steering wheel angle being less than a second threshold, and the yaw rate gradient being greater than or equal to a third threshold, it is determined that the state information satisfies the preset conditions.

4. The method according to claim 1, characterized in that, The determination of the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the yaw rate deviation of the vehicle includes: In response to the absolute value of the yaw rate deviation being less than or equal to a third threshold, a first weight, a second weight, and a first operating strategy are determined, wherein the first weight is a first value, the second weight is a second value, the first value is greater than the second value, and the first operating strategy is used to independently operate the rear wheel steering system.

5. The method according to claim 4, characterized in that, The determination of the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the yaw rate deviation of the vehicle also includes: In response to the absolute value being greater than the third threshold and less than or equal to the fourth threshold, a first weight, a second weight, and a second operating strategy are determined, wherein the first weight is greater than the second weight, the first weight is less than the first value, the second weight is greater than the second value, and the second operating strategy is used to control the rear wheel steering system to output yaw moment and to control the electronic stability control system to assist in suppressing the yaw rate deviation. In response to the absolute value being greater than the fourth threshold, a first weight, a second weight, and a third operating strategy are determined, wherein the first weight is less than the second weight, the first weight is less than the first value, the second weight is greater than the second value, and the third operating strategy is used to control the electronic stability control system to output yaw moment and to control the rear wheel steering system to assist in suppressing the yaw rate deviation.

6. The method according to claim 5, characterized in that, The determination of the first weight of the rear-wheel steering system, the second weight of the electronic stability control system, and the operating strategy based on the yaw rate deviation of the vehicle also includes: In response to the absolute value being less than a fifth threshold and the steering wheel angle being less than a sixth threshold, the operation of the rear wheel steering system and the electronic stability control system is discontinued, wherein the fifth threshold is less than the third threshold.

7. The method according to claim 3, characterized in that, Determining the target rear wheel steering angle of the vehicle based on the vehicle's wheel slip ratio and the first weight includes: The wheel slip ratio is determined based on the wheel speed and the vehicle speed; The target rear wheel steering angle is determined based on the yaw rate deviation, the wheel slip ratio, and the first weight.

8. The method according to any one of claims 1-7, characterized in that, The step of adjusting the rear wheel steering angle of the vehicle to the target rear wheel steering angle based on execution constraints includes: Control commands are generated based on the execution constraints, the rear wheel angle, and the target rear wheel angle. According to the control command, the actuator motor is controlled to adjust its output through the first feedback control of the position loop and the second feedback control of the speed loop until the rear wheel angle is adjusted to the target rear wheel angle.

9. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the wheel angle adjustment method for a vehicle as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program is configured to execute the wheel angle adjustment method for a vehicle as described in any one of claims 1 to 8 when run on a computer or processor.

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