A vehicle pre-control method, electronic device and vehicle

Abstract

This application provides a vehicle pre-control method, electronic device, and vehicle, relating to the field of vehicle control technology. The vehicle pre-control method includes: acquiring the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel of the vehicle; determining multiple longitudinal stiffnesses of each wheel within a preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel; and determining whether the longitudinal stiffness of each wheel exhibits a decaying trend based on the multiple longitudinal stiffnesses within the preset time window, and adjusting the torque distribution of each wheel if a decaying trend is observed. This application, through the above method, can determine the wheel state based on the changing trend of longitudinal stiffness within a preset time window, thereby realizing a shift from hysteresis feedback control dependent on slip ratio to proactive control based on longitudinal stiffness.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and more particularly to a vehicle pre-control method, electronic equipment, and vehicle. Background Technology

[0002] With the development of active safety technologies for vehicles, electronically controlled vehicle stability control systems have been widely used in mass-produced vehicles. These systems typically assess the vehicle's current driving stability by collecting macroscopic kinematic parameters such as wheel speed, slip ratio, yaw rate, and their deviations from target values. When they detect that the vehicle is entering an unstable state, they achieve stability control through braking or driving force adjustment. However, because the control triggering of such systems relies on macroscopic parameters that already indicate significant changes in the vehicle's dynamic state, such as increased slip ratio and rising yaw rate deviation, the tire adhesion often deteriorates significantly by the time these systems begin to intervene. This results in a relatively late control timing, making it difficult to proactively intervene when tire adhesion performance has just begun to decline.

[0003] Therefore, how to design a pre-control method that can identify and actively control tire performance in the early stages of micro-degradation has become an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a vehicle pre-control method, electronic equipment and vehicle to solve or partially solve the above problems.

[0005] To achieve the above objectives, this application provides a vehicle pre-control method, comprising:

[0006] Obtain the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel of the vehicle; Based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel, determine multiple longitudinal stiffnesses of each wheel within a preset time window; Based on the longitudinal stiffness of each wheel within a preset time window, it is determined whether the longitudinal stiffness of each wheel exhibits a decaying trend, and if it does, the torque distribution of each wheel is adjusted.

[0007] Optionally, the time window includes multiple sampling periods; determining whether the longitudinal stiffness of each wheel exhibits a decaying trend based on the multiple longitudinal stiffnesses of each wheel within the preset time window includes: Determine the longitudinal stiffness of each wheel in each sampling period; Based on the longitudinal stiffness of each sampling period, determine the slope of the change in longitudinal stiffness of each wheel within the time window; Based on the longitudinal stiffness and the slope of change of each wheel, the variation range of the longitudinal stiffness of each wheel is determined; Based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel in each sampling period, it is determined whether the longitudinal stiffness of each wheel exhibits a decreasing trend.

[0008] Optionally, determining whether the longitudinal stiffness of each wheel exhibits a decreasing trend based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel within each sampling period includes: In response to determining that the longitudinal stiffness, the slope of change, and the magnitude of change of a wheel meet preset judgment conditions, it is determined that the longitudinal stiffness of the wheel exhibits a decreasing trend. The preset determination conditions include at least one of the following: The slope of the change in the longitudinal stiffness of the wheel is less than 0, and the magnitude of the change in the longitudinal stiffness is greater than or equal to a preset first judgment threshold. Within the time window, the proportion of sampling periods in which the longitudinal stiffness continuously decreases is greater than or equal to a preset second judgment threshold. The slope of the longitudinal stiffness change of this wheel is less than the slope of the change of the other wheel on the same axle, and the difference between the two is less than the preset third judgment threshold.

[0009] Optionally, adjusting the torque distribution to each wheel when it exhibits a decreasing trend includes: In response to the determination that the longitudinal stiffness of a wheel exhibits a decreasing trend, the wheel is identified as the target wheel, and the torque to be transferred is determined based on the slope of the change of the target wheel. The torque to be transferred is transferred from the target wheel to at least one non-target wheel to keep the total longitudinal force requirement of the vehicle constant.

[0010] Optionally, adjusting the torque distribution to each wheel when it exhibits a decreasing trend further includes: In response to the determination that the longitudinal stiffness of a wheel is showing a decreasing trend, the wheel is identified as the target wheel, and an adjustment request is sent to the vehicle's active suspension system. In response to the vehicle's active suspension system receiving an adjustment request, the damping of the target wheel is increased by a preset first threshold within a preset time.

[0011] Optionally, the time window includes multiple sampling periods, each sampling period includes multiple sampling points, and determining multiple longitudinal stiffnesses of each wheel within a preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel includes: The longitudinal acceleration change of each wheel is determined based on the longitudinal acceleration of adjacent sampling points of each wheel; The torque variation of each wheel is determined based on the torque at adjacent sampling points of each wheel. Based on the longitudinal acceleration change, torque change, moment of inertia, and effective rolling radius of each wheel, multiple longitudinal stiffnesses of each wheel within a preset time window are determined.

[0012] Optionally, after adjusting the torque distribution to each wheel, the process includes: The slip ratio of each wheel is obtained, and the longitudinal stiffness of each wheel within a preset time window is re-determined. Based on the re-determined longitudinal stiffness, it is determined whether the longitudinal stiffness of each wheel shows a decaying trend. In response to determining that the longitudinal stiffness of at least one wheel exhibits a decreasing trend and that the slip ratio of at least one wheel is greater than or equal to a preset slip threshold, the step of re-determining the multiple longitudinal stiffnesses of each wheel within a preset time window is no longer performed.

[0013] Optionally, obtaining the longitudinal acceleration of each wheel of the vehicle includes: Determine multiple wheel speeds for each wheel within a preset time window; The rate of change of wheel speed for each wheel is determined based on the multiple wheel speeds of each wheel. The longitudinal acceleration of the corresponding wheel is determined based on the wheel speed change rate and the effective rolling radius of each wheel.

[0014] Based on the same inventive concept, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the method described above when executing the computer program.

[0015] Based on the same inventive concept, this application also provides a vehicle including the electronic equipment described above.

[0016] As can be seen from the above, the vehicle pre-control method, electronic device, and vehicle provided in this application include: acquiring the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel of the vehicle; determining multiple longitudinal stiffnesses of each wheel within a preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel; and determining whether the longitudinal stiffness of each wheel exhibits a decaying trend based on the multiple longitudinal stiffnesses of each wheel within the preset time window, and adjusting the torque distribution of each wheel if a decaying trend is observed. This application introduces a longitudinal stiffness parameter that can directly characterize the tire's adhesion state through the aforementioned method. Based on the changing trend of this longitudinal stiffness within a preset time window, the tire's adhesion state is pre-determined, thereby realizing a shift from hysteresis feedback control dependent on slip ratio to forward-looking control based on longitudinal stiffness. This allows for the identification of adhesion degradation before the slip ratio changes significantly, and by coordinating and fine-tuning the torque of each wheel, the tire is kept in the linear operating range, thus reducing the risk of slippage and instability. Furthermore, this solution can be implemented based on existing vehicle sensors and controllers without adding new hardware, demonstrating good engineering applicability and promotional value. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the vehicle pre-control method according to an embodiment of this application. Figure 1 ; Figure 2 This is a flowchart illustrating the vehicle pre-control method according to an embodiment of this application. Figure 2 ; Figure 3 This is a schematic diagram of a vehicle control device according to an embodiment of this application; Figure 4 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] As described in the background section, with the continuous development of vehicle active safety technologies, electronically controlled vehicle stability control systems have been widely used in mass-produced vehicles, such as Anti-lock Braking System (ABS), Traction Control System (TCS), and Electronic Stability Program (ESP). These systems typically rely on onboard sensors to acquire macroscopic kinematic parameters such as wheel speed, slip ratio, yaw rate, and deviation from the target state, and perform real-time assessments of vehicle stability based on preset control logic. When an abnormal increase in slip ratio or a yaw rate deviating from the target range is detected, vehicle stability control is achieved through braking intervention or drive force adjustment, thereby suppressing wheel slippage or vehicle instability.

[0022] Furthermore, the aforementioned control methods are essentially closed-loop control mechanisms based on macroscopic state feedback. Their control triggering depends on the manifestation of the interaction between the tire and the road surface at the vehicle's kinematic level. For example, a significant increase in slip ratio reflects that the tire's longitudinal adhesion has approached or exceeded its limit, while a deviation in yaw rate reflects an imbalance in lateral force distribution. Therefore, the control basis of this type of system is an outcome quantity; that is, the response only occurs after the decline in tire adhesion performance has already manifested in the overall vehicle motion.

[0023] However, the degradation of tire adhesion performance is not abrupt, but rather a gradual evolution from changes in microscopic mechanical properties to macroscopic motion anomalies. For example, on low-adhesion surfaces or during rapid acceleration and deceleration, the relationship between tire longitudinal force and slip ratio gradually transitions from an initial approximately linear region to a nonlinear region. During this process, the contact characteristics between the tire's internal rubber and the road surface change, manifested as a decrease in the longitudinal acceleration response caused by unit torque changes, i.e., an early decrease in the tire's longitudinal stiffness. This decrease occurs before the slip ratio increases significantly, representing an early sign of instability.

[0024] To address the aforementioned issues, related technologies have proposed pre-control strategies that attempt to proactively intervene before instability occurs by sensing changes in tire adhesion in advance. These methods primarily focus on lateral dynamics scenarios, such as during vehicle cornering or lane changes. They estimate tire lateral adhesion capability using signals like lateral / lateral acceleration and yaw rate trends, and apply additional yaw moment in advance to improve vehicle stability.

[0025] However, the pre-control methods in related technologies still have significant shortcomings in longitudinal dynamic scenarios. On the one hand, the methods in related technologies still largely rely on macroscopic characterization parameters such as slip ratio. However, slip ratio is essentially a result of the tire having already slipped relative to each other, and its changes have a certain lag, making it difficult to reflect the initial degradation process of tire adhesion performance. On the other hand, for longitudinal conditions, there is a lack of intermediate physical quantities that can directly characterize the changes in the relationship between torque input and acceleration output, which prevents the control system from effectively identifying and intervening in the early stages of the tire's transition from the linear to the nonlinear region.

[0026] In light of this, the applicant proposes a vehicle pre-control method oriented towards longitudinal dynamics. This method should be able to utilize existing vehicle signals to construct key characterization quantities reflecting changes in the longitudinal mechanical properties of the tire, and based on the changing trend of these characterization quantities over time, achieve real-time identification of the initial degradation of tire adhesion performance. Specifically, by acquiring parameters such as wheel longitudinal acceleration, driving / braking torque, moment of inertia, and effective rolling radius, the longitudinal stiffness of the tire is determined. Furthermore, the longitudinal stiffness is sampled multiple times within a preset time window to determine its rate of change, which is then used as the basis for judging the changing trend of the tire's longitudinal stiffness.

[0027] When a decreasing trend in longitudinal stiffness is detected, it indicates that the tire is transitioning from the linear working region to the nonlinear region. At this stage, before the slip ratio changes significantly, by making minor and coordinated adjustments to the driving or braking torque of each wheel, the tire can be brought back to or maintained in the linear working range, thereby achieving early suppression of the nonlinearization of longitudinal adhesion.

[0028] By adopting the above approach, the timing of control triggering can be shifted from after macroscopic instability to the early stage of microscopic performance degradation, thereby overcoming the lag problem of control methods in related technologies from a mechanistic perspective. It also complements existing lateral pre-control technologies, improving the overall stability control level of vehicles under complex operating conditions.

[0029] The following is in conjunction with the appendix Figure 1-4 The embodiments of this application will be described in detail below.

[0030] In some embodiments, such as Figure 1 As shown, a vehicle pre-control method is provided. This method can be executed by the vehicle controller or by other controllers independent of the vehicle controller. For the convenience of subsequent description, unless otherwise specified, the method is described using the vehicle controller as an example.

[0031] The vehicle pre-control method includes: S101. Obtain the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel of the vehicle.

[0032] In this step, the vehicle controller (or controller) can acquire relevant parameters of each wheel through onboard sensors and the vehicle control network. Specifically, longitudinal acceleration can be obtained by differential calculation using wheel speed signals (or wheel speed, angular velocity) or by a preset algorithm from the vehicle body acceleration sensor; wheel torque (such as drive / brake torque) can be obtained from the drive motor controller or feedback from the braking system / sensors; moment of inertia can be obtained from vehicle calibration parameters or preset based on vehicle structure; effective rolling radius can be obtained from tire calibration values ​​or by dynamic estimation combining wheel speed and vehicle speed.

[0033] The parameters mentioned above reflect the power input and dynamic response characteristics of the wheel from different dimensions. Among them, torque characterizes the driving or braking force input to the wheel, longitudinal acceleration characterizes the vehicle's dynamic response capability in the longitudinal direction, and moment of inertia and effective rolling radius are used to link torque input with longitudinal acceleration response to determine the rate of change of longitudinal acceleration caused by torque change (i.e., longitudinal stiffness).

[0034] By obtaining the above parameters, we can provide data support for subsequent characterization of the tire's longitudinal mechanical properties and determination of the tire's longitudinal stiffness variation.

[0035] S102. Based on the longitudinal acceleration, torque, moment of inertia and effective rolling radius of each wheel, determine multiple longitudinal stiffnesses of each wheel within a preset time window.

[0036] In this step, the vehicle controller can determine the longitudinal stiffness of the tire based on wheel dynamics and related parameters such as longitudinal acceleration, torque, moment of inertia, and effective rolling radius. Specifically, longitudinal stiffness can be characterized as the rate of change of longitudinal acceleration caused by a unit change in torque, reflecting the tire's responsiveness to driving or braking inputs under the current grip condition. It should also be noted that higher longitudinal stiffness indicates a more stable and linear response of the tire to torque inputs, resulting in smoother acceleration or deceleration of the vehicle. Conversely, a decrease in longitudinal stiffness indicates a degradation in the tire's longitudinal grip, with the tire gradually approaching its grip limit. In this case, the vehicle is more prone to driving slippage, braking instability, or longitudinal instability.

[0037] For example, the longitudinal stiffness can be continuously calculated at multiple times within a preset time window (e.g., 50ms to 500ms) according to multiple sampling periods (e.g., 10ms or 20ms), thereby forming a set of time series data. The setting of this time window can, on the one hand, filter out the influence of single sampling noise on stiffness calculation, and on the other hand, reflect the dynamic change trend of tire mechanical properties in a short period of time.

[0038] Furthermore, when the tire operates within the linear adhesion range, the torque change and the longitudinal acceleration change are approximately linearly related, and the corresponding longitudinal stiffness remains relatively stable. At this time, the vehicle can respond to the driver's acceleration or braking needs relatively stably, and the wheels are not prone to significant slippage. However, as the tire gradually approaches the adhesion limit, due to the increase in micro-slippage within the contact patch, the contact state between the rubber and the road surface changes, resulting in a weakening of the acceleration response caused by a unit torque change. This manifests as a gradual decrease in longitudinal stiffness. At this time, the vehicle's responsiveness to driving or braking inputs begins to decline, and the wheels are more prone to slippage and adhesion degradation.

[0039] By continuously acquiring multiple longitudinal stiffness values ​​within a time window, a basis can be provided for identifying the evolution trend of tire adhesion performance.

[0040] More specifically, in some embodiments, the time window includes multiple sampling periods, each sampling period includes multiple sampling points, and step S102, determining multiple longitudinal stiffnesses of each wheel within a preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel, includes: S201. Determine the change in longitudinal acceleration of each wheel based on the longitudinal acceleration of adjacent sampling points of each wheel.

[0041] In this step, the vehicle controller acquires the longitudinal acceleration data of each wheel within each sampling period and calculates the change in longitudinal acceleration Δax between adjacent sampling points, i.e.: ; in, This is the filtered longitudinal acceleration value of the wheel center at the current sampling point (unit: m / s²).

[0042] This step is used to characterize the tire's acceleration response under transient driving forces, reflecting the tire's sensitivity to torque input.

[0043] S202. Determine the torque change of each wheel based on the torque of adjacent sampling points of each wheel.

[0044] In this step, the vehicle controller acquires the driving or braking torque data of the wheels within each sampling period and calculates the torque change ΔT between adjacent sampling points, i.e.: ; in, The driving or braking torque at the current sampling point (unit: Nm).

[0045] By recording torque changes, the vehicle controller can quantify the dynamic relationship between tire input and response, providing input data for longitudinal stiffness calculation.

[0046] S203. Based on the longitudinal acceleration change, torque change, moment of inertia and effective rolling radius of each wheel, determine multiple longitudinal stiffnesses of each wheel within a preset time window.

[0047] In this step, the vehicle controller combines the longitudinal acceleration change Δax, the torque change ΔT, and the wheel's moment of inertia. and effective rolling radius Calculate the longitudinal stiffness (or dynamic longitudinal stiffness) of each sampling point. For example, the specific formula is as follows: ; in, The rate of change of longitudinal acceleration at the wheel end, reflecting the change in unit driving / braking torque, is a direct measure of the tire's longitudinal transient response sensitivity. Dynamic longitudinal stiffness exhibits a decay phenomenon near the adhesion limit, meaning a decrease in response due to microscopic deformation of the rubber material. This indicator can be used to promptly identify trends in tire adhesion degradation.

[0048] For example, the effective rolling radius It can be determined in the following ways: During actual vehicle operation, the effective rolling radius can be calculated by measuring the relationship between vehicle speed and wheel speed (or wheel angular velocity), based on the following formula: ; Where v is the actual vehicle speed and ω is the angular velocity of the wheel; this method is simple and reliable, and applicable to most mass-produced models.

[0049] For example, moment of inertia It can be used to calibrate vehicle parameters or preset based on vehicle model structure.

[0050] Furthermore, it should be noted that, to ensure the stability of the longitudinal stiffness calculation, the vehicle controller in this embodiment can perform sampling at the sampling points. The values ​​and related parameters are filtered (such as low-pass filtering or median filtering), and the rate of change and magnitude of change are calculated based on multiple sampling points to further improve the robustness of the decay trend identification and avoid misjudgment caused by single-point abnormal data.

[0051] This embodiment provides a reliable data foundation for identifying the attenuation trend of each wheel based on real-time longitudinal stiffness data before adhesion degradation occurs, using the method described above.

[0052] S103. Based on the longitudinal stiffness of each wheel within a preset time window, determine whether the longitudinal stiffness of each wheel shows a decaying trend, and adjust the torque distribution of each wheel if it shows a decaying trend.

[0053] In this step, the vehicle controller performs trend analysis on multiple longitudinal stiffnesses within the time window, such as by slope calculation, linear fitting, or difference judgment, to determine the trend of longitudinal stiffness change over time.

[0054] Specifically, when the longitudinal stiffness shows an overall decreasing trend over multiple sampling periods (e.g., the fitting slope is less than a preset threshold), it can be determined that the longitudinal stiffness of the current wheel is showing a decay trend. This decay trend indicates that the tire is transitioning from the linear adhesion region to the nonlinear region, which is an early stage of adhesion degradation.

[0055] In this situation, the vehicle controller can adjust the torque distribution to each wheel. For example, it can reduce the driving torque or braking force of the wheel experiencing stiffness degradation, while transferring some torque to the wheel with better traction through a differential distribution strategy, thereby preventing the target wheel from entering a deeper slip state.

[0056] Furthermore, the torque adjustment can be a minute, continuous adjustment to achieve precise control of the tire's working range without affecting the driver's perception. In this way, the tire can be brought back to or maintained within the linear working range of its longitudinal mechanical properties, thereby suppressing the nonlinear development of longitudinal adhesion.

[0057] The vehicle pre-control method provided in this embodiment includes: acquiring the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel of the vehicle; determining multiple longitudinal stiffnesses of each wheel within a preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel; and determining whether the longitudinal stiffness of each wheel exhibits a decaying trend based on the multiple longitudinal stiffnesses of each wheel within the preset time window, and adjusting the torque distribution of each wheel if a decaying trend is observed. This embodiment introduces a longitudinal stiffness parameter that directly characterizes the tire adhesion state, and pre-determines the tire adhesion state based on the changing trend of this longitudinal stiffness within a preset time window. This achieves a shift from hysteresis feedback control dependent on slip ratio to proactive control based on longitudinal stiffness. It can identify adhesion degradation before the slip ratio changes significantly, and maintain the tire in the linear operating range by coordinating and fine-tuning the torque of each wheel, thereby reducing the risk of slippage and instability. Furthermore, this solution can be implemented based on existing vehicle sensors and controllers without requiring additional hardware, demonstrating good engineering applicability and promotional value.

[0058] In some embodiments, such as Figure 2 As shown, the time window includes multiple sampling periods; in step S103, based on the multiple longitudinal stiffnesses of each wheel within the preset time window, it is determined whether the longitudinal stiffness of each wheel exhibits a decaying trend, including: S301. Determine the longitudinal stiffness of each wheel in each sampling period.

[0059] In this step, the vehicle controller continuously collects the operating status of each wheel within a preset time window at a preset sampling period (e.g., 10ms or 20ms), and calculates the longitudinal stiffness corresponding to each sampling period based on the longitudinal acceleration, torque, moment of inertia and effective rolling radius corresponding to each sampling period.

[0060] Using the above method, a discrete sequence of longitudinal stiffness for each wheel can be generated over time. For example, within a 200ms time window, if the sampling period is 20ms, 10 sets of longitudinal stiffness data can be obtained. Alternatively, within a 50ms time window, if the sampling period is 10ms, 5 sets of longitudinal stiffness data can be obtained.

[0061] This sequence can reflect the dynamic response of the tire to torque input over a short period of time.

[0062] S302. Based on the longitudinal stiffness of each sampling period, determine the slope of the change in longitudinal stiffness of each wheel within the time window.

[0063] In this step, after acquiring the longitudinal stiffness data for each sampling period, the vehicle controller does not make a judgment based directly on the stiffness value at a single moment. Instead, it introduces a time window mechanism to extract the dynamic change trend of the longitudinal stiffness in order to improve the sensitivity and stability to changes in tire adhesion state.

[0064] Specifically, the time window can be a preset observation window of length Δt (e.g., initially set to 50ms), and dynamic longitudinal stiffness data for multiple sampling periods are continuously collected within this time window. For example, when the sampling period is 10ms, 5 sets of longitudinal stiffness data points can be obtained within a single time window, thus constituting a set of short-time series data.

[0065] Based on this, the vehicle controller can perform a first-order linear fitting process (e.g., using the least squares method) on the longitudinal stiffness sequence within the time window to obtain the slope of the longitudinal stiffness change over time within that time window. (Or trend slope). Optionally, slope estimation can also be achieved by differencing adjacent data or moving regression, but linear fitting is preferred to reduce noise interference and improve the robustness of trend extraction.

[0066] Furthermore, through the above processing, the original discrete longitudinal stiffness data is converted into a characteristic quantity reflecting the changing trend, so that it can be transformed from a state quantity into a rate of change quantity, thereby more effectively characterizing the dynamic evolution process of tire adhesion performance.

[0067] Furthermore, it should be noted that the slope of the longitudinal stiffness change essentially reflects the rate of change in the tire's responsiveness to the ground contact state: When the slope of the change in longitudinal stiffness is close to zero, it indicates that the longitudinal stiffness remains basically stable and the tire adhesion state is in a relatively balanced stage. When the slope of the change in longitudinal stiffness is negative and the absolute value is large, it indicates that the longitudinal stiffness decays rapidly, which usually corresponds to the tire slipping or a decrease in adhesion. When the slope of the change in longitudinal stiffness is positive, it indicates that the longitudinal stiffness is in a recovery trend or in a normal state, which can correspond to working conditions where adhesion conditions are improved or slippage is suppressed.

[0068] Therefore, compared to judging solely based on instantaneous longitudinal stiffness, this step, by introducing a time window and slope extraction mechanism, enables early perception of the changing trend of tire adhesion state. It can identify the attenuation trend before the stiffness decreases significantly, thus providing a more forward-looking decision-making basis for subsequent torque distribution or stability control.

[0069] S303. Based on the longitudinal stiffness and the slope of change of each wheel, determine the variation range of the longitudinal stiffness of each wheel.

[0070] In this step, after completing the calculation of the slope of the longitudinal stiffness change... After extraction, this step further transitions the relevant data from trend to degree of change, that is, to quantify the actual change in longitudinal stiffness within the time window, thereby avoiding the uncertainty brought about by relying solely on slope information.

[0071] Specifically, the vehicle controller can base its actions on the slope of change. The overall change in longitudinal stiffness within the time window is estimated using the time window length Δt. Since... Characterizing the rate of change of longitudinal stiffness per unit time (i.e., "stiffness / time"), therefore through The product of Δt and Δt yields the magnitude of stiffness change within that time window. For example, the specific formula could be: magnitude of change ≈ ×Δt.

[0072] In other words, this process is equivalent to integrating the "rate of change" into the "change amount," similar to the relationship "velocity × time = displacement." When When the value is negative, the above product represents the amount of attenuation of longitudinal stiffness within that time window; when When the value is positive, it corresponds to the amount of stiffness recovery. Therefore, slope information can be converted into stiffness change.

[0073] Furthermore, considering that the absolute levels of longitudinal stiffness of different wheels vary significantly under different loads and road surface adhesion conditions, directly using absolute changes for judgment can easily lead to inconsistent thresholds and thus misjudgments. To avoid problems such as oversensitivity to short-term noise due to relying solely on slope, threshold failure under different road surface conditions due to relying solely on absolute changes, and insufficient characterization of dynamic processes due to judging solely based on single-point stiffness, a normalization mechanism is introduced in some embodiments to improve the algorithm's adaptability.

[0074] Specifically, within the time window Δt, multiple longitudinal stiffness data can be collected. Sort the data and take its median, denoted as . Compared to the mean, the median is less sensitive to instantaneous shocks and abnormal fluctuations, and can more stably reflect the stiffness level within the time window.

[0075] Based on this, the magnitude of change is normalized to obtain a relative magnitude of change index: ; Through the above processing, absolute changes can be converted into relative changes, thereby eliminating the influence of differences in stiffness baseline values ​​under different working conditions. For example, the same decrease in stiffness may only account for a small proportion under high-adhesion road surfaces, while it may already represent a significant attenuation under low-adhesion road surfaces. Optionally, after normalization, a uniform threshold (e.g., 15%) can be used to consistently determine different working conditions; when the relative change exceeds the preset threshold, it can be preliminarily determined that the longitudinal stiffness of the corresponding wheel has decreased; conversely, if the change is small, it indicates that the current situation is only a short-term fluctuation or noise disturbance, and subsequent control should not be triggered.

[0076] By introducing a combination of change estimation and median normalization, this step achieves amplitude constraint and adaptive calibration of longitudinal stiffness change, enabling the determination of longitudinal stiffness change to have both trend sensitivity and amplitude reliability, providing a more robust criterion basis for subsequent trend classification and torque control.

[0077] S304. Based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel in each sampling period, determine whether the longitudinal stiffness of each wheel shows a decreasing trend.

[0078] In this step, after obtaining the slope and normalized change of longitudinal stiffness, the evolution of longitudinal stiffness of each wheel is further comprehensively judged. Specifically, the vehicle controller can combine the longitudinal stiffness data, as well as its slope and change range, to determine whether the longitudinal stiffness of the tire shows a decay trend.

[0079] For example, in a specific implementation, the following judgment condition can be set: when the slope of the longitudinal stiffness change is less than a preset threshold (e.g., 0) and the change amplitude is greater than a preset amplitude threshold, it is initially determined that the longitudinal stiffness of the wheel shows a decreasing trend; otherwise, it is determined that there is no decreasing trend or that it is in a stable state.

[0080] Furthermore, to enhance the robustness of the judgment, auxiliary criteria based on time series consistency can be introduced in some specific examples. For example, the longitudinal stiffness values ​​at different times within a time window can be compared, or the consistency of the sign of the change slope within multiple consecutive time windows can be verified. When multiple consecutive periods satisfy a downward trend, the confidence of the attenuation trend judgment can be improved; conversely, it can suppress false triggering caused by occasional fluctuations.

[0081] In addition, the absolute level of longitudinal stiffness can be used as a supplementary constraint. For example, when the longitudinal stiffness is already in a low range and continues to decrease, it can be determined that the tire is approaching its adhesion limit, thereby increasing the priority of control response.

[0082] It should also be noted that the above judgment conditions are merely illustrative examples used to explain the judgment approach for the longitudinal stiffness attenuation trend in this application. In practical applications, the relevant judgment conditions can be flexibly adjusted or expanded according to different vehicle configurations, control strategy requirements, and road environment characteristics. For example, the threshold size, judgment dimensions, or combination logic can be optimized, and other auxiliary parameters can be introduced to participate in the joint judgment.

[0083] By setting multiple judgment conditions in this way, a multi-dimensional fusion judgment mechanism can be formed, which can effectively distinguish between short-term stiffness fluctuations caused by road disturbances or measurement noise and the real stiffness decay process caused by increased tire slippage or deterioration of adhesion conditions, thereby improving the reliability of tire condition identification.

[0084] After determining that the longitudinal stiffness of a certain wheel is showing a decreasing trend, the vehicle controller can further execute a torque distribution adjustment strategy to suppress or transfer the torque of that wheel in order to prevent it from further entering the nonlinear or even runaway operating range.

[0085] This embodiment continuously calculates the longitudinal stiffness of each wheel over multiple sampling periods within a preset time window, and introduces the change slope and change amplitude to jointly determine its evolution trend. This transforms the identification of tire adhesion state from a static judgment at a single moment to a dynamic trend analysis based on time series. As a result, it can more accurately capture the continuous attenuation characteristics of longitudinal stiffness during the transition of the tire from the linear working region to the nonlinear region, providing a more accurate triggering basis for the forward-looking adjustment of subsequent torque distribution, and further improving the stability control effect of the vehicle under low adhesion and longitudinal extreme conditions.

[0086] In some embodiments, step S304, determining whether the longitudinal stiffness of each wheel exhibits a decreasing trend based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel within each sampling period, includes: In response to determining that the longitudinal stiffness, the slope of change, and the magnitude of change of a wheel meet preset judgment conditions, it is determined that the longitudinal stiffness of the wheel exhibits a decreasing trend. The preset determination conditions include at least one of the following: The slope of the change in the longitudinal stiffness of the wheel is less than 0, and the magnitude of the change in the longitudinal stiffness is greater than or equal to a preset first judgment threshold. Within the time window, the proportion of sampling periods in which the longitudinal stiffness continuously decreases is greater than or equal to a preset second judgment threshold. The slope of the longitudinal stiffness change of this wheel is less than the slope of the change of the other wheel on the same axle, and the difference between the two is less than the preset third judgment threshold.

[0087] Specifically, in this embodiment, the vehicle controller can identify the trend of longitudinal stiffness change of each wheel based on preset judgment conditions; when it is determined that the longitudinal stiffness, change slope and change amplitude of a certain wheel meet at least one of the judgment conditions, it is determined that the longitudinal stiffness of the wheel shows a decay trend and the corresponding trend flag signal is output.

[0088] Furthermore, to improve the accuracy and robustness of the determination, a trend confidence level determination method can be introduced, that is, the longitudinal stiffness attenuation trend can be confirmed through a combination or cross-validation of multiple criteria. The preset determination conditions may include at least one of the following, and preferably a combination of multiple conditions: For example, the slope of the change in the longitudinal stiffness of the wheel is less than 0, and the magnitude of the change in the longitudinal stiffness is greater than or equal to a preset first determination threshold.

[0089] Specifically, the above are judgment conditions based on the slope and magnitude of the change in longitudinal stiffness. When the slope of the change in longitudinal stiffness of the wheel... The slope is less than a preset slope threshold (e.g., less than 0), and the normalized change magnitude obtained based on the slope estimation satisfies the following: <0, and ; in, λ1 is the median of the longitudinal stiffness samples within the preset time window Δt; λ1 is the first judgment threshold, which is the threshold used to characterize the attenuation magnitude (e.g., 15%).

[0090] In this condition, the slope of change is used to characterize the direction and trend of longitudinal stiffness change, while the normalized amplitude of change is used to measure the degree of change. By converting the rate of change within the time window (preset time window) into a change quantity, and further normalizing it through the median, the absolute attenuation quantity is converted into a relative attenuation ratio, thereby achieving adaptive and unified determination for different road surface adhesion conditions.

[0091] Therefore, only when the longitudinal stiffness shows a continuous decrease and the decrease reaches a certain proportion is it considered that there is substantial attenuation, thus avoiding misjudgment caused by short-term disturbances.

[0092] For example, within the time window, the proportion of sampling periods in which the longitudinal stiffness continuously decreases is greater than or equal to a preset second determination threshold.

[0093] Specifically, the above are the consistency judgment conditions based on the proportion of continuity; Within the time window Δt, the following condition is satisfied: The proportion of negative values ​​to the total number of data points exceeds

[0094] Wherein, λ2 is the second judgment threshold, which is the threshold used to characterize the proportion of continuity (e.g., 70%).

[0095] This condition characterizes the temporal consistency of the attenuation trend by statistically analyzing the monotonically decreasing degree of longitudinal stiffness over a time series. When most sampling periods show a continuous decrease, it indicates that the attenuation process is stable and continuous, rather than being caused by discrete fluctuations due to random noise or road impacts.

[0096] Furthermore, since the degradation of tire adhesion usually manifests as a continuous decrease in response capability over a period of time, compared to single-point changes or local slopes, the aforementioned continuous proportion can more intuitively reflect the dynamic degradation process of tire adhesion, and mechanistically conforms to the actual evolution law of tires gradually entering a slipping state from stable adhesion.

[0097] For example, the slope of the change in the longitudinal stiffness of the wheel is less than the slope of the change in the other wheel on the same axle, and the difference between the two is less than a preset third judgment threshold.

[0098] Specifically, the above are the difference judgment conditions based on the comparison of coaxial wheels, in other words, local anomaly identification.

[0099] The slope of the longitudinal stiffness change of the wheel The slope of the change with the other wheel on the same axle satisfy: <

[0100] Wherein, λ3 is the third judgment threshold, that is, the threshold used to characterize the difference judgment (e.g., -0.01).

[0101] This condition is used to identify abnormal local adhesion conditions by comparing the left and right wheels on the same axle. On the same axle, the two wheels are usually under similar load and environmental conditions, and their stiffness change trends should be consistent. When the descent speed of the target wheel is significantly greater than that of the other wheel (i.e., the difference is significantly negative), it can be determined that the wheel has abnormal attenuation.

[0102] This criterion is applicable to identifying localized decreases in adhesion caused by uneven road surfaces (such as unilateral ice and snow or unilateral slipperiness), while effectively filtering out synchronous changes caused by overall road surface adhesion changes (such as an overall decrease in μ).

[0103] It should also be noted that in practical applications, the above-mentioned judgment conditions can be used individually or flexibly combined according to control requirements. Optionally, in complex situations, the attenuation trend can be confirmed by satisfying at least two criteria simultaneously, or by satisfying all criteria simultaneously. For example, under normal operating conditions, the slope and amplitude of change can be used as basic criteria; under complex or noisy operating conditions, the proportion of continuity can be introduced to enhance stability; under uneven road conditions, the comparison of co-axle wheels can be introduced to improve local recognition capabilities.

[0104] This embodiment, through the aforementioned multi-dimensional judgment mechanism, can achieve high-confidence identification of the longitudinal stiffness decay trend of tires, providing a reliable triggering basis for subsequent control strategies.

[0105] In some embodiments, adjusting the torque distribution to each wheel in S103 when a decreasing trend is observed includes: S310. In response to determining that the longitudinal stiffness of a wheel exhibits a decreasing trend, the wheel is identified as the target wheel, and the torque to be transferred is determined based on the slope of the change of the target wheel.

[0106] In this step, in response to the determination that the longitudinal stiffness of a wheel exhibits a decreasing trend, that wheel is identified as the target wheel. The torque to be transferred is calculated based on the slope of the change in the longitudinal stiffness of the target wheel, which can be specifically expressed as:

[0107] in, The slope of the change in the longitudinal stiffness of the target wheel within a preset time window. This is the torque adjustment proportional gain coefficient (in the example, the initial value is set to 2000, dimensionless), used to convert the decreasing trend of longitudinal stiffness into the magnitude of the torque that needs to be transferred.

[0108] Furthermore, to ensure the driver is unaware of the change, i.e., the longitudinal acceleration fluctuation of the vehicle is less than 0.05 m / s², the torque to be transferred... It is limited to an acceptable range, for example, 3 N·m to 20 N·m.

[0109] S320. Transfer the torque to be transferred from the target wheel to at least one non-target wheel to keep the total longitudinal force requirement of the vehicle unchanged.

[0110] Specifically, when the vehicle controller detects that a wheel has triggered a "trend decay" confirmation flag (i.e., confirms a decay trend), and confirms the torque to be transferred that needs adjustment... If the torque is transferred from the target wheel to at least one non-target wheel, then the torque is transferred from the target wheel to at least one non-target wheel.

[0111] Furthermore, to avoid affecting the overall longitudinal dynamic performance of the vehicle, the transferred torque is not directly lost, but is smoothly redistributed to at least one non-target wheel, such as a wheel on the other side of the same axle or a wheel on the rear axle. Through this torque redistribution, the total longitudinal force demand of the vehicle remains unchanged, while reducing the load on the target wheel and lowering the risk of it entering the nonlinear operating region or even slip saturation.

[0112] For example, if the left front wheel (LF) triggers the "trend decay" confirmation flag, the vehicle first initiates torque pre-control logic. Based on the calculated torque to be transferred... The torque value is deducted from the torque command of the left front wheel; at the same time, the deducted torque is smoothly added to the torque command of the right front wheel (RF) or the rear axle wheel. In order to ensure the continuity of vehicle handling and the smoothness of driving feel, the torque transfer process is adjusted gradually to avoid abrupt power changes or steering instability.

[0113] The above method intervenes by utilizing early signals before the tire's longitudinal stiffness degrades, reducing the load on the target wheel before the slip ratio increases significantly, thereby delaying the time when the tire enters the nonlinear region. Simultaneously, by distributing torque to wheels with better traction, it achieves coordinated power distribution, maintaining not only the vehicle's longitudinal acceleration or braking force requirements but also ensuring vehicle stability and comfort.

[0114] Through the above-described strategy, the vehicle control system in this embodiment can achieve early intervention, fine-tuning, and smooth redistribution of torque control, thereby protecting the target wheels under low-adhesion and non-uniform road surface conditions, while ensuring the continuity and safety of the vehicle's power response.

[0115] In some embodiments, adjusting the torque distribution to each wheel in S103 when a decreasing trend is observed further includes: S410. In response to determining that the longitudinal stiffness of a wheel is showing a decreasing trend, the wheel is identified as the target wheel, and an adjustment request is sent to the vehicle's active suspension system.

[0116] In this step, after the vehicle controller detects that the longitudinal stiffness of a certain wheel is showing a decreasing trend, it identifies that wheel as the target wheel; at the same time, the vehicle controller sends an adjustment request to the vehicle active suspension system, instructing the suspension system to adjust the vertical load on the target wheel. Specifically, the aforementioned adjustment request includes the target wheel identification and preset damping adjustment parameters, enabling the active suspension system to adjust the contact state between the tire and the ground based on this information, thereby assisting in the recovery of longitudinal stiffness in terms of physical mechanism. For example, when the left front wheel triggers the "trend decay" confirmation flag, the system identifies the left front wheel as the target wheel and sends an adjustment request to the active suspension to initiate subsequent damping adjustment logic.

[0117] S420. In response to the vehicle active suspension system receiving an adjustment request, the damping of the target wheel is increased by a preset first threshold within a preset time.

[0118] In this step, after receiving an adjustment request, the vehicle's active suspension system slightly increases the suspension damping of the target wheel (e.g., by about 10%) within a calibrated time window (e.g., 100ms). This damping increment can fine-tune the vertical load distribution of the target wheel, thereby enhancing the tire's contact with the road surface and helping to mitigate the trend decay caused by the decrease in longitudinal stiffness.

[0119] For example, after the left front wheel triggers the "trend decay" confirmation flag, the active suspension increases the left front wheel suspension damping by about 10% within the next 100ms. By fine-tuning the vertical load, it assists the wheel in restoring longitudinal stiffness, while reducing the impact of trend decay on the longitudinal force distribution and handling stability of the whole vehicle.

[0120] This embodiment uses the above method to enable timely intervention in the early attenuation of the target wheel, achieving coordinated control of suspension assistance and torque distribution, and improving driving stability and safety under low adhesion and non-uniform road surface conditions.

[0121] In some embodiments, after adjusting the torque distribution of each wheel in S103, the process includes: S401. Obtain the slip ratio of each wheel and redetermine multiple longitudinal stiffnesses of each wheel within a preset time window, so as to determine whether the longitudinal stiffness of each wheel shows a decaying trend based on the redetermined multiple longitudinal stiffnesses.

[0122] In this step, the vehicle controller first acquires the slip ratio of each wheel, and then remeasures or calculates multiple longitudinal stiffness values ​​of each wheel within multiple sampling periods over a preset time window, forming a longitudinal stiffness sequence. This sequence can be used to monitor tire adhesion performance in real time and evaluate the control effect of vehicle torque distribution.

[0123] Furthermore, the vehicle controller performs trend analysis on the longitudinal stiffness sequence within the time window to identify a continuous decline. If the longitudinal stiffness of the target wheel continues to decline after torque redistribution, it indicates that the previous torque adjustment failed to effectively alleviate the tire degradation problem, meaning that the vehicle's pre-control strategy failed to achieve its intended effect.

[0124] Furthermore, it should be noted that before performing this step, the vehicle may have undergone multiple or single-round torque distribution adjustments based on the longitudinal stiffness decay trend for each wheel. Each time the longitudinal stiffness decay trend is redefined, the vehicle controller records the number of decays for that wheel. Only when the cumulative number of decays reaches a preset threshold will the system obtain the slip ratio of each wheel and reassess whether the longitudinal stiffness of each wheel exhibits a decay trend, in order to evaluate the actual effectiveness of the aforementioned torque control operation.

[0125] In other words, this scheme can make a determination after multiple rounds of longitudinal stiffness remeasurement, or it can make a determination immediately after a single torque distribution, thus taking into account both the requirements of fine control and high response speed.

[0126] This step not only captures the decay of tire longitudinal stiffness, but also evaluates the effectiveness of the control strategy in conjunction with the torque distribution results. This allows for the timely detection of wheels with control failures before significant tire slippage occurs, providing a reliable basis for further torque limiting or triggering safety control strategies. At the same time, it ensures the real-time nature and sensitivity of the monitoring process to the vehicle's dynamic response.

[0127] S402. In response to determining that the longitudinal stiffness of at least one wheel exhibits a decreasing trend and that the slip ratio of at least one wheel is greater than or equal to a preset slip threshold, the step of re-determining the multiple longitudinal stiffnesses of each wheel within a preset time window is no longer performed.

[0128] In this step, the vehicle controller can determine the effectiveness of the current torque distribution strategy based on the longitudinal stiffness change trend and slip ratio information of each wheel obtained by S401.

[0129] Specifically, the longitudinal stiffness of the target wheel can be determined according to the judgment conditions in the aforementioned embodiments to determine whether it is showing a decreasing trend; at the same time, the slip ratio of the target wheel is monitored in real time. When the slip ratio is greater than or equal to a preset threshold (e.g., 70%), it indicates that the current torque distribution strategy can no longer effectively control the tire adhesion state, that is, the torque regulation has failed.

[0130] By combining longitudinal stiffness trend and slip ratio for judgment, the vehicle controller can accurately identify whether the tire is still under control, thereby avoiding misjudgment and unnecessary control actions.

[0131] Furthermore, when it is confirmed that the longitudinal stiffness is continuously decreasing and the slip ratio exceeds the threshold, the controller will stop further longitudinal stiffness calculation and torque redistribution, and directly switch to slip response strategies, such as limiting torque output or triggering ABS / ESC control, to prevent excessive tire slippage and maintain the longitudinal stability of the vehicle.

[0132] Furthermore, once the decline trend was identified as being contained, When the trend returns to positive, it indicates that the pre-control method is effective, and the current operation can be smoothly exited, returning to normal driving.

[0133] This embodiment uses the above method to quickly identify invalid torque distribution, avoid unnecessary control operations that waste time and energy, and accurately determine the tire control status to prevent vehicle slippage or abnormal handling.

[0134] In some embodiments, obtaining the longitudinal acceleration of each wheel of the vehicle in S101 includes: S110. Determine multiple wheel speeds for each wheel within a preset time window.

[0135] In this step, the vehicle controller acquires multiple wheel speeds ω(k) (or wheel angular velocities) of each wheel within a preset time window using wheel speed sensors, which characterize the rotational state of the wheels. The time window may include multiple sampling periods, each corresponding to a wheel speed sampling point, thus forming a wheel speed time series.

[0136] Furthermore, in the actual engineering implementation process, the angular velocity can be sampled in a discrete form to obtain the wheel velocity sequence ω(k) at each sampling time, where k represents the sampling time number.

[0137] By continuously collecting multiple sampling points within a time window, a time series of wheel angular velocity can be constructed, providing basic data for subsequent rate of change calculation.

[0138] S120. Determine the wheel speed change rate of each wheel based on the multiple wheel speeds of each wheel.

[0139] In this step, the vehicle controller can determine the wheel speed change rate (i.e., wheel angular acceleration) based on the time-varying relationship of wheel speed (or angular velocity).

[0140] For example, the rate of change of wheel speed can be expressed as the derivative of angular velocity with respect to time, i.e.: .

[0141] This quantity is used to characterize how quickly the wheel's rotational speed changes over time, and is an important parameter for describing the wheel's dynamic response.

[0142] Furthermore, in actual engineering implementation, the derivative of the angular velocity with respect to time can be approximated using a discrete difference method, that is: ; Where Δt is the sampling period and ω(k) is the angular velocity of the wheel.

[0143] Through the above calculations, discrete wheel speed data can be transformed into a rate of change in a continuous sense, thereby providing an intermediate variable for subsequent longitudinal acceleration calculations and enabling the vehicle controller to more intuitively characterize the dynamic response characteristics of the wheels.

[0144] S130. Determine the longitudinal acceleration of the corresponding wheel based on the wheel speed change rate and the effective rolling radius of each wheel.

[0145] In this step, the vehicle controller can determine the longitudinal acceleration of each wheel based on the relationship between wheel speed (angular velocity) and the longitudinal motion of the vehicle.

[0146] For example, the linear velocity v and angular velocity ω of a wheel satisfy the following relationship: ; Taking the derivative of the above relationship with respect to time, we can obtain the longitudinal acceleration of the wheel. for: ; in, The effective rolling radius of the wheel is the formula used to characterize the conversion from wheel rotational motion to vehicle longitudinal translation.

[0147] In actual engineering implementation, the derivative of the angular velocity with respect to time can be approximated using the discrete difference method. Therefore, the longitudinal acceleration of the wheel can be expressed as: ; Where Δt is the sampling period, ω(k) and ω(k) are... 1) These are the wheel speeds at the current sampling time and the previous sampling time, respectively.

[0148] Using the above calculation method, the vehicle controller can obtain the longitudinal acceleration of each wheel in real time based solely on the wheel speed signal without the need for additional longitudinal acceleration sensors, thereby reducing the system hardware complexity and improving the feasibility of engineering implementation.

[0149] Furthermore, the longitudinal acceleration can serve as an important input parameter for subsequent calculation of the tire's longitudinal stiffness, characterizing the tire's transient response characteristics during driving or braking, and providing basic data support for tire adhesion state identification and torque distribution control.

[0150] This embodiment uses the above method to calculate longitudinal acceleration using only existing wheel speed sensors, effectively reducing system hardware costs and improving engineering feasibility. At the same time, the longitudinal acceleration obtained by this method can be further used for tire dynamic longitudinal stiffness calculation and adhesion state identification, thereby providing a reliable data foundation for subsequent torque distribution control and vehicle stability adjustment.

[0151] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0152] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0153] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides a vehicle pre-control device.

[0154] refer to Figure 3 The vehicle pre-control device includes: an acquisition module 601, an analysis module 602, and an execution module 603.

[0155] The acquisition module 601 is configured to acquire the longitudinal acceleration, torque, moment of inertia and effective rolling radius of each wheel of the vehicle.

[0156] The analysis module 602 is configured to determine multiple longitudinal stiffnesses of each wheel within a preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel.

[0157] The execution module 603 is configured to: determine whether the longitudinal stiffness of each wheel shows a decaying trend based on the multiple longitudinal stiffnesses of each wheel within a preset time window, and adjust the torque distribution of each wheel if the longitudinal stiffness shows a decaying trend.

[0158] Furthermore, the acquisition module 601 is also configured to: Determine multiple wheel speeds for each wheel within a preset time window; The rate of change of wheel speed for each wheel is determined based on the multiple wheel speeds of each wheel. The longitudinal acceleration of the corresponding wheel is determined based on the wheel speed change rate and the effective rolling radius of each wheel.

[0159] Furthermore, the analysis module 602 is also configured to: The longitudinal acceleration change of each wheel is determined based on the longitudinal acceleration of adjacent sampling points of each wheel; The torque variation of each wheel is determined based on the torque at adjacent sampling points of each wheel. Based on the longitudinal acceleration change, torque change, moment of inertia, and effective rolling radius of each wheel, multiple longitudinal stiffnesses of each wheel within a preset time window are determined.

[0160] Furthermore, the execution module 603 is configured as follows: Determine the longitudinal stiffness of each wheel in each sampling period; Based on the longitudinal stiffness of each sampling period, determine the slope of the change in longitudinal stiffness of each wheel within the time window; Based on the longitudinal stiffness and the slope of change of each wheel, the variation range of the longitudinal stiffness of each wheel is determined; Based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel in each sampling period, it is determined whether the longitudinal stiffness of each wheel exhibits a decreasing trend.

[0161] Furthermore, the execution module 603 is configured as follows: In response to determining that the longitudinal stiffness, the slope of change, and the magnitude of change of a wheel meet preset judgment conditions, it is determined that the longitudinal stiffness of the wheel exhibits a decreasing trend. The preset determination conditions include at least one of the following: The slope of the change in the longitudinal stiffness of the wheel is less than 0, and the magnitude of the change in the longitudinal stiffness is greater than or equal to a preset first judgment threshold. Within the time window, the proportion of sampling periods in which the longitudinal stiffness continuously decreases is greater than or equal to a preset second judgment threshold. The slope of the longitudinal stiffness change of this wheel is less than the slope of the change of the other wheel on the same axle, and the difference between the two is less than the preset third judgment threshold.

[0162] Furthermore, the execution module 603 is configured as follows: In response to the determination that the longitudinal stiffness of a wheel exhibits a decreasing trend, the wheel is identified as the target wheel, and the torque to be transferred is determined based on the slope of the change of the target wheel. The torque to be transferred is transferred from the target wheel to at least one non-target wheel to keep the total longitudinal force requirement of the vehicle constant.

[0163] Furthermore, the execution module 603 is configured as follows: In response to the determination that the longitudinal stiffness of a wheel is showing a decreasing trend, the wheel is identified as the target wheel, and an adjustment request is sent to the vehicle's active suspension system. In response to the vehicle's active suspension system receiving an adjustment request, the damping of the target wheel is increased by a preset first threshold within a preset time.

[0164] Furthermore, the execution module 603 is configured as follows: The slip ratio of each wheel is obtained, and the longitudinal stiffness of each wheel within a preset time window is re-determined. Based on the re-determined longitudinal stiffness, it is determined whether the longitudinal stiffness of each wheel shows a decaying trend. In response to determining that the longitudinal stiffness of at least one wheel exhibits a decreasing trend and that the slip ratio of at least one wheel is greater than or equal to a preset slip threshold, the step of re-determining the multiple longitudinal stiffnesses of each wheel within a preset time window is no longer performed.

[0165] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing this application, the functions of each module can be implemented in one or more software and / or hardware.

[0166] The apparatus of the above embodiments is used to implement the corresponding vehicle pre-control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0167] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the vehicle pre-control method described in any of the above embodiments.

[0168] Figure 4 This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0169] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0170] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0171] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0172] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0173] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0174] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0175] The electronic devices described above are used to implement the corresponding vehicle pre-control methods in any of the foregoing embodiments and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0176] Based on the same inventive concept, this application also provides a vehicle including the electronic equipment described above.

[0177] The beneficial effects of this vehicle are the same as those of the electronic equipment in the above embodiments, and will not be repeated here.

[0178] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the vehicle pre-control method as described in any of the above embodiments.

[0179] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0180] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the vehicle pre-control method as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0181] It is understood that before using the technical solutions of the various embodiments in this application, users will be informed of the type, scope of use, and usage scenarios of the personal information involved in an appropriate manner, and user authorization will be obtained.

[0182] For example, upon receiving a user's active request, a prompt message is sent to the user to explicitly inform them that the requested operation will require the acquisition and use of the user's personal information. This allows the user to independently choose, based on the prompt message, whether to provide personal information to the software or hardware such as electronic devices, applications, servers, or storage media performing the operations described in this application.

[0183] As an optional but not limited implementation, in response to a user's active request, sending a prompt message to the user can be done via a pop-up window, where the prompt message can be presented in text format. Furthermore, the pop-up window can also include a selection control allowing the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0184] It is understood that the above notification and user authorization process is merely illustrative and does not limit the implementation of this application. Other methods that comply with relevant laws and regulations may also be applied to the implementation of this application.

[0185] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0186] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0187] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0188] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A vehicle pre-control method, characterized in that, include: Obtain the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel of the vehicle; Based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel, determine multiple longitudinal stiffnesses of each wheel within a preset time window; Based on the longitudinal stiffness of each wheel within a preset time window, it is determined whether the longitudinal stiffness of each wheel exhibits a decaying trend, and if it does, the torque distribution of each wheel is adjusted.

2. The vehicle pre-control method according to claim 1, characterized in that, The time window includes multiple sampling periods; determining whether the longitudinal stiffness of each wheel exhibits a decaying trend based on the multiple longitudinal stiffnesses of each wheel within the preset time window includes: Determine the longitudinal stiffness of each wheel in each sampling period; Based on the longitudinal stiffness of each sampling period, determine the slope of the change in longitudinal stiffness of each wheel within the time window; Based on the longitudinal stiffness and the slope of change of each wheel, the variation range of the longitudinal stiffness of each wheel is determined; Based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel in each sampling period, it is determined whether the longitudinal stiffness of each wheel exhibits a decreasing trend.

3. The vehicle pre-control method according to claim 2, characterized in that, The step of determining whether the longitudinal stiffness of each wheel exhibits a decreasing trend based on the longitudinal stiffness, the slope of change, and the magnitude of change of each wheel within each sampling period includes: In response to determining that the longitudinal stiffness, the slope of change, and the magnitude of change of a wheel meet preset judgment conditions, it is determined that the longitudinal stiffness of the wheel exhibits a decreasing trend. The preset determination conditions include at least one of the following: The slope of the change in the longitudinal stiffness of the wheel is less than 0, and the magnitude of the change in the longitudinal stiffness is greater than or equal to a preset first judgment threshold. Within the time window, the proportion of sampling periods in which the longitudinal stiffness continuously decreases is greater than or equal to a preset second judgment threshold. The slope of the longitudinal stiffness change of this wheel is less than the slope of the change of the other wheel on the same axle, and the difference between the two is less than the preset third judgment threshold.

4. The vehicle pre-control method according to claim 3, characterized in that, The method of adjusting the torque distribution to each wheel when it exhibits a decreasing trend includes: In response to the determination that the longitudinal stiffness of a wheel exhibits a decreasing trend, the wheel is identified as the target wheel, and the torque to be transferred is determined based on the slope of the change of the target wheel. The torque to be transferred is transferred from the target wheel to at least one non-target wheel to keep the total longitudinal force requirement of the vehicle constant.

5. The vehicle pre-control method according to claim 3, characterized in that, The method of adjusting the torque distribution to each wheel when it exhibits a decreasing trend also includes: In response to the determination that the longitudinal stiffness of a wheel is showing a decreasing trend, the wheel is identified as the target wheel, and an adjustment request is sent to the vehicle's active suspension system. In response to the vehicle's active suspension system receiving an adjustment request, the damping of the target wheel is increased by a preset first threshold within a preset time.

6. The vehicle pre-control method according to claim 1, characterized in that, The time window includes multiple sampling periods, and each sampling period includes multiple sampling points. The determination of multiple longitudinal stiffnesses of each wheel within the preset time window based on the longitudinal acceleration, torque, moment of inertia, and effective rolling radius of each wheel includes: The longitudinal acceleration change of each wheel is determined based on the longitudinal acceleration of adjacent sampling points of each wheel; The torque variation of each wheel is determined based on the torque at adjacent sampling points of each wheel. Based on the longitudinal acceleration change, torque change, moment of inertia, and effective rolling radius of each wheel, multiple longitudinal stiffnesses of each wheel within a preset time window are determined.

7. The vehicle pre-control method according to claim 1, characterized in that, After adjusting the torque distribution to each wheel, the following steps are included: The slip ratio of each wheel is obtained, and the longitudinal stiffness of each wheel within a preset time window is re-determined. Based on the re-determined longitudinal stiffness, it is determined whether the longitudinal stiffness of each wheel shows a decaying trend. In response to determining that the longitudinal stiffness of at least one wheel exhibits a decreasing trend and that the slip ratio of at least one wheel is greater than or equal to a preset slip threshold, the step of re-determining the multiple longitudinal stiffnesses of each wheel within a preset time window is no longer performed.

8. The vehicle pre-control method according to claim 1, characterized in that, The acquisition of the longitudinal acceleration of each wheel of the vehicle includes: Determine multiple wheel speeds for each wheel within a preset time window; The rate of change of wheel speed for each wheel is determined based on the multiple wheel speeds of each wheel. The longitudinal acceleration of the corresponding wheel is determined based on the wheel speed change rate and the effective rolling radius of each wheel.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 8.

10. A vehicle, characterized in that, Including the electronic device as described in claim 9.

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