A vehicle escape method and vehicle

Abstract

The application discloses a vehicle escape method and a vehicle, and relates to the field of vehicle control, which comprises the following steps: acquiring vehicle state parameters including tire tread temperature, wheel slip rate and tire surface mud wrapping parameters; quantitatively evaluating the risk degree of mud hardening caused by frictional heat at the tire and road interface based on the vehicle state parameters; determining the thermodynamic risk level of the vehicle; executing an escape strategy matched with the thermodynamic risk level; limiting the driving motor current to reduce the frictional heat power at the tire and mud interface and curb temperature soaring; switching the torque output mode of the driving motor from continuous output to pulse output, using the inertial impact of the power-on stage to break through the static friction, and allowing the tire to dissipate heat and the mud to fall off under gravity in the power-off stage; and performing high-frequency micro-amplitude vibration on the active suspension of the vehicle to weaken the adhesion between the mud and the tire tread and promote the shaking off of the attached mud. The application solves the vicious cycle problem in the traditional scheme and improves the escape success rate of the vehicle in a soft road environment.

Description

Technical Field

[0001] This application relates to the field of vehicle control, and more particularly to a method for vehicle extrication and a vehicle. Background Technology

[0002] In off-road driving scenarios, the interaction mechanism between tires and the road surface is extremely complex when vehicles travel on soft surfaces such as swamps and mud pits. Existing vehicle traction control technologies typically rely on the torque output control of the drive motor. Their core logic involves calculating the slip ratio by monitoring wheel speed and vehicle speed. When wheel spin is detected, the system adjusts the motor output according to a preset torque mapping curve, attempting to use continuous driving force to help the vehicle out of trouble. Some advanced systems also incorporate electronic differential locks or simple traction control systems, distributing torque by limiting the speed of slipping wheels. These solutions primarily focus on the response characteristics of the powertrain and the kinematic state of the wheels, aiming to maximize the use of existing traction for traction escape.

[0003] However, when a tire continuously slips at high speed in mud, the large amount of heat generated by the friction during wheel spin is rapidly transferred to the mud covering the tire, causing the moisture to evaporate quickly. The wet mud dehydrates and hardens on the tire tread, forming a smooth and hard mud shell. This mud shell not only blocks the tread pattern but also causes irreversible loss of adhesion—even if the torque is subsequently reduced, the hardened mud shell cannot be removed on its own. This creates a vicious thermodynamic cycle where the more you step on the tire, the more slippery it becomes, and the more you get stuck, significantly reducing the success rate of getting out of trouble. Summary of the Invention

[0004] This application provides a vehicle extrication method and vehicle to solve the vicious cycle of power interruption caused by the frictional heat generated at the tire-mud interface during vehicle entrapment on soft surfaces such as swamps, which leads to mud dehydration and hardening, a sudden drop in adhesion.

[0005] The first aspect of this application provides a vehicle traction method, applied to an on-board controller of a vehicle, wherein the vehicle is equipped with a drive motor and an active suspension system, comprising:

[0006] Obtain vehicle status parameters, which include at least tire tread temperature, wheel slip ratio, and mud coating parameters on the tire surface;

[0007] Based on the vehicle's state parameters, the thermodynamic risk level of the vehicle is determined. The thermodynamic risk level is used to characterize the risk of mud hardening caused by frictional heat generation at the tire-road interface. The thermodynamic risk level includes at least two levels.

[0008] Implement the escape strategy corresponding to the aforementioned thermodynamic risk level;

[0009] The extrication strategy includes at least two of the following: limiting the peak current of the drive motor to reduce the frictional heat generation power at the tire-mud interface; switching the torque output mode of the drive motor from continuous torque output to pulse torque output to overcome static friction force by using inertial impact while suppressing the temperature rise of the tire surface; and controlling the high-frequency micro-amplitude vibration of the vehicle's active suspension to shake off the mud adhering to the tire surface.

[0010] A second aspect of this application provides a vehicle, comprising:

[0011] Memory, used to store executable program code;

[0012] A processor is configured to call and run the executable program code from the memory, so that the vehicle implements the vehicle extrication method of the first aspect or any implementation thereof.

[0013] A third aspect of this application provides a computer program product including computer-readable instructions that, when executed on a vehicle's onboard controller, cause the vehicle to implement the vehicle extrication method described in the first aspect or any implementation thereof.

[0014] A fourth aspect of this application provides an on-board controller, including at least one processor and a memory connected to the processor, wherein:

[0015] The memory is used to store computer programs;

[0016] The processor is used to execute the computer program, enabling the vehicle to implement the vehicle extrication method described in the first aspect or any implementation thereof.

[0017] The fifth aspect of this application provides a computer storage medium carrying one or more computer programs that, when executed by a vehicle's onboard controller, enable the vehicle to implement the vehicle extrication method described in the first aspect or any implementation thereof.

[0018] In summary, this application provides a vehicle extrication method and vehicle. This method acquires vehicle state parameters, including tire tread temperature, wheel slip ratio, and mud coating parameters on the tire surface, to construct a multi-dimensional tire-mud interface state perception system. Based on these vehicle state parameters, the risk level of mud hardening due to frictional heat generation at the tire-road interface is quantitatively assessed, thereby determining the vehicle's thermodynamic risk level. An extrication strategy matching this thermodynamic risk level is then implemented. This involves directly reducing the frictional heat generation power at the tire-mud interface by limiting the peak current of the drive motor, thus curbing temperature spikes at the source. By switching the drive motor's torque output mode from continuous output to pulsed output, the inertial impact during the energized phase overcomes static friction, providing a time window for tire cooling and mud gravity shedding during the power-off interval. Finally, by controlling the vehicle's active suspension to perform high-frequency micro-amplitude vibrations, periodic mechanical excitation is applied to weaken the adhesion between the mud and the tire tread, promoting the shedding of the attached mud. This solution addresses the vicious cycle of getting stuck deeper and deeper due to mud dehydration and hardening caused by blindly increasing torque in traditional solutions, which leads to a sharp drop in adhesion. It improves the vehicle's success rate in getting out of trouble, as well as its driving stability and reliability in soft road conditions. Attached Figure Description

[0019] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0020] Figure 1 This is a flowchart illustrating a vehicle extrication method provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the process for obtaining vehicle status parameters provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the process for controlling high-frequency micro-amplitude vibrations of a vehicle's active suspension, provided in an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the process for limiting the peak current of the drive motor provided in an embodiment of this application;

[0024] Figure 5 This is another schematic flowchart of the vehicle extrication method provided in the embodiments of this application;

[0025] Figure 6 This is another schematic diagram of the vehicle extrication method provided in the embodiments of this application;

[0026] Figure 7 This is a schematic diagram of the tire condition monitoring interface provided in an embodiment of this application;

[0027] Figure 8 This is a schematic diagram of the error warning interface provided in an embodiment of this application;

[0028] Figure 9 This is a schematic diagram of the escape interface provided in the embodiments of this application;

[0029] Figure 10 This is another schematic diagram of the vehicle extrication method provided in the embodiments of this application;

[0030] Figure 11 This is a schematic diagram of the vehicle escaping system provided in the embodiments of this application;

[0031] Figure 12 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0032] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0033] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0034] The terms "first," "second," etc., used 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 terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0035] In off-road scenarios involving soft surfaces, current technologies often blindly increase drive torque in an attempt to overcome difficulties. This single-point control strategy ignores the thermodynamic state of the tire-mud interface. The intense frictional heat generated by the tire spinning at high speed causes the mud to dehydrate and harden rapidly, forming a hard shell with a low coefficient of friction that clogs the tire tread, resulting in a sharp drop in adhesion. At the same time, continuous high current output can easily trigger the motor's overheat protection and shut it down, causing the vehicle to completely lose power.

[0036] Furthermore, due to the lack of effective means of dynamically perceiving the interface, drivers are in a state of blind driving, making it difficult to predict the risk of irreversible vehicle entrapment. Moreover, due to the inability to perceive changes in adhesion, they continue to make mistakes, further exacerbating the vicious cycle of getting deeper and deeper into the slump and slipping more and more.

[0037] Based on the above problems, this application provides a vehicle extrication method that can acquire vehicle state parameters, construct a multi-dimensional state perception system of the tire-mud interface, use the vehicle state parameters to determine the vehicle's thermodynamic risk level, and execute an extrication strategy that matches the thermodynamic risk level, so as to solve the problem of mud dehydration and hardening caused by blindly increasing torque in traditional solutions.

[0038] Figure 1 This is a flowchart illustrating a vehicle extrication method provided in an embodiment of this application. The method is applied to the vehicle's on-board controller, and the vehicle is equipped with a drive motor and an active suspension system. It may include steps 101 to 103, which are described in detail below.

[0039] 101. Obtain the vehicle's status parameters, which include at least the tire tread temperature, wheel slip ratio, and mud coating parameters on the tire surface.

[0040] State parameters are the fundamental data source for constructing a thermal coupling sensing system for vehicle tires.

[0041] The tire tread temperature is the real-time temperature value of the interface between the tire rubber surface and the mud. It can be measured by a temperature acquisition unit installed inside the tire. This tread temperature reflects the cumulative degree of frictional heat and is a thermodynamic indicator for judging whether the mud is about to dehydrate and harden. When this temperature approaches the critical point of mud dehydration, it means that the risk of mud hardening increases sharply.

[0042] Wheel slip ratio characterizes the motion state of the tire relative to the ground, reflecting the effective conversion efficiency of driving energy and the rate of shear heat generation.

[0043] Mud encapsulation parameters characterize the degree to which the tire tread pattern is filled or covered by mud, directly affecting the tire's mechanical grip and heat dissipation.

[0044] During implementation, state parameters can be acquired in real time through temperature sensors and wheel speed sensors installed inside the tires, as well as an estimation model based on motor current characteristic fusion, thus providing accurate data support for subsequent decision-making.

[0045] 102. Based on the vehicle's state parameters, determine the vehicle's thermodynamic risk level. The thermodynamic risk level is used to characterize the degree of risk of mud hardening caused by frictional heat generation at the tire-road interface. The thermodynamic risk level includes at least two levels.

[0046] This thermodynamic risk level is a quantitative assessment of the phase change trend of the mud.

[0047] In sticky soil environments such as swamps, mud possesses fluid lubricating properties at room temperature, providing a certain degree of adhesion. However, when a tire continuously idles and generates high temperatures, the water in the mud evaporates rapidly, causing it to transform from a fluid state into a hard solid shell. This process not only drastically reduces the coefficient of friction but also clogs the tire tread, creating a vicious cycle. Thermodynamic risk levels are warning classifications for this irreversible physical change.

[0048] For example, a low-risk level can be set to indicate that the mud is still in the fluid lubrication zone and only preventive intervention is needed; while a high-risk level indicates that the mud is close to or has entered the hardening critical zone and strong blocking measures must be taken immediately.

[0049] Of course, the thermodynamic risk level is not initially set at two levels; it can be three or more levels to achieve more refined control.

[0050] The specific process for determining the thermodynamic risk level will be described in detail in subsequent embodiments, and will not be elaborated here.

[0051] 103. Implement the escape strategy corresponding to the thermodynamic risk level;

[0052] The extrication strategy includes at least two of the following: limiting the peak current of the drive motor to reduce the frictional heat generation power at the tire-mud interface; switching the torque output mode of the drive motor from continuous torque output to pulse torque output to overcome static friction by using inertial impact while suppressing the temperature rise of the tire surface; and controlling the high-frequency micro-amplitude vibration of the vehicle's active suspension to shake off the mud adhering to the tire tread.

[0053] The extrication strategy addresses the mud hardening problem in a coordinated manner from three dimensions: heat source suppression, dynamic reconfiguration, and mechanical removal.

[0054] Limiting the peak current of the drive motor reduces Joule heating and frictional heat at the source, preventing the temperature from rising further.

[0055] Among them, the torque output mode of the drive motor is switched from continuous torque output to pulse torque output. This pulse torque output takes advantage of the motor's strong short-term overload capacity and heat dissipation during power-off. At the moment of power-on, the vehicle's inertia is used to overcome static friction. During the power-off interval, a time window is reserved for tire heat dissipation and mud gravity shedding, thus breaking the heat accumulation caused by continuous idling.

[0056] In one possible implementation, the torque output mode of the drive motor is switched from continuous torque output to pulse torque output, which may include: dividing the working time of the drive motor into a power-on stage and a power-off stage according to preset pulse operating parameters and running them alternately; during the power-on stage, controlling the drive motor to output short-term overload torque to overcome the static friction between the tire and the mud by means of inertia; during the power-off stage, cutting off the torque output of the drive motor to allow time for tire cooling and for the mud adhering to the tire tread to fall off.

[0057] Among them, the high-frequency micro-amplitude vibration of the active suspension is to forcibly peel off the mud that has adhered but has not yet fully hardened through mechanical external force, thereby restoring the drainage and mud removal function of the tire tread pattern.

[0058] Since a single approach is often insufficient to handle complex thermo-coupling conditions, the execution of an escape strategy should involve at least two strategies simultaneously. Only through a combination of multiple strategies can the fluid lubrication characteristics of the mud be maintained while ensuring the escape power.

[0059] In practice, the above strategies can be dynamically selected and combined according to the currently determined thermodynamic risk level. For example, flow restriction and slight vibration can be used when the risk is low, while pulse torque and strong vibration can be switched when the risk is high, thereby achieving adaptive and coordinated escape.

[0060] In this embodiment, a multi-dimensional interface state perception system is constructed by acquiring vehicle state parameters including tire tread temperature, wheel slip ratio, and mud coating parameters on the tire surface. Based on these state parameters, the risk level of mud hardening caused by frictional heat generation at the tire-road interface is quantitatively assessed, thereby determining the vehicle's thermodynamic risk level. A get-out-of-trouble strategy matching the thermodynamic risk level is then implemented. This involves directly reducing the frictional heat generation power at the tire-mud interface by limiting the peak current of the drive motor, thus curbing temperature spikes at the source. Switching the drive motor's torque output mode from continuous output to pulsed output utilizes the inertial impact during the energized phase to overcome static friction, and providing a time window for tire cooling and mud gravity shedding during the power-off interval. Furthermore, controlling the vehicle's active suspension to perform high-frequency micro-amplitude vibrations applies periodic mechanical excitation to weaken the adhesion between mud and the tire tread, promoting the shedding of adhering mud. This solves the vicious cycle problem in traditional solutions where blindly increasing torque leads to mud dehydration and hardening, causing a sudden drop in adhesion and resulting in the vehicle sinking deeper into the mud. This improves the vehicle's success rate, driving stability, and reliability in soft road conditions.

[0061] Figure 2 This is a flowchart illustrating the process of obtaining vehicle status parameters according to an embodiment of this application, which may include steps 201 to 205. These steps are described in detail below.

[0062] 201. The tire tread temperature is collected by a temperature acquisition unit installed inside the tire;

[0063] The temperature acquisition unit can be a thin temperature sensor embedded inside the tire tread rubber layer or close to the tire carcass ply layer. This temperature sensor can capture the instantaneous temperature rise generated by the friction between the tire and the mud interface in real time.

[0064] The tread temperature is a fundamental physical quantity that directly reflects the thermodynamic state of the tire-mud interface. This temperature serves as the basis for subsequent calculations of the tire temperature change rate and directly participates in determining the thermodynamic risk level.

[0065] The temperature acquisition unit can continuously read temperature values ​​at a preset sampling period and send the data to the vehicle controller. This detection period can be short, such as 10ms, to achieve timely and effective vehicle extrication. High-frequency measurement allows for precise capture of the critical temperature rise trend before mud hardening, providing a thermal basis for anti-hardening control.

[0066] For example, when a vehicle is driving in a swamp, if the tire surface begins to be covered with mud and experiences violent slippage, the shear heat will cause the tire tread temperature to rise rapidly from 45°C to 60°C in a short period of time. The temperature acquisition unit will upload this continuous temperature sequence T(t) to the vehicle controller in real time.

[0067] 202. Determine the tire temperature change rate based on the collected tread temperature data;

[0068] Tire temperature change rate can be the range of change in tread temperature per unit time, which is obtained by differential processing or difference calculation of the continuous tread temperature data collected above.

[0069] The vehicle controller performs slope fitting or difference ΔT / Δt between adjacent time points on the temperature data T(t) in the time series to obtain the real-time temperature change rate dT / dt.

[0070] Tire temperature change rate can characterize the intensity of abnormal frictional heat generation caused by mud encapsulation: when the tread is covered by thick mud, the rigid contact between the tire and the hard ground is reduced, and the heat generation is transformed into viscous shear heat generation inside the mud, resulting in a significant increase in the slope of temperature rise.

[0071] For example, when sliding on dry, hard ground, the temperature rise may be relatively gradual (e.g., 0.5℃ / s); however, when sliding in thick mud, the temperature change rate may surge to over 2.0℃ / s due to the thermal resistance and viscous shear of the mud. By monitoring this rate of change, it is possible to distinguish between a simple ambient high temperature and a rapid temperature rise caused by mud encapsulation, thus more accurately assessing the adhesion state of the mud.

[0072] 203. The wheel slip ratio is calculated based on the vehicle's speed and the wheel's rotational angular velocity;

[0073] Wheel slip ratio is a dimensionless parameter that characterizes the degree to which a tire slips relative to the ground. It is calculated as the ratio of the difference between the actual vehicle speed and the theoretical wheel rolling speed.

[0074] The onboard controller acquires the wheel rotational angular velocity from the wheel speed sensor and the actual vehicle speed from the vehicle dynamics model or GPS / radar, and calculates the wheel slip ratio.

[0075] The wheel slip ratio λ can be calculated using the following formula:

[0076] λ=(v-ω·r) / v×100% (1)

[0077] Where λ represents the wheel slip ratio, v represents the vehicle speed, r represents the effective rolling radius of the wheel, and ω represents the wheel rotational angular velocity.

[0078] This slip ratio can quantify the tire's idling intensity and can be used to determine the dynamic friction coefficient required to classify thermodynamic risk levels, as well as serve as a time reference for calculating the duration of slip ratio in mud encapsulation parameters.

[0079] For example, when the driver presses the accelerator hard and the vehicle gets stuck, the rotational angular velocity of the wheels increases sharply while the vehicle speed approaches zero. The calculated slip ratio may instantly exceed 60%. Not only is the current slip ratio value recorded, but a timer is also started to count the duration for which the slip ratio exceeds a preset threshold. This duration directly reflects the time window in which mud accumulates on the tire tread like a snowball.

[0080] 204. Collect the drive current of the drive motor and extract the current harmonic fluctuation characteristics of the drive current;

[0081] The characteristics of current harmonic fluctuations are the components in the current signal of a drive motor that deviate from the fundamental frequency. They can be obtained by acquiring the three-phase current of the motor and performing FFT (Fast Fourier Transform) or wavelet analysis.

[0082] When uneven mud clumps adhere to the tire surface, the tire's rotational mass distribution becomes unbalanced, and the mud clumps intermittently scrape and impact the road surface and vehicle body parts. These mechanical disturbances are transmitted in reverse to the motor shaft, causing the motor's output current to fluctuate at a specific frequency.

[0083] The current harmonic fluctuation characteristics of the driving current can indirectly characterize the amount and distribution uniformity of the tread deposits: the more intense the fluctuation, the larger and more irregular the mud clumps attached to the tread.

[0084] For example, when the tire tread is clean, the motor current waveform is smooth and the harmonic content is extremely low; however, when the tire tread is covered with a mud shell of uneven thickness, significant low-frequency harmonic components appear in the current spectrum, and their amplitude increases nonlinearly with the increase of the mud coating thickness.

[0085] By extracting the characteristics of this current harmonic fluctuation, it is possible to transform the invisible mud adhesion into a quantifiable electrical signal indicator.

[0086] 205. Based on the characteristics of current harmonic fluctuations, tire temperature change rate, and duration of slip ratio, a weighted calculation is performed to obtain the mud coating parameters on the tire surface.

[0087] Mud coating parameters can be a comprehensive indicator that is equivalent to the mud coating thickness and mud coverage of the tire surface.

[0088] Since the characteristics of current harmonic fluctuations can reflect the uneven mass distribution of wheels and tires, the tire temperature change rate can reflect the viscous shear heat generation intensity, and the duration of slip ratio can reflect the mud accumulation effect, the mud coating parameter is calculated by integrating the characteristics of current harmonic fluctuations, tire temperature change rate, and duration of slip ratio through calibrated weighting coefficients based on the principle of dynamic adhesion and detachment balance.

[0089] Among them, the mud encapsulation parameters can be calculated by normalizing the characteristics of current harmonic fluctuations, tire temperature change rate, and slip rate duration.

[0090] The thickness of the mud coating can be calculated using the following formula:

[0091] D=k1·H current +k2·(dT / dt)+k3·t slip (2)

[0092] Where k1, k2, and k3 are weighting coefficients calibrated based on experiments, H current The dT / dt represents the characteristic of current harmonic fluctuations, and the t represents the tire temperature change rate. slip This indicates the duration of the slip ratio.

[0093] For example, when a large fluctuation in current harmonics, a sharp rise in temperature, and slippage have been detected for 5 seconds, the weighted calculation of mud encapsulation parameters will be significantly higher than the threshold, indicating that the tread has been completely encapsulated by thick mud.

[0094] In one possible implementation, the real-time mud coating thickness on the tire surface can be determined using a mud coating thickness estimation model. This model is based on the physical concept of dynamic adhesion-detachment equilibrium. The rate of change in coating thickness is a result of the competition between mud adhesion rate and detachment rate.

[0095] The mud coating thickness estimation model can be represented by the following formula:

[0096] dD(t) / dt=R_attachment-R_detachment (3)

[0097] D(t) = D0 + ∫0 t (R_attachment-R_detachment)dτ (4)

[0098] Where D(t) represents the total thickness of the mud coating on the tire tread at time t; dD(t) / dt represents the rate of change of the mud coating thickness D with time t, a positive value indicates a net increase in mud thickness, and a negative value indicates a net decrease in mud thickness; R_attachment represents the attachment rate of mud on the tire tread, which characterizes the mass or equivalent thickness of mud adhering to the tire tread from the road surface or environment per unit time; R_detachment represents the detachment rate of mud from the tire tread, which characterizes the detachment rate of mud per unit time due to centrifugal force, airflow shear, and contact with the road surface. Factors such as scratches and tire deformation cause the mass or equivalent thickness of mud that detaches or is thrown off the tire surface; D0 represents the initial value of the mud coating thickness at time t=0; ∫(R_attachment-R_detachment)dτ represents the integral of the net attachment rate (R_attachment-R_detachment) over time from the initial time 0 to the current time t. This integral result represents the amount of change in mud thickness accumulated from the initial time to time t due to the dynamic equilibrium process of attachment and detachment.

[0099] In this embodiment, the tire temperature change rate is determined based on the tire tread temperature to capture the thermal effect caused by the viscous shear of the mud. The wheel slip ratio is determined using the vehicle speed and the wheel rotational angular velocity, and the slip ratio duration is determined based on this wheel slip ratio to quantify the time integral effect of mud accumulation. The drive current of the drive motor is used to determine the current harmonic fluctuation characteristics to intuitively reflect the non-uniformity of the tread mass distribution. By weighted fusion of the current harmonic fluctuation characteristics, tire temperature change rate, and slip ratio duration, the observations of these three different physical mechanisms are transformed into unified mud encapsulation parameters, realizing the digital reconstruction of the invisible mud thickness. This provides reliable data for subsequent classification of thermodynamic risk levels, triggering active suspension vibration for mud removal, and adjusting motor pulse torque based on these parameters, thereby effectively solving the problems of blind escape and mud hardening caused by the lack of interface dynamic perception in existing technologies.

[0100] In one possible implementation, the vehicle extrication method also includes:

[0101] Based on the relationship between wheel slip ratio and road surface adhesion characteristics, the dynamic friction coefficient of the tire-mud interface is estimated in intervals.

[0102] Wheel slip ratio is a key physical quantity that characterizes the degree of wheel slippage relative to the ground. It can be calculated based on the vehicle speed and the wheel's rotational angular velocity. The dynamic friction coefficient is the effective grip force between the tire tread and the mud interface under current working conditions, reflecting the upper limit of the road surface's ability to bear driving torque.

[0103] The dynamic friction coefficient is obtained by constructing a slip ratio friction coefficient mapping model. This slip ratio friction coefficient mapping model is based on the inverted U-shaped curve law of slip ratio and road surface adhesion coefficient in vehicle dynamics, which first rises and then falls. The real-time detected slip ratio is divided into different intervals for differentiated estimation.

[0104] Table 1 below shows the relationship between slip ratio and friction coefficient.

[0105] Table 1

[0106]

[0107] By using interval estimation, the abstract road grip force can be transformed into quantifiable control parameters, providing a direct input basis for subsequent risk classification and torque limitation, and avoiding severe wheel spin caused by torque commands exceeding the road bearing limit.

[0108] Accordingly, based on the vehicle's state parameters, the thermodynamic risk level of the vehicle is determined, including:

[0109] The thermodynamic risk level of the vehicle is determined based on the dynamic friction coefficient, tire tread temperature, and mud encapsulation parameters; the maximum allowable torque output limit of the drive motor is limited based on the dynamic friction coefficient.

[0110] Among them, the thermodynamic risk level is a comprehensive evaluation index that characterizes the degree of risk of mud hardening caused by frictional heat generation at the tire-road interface.

[0111] The estimated dynamic friction coefficient is combined with tread temperature and mud encapsulation parameters in a multi-dimensional manner to determine the thermodynamic risk level.

[0112] The maximum permissible torque output limit is the peak torque boundary that the drive motor can safely output under the current road surface adhesion conditions. It is used to prevent the drive torque from instantly exceeding the static friction force and causing the wheels to spin out of control.

[0113] The maximum allowable torque output limit is set based on a feedforward constraint according to the dynamic friction coefficient, which can use the physical bearing capacity of the road surface as the ceiling for torque output.

[0114] The vehicle controller dynamically adjusts the torque limit command of the motor controller based on the current dynamic friction coefficient: when the dynamic friction coefficient is high, the motor is allowed to output a larger torque to meet the needs of getting out of trouble; when the dynamic friction coefficient decreases, the maximum allowable torque output limit is actively reduced, so even if the driver presses the accelerator hard to request high torque, the actual torque output of the motor will not exceed this limit. This mechanism of limiting the maximum allowable torque output based on the dynamic friction coefficient enables preventative torque control. Compared to traditional feedback-based current limiting that only occurs after idling is detected, it has a faster response speed and stronger stability, effectively preventing a vicious cycle where high torque leads to severe idling, which in turn leads to high-temperature hardening and further reduction in adhesion.

[0115] For example, if the estimated dynamic friction coefficient shows that the road surface adhesion has dropped to 50% of its peak value, the system will synchronously limit the maximum allowable torque of the drive motor to within 50% of the rated maximum torque, thereby eliminating ineffective slippage and heat accumulation caused by insufficient force.

[0116] The dynamic friction coefficient characterizes the level of adhesion. Under normal tread temperature, if the dynamic friction coefficient is extremely low and accompanied by a high slip ratio, it means that the vehicle is in a dangerous condition of low adhesion and high heat generation, and therefore it will be judged as a high-risk level. Conversely, if the dynamic friction coefficient is maintained at a high level, even if there is a slight temperature rise or mud adhesion, the risk level may be assessed as a low level.

[0117] In one possible implementation, the thermodynamic risk level includes a first risk level, a second risk level, and a third risk level. The vehicle's thermodynamic risk level is determined based on the dynamic friction coefficient, tire tread temperature, and mud encapsulation parameters, including:

[0118] If any one of the following conditions is met: the mud coating parameter is greater than the first coating threshold, the tread temperature is greater than the first temperature threshold, the dynamic friction coefficient is lower than the preset friction threshold, and the wheel slip rate exceeds the preset slip threshold, the vehicle is determined to be in the first risk level.

[0119] The first risk level indicates that the tire-mud interface is in an extremely dangerous state, facing the risk of irreversible hardening of the mud or complete loss of adhesion.

[0120] The key indicators for determining whether the tire-mud interface is in an extremely dangerous state are: mud encapsulation parameters exceeding the first encapsulation threshold, tread temperature exceeding the first temperature threshold, dynamic friction coefficient below the preset friction threshold, and wheel slip ratio exceeding the preset slip threshold. The presence of any one of these three conditions indicates that the highest level of protection response is triggered as soon as any one of these key indicators exceeds the safety limit, without waiting for other indicators to deteriorate simultaneously, thus ensuring the real-time performance and safety of the control strategy. This strategy, which triggers the highest level of response upon the fulfillment of any one condition, ensures that the strongest intervention measures, such as pulse torque traction, vibration desliming, and limiting current peaks, are immediately initiated at the initial stage of risk development or at the moment of rapid deterioration, to quickly halt the mud hardening process.

[0121] If the mud encapsulation parameter is greater than the first encapsulation threshold, it means that the tread pattern has been completely filled with mud, the tire has lost its ability to expel mud and water, which is equivalent to driving on a smooth mud ball.

[0122] If the tread temperature exceeds a first temperature threshold, it indicates that the moisture in the mud is evaporating rapidly, and the surface mud is dehydrating at an accelerated rate to form a hard, low-friction outer shell. For example, this first temperature threshold could be 85°C.

[0123] If the dynamic friction coefficient is lower than a preset friction threshold and the wheel slip ratio exceeds a preset slip threshold, it indicates that the tire is in a state of severe slippage, resulting in extremely low grip and the generation of a large amount of frictional heat. For example, the preset friction threshold is set to 0.2 and the real-time slip ratio is set to 60%.

[0124] If the vehicle is not classified as a first-risk level, and any one of the following conditions is met: the mud coating parameter is within a preset coating range, the tread temperature is within a preset temperature range, or the dynamic friction coefficient is within a first preset friction coefficient range, the vehicle is classified as a second-risk level. Among these conditions, the first coating threshold is greater than the upper limit of the preset coating range, the first temperature threshold is greater than the upper limit of the preset temperature range, and the severity of the first-risk level is higher than the severity of the second-risk level.

[0125] The second risk level indicates that the vehicle is in a state of mild risk or warning. Although it has not yet reached the irreversible critical point, there is a clear trend of performance degradation, and preventive control measures need to be taken.

[0126] The failure to classify a wind turbine as having the first risk level constitutes a prerequisite for determining whether the second risk level is met. This risk assessment priority order avoids the misclassification of low-risk levels overshadowing high-risk states.

[0127] The preset package range, preset temperature range, and first preset friction coefficient range serve as moderate anomaly indicators. If any one of these moderate anomaly indicators is met by the corresponding parameter, the vehicle is determined to be at the second risk level.

[0128] Among them, mud coating parameters within the preset coating range indicate that the tread pattern has begun to be partially blocked, and the mud removal capacity has decreased. The preset coating range can be between 2 mm and 5 mm of mud thickness. Tread temperature within the preset temperature range indicates that although the dehydration and hardening point has not been reached, there is already a significant trend of heat accumulation. For example, the preset temperature range can be between 60°C and 70°C. Dynamic friction coefficient within the first preset friction coefficient range indicates that the tire's usable adhesion has dropped from its peak and the traction efficiency has deteriorated. For example, the first preset friction coefficient range can be between 0.3 and 0.5.

[0129] For example, the first preset friction coefficient range can correspond to the range where the dynamic friction coefficient decreases as the slip ratio increases when the wheel slip ratio is between 10% and 30%; the second preset friction coefficient range corresponds to the range where the dynamic friction coefficient is a high reference value when the wheel slip ratio is less than 10%.

[0130] After ruling out the first risk level, if any of the above-mentioned moderate abnormal indicators are detected, the risk level is determined to be the second risk level. Under this level, preventive strategies such as limiting the peak current of the drive motor and activating the active suspension for high-frequency micro-vibration can be implemented to suppress the continued generation of heat and shake off the uncompacted and hardened mud, preventing the working conditions from further deteriorating to the first risk level.

[0131] If the mud coating parameter is lower than the second coating threshold, the tread temperature is lower than the second temperature threshold, the dynamic friction coefficient is within the second preset friction coefficient range, and the wheel slip rate is within the preset slip rate range, all of these conditions are met simultaneously, the vehicle is determined to be in the third risk level. Among these conditions, the second coating threshold is less than the lower limit of the preset coating range, the second temperature threshold is less than the lower limit of the preset temperature range, the lower limit of the first preset friction coefficient range is greater than the upper limit of the second preset friction coefficient range, and the severity of the second risk level is higher than that of the third risk level.

[0132] The third risk level indicates that the vehicle is in a safe or normal driving state, and all interface parameters are within the ideal range, so no special intervention is required to get out of trouble.

[0133] The determination of the third risk level adopts a conservative confirmation-based judgment logic that requires all indicators to be true simultaneously. Only when all monitoring indicators return to below the safety baseline will the restrictions be lifted and the normal driving mode be restored, thus providing sufficient safety redundancy.

[0134] Mud coating parameters below the second coating threshold indicate clean tread pattern; for example, the second coating threshold can be 2mm. Tread temperature below the second temperature threshold indicates no heat buildup; for example, the second temperature threshold can be 50℃. Dynamic friction coefficient within the second preset friction coefficient range and wheel slip ratio within the preset slip ratio range indicate good tire-road engagement; for example, the second preset friction coefficient range is a friction coefficient greater than or equal to 0.6, and the preset slip ratio range is a slip ratio less than 10%.

[0135] If all three conditions are met simultaneously: mud coating parameters are below the second coating threshold, tread temperature is below the second temperature threshold, dynamic friction coefficient is within the second preset friction coefficient range, and wheel slip ratio is within the preset slip ratio range, the risk level is determined to be level three.

[0136] By setting strict threshold boundaries, a multi-tiered risk defense system is constructed. The first risk level is responsible for emergency blocking, the second risk level for early prevention, and the third risk level for normal maintenance. The hierarchical judgment logic enables the vehicle controller to match control strategies of different intensities based on the real-time perceived thermodynamic state. This avoids excessive intervention that affects the driving experience during slight slippage, while also enabling rapid intervention to prevent vehicles from getting stuck in extreme conditions.

[0137] Furthermore, the first risk level's trigger mechanism ensures a rapid response in critical moments when the mud is about to harden or adhesion suddenly drops, breaking the vicious cycle with pulse torque and strong vibration. The second risk level's interval warning and trigger mechanism proactively eliminate heat accumulation and mud adhesion hazards in the early stages of risk through flow restriction and micro-vibration, preventing the working condition from escalating. The third risk level's full-condition confirmation mechanism ensures the smoothness and economy of vehicle power output under safe conditions. Based on real-time changes in dynamic friction coefficient, tire temperature, and mud coating parameters, the control intensity is dynamically adjusted to solve the problem of adhesion deterioration exacerbating the predicament caused by thermodynamic runaway in traditional extrication solutions, improving the vehicle's success rate in extricating itself from ruts and other soft surfaces such as swamps and enhancing driving safety.

[0138] In this embodiment, the dynamic friction coefficient is estimated in intervals by utilizing the correspondence between slip ratio and road surface adhesion characteristics, achieving quantitative perception of the grip force at the tire-mud interface and solving the problem of being unable to predict adhesion changes. This dynamic friction coefficient is incorporated into the thermodynamic risk level assessment dimension, forming an evaluation model together with tire temperature and mud encapsulation parameters. This model can more accurately identify potentially high-risk conditions where the temperature is still low but adhesion is already severely insufficient. By limiting the maximum allowable torque output of the drive motor based on the dynamic friction coefficient, preventative torque control based on road surface load-bearing capacity is achieved. This allows the vehicle to proactively reduce power output in the early stages of adhesion decline, avoiding sudden breakthroughs in static friction that could cause violent idling. This reduces frictional heat generation and the tendency for mud encapsulation to worsen, preventing irreversible loss of adhesion due to mud dehydration and hardening, and improving the vehicle's success rate and safety on soft surfaces such as swamps.

[0139] Figure 3 This is a flowchart illustrating the control of high-frequency micro-amplitude vibration of a vehicle's active suspension, provided in an embodiment of this application. It may include steps 301 to 304, which are described in detail below.

[0140] 301. Based on the current thermodynamic risk level, determine the target vibration parameters. The target vibration parameters are positively correlated with the severity of the current thermodynamic risk level.

[0141] The target vibration parameters are the set of frequency, amplitude, and duration used when the active suspension performs vibration desiccation.

[0142] The value of the target vibration parameter can be determined based on the thermodynamic risk level as determined above, and there can be a preset mapping relationship between the two. For example, the higher the risk level, the more severe the risk of mud hardening or encapsulation on the tire surface, and the greater the intensity of the determined target vibration parameter.

[0143] Specifically, when the risk level is determined to be Level 2 (mild risk), a lower target vibration frequency and smaller amplitude are selected to loosen the initially attached mud through gentle mechanical excitation, avoiding excessive interference with vehicle stability. When the risk level is determined to be Level 1 (severe risk), a higher target vibration frequency and larger amplitude are selected to use high-intensity impact force to peel off the hardened or thickly coated mud crust. Through a dynamic adjustment mechanism, the target vibration parameters are positively correlated with the severity of the risk level, enabling optimal energy output to be matched when facing different difficulties, ensuring mud removal effectiveness while avoiding excessive disturbance and high energy consumption in low-risk states.

[0144] For example, if the current thermodynamic risk level is the second risk level, the target vibration frequency can be set to 2Hz (Hertz) to 3Hz, and the amplitude can be set to ±3mm; if the current thermodynamic risk level is the first risk level, the target vibration frequency can be set to 4Hz to 5Hz, and the amplitude can be set to ±5mm.

[0145] 302. Based on the target vibration parameters, control the active suspension to perform simple harmonic reciprocating motion;

[0146] This simple harmonic reciprocating motion can be a periodic displacement change of the actuator controlling the active suspension according to a sinusoidal law, thereby controlling the active suspension to vibrate. This actuator can be a hydraulic cylinder, etc.

[0147] Specifically, the vibration frequency and amplitude in the target vibration parameters can be substituted into the simple harmonic motion equation to obtain the corresponding driving signal. This driving signal is then sent to the active suspension controller. The high-frequency micro-amplitude mechanical waves generated by the movement of the active suspension controller actuator are transmitted to the wheel and tire tread, disrupting the van der Waals force and mechanical engagement force between the mud and the tire tread.

[0148] Under severe risk conditions, high-frequency simple harmonic reciprocating motion can generate more impacts per unit time, effectively breaking up the hard mud crust formed by high-temperature dehydration; while under mild risk conditions, low-frequency, small-amplitude simple harmonic motion is sufficient to cause shear slippage in the uncompacted viscous mud. Through precise waveform control, electrical energy can be converted into mechanical energy for removing mud from the tire tread, achieving physical desliming.

[0149] 303. After each preset number of vibration cycles, pause for a preset time to allow the detached mud to detach from the tire surface;

[0150] The preset number of cycles can refer to the number of cycles of continuous simple harmonic reciprocating motion, and the preset duration can refer to the resting time after the vibration stops.

[0151] Continuous vibration may cause loose mud to fail to be ejected in time under centrifugal force, instead being recompacted by tire rotation and road surface pressure. However, during periods of vibration pause, the loose mud adhering to the tire tread surface has sufficient time to detach from the tread grooves under the influence of gravity and the centrifugal force generated by tire rolling. Therefore, during the pause period, the active suspension remains stationary or resumes its normal vibration filtering mode, allowing the mud clumps that have been loosened by vibration to fall off naturally. Intermittent vibration control mimics the rhythm of manually beating clothes to remove dust, improving the actual mud removal rate, avoiding the phenomenon of mud becoming more compacted with repeated vibration, and enhancing the effectiveness of the mud removal process.

[0152] For example, the preset number of times is 10 times and the preset duration is 3 seconds. After each 10 vibration cycles, there is a 3-second pause. This application does not restrict the values ​​of the preset number of times and the preset duration.

[0153] 304. When the mud encapsulation parameter is detected to be lower than the second encapsulation threshold, stop the active suspension vibration.

[0154] The second encapsulation threshold is a pre-defined safe lower limit for the degree of mud encapsulation, indicating that the tire tread in the tire shop has basically returned to a clean state.

[0155] The mud encapsulation parameter being lower than the second encapsulation threshold is used as the closed-loop termination condition for the vibration desliming process.

[0156] The system monitors mud coating parameters in real time and compares them to a second coating threshold. Once the mud coating parameter value drops below the second coating threshold, it indicates that the mud thickness adhering to the tire tread has decreased to a safe range that does not affect the vehicle's grip. Continued vibration will cause unnecessary energy loss and component wear. At this point, the vibration drive signal of the active suspension is cut off, causing the vehicle to exit the high-frequency micro-amplitude vibration mode and return to the normal driving suspension control strategy. This process, based on adaptive control of actual results, ensures the accuracy and economy of the traction strategy.

[0157] For example, if the second wrapping threshold is set to an equivalent thickness of 2 mm, vibration will be terminated when the real-time estimated mud wrapping parameters drop to 1.8 mm.

[0158] In this embodiment, by establishing a positive correlation mapping between target vibration parameters and thermodynamic risk levels, the vibration intensity is dynamically adjusted according to the urgency of mud hardening, solving the problem that fixed parameters cannot adapt to varying vehicle entrapment conditions. Combined with precise waveform control of simple harmonic reciprocating motion, stable and targeted mechanical excitation is provided to break the mud adhesion. By setting a vibration pause cycle mechanism, the time difference is used to provide a release window for loosened mud, improving mud removal efficiency and preventing secondary compaction. The control closed loop is formed by using the mud encapsulation parameter falling back to the second encapsulation threshold as the termination condition. After achieving the goal of getting out of trouble, the vibration automatically stops, avoiding ineffective work. This process restores the drainage and mud removal capacity of the tire tread, improving the success rate of vehicle extrication on soft surfaces such as swamps.

[0159] Figure 4 This is a flowchart illustrating the process of limiting the peak current of a drive motor according to an embodiment of this application. It may include steps 401 to 404, which are described in detail below.

[0160] 401. Determine the rate of temperature change based on the tread temperature obtained in each preset testing cycle;

[0161] The rate of temperature change is the amount of change in tire tread temperature per unit time, representing the acceleration of heat accumulation at the tire-mud interface.

[0162] The vehicle controller continuously collects tire tread temperature values ​​from the temperature sensor embedded inside the tire at a preset time interval as a detection cycle. For example, the detection cycle can be set to 100ms or 200ms, etc., and this application does not impose any restrictions.

[0163] The rate of temperature change can be calculated by subtracting the tread temperature of the current testing cycle from the tread temperature of the previous one or more testing cycles and then dividing by the time interval.

[0164] The rate of temperature change can keenly detect the explosive growth trend of frictional heat generation caused by a sudden increase in wheel slip rate. Therefore, it can identify early signs of thermal runaway before the absolute temperature reaches the danger threshold, thus buying more response time for subsequent intervention measures.

[0165] For example, when a vehicle suddenly enters high-speed idling from a stationary slipping state, the tire tread temperature rises sharply from 55°C to 75°C within 2 seconds. The calculated rate of temperature change at this time will be significantly higher than the value under normal driving or slow warm-up conditions.

[0166] 402. Determine the first peak current of the drive motor based on the tire tread temperature;

[0167] The first peak current is the upper limit of the basic current allowed based solely on the current tread temperature level, without taking into account drastic temperature changes.

[0168] The vehicle controller has a pre-stored mapping table or function curve between tire tread temperature and motor peak current. As the tire tread temperature rises, to protect the motor insulation and prevent tire overheating, the first peak current output is allowed to decrease non-linearly. By determining this first peak current, a basic safety boundary is established under the current thermal load condition. This first peak current ensures that the motor output will not exceed the static safety limit under the current temperature conditions under any circumstances.

[0169] For example, when the tire tread temperature is detected to be 40°C, the first peak current can be set to 100% of the motor's rated peak current; while when the tire tread temperature rises to 65°C, the first peak current may be derated to 80% of the motor's rated peak current.

[0170] 403. When the rate of temperature change exceeds the preset rate threshold, determine the corresponding current limit ratio based on the current thermodynamic risk level.

[0171] The preset rate threshold is the critical value for determining whether heat accumulation has entered a state of accelerated deterioration, and the current limit ratio is a decay coefficient that is dynamically adjusted according to the severity of the thermodynamic risk level.

[0172] The rate of temperature change is compared to a preset threshold. If the rate of temperature change does not exceed the threshold, it indicates that heat accumulation is within a controllable range, and the current limiting ratio remains at 1, with no additional current restriction. If the rate of temperature change exceeds the threshold, it indicates that the interfacial frictional heat generation power is increasing rapidly, and the risk of mud hardening is imminent. At this point, a current limiting ratio strictly corresponding to the current thermodynamic risk level is determined. The higher the risk level, the greater the risk of mud hardening and loss of adhesion, and the smaller the corresponding current limiting ratio. This current limiting ratio corresponding to the level can be determined by looking up a table. This graded limiting method achieves a refined thermal management strategy, ensuring that the current limiting intensity is precisely matched with the real-time risk level.

[0173] For example, if the risk level is determined to be less severe (Level 2), the current limit ratio may be set to 0.8; if the risk level is determined to be more severe (Level 1), the current limit ratio may be set to 0.5 or even lower.

[0174] 404. Adjust the first peak current according to the current limit ratio to obtain the target peak current of the drive motor. The target peak current is used to suppress the frictional heat generated at the interface between the tire and the mud.

[0175] The target peak current is the final upper limit of the execution current after dynamic thermal risk correction.

[0176] The onboard controller multiplies the determined first peak current by a determined current limit ratio to obtain the target peak current. This target peak current is then sent to the motor controller as a hard constraint on torque output. By imposing a hard constraint on torque output, even when the driver presses the accelerator hard to request high torque, the actual output current is forcibly limited to within the target peak current, thereby directly reducing the shear power and frictional heat generation power at the tire-mud interface.

[0177] By rigidly constraining the torque output with the target peak current, the source of rapid heat accumulation is cut off, preventing the tread temperature from exceeding the irreversible critical point. This keeps the mud in a fluid or semi-fluid state with lubricating properties, avoiding the formation of a hard shell with a low coefficient of friction due to dehydration and hardening. This creates the necessary physical conditions for getting out of trouble using pulse torque or suspension vibration.

[0178] For example, if the first peak current is 200A (amperes), and the current limit ratio is 0.6 due to the rapid rate of temperature change and the high-risk level, the target peak current is determined to be 120A.

[0179] It should be noted that the preset rate threshold and the current limit ratio under each risk level are calibrable parameters. In actual applications, they can be set differently according to the motor heat capacity, tire heat dissipation characteristics and typical muddy working conditions. This invention does not limit them.

[0180] In this embodiment, a baseline first peak current is determined based on the tire tread temperature, establishing a safety baseline that naturally derating with increasing temperature. By monitoring whether the rate of temperature change exceeds a preset threshold, abrupt changes in heat accumulation are captured. Once an abnormal acceleration in temperature is detected, an additional current limiting ratio is immediately applied based on the current thermodynamic risk level. This synergistic mechanism of static baseline and dynamic correction solves the problem of traditional solutions relying solely on absolute temperature for delayed intervention. When the rate of temperature change increases sharply, even if the absolute temperature is still at a moderate level, the risk of impending thermal runaway can be predicted, significantly reducing the target peak current in advance. This not only suppresses frictional heat generation at the tire-mud interface, preventing the mud from hardening due to high-temperature dehydration, but also implements differentiated current limiting strategies according to different risk levels. While ensuring the vehicle has a certain amount of power to get out of trouble, it maximizes thermal safety and maintains the plasticity and adhesion recovery potential of the mud interface.

[0181] Figure 5 This is another schematic flowchart of the vehicle extrication method provided in the embodiments of this application, which may include steps 501 to 503, which can be executed before step 101. These steps are described in detail below.

[0182] 501. Obtain accelerator pedal opening, vehicle speed, and wheel slip ratio;

[0183] The accelerator pedal opening can be the physical travel of the driver pressing the accelerator pedal or a percentage value converted from an electrical signal. It is used to characterize the intensity of the driver's power request and can be a pedal position sensor signal read in real time by the vehicle controller via the bus.

[0184] Vehicle speed can be the actual rate of movement of the vehicle relative to the ground, which reflects the macroscopic motion state of the vehicle. It is obtained by collecting data from wheel speed sensors and filtering it using a vehicle speed algorithm.

[0185] Wheel slip ratio is the ratio of the difference between the wheel rotation speed and the actual vehicle speed. It is used to quantify the relative degree of slip between the tire and the road surface and can be calculated based on the vehicle speed and wheel rotation speed.

[0186] Accelerator pedal opening, vehicle speed, and wheel slip ratio together constitute the basic data source for identifying the match between the driver's intention and the vehicle's actual response. By simultaneously collecting these three types of heterogeneous data, a feature map of high power request, low actual response, and high slippage can be constructed, providing input conditions for subsequent state determination.

[0187] For example, when a driver presses the accelerator pedal hard on a muddy road, the accelerator pedal opening may instantly reach more than 90%. However, if the vehicle stops moving due to insufficient traction, the vehicle speed will approach zero, and the wheel slip ratio will rise sharply to a high level.

[0188] 502. When the accelerator pedal opening, vehicle speed, and wheel slip ratio all meet the corresponding preset thresholds and continue for a preset duration, the vehicle is determined to be in a state of being stuck due to misoperation.

[0189] The accelerator pedal opening threshold is a pre-calibrated set of critical values ​​used by the system to define irrational idling and to filter out drivers' high-power-demand behaviors. For example, this accelerator pedal opening threshold can be set to 80%.

[0190] The vehicle speed threshold is used to confirm that the vehicle is in a trapped state where it is nearly stationary or moving at extremely low speeds. For example, it can be set to 5 km / h.

[0191] The wheel slip ratio threshold is used to confirm that the tire has experienced significant relative slippage. For example, it can be set to 30%.

[0192] The preset duration is a time window during which three conditions must be met simultaneously and maintained. This duration is designed to filter out brief slippage at the moment of starting or instantaneous signal fluctuations when driving over bumpy roads, ensuring the accuracy and robustness of the judgment. For example, the preset duration is 3 seconds.

[0193] Only when the three conditions form a stable overlapping interval in the time dimension will the vehicle controller logically determine that the vehicle is currently in a state of accidental operation due to being stuck. This judgment rule excludes scenarios of high throttle or high slippage that occur under normal operating conditions such as climbing steep slopes or crawling at low speeds, thus avoiding false triggering. By introducing a time integral dimension for verification, the confidence of state recognition is improved, ensuring that intervention only occurs when the driver is truly trapped in a vicious cycle of increasing slippage.

[0194] For example, if the throttle opening is detected to be 85%, the vehicle speed is 2 km / h, and the slip ratio is 45%, and this state lasts for 3.5 seconds, the state is immediately determined to be a misoperation; conversely, if the same parameters only last for 0.5 seconds and then disappear, it is considered a transient adjustment during normal start-up and does not trigger a misoperation judgment.

[0195] 503. Prohibit the response to accelerator pedal control commands, limit the output torque of the drive motor to within the preset torque upper limit and adjust it downward to suppress continuous tire spinning.

[0196] Disabling the response to accelerator pedal control commands can be achieved by the onboard controller temporarily cutting off or ignoring the original torque request signal from the pedal sensor after determining that the vehicle is stuck due to misoperation. Instead of linearly mapping the output torque according to the driver's pedal depth, it can forcibly take over the power control of the vehicle.

[0197] The preset torque limit can refer to the maximum safe torque value that the system is allowed to output in the off-road mode. This value is much lower than the peak torque in the normal driving mode, which is designed to cut off the energy supply that causes mud to harden and tires to spin excessively from the source.

[0198] The reduction can be based on the upper limit of torque, and then dynamically and stepwise further reduce the actual output torque according to real-time slip ratio feedback or temperature change trends, until the tire regains effective grip or stops spinning. This reduction process uses thermo-coupled control logic to rapidly reduce the frictional heat generation power at the tire-mud interface, preventing the mud from forming a hard, low-friction outer shell due to high-temperature dehydration.

[0199] The torque cutoff and reduction strategy in this embodiment breaks the psychological and physical loop of the driver continuously pressing the accelerator due to anxiety, leading to heat accumulation and further loss of traction. This provides a time window for subsequent automated strategies such as pulse torque traction or active suspension vibration mud removal, while also protecting the drive motor from overheating due to prolonged stalling and shutting down.

[0200] For example, once a vehicle is stuck in a misoperation state, no matter how hard the driver presses the accelerator, the motor output torque will be forcibly clamped within 50 Nm (Newton-meters), and will continue to decrease at a rate of 5 Nm per second as the slip ratio remains high, until the slip ratio falls back to a safe range.

[0201] In this embodiment, based on verification logic of accelerator pedal opening, vehicle speed, wheel slip rate, and time duration, the system identifies driver misoperation behaviors when stuck in the vehicle. By forcibly prohibiting the response to accelerator commands and limiting the drive motor output torque to an extremely low upper limit and dynamically adjusting it, not only are the heat sources that cause mud hardening and the ineffective kinetic energy that causes tires to sink eliminated physically, but the erroneous operation loop of the driver pressing the pedal too hard is also blocked from the human-machine interaction level, avoiding the problem of human error exacerbating the vehicle's entrapment during traditional extrication processes. Moreover, the suppressed tire spin creates a stable execution environment for the vibration mud-removing action of the active suspension system, allowing the mud adhering to the tire tread to be effectively shaken off under low shear force, thereby restoring the tire tread's water and mud-removing capabilities and improving the vehicle's success rate and safety on soft surfaces such as swamps.

[0202] Figure 6This is another flowchart illustrating the vehicle extrication method provided in this application embodiment, which may include steps 601 to 603, and... Figure 1 The steps are performed in parallel, and each step is described in detail below.

[0203] 601. The vehicle-mounted display device visually displays the tire tread temperature, mud coating parameters, current traction actions, and traction progress.

[0204] In-vehicle display devices are display devices inside vehicles, such as central control displays, instrument panels, or HUDs (Head-Up Displays). They are used to convert abstract physical quantities calculated by the perception layer into graphical information that the driver can intuitively understand.

[0205] Tire tread temperature can be displayed on a heat map, with different color ranges corresponding to different temperature states. For example, green represents normal, yellow represents warning, and red represents danger or criticality. Normal is a temperature below 50°C, warning is a temperature between 50°C and 70°C, and danger or criticality is a temperature above 70°C. Tire tread temperature can also be displayed numerically. This application does not limit the specific method of presentation.

[0206] The mud coating parameters can be represented by the equivalent mud thickness. On the display device interface, the proportion of the mud coating to the maximum allowable thickness can be shown through a bar chart or a circular progress bar, or the specific millimeter value can be directly marked.

[0207] The current escape action is the specific control strategy that the system is executing, such as pulse torque output, active suspension high-frequency vibration, or current limiting. The interface can refresh this status in real time through dynamic icons or text labels.

[0208] The progress of getting out of trouble is a percentage value estimated based on the degree of improvement of vehicle status parameters within a preset detection cycle. This degree of improvement can be determined by the decrease in mobility rate and the reduction in package parameters.

[0209] Figure 7 This is a schematic diagram of the tire condition monitoring interface provided in this application embodiment. The diagram shows the layout of the four wheels on the screen and their corresponding status data. Each wheel area independently displays a real-time tread temperature value and a visual icon indicating the degree of mud coating. The tread temperature value of the left front wheel is 72°C and the mud coating degree is 60%; the tread temperature value of the right front wheel is 68°C and the mud coating degree is 45%; the tread temperature value of the left rear wheel is 72°C and the mud coating degree is 60%; and the tread temperature value of the right rear wheel is 68°C and the mud coating degree is 45%.

[0210] 602. If the vehicle is stuck in a state of misoperation, output preset dynamic demonstration content to guide the driver to perform standard operations and trigger an alarm prompt;

[0211] The stuck vehicle misoperation state is determined based on the logic of the above embodiment, that is, when the accelerator pedal opening, vehicle speed, and wheel slip ratio all meet the corresponding preset thresholds and continue for a preset duration.

[0212] The preset dynamic demonstration content can be an interactive guide animation specially designed for accidental operation scenarios. Its core purpose is to transform the abstract command of releasing the accelerator or tapping the pedal into a visual action rhythm.

[0213] When a misoperation is detected, the display device will pop up a full-screen warning box and highlight a virtual accelerator pedal icon in a prominent position. This icon dynamically scales or changes color according to the calculated optimal escape rhythm, guiding the driver to imitate this rhythm. The alarm prompts include visual and auditory warnings. The visual warning may be a flashing interface or a red highlight, while the auditory warning may be a buzzer sound or a voice announcement indicating that idling has been detected and requesting the driver to release the accelerator. By immediately preventing erroneous behavior and providing clear action guidelines, this approach breaks the vicious cycle of panic leading to further entrapment and integrates human operation into the system's collaborative escape loop.

[0214] For example, when it is determined that the driver has pressed the accelerator hard, causing the wheels to spin continuously and the vehicle speed to zero, the display device immediately switches to a red warning theme. A dynamic demonstration video simulating a pedal is played in the center of the screen, instructing the driver to intermittently press the pedal once per second. At the same time, a voice message loops, asking the driver to press the accelerator in rhythm to avoid continuous spinning. The countdown time for getting out of trouble can also be displayed on the interface.

[0215] Figure 8 This is a schematic diagram of the misoperation warning interface provided in this application embodiment. The top of the interface indicates that the vehicle has detected wheel spin and is stuck, highlighted with an exclamation mark. The middle area of ​​the interface displays the current vehicle status and a warning: immediately release the accelerator to avoid continuous wheel spin; the current status is: left rear tire temperature: 78℃ [exceeding critical temperature], mud coating: 65% [severely coated]. The bottom area of ​​the interface displays suggested actions, recommending pulse traction for getting out of trouble, and outputting the action with an animation, as well as a prompt to change "continuous pressing" to "point pressing".

[0216] 603. If the vehicle is not stuck due to misoperation, output a visual prompt corresponding to the current thermodynamic risk level of the vehicle.

[0217] The method for determining the thermodynamic risk level can be found in the explanation in the foregoing embodiments, and will not be repeated here.

[0218] The thermodynamic risk level includes a first risk level (indicating severe risk), a second risk level (indicating mild risk), and a third risk level (normal / low risk).

[0219] The visual prompts may include: real-time action display to clearly inform the driver what actions the vehicle is currently performing; progress information to show the progress of getting out of trouble to provide the driver with psychological expectations; estimates of the time to get out of trouble / required battery power to reduce driver anxiety and prevent them from making incorrect operations due to anxiety; and operation guidance to indicate the correct operating methods to guide the driver to perform the correct operations.

[0220] The visual prompts are configured differently based on the severity of different risk levels. At the first risk level, the display outputs a strong warning signal, such as a flashing red light on the wheel area, along with a text message indicating that pulse traction and powerful mud removal are in progress, informing the driver that the system has taken over control. At the second risk level, the display outputs a warning signal, such as a solid yellow light on the wheel area, indicating preventative mud removal and a prompt to gently press the accelerator, reminding the driver to cooperate with the system to reduce torque demand. At the third risk level, the display maintains a normal display or shows a green indicator indicating a normal status, without displaying any additional distracting information.

[0221] Figure 9 This is a schematic diagram of the traction control interface provided in this application embodiment. The top area of ​​the interface shows the current state as active traction control mode. The middle area of ​​the interface displays the current action, tire status, estimated traction time, and required power. The current action is vibrating to remove mud, with a progress of 40%. The tire status includes the temperature of each tire and whether the mud coating thickness is normal. The estimated traction time is 8-12 seconds, and the required power is +3%. The bottom area of ​​the interface displays an operation prompt: Please release the accelerator; the system will automatically perform traction control.

[0222] This diagram of the escape interface illustrates how the vehicle system automatically executes the escape process under severe risk conditions without user error. It makes the thermodynamic state of the invisible tire mud interface transparent, allowing the driver to intuitively understand the system's current control intent and the escape status. This reduces panic-induced intervention due to the unknown, eliminates driver anxiety caused by lack of information, and ensures the high efficiency of human-machine collaboration.

[0223] In this embodiment, an onboard display device visualizes underlying data such as tire tread temperature and mud encapsulation parameters, along with upper-level information on extrication actions and progress. The system branches processing based on whether the driver is in a state of misoperation while stuck. In this state, dynamic demonstrations guide the driver to perform standard operations, correcting instinctive errors and forcibly cutting off heat sources. In the non-misoperation state, tiered warnings are provided based on thermodynamic risk levels, clearly informing the driver of the system's anti-hardening or mud-removal operations. This not only eliminates anxiety caused by information asymmetry but also standardizes driver behavior through intuitive visual guidance. This allows human operation to work in conjunction with automated strategies such as the vehicle's pulse torque output and active suspension vibration, improving the success rate of extrication from difficult terrain such as swamps.

[0224] Figure 10 This is another schematic flowchart of the vehicle extrication method provided in the embodiments of this application, which may include steps 1001 to 1003. These steps are described in detail below.

[0225] 1001. During the execution of the escape strategy, vehicle status parameters are collected according to the preset detection cycle, and the thermodynamic risk level is updated based on the vehicle status parameters;

[0226] The preset detection cycle is the time interval during which the road surface adhesion state is reassessed during pulse torque output or active suspension vibration to ensure real-time control. This time interval is usually set to be shorter than a complete pulse on / off cycle, such as 200ms to 500ms.

[0227] The collected vehicle status parameters include at least the tire tread temperature, wheel slip ratio, mud coating parameters on the tire surface, drive motor current, vehicle speed and wheel rotational angular velocity, etc. The specific determination process of each parameter can be referred to the explanation in the aforementioned embodiments.

[0228] These real-time updated vehicle status parameters are then re-applied to the thermodynamic risk level determination logic. If any of the following indicators—mud coating parameters, tire tread temperature, or dynamic friction coefficient—changes significantly, causing it to cross a preset threshold boundary (e.g., moving from the second risk level to the first), the current thermodynamic risk level is updated. This high-frequency re-sampling and re-determination of status eliminates misjudgments caused by single measurement errors, ensuring that the control system always makes decisions based on the latest road surface physical conditions.

[0229] For example, when implementing a preventative vibration strategy with mild risk, if the rate of increase in tread temperature suddenly accelerates and exceeds a preset rate threshold within a detection cycle, the risk level is updated from the second risk level to the first risk level in real time.

[0230] 1002. When the thermodynamic risk level decreases, the corresponding escape strategy is executed according to the updated level until the vehicle returns to normal driving state; normal driving state is when the vehicle exits the escape control strategy and each component responds to the driver's operation according to the default mode.

[0231] The reduction in the thermodynamic risk level indicates that the adhesion between the tire and the mud interface is recovering and the risk of mud hardening is subsiding.

[0232] When a risk level is detected to jump from high to low, a tiered downgrade strategy is implemented. This downgrade can be from the first risk level, which represents severe hardening, to the second risk level, which represents mild risk, or further downgrade to the third risk level (normal state).

[0233] If the level is lowered, the restrictions on the drive motor can be gradually relaxed, smoothly switching the pulse torque output mode back to the continuous torque output mode, and correspondingly reducing or stopping the vibration amplitude of the active suspension. This process is gradual to avoid abrupt changes in the control mode that could cause the vehicle to lose stability again.

[0234] This normal driving state can be a special intervention mode in which the vehicle completely exits the traction control logic. At this time, the on-board controller no longer limits the peak current of the drive motor, no longer forcibly switches the torque output waveform, and the active suspension system also returns to the standard vibration filtering mode. All actuators respond to the driver's operation commands on the accelerator pedal and steering wheel by default.

[0235] For example, when the mud coating parameter drops to below 2mm and the tire tread temperature remains stable below 50℃ for two consecutive detection cycles, it can be determined that the vehicle has escaped danger, automatically remove all restrictions, and return to the normal driving mode, so as to maximize driving comfort and reduce energy consumption on the premise of successfully getting out of trouble.

[0236] 1003. If the vehicle condition does not improve within the preset detection period, adjust the pulse torque parameters and suspension vibration parameters, and continue to implement the get-out-of-trouble strategy.

[0237] The vehicle condition has not improved, which may mean that the thermodynamic risk level has not decreased or has even increased over multiple consecutive preset testing cycles, or that indicators such as slip ratio and tread temperature remain above the high-risk threshold.

[0238] The lack of improvement in the vehicle's condition indicates that the currently applied parameters, such as pulse frequency and vibration amplitude, are insufficient to overcome the current mud resistance or to effectively remove the tread deposits.

[0239] At this point, continue implementing the escape strategy and adjust the parameters.

[0240] This parameter adaptive adjustment can include adjusting one or both of the pulse torque parameter and the suspension vibration parameter.

[0241] The adjustment of the pulse torque parameter can be achieved by shortening the duration of the energizing phase to increase the instantaneous impact force, or by adjusting the duration of the de-energizing phase to optimize the mud backflow and settling time. The adjustment of the suspension vibration parameter can be achieved by increasing the vibration frequency or the amplitude, for example, by increasing the vibration frequency from 2Hz to 5Hz to avoid specific mud viscosity resonance points, or by increasing the amplitude from ±3mm to ±5mm to enhance physical peeling force.

[0242] After adjustment, the vehicle continues to execute the escape strategy in a loop, forming a closed loop of control adjustment. This gives the vehicle the trial-and-error and evolution capabilities similar to a human driver, enabling it to automatically search for the optimal combination of escape parameters under extreme conditions where the hardness and depth of the mud are unknown, thereby improving the success rate of escape.

[0243] In this embodiment, the execution of the escape strategy is not a static execution of a single command. Instead, vehicle state parameters are collected at preset detection cycles, enabling real-time monitoring of the thermodynamic state of the tire-mud interface. The thermodynamic risk level is dynamically updated based on the real-time collected state parameters, allowing the control strategy to capture changes in the vehicle tire-mud interface and ensure that the strategy always matches the current actual risk level. When the thermodynamic risk level decreases, a corresponding downgraded escape strategy is executed according to the updated level. This not only achieves a smooth transition from forceful escape to normal driving, avoiding damage to vehicle components and energy waste from over-control, but also allows for immediate release of vehicle performance after escaping danger. When the vehicle's condition does not improve, the pulse torque parameters and suspension vibration parameters are adjusted, and the strategy is continuously executed. The feedback mechanism continuously corrects the control variables, solving the problem in traditional solutions where fixed parameters cannot adapt to complex and variable soft road surfaces. By combining limiting peak current to reduce frictional heat, switching pulse torque to overcome static friction using inertia, and controlling the active suspension to vibrate at high frequency to shake off mud, a smart escape system with self-sensing, self-decision-making, and self-evolution capabilities is formed. This breaks the vicious cycle of getting deeper and deeper into trouble and slipping more and more, and improves the vehicle's survival and escape capabilities in extreme environments such as swamps.

[0244] Figure 11 This is a schematic diagram of the vehicle extrication system provided in the embodiments of this application. The system includes a perception layer and a human-machine interaction layer.

[0245] The sensing layer is equipped with motor current sensors, wheel speed sensors, tire pressure sensors, temperature sensors, etc., which are used to collect data on motor current, wheel speed, vehicle speed, and tire temperature.

[0246] The sensing layer includes an adhesion estimation module, a friction coefficient model, a thermal management strategy, and an escape strategy. The adhesion estimation module calculates the wheel slip ratio, the friction coefficient model determines the vehicle's friction coefficient, and the thermal management strategy determines the tire temperature change rate and mud coating parameters. The escape strategy is then selected using these parameters. The selection of this escape strategy is explained in the aforementioned method embodiments and will not be elaborated upon here.

[0247] The perception layer also includes a motor torque controller, an active suspension controller, a display screen / HUD, and an instrument warning system. The motor torque controller is used to respond to the traction strategy and control the motor torque output; the active suspension controller is used to respond to the traction strategy and control the suspension movement; the display screen / HUD outputs the displayed content; and the instrument warning system is used to issue alarms for situations such as getting stuck or misoperation.

[0248] The human-machine interface layer is equipped with operation intent recognition, warning, and guidance functions. The operation intent recognition function is used to identify the driver's operation intent to determine whether a misoperation has occurred. The warning and guidance function is used to determine preset dynamic demonstration content when the vehicle is stuck in a misoperation state, providing guidance through the display screen and warnings through the instrument panel. When the vehicle is not stuck in a misoperation state, the visual prompts corresponding to the current thermodynamic risk level of the vehicle are displayed on the screen to guide the driver to avoid misoperation.

[0249] To more intuitively demonstrate the vehicle extrication method provided in this application, this embodiment provides a full-process application scenario example of vehicle extrication from a swamp. It should be understood that this scenario is only a preferred embodiment for explaining the principles of the present invention and is not a limitation on the scope of protection. In actual applications, the vehicle state and environmental parameters may differ, but the control logic described in the foregoing embodiments of this application still applies.

[0250] In this application scenario, suppose a vehicle equipped with a drive motor and active suspension system gets stuck while traversing a swamp. Due to the tires sinking into the sticky mud, the driver becomes anxious and instinctively presses the accelerator pedal to over 80% to try and force the vehicle out of the slump, causing the wheels to spin violently. At this moment, the onboard controller acquires three real-time status variables: accelerator pedal opening greater than 80%, vehicle speed less than 2 km / h for more than 1 second, and wheel slip rate greater than 30%. This indicates the vehicle is in a state of accidental stuck operation. Immediately, the controller disables accelerator pedal control commands, limits the drive motor's output torque to a preset torque limit and reduces it, cutting off the artificially created heat source at the source. Simultaneously, the onboard display immediately pops up a full-screen red warning box, displaying the text "Spinning vehicle detected, please release the accelerator immediately" along with an audible alarm, and simultaneously plays a dynamic demonstration animation of the "press-release-press" rhythm to guide the driver to correct the erroneous operation. This stage demonstrates the real-time linkage between the human-machine interaction layer and the execution layer, effectively preventing the rapid hardening of mud and the aggravation of vehicle entrapment caused by continuous driver misoperation.

[0251] When the driver sees the warning and releases the accelerator pedal, the system automatically exits the misoperation prevention mode and switches to the escape mode. At this time, the latest status parameters collected by the sensing layer show that the mud coating on the tire surface has reached 6mm, the tire tread temperature has risen to 75℃, and the dynamic friction coefficient is below 0.3. Since the mud coating parameter is greater than the first coating threshold (set to 5mm) and the tire tread temperature is greater than the first temperature threshold (set to 70℃), the system directly determines that the vehicle is in the first risk level (severe risk). This indicates that the tire-mud interface is close to the irreversible hardening critical point, and the strongest level of coordinated intervention measures must be taken.

[0252] For the first level of risk, the vehicle controller immediately executes a combined escape strategy. First, the drive motor's torque output mode switches from continuous torque output to pulse torque output, cycling according to a preset on / off sequence, with a 200ms on-time and 600ms off-time. This utilizes the inertial impact of the on-time to overcome static friction, and provides a window for tire cooling and mud shedding due to gravity during the off-time intervals. Second, the active suspension system is activated into a strong vibration mode, performing simple harmonic reciprocating motion at a frequency of 4.5Hz and an amplitude of ±5mm, pausing for 1 second after every 3 vibration cycles to physically peel off the thick layer of mud that has adhered but not yet fully hardened. Simultaneously, given that the current tire temperature has reached 75℃ and is in a high-risk zone, the system's base peak current, determined based on the tire tread temperature, is subject to a current limiting ratio of 0.5, resulting in a lower target peak current. This strongly suppresses frictional heat generation and prevents the temperature from further exceeding the 85℃ phase transition critical point. During this period, the in-vehicle display device shows the interface corresponding to the active escape mode in real time, and provides feedback on the escape progress through a progress bar and the estimated remaining time, thereby eliminating driver anxiety.

[0253] Approximately 3 seconds after executing the aforementioned combined strategy, the system re-collected vehicle status parameters according to the preset detection cycle. Sensing data showed that the tire tread temperature had dropped to 60℃, the mud coating parameter had decreased to 3mm, and the dynamic friction coefficient had risen to 0.4. It was determined that all indicators had moved out of the range corresponding to the first risk level, but the mud coating parameter of 3.5mm remained within the preset coating range of 2mm-5mm, and the tire tread temperature of 65℃ was within the preset temperature range of 50℃-70℃. Therefore, the thermodynamic risk level was determined to have decreased to the second risk level (mild risk). The escape strategy was adjusted by switching the drive motor from pulse torque output back to limited linear torque output, maintaining sufficient traction while avoiding excessive impact; adjusting the active suspension vibration parameters to a lower 3Hz frequency and ±3mm amplitude, switching to a preventative mud-clearing mode; and simultaneously relaxing the current limit ratio to 0.8, allowing the motor to output more power to assist in escape. This dynamic downgrading of the strategy avoided energy waste and component wear after high-intensity intervention following risk mitigation, while maintaining the continuous ability to clean residual mud.

[0254] As the vehicle gradually drove out of the mud, when the mud encapsulation parameters were less than 2mm, the tire tread temperature was below 50℃, the dynamic friction coefficient was above 0.5, and the slip ratio was below 10%, the system determined that the thermodynamic risk level had been reduced to level three (normal state). At this point, the onboard controller completely disengaged all special traction control strategies, the drive motor resumed its default linear response to the accelerator pedal, the active suspension reverted to its conventional vibration filtering and attitude control algorithms, and the human-machine interface simultaneously resumed normal driving information display. Thus, the vehicle completed a full process from identifying the vehicle's entrapment, assisting in traction during severe risks, adaptively adjusting to mitigate minor risks, to finally exiting safely.

[0255] As can be seen from the above-described full-process application scenarios, the vehicle extrication method provided in this application constructs an organic whole with perception, decision-making, execution, and cognitive feedback capabilities. The misoperation prevention mechanism creates the necessary thermodynamic window for automatic extrication; thermodynamic risk grading ensures precise matching between intervention intensity and the severity of the working condition; the synergistic effect of pulse torque, active vibration, and dynamic current limiting breaks the vicious cycle of mud hardening at the physical level; and closed-loop feedback control enables the system to adapt to dynamic environmental changes. The technical features described in each embodiment support each other and are indispensable in this scenario, jointly achieving an efficient and safe extrication effect in swampy areas.

[0256] The above describes a vehicle extrication method provided by the embodiments of this application. The following will describe a vehicle that performs the above vehicle extrication method.

[0257] Please see Figure 12 , Figure 12 This is a structural schematic diagram of a vehicle provided in an embodiment of this application. For example...Figure 12 As shown, the vehicle includes:

[0258] Memory 1201 is used to store executable program code;

[0259] The processor 1202 is configured to call and run executable program code from memory, causing the vehicle to perform any of the vehicle skidding prediction control methods provided in the embodiments of this application.

[0260] The memory is used to store executable program code. This memory can be a non-volatile storage medium inside the vehicle controller, such as flash memory or EEPROM (Electrically Erasable Programmable Read-Only Memory), which contains computer program instructions that implement any of the vehicle traction methods described in the aforementioned method embodiments. This program code includes not only the logic for determining the thermodynamic risk level and the weighted fusion algorithm for mud-covering parameters, but also preset pulse torque timing parameters, active suspension vibration waveform parameters, and rendering resources for the human-machine interface for different risk levels. By storing complex traction strategies in software, the vehicle's traction capability no longer relies entirely on the inherent characteristics of its mechanical structure, but rather possesses the potential for continuous evolution through software definition and subsequent OTA (Over-the-Air Technology) upgrades.

[0261] The processor is used to retrieve and run executable program code from memory, enabling the vehicle to perform the vehicle extrication method as described in any of the foregoing embodiments. This processor is typically the core computing unit of an onboard controller, which can be a VCU (Vehicle Control Unit), an MCU (Micro Control Unit), or a dedicated extrication domain controller. When the vehicle is stuck in soft road conditions such as swamps, the processor reads sensor data in real time, runs the extrication algorithm in memory, and completes a closed-loop control from state perception and risk assessment to strategy execution.

[0262] Although this embodiment is described using a single processor for centralized execution as an example, in other embodiments, a distributed computing architecture can also be adopted. For example, the chassis domain controller is responsible for the coordination of suspension vibration and braking, and the power domain controller is responsible for motor torque and thermal management. The two work together through a high-speed bus to complete the task of getting out of trouble. As long as the logical functions of the aforementioned method embodiment can be realized, this application does not impose any restrictions on this.

[0263] To support the efficient execution of the above methods, the vehicle's hardware architecture also includes a robust communication network. The onboard controller establishes signal connections with the drive motor controller, active suspension controller, and onboard display device via an onboard communication bus. For example, a CAN (Controller Area Network) bus or an Ethernet bus can be used to achieve data interaction between the nodes. In this architecture, control commands such as the target peak current, pulse on / off timing, and suspension vibration frequency calculated by the processor can be transmitted to the corresponding actuators with millisecond-level low latency; simultaneously, high-frequency sensor data such as wheel speed, tire temperature, and motor current can also be transmitted back to the processor in real time for status updates. This high-bandwidth, low-latency hardware communication link is the physical basis for realizing thermo-coupled collaborative control and cognitive execution closed-loop human-machine interaction, ensuring that during the brief window before the mud hardens, multiple actuators can be precisely and synchronously mobilized to jointly escape the predicament, avoiding strategy failure or action misalignment due to communication lag.

[0264] This application also provides a computer program product including computer-readable instructions, which, when executed on the vehicle's onboard controller, cause the vehicle to implement any of the vehicle skidding prediction control methods provided in this application.

[0265] A fourth aspect of this application provides an on-board controller, including at least one processor and a memory connected to the processor, wherein:

[0266] The memory is used to store computer programs;

[0267] The processor is used to execute the computer program, enabling the vehicle to implement any of the vehicle skidding prediction and control methods provided in the embodiments of this application.

[0268] This application also provides a computer-readable storage medium carrying one or more computer programs. When the one or more computer programs are executed by the vehicle's onboard controller, the vehicle can implement any of the vehicle skidding prediction control methods provided in this application.

[0269] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0270] It is understood that the data involved in this technical solution (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of relevant laws, regulations and related provisions.

[0271] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and 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 network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the accompanying drawings of the device embodiments provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.

Claims

1. A method for getting a vehicle out of trouble, characterized in that, An onboard controller for a vehicle equipped with a drive motor and an active suspension system, comprising: Obtain vehicle status parameters, which include at least tire tread temperature, wheel slip ratio, and mud coating parameters on the tire surface; Based on the vehicle's state parameters, the thermodynamic risk level of the vehicle is determined. The thermodynamic risk level is used to characterize the risk of mud hardening caused by frictional heat generation at the tire-road interface. The thermodynamic risk level includes at least two levels. Implement the escape strategy corresponding to the aforementioned thermodynamic risk level; The extrication strategy includes at least two of the following: limiting the peak current of the drive motor to reduce the frictional heat generation power at the tire-mud interface; switching the torque output mode of the drive motor from continuous torque output to pulse torque output to overcome static friction force by using inertial impact while suppressing the temperature rise of the tire surface; and controlling the high-frequency micro-amplitude vibration of the vehicle's active suspension to shake off the mud adhering to the tire surface.

2. The vehicle extrication method according to claim 1, characterized in that, The acquisition of vehicle status parameters includes: The tire tread temperature is collected by a temperature acquisition unit installed inside the tire. Based on the collected tread temperature data, determine the tire temperature change rate; The wheel slip ratio is calculated based on the vehicle's speed and the wheel's rotational angular velocity. The drive current of the drive motor is collected, and the current harmonic fluctuation characteristics of the drive current are extracted. The mud coating parameters on the tire surface are obtained by weighted calculation based on the current harmonic fluctuation characteristics, tire temperature change rate, and slip rate duration.

3. The vehicle extrication method according to claim 1, characterized in that, Also includes: Based on the relationship between wheel slip ratio and road surface adhesion characteristics, the dynamic friction coefficient of the tire-mud interface is estimated in intervals. Accordingly, determining the thermodynamic risk level of the vehicle based on its state parameters includes: Based on the dynamic friction coefficient, tire tread temperature, and mud encapsulation parameters, the thermodynamic risk level of the vehicle is determined. Based on the dynamic friction coefficient, the maximum allowable torque output limit of the drive motor is restricted.

4. The vehicle extrication method according to claim 3, characterized in that, The thermodynamic risk level includes a first risk level, a second risk level, and a third risk level. Determining the vehicle's thermodynamic risk level based on the dynamic friction coefficient, tire tread temperature, and mud encapsulation parameters includes: If any one of the following conditions is met: the mud coating parameter is greater than the first coating threshold, the tread temperature is greater than the first temperature threshold, the dynamic friction coefficient is lower than the preset friction threshold, and the wheel slip rate exceeds the preset slip threshold, the vehicle is determined to be in the first risk level. If the vehicle is not classified as a first-risk level, and any one of the following conditions is met: the mud coating parameter is within a preset coating range, the tread temperature is within a preset temperature range, or the dynamic friction coefficient is within a first preset friction coefficient range, the vehicle is classified as a second-risk level. Wherein, the first coating threshold is greater than the upper limit of the preset coating range, the first temperature threshold is greater than the upper limit of the preset temperature range, and the severity of the first-risk level is higher than the severity of the second-risk level. If the mud coating parameter is lower than the second coating threshold, the tread temperature is lower than the second temperature threshold, the dynamic friction coefficient is within the second preset friction coefficient range, and the wheel slip rate is within the preset slip rate range, all of these conditions are met simultaneously, the vehicle is determined to be in the third risk level. Among these conditions, the second coating threshold is less than the lower limit of the preset coating range, the second temperature threshold is less than the lower limit of the preset temperature range, the lower limit of the first preset friction coefficient range is greater than the upper limit of the second preset friction coefficient range, and the severity of the second risk level is higher than the severity of the third risk level.

5. The vehicle extrication method according to claim 4, characterized in that, The control of high-frequency micro-amplitude vibration of the vehicle's active suspension includes: Based on the current thermodynamic risk level, target vibration parameters are determined, and the target vibration parameters are positively correlated with the severity corresponding to the current thermodynamic risk level; Based on the target vibration parameters, the active suspension is controlled to perform simple harmonic reciprocating motion; After each preset number of vibration cycles is completed, the cycle is paused for a preset duration to allow the detached mud to detach from the tire tread. When the mud encapsulation parameter is detected to be lower than the second encapsulation threshold, the active suspension vibration is stopped.

6. The vehicle extrication method according to claim 1, characterized in that, The limitation of the peak current of the drive motor includes: The rate of temperature change is determined based on the tread temperature obtained in each preset testing cycle. Based on the tire tread temperature, determine the first peak current of the drive motor; If the rate of temperature change exceeds a preset rate threshold, the corresponding current limiting ratio is determined based on the current thermodynamic risk level. The first peak current is adjusted according to the current limiting ratio to obtain the target peak current of the drive motor. The target peak current is used to suppress frictional heat generation at the tire-mud interface.

7. The vehicle extrication method according to claim 1, characterized in that, Also includes: Obtain accelerator pedal opening, vehicle speed, and wheel slip ratio; When the accelerator pedal opening, vehicle speed and wheel slip ratio all meet the corresponding preset thresholds and remain for a preset duration, it is determined that the vehicle is in a state of being stuck due to misoperation. The system disables accelerator pedal control commands, limits the drive motor output torque to a preset torque limit and lowers it to suppress continuous tire spinning.

8. The vehicle extrication method according to claim 7, characterized in that, Also includes: The vehicle-mounted display device visually displays tire tread temperature, mud encapsulation parameters, current extrication actions, and extrication progress. If the vehicle is stuck in a state of misoperation, output preset dynamic demonstration content to guide the driver to perform standard operations and trigger an alarm prompt; If the vehicle is not stuck due to misoperation, output a visual prompt corresponding to the current thermodynamic risk level of the vehicle.

9. The vehicle extrication method according to claim 1, characterized in that, Also includes: During the execution of the escape strategy, vehicle status parameters are collected according to a preset detection cycle, and the thermodynamic risk level is updated based on the vehicle status parameters. When the thermodynamic risk level decreases, the corresponding escape strategy is executed according to the updated level until the vehicle returns to normal driving state. The normal driving state is the vehicle exit traction control strategy, and each component responds to the driver's operation according to the default mode. If the vehicle condition does not improve within the preset detection period, the traction strategy will continue to be implemented after adjusting the pulse torque parameters and suspension vibration parameters.

10. A vehicle, characterized in that, include: Memory, used to store executable program code; A processor is configured to call and run the executable program code from the memory, causing the vehicle to perform the vehicle extrication method as described in any one of claims 1 to 9.

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