All-terrain tank turning method and system

Abstract

This invention discloses a method and system for achieving tank turns in all terrains, relating to the field of vehicle technology. The method includes: when a vehicle needs to turn, firstly, acquiring rotational speed signals via ABS wheel speed sensors to determine a reference vehicle speed and the actual rotational speed of the inner rear wheel; then calculating the slip ratio, combining it with an all-terrain switch signal to determine the terrain and target slip ratio, obtaining the slip ratio deviation; based on the deviation, obtaining a clamping force control quantity through PID calculation, converting it into an EPB motor drive signal to adjust the clamping force, and achieving continuous dynamic adjustment of the clamping force by re-acquiring wheel speed signals. This invention solves the problem in existing tank turn implementation methods that struggle to balance steering performance, road adaptability, and chassis system durability.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method and system for enabling tanks to turn around in all terrains. Background Technology

[0002] Vehicle's extreme maneuverability and off-road capability are core technological characteristics of off-road vehicles. Functions such as small turning radius steering and U-turns directly determine a vehicle's ability to pass through narrow terrain and complex road conditions and survive. With the development of vehicle electrification and drive-by-wire technology, the electronic parking brake (EPB) system has evolved from traditional parking functions to advanced functions such as dynamic service braking, dynamic limited slip, and dynamic steering assist.

[0003] Tank turn (also known as tank steering, stationary turn, or inner wheel brake-assisted steering) significantly reduces the turning radius by applying a controllable torque to the inner rear wheel, forcibly establishing a speed difference between the left and right drive wheels. Current mainstream technology in the industry still primarily relies on open-loop fixed torque / direct locking, lacking a closed-loop adjustment mechanism based on wheel motion states, making it difficult to balance steering performance, road adaptability, and chassis system durability. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method and system for realizing tank turning around in all terrains, which aims to solve the problem that the existing tank turning methods are difficult to balance steering performance, road adaptability and chassis system durability.

[0005] This invention proposes a method for achieving tank turning in all terrains, applied to a vehicle stability control system integrating EPB software. The vehicle stability control system is communicatively connected to ABS wheel speed sensors, an all-terrain mode selection switch, and EPB electronic calipers. The method includes: When it is detected that the vehicle needs to perform a tank turn, the rotational speed signal of the wheels is acquired in real time by the ABS wheel speed sensor, and the reference speed of the vehicle and the actual rotational speed of the inner rear wheel are determined based on the rotational speed signal. The vehicle's slip ratio is determined based on the reference vehicle speed and the actual rotation speed of the inner rear wheel. The current terrain of the vehicle is determined based on the all-terrain mode selection switch signal. The slip ratio deviation is obtained based on the slip ratio and the target slip ratio corresponding to the current terrain of the vehicle. The clamping force control quantity is obtained by PID calculation based on the slip ratio deviation. The clamping force control quantity is then converted into a drive signal for the EPB motor, which drives the motor of the EPB electronic caliper to rotate, thereby realizing the dynamic adjustment of the clamping force. The wheel speed signal collected in real time by the ABS wheel speed sensor is reacquired to determine the clamping force control amount at the current wheel speed, and the clamping force is continuously and dynamically adjusted based on the clamping force control amount.

[0006] Furthermore, in the aforementioned method for achieving tank turning in all terrains, the step of determining the vehicle's reference speed and the actual rotational speed of the inner rear wheel based on the rotational speed signal includes: The rotation speed signal is filtered and denoised, and the wheel speed of each wheel of the vehicle is determined based on the wheel speed signal; The reference speed is obtained by adjusting the speed of the outer rear wheel based on the speed of the outer rear wheel and taking into account the overall vehicle driving conditions. The steps for determining the vehicle's slip ratio based on the reference vehicle speed and the actual rotational speed of the inner rear wheel include: ; in, This represents the actual slip ratio. For reference speed, This represents the actual rotational speed of the inner rear wheel.

[0007] Furthermore, in the above-mentioned method for tank turning around in all terrains, the step of obtaining the clamping force control quantity by performing PID calculation based on the slip ratio deviation includes: ; ; in, This is the proportionality coefficient. The integral coefficient is... These are the differential coefficients. For slip ratio deviation, For the target slip ratio, This represents the actual slip ratio.

[0008] Furthermore, in the aforementioned method for tank turning around in all terrains, the step of obtaining the target slip ratio corresponding to the current terrain of the vehicle includes: Based on the preset vehicle model parameters, a benchmark dynamic model of the slip ratio of the inner rear wheel tank turn target is built. Combined with the vehicle braking and transmission matching dynamic simulation, the critical constraint value of the inner rear wheel brake lock-up and the critical value of the transmission system impact tolerance are solved to determine the initial theoretical range threshold of the target slip ratio. Based on the initial theoretical interval threshold, bench calibration tests and multi-road condition vehicle calibration tests were carried out respectively. The theoretical deviation of the benchmark dynamic model was corrected through bench calibration. Through vehicle calibration corresponding to different terrain modes, measured data of tank turning radius, tire wear, transmission shock and brake thermal load were collected. The optimal correction coefficient of target slip ratio corresponding to each terrain condition was iteratively optimized. The target slip ratio values ​​corresponding to each terrain after calibration and iterative optimization are solidified to generate the all-terrain target slip ratio MAP solidification curve built into the vehicle stability control system. The MAP solidification curve uses the all-terrain mode selection switch signal as a one-dimensional query index and the real-time reference vehicle speed as a two-dimensional compensation variable to achieve dynamic adaptive matching of the target slip ratio. The system collects all-terrain mode selection switch signals in real time and identifies the current terrain conditions. Based on the reference vehicle speed, it finds the corresponding target slip ratio in the target slip ratio MAP fixed curve.

[0009] Furthermore, the above-mentioned method for achieving tank turning in all terrains, after the step of driving the motor of the EPB electronic caliper to rotate and dynamically adjust the clamping force, further includes: Synchronously start the fault counter and fault timer to begin real-time counting and timing; When the system experiences any of the following faults: mechanical jamming of the caliper, damage to the EPB motor, communication interruption between the controller and the actuator, or inability to establish clamping force, the inner wheel cannot reach the target slip ratio. The controller drives the caliper to enter repeated clamping attempts. Each time a clamping action is performed, the counter is decremented by 1. When the counter equals zero, the EPB clamping action is immediately terminated, the motor drive signal is cut off, a fault code is reported, and the fault indicator light is illuminated; or When the timer reaches ≥t seconds, the EPB clamping action is immediately forcibly stopped, the motor drive signal is cut off, a fault code is reported through the fault diagnosis module, the instrument fault indicator light is illuminated, and the tank turning function is prevented from being reactivated until the fault is resolved.

[0010] Furthermore, in the above-mentioned method for tank turning around in all terrains, the step of obtaining the clamping force control quantity by performing PID calculation based on the slip ratio deviation includes: The system acquires the actual rotational speed signal of the inner rear wheel in real time, and performs differential processing on the rotational speed signals of multiple consecutive control cycles to obtain the instantaneous angular acceleration of the inner rear wheel. ; Based on instantaneous angular acceleration Moment of inertia of the inner rear wheel Calculate the dynamic torque fluctuation energy of the current transmission system. ; Determine the energy of dynamic torque fluctuation Trend of change: If If the transmission system exhibits a divergent trend and exceeds the preset transmission tolerance threshold, it is determined that there is a risk of resonance. When a resonance risk is determined, the differential coefficients in the PID calculation are... Perform negative dynamic attenuation, while adjusting the scaling factor. Perform small positive compensation to maintain system response speed; The adjusted and Substituting into the PID calculation formula, the clamping force control quantity for the current control cycle is calculated. This is to suppress transmission system impact and maintain a stable slip ratio.

[0011] Furthermore, in the aforementioned method for achieving tank turning in all terrains, the determination of dynamic torque fluctuation energy... Trend of change: If If the transmission system exhibits a divergent trend and exceeds a preset transmission tolerance threshold, the steps to determine if there is a risk of resonance include: Calculate dynamic torque fluctuation energy The first derivative with respect to time yields the energy dissipation rate of the current transmission system. ; Build with For the horizontal axis, The two-dimensional phase plane is the vertical axis, and is based on the current point. , Based on the historical points of the previous cycle, the tangential vector direction of the phase trajectory is fitted and predicted; If the tangential vector points into the phase plane The increased area, and If the absolute value of the signal shows an increasing trend, it is determined that the transmission system is in a divergent and unstable state, and there is a risk of resonance. If the tangential vector points towards the origin of the phase plane, the transmission system is determined to be in a stable attenuation state.

[0012] Another objective of this invention is to provide a tank turn-around system for all terrains, applied in a vehicle stability control system integrating EPB software. The vehicle stability control system is communicatively connected to ABS wheel speed sensors, an all-terrain mode selection switch, and EPB electronic calipers. The system includes: The acquisition module is used to acquire the wheel speed signals collected in real time by the ABS wheel speed sensors when the vehicle needs to perform a tank turn. Based on the speed signals, the reference vehicle speed and the actual speed of the inner rear wheel are determined respectively. The determination module is used to determine the vehicle's slip ratio based on the reference vehicle speed and the actual rotation speed of the inner rear wheel, determine the current terrain of the vehicle based on the all-terrain mode selection switch signal, and obtain the slip ratio deviation based on the slip ratio and the target slip ratio corresponding to the current terrain of the vehicle. The calculation module is used to perform PID calculations based on the slip ratio deviation to obtain the clamping force control quantity, and convert the clamping force control quantity into a drive signal for the EPB motor to drive the motor of the EPB electronic caliper to rotate, thereby realizing dynamic adjustment of the clamping force. The adjustment module is used to reacquire the wheel speed signal collected in real time by the ABS wheel speed sensor, determine the clamping force control amount at the current wheel speed, and realize continuous dynamic adjustment of the clamping force based on the clamping force control amount.

[0013] Another object of the present invention is to provide a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0014] Another object of the present invention is to provide an electronic device including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of the method described above.

[0015] This invention acquires the wheel speed signals collected in real time by the ABS wheel speed sensor when a tank turn is detected. Based on the speed signals, it determines the vehicle's reference speed and the actual speed of the inner rear wheel. The vehicle's slip ratio is determined based on the reference speed and the actual speed of the inner rear wheel. The current terrain of the vehicle is determined based on the all-terrain mode selection switch signal, and the slip ratio deviation is obtained based on the slip ratio and the target slip ratio corresponding to the current terrain. A PID calculation is performed based on the slip ratio deviation to obtain the clamping force control quantity, which is then converted into a drive signal for the EPB motor to drive the EPB electronic caliper motor, achieving dynamic adjustment of the clamping force. The wheel speed signals collected in real time by the ABS wheel speed sensor are acquired again to determine the clamping force control quantity at the current wheel speed, and continuous dynamic adjustment of the clamping force is achieved based on this clamping force control quantity. By using wheel slip ratio as feedback, and adjusting the EPB clamping force in real time through a PID controller, high-precision closed-loop servo control of the inner rear wheel slip ratio is achieved. This ensures that the vehicle maintains the optimal slip ratio under different road conditions, guaranteeing a minimum turning radius while avoiding system impact and component damage caused by complete wheel lock-up, ultimately achieving adaptability to different terrains. This solves the problems of existing tank turning technologies that mostly use open-loop fixed torque control without closed-loop adjustment, resulting in poor road adaptability and difficulty in balancing steering performance and chassis durability.

[0016] In addition, the embodiments of the present invention also have at least the following beneficial effects: 1. Strong all-terrain adaptive capability: Automatically matches the target slip ratio based on road surface adhesion, combined with PID closed-loop adjustment, resulting in a smaller turning radius on low-adhesion roads and better protection on medium- and high-adhesion roads, covering the needs of various scenarios such as off-road and special operations; 2. High closed-loop control accuracy: The slip ratio PID servo adjustment is adopted, which has high control accuracy of the deviation between the actual slip ratio and the target slip ratio. The braking force is soft, precise and stable with small impact, which improves steering smoothness and controllability. 3. Avoid component damage: Instead of directly locking up or using maximum clamping force, the tank turns around using optimal clamping force, which significantly reduces transmission system impact, brake load and localized abnormal tire wear, and extends the service life of key chassis components; 4. High fail-safe level: The dual fault detection mechanism of counter limit + timer timeout is robust and can effectively identify various faults such as caliper failure, mechanical jamming, and execution failure, eliminating secondary damage caused by ineffective repeated clamping and improving system safety and reliability. 5. Strong system compatibility and easy mass production: Based on the existing EPB hardware architecture, it does not require the addition of a large number of sensors and actuators. It can be achieved through software algorithm optimization alone. It is low in cost, highly adaptable, and can be quickly installed in various vehicles with EPB systems. 6. Fast control response: Real-time data acquisition and control, combined with dynamic optimization of PID parameters, enables rapid response to changes in road surface and slip ratio deviations, ensuring the stability and timeliness of steering performance. Attached Figure Description

[0017] Figure 1 This is a flowchart of the tank turning method for all terrains in the first embodiment of the present invention; Figure 2 This is a structural block diagram of the tank turning-around system for all terrains in the third embodiment of the present invention.

[0018] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0019] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0020] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Example 1 Please see Figure 1 The figure shows a method for tank turning around in all terrains according to the first embodiment of the present invention, the method including steps S10 to S13.

[0023] Step S10: When it is detected that the vehicle needs to perform a tank turn, the rotational speed signal of the wheels collected in real time by the ABS wheel speed sensor is obtained, and the reference vehicle speed and the actual rotational speed of the inner rear wheel are determined based on the rotational speed signal.

[0024] When the vehicle control system detects that the driver issues a tank turn operation command (such as by means of steering wheel limit angle, dedicated control button, etc.) and determines that the vehicle needs to perform a tank turn, the system will immediately start signal interaction with the ABS wheel speed sensor to obtain the rotation speed signal of the vehicle's four wheels collected by the sensor in real time. This rotation speed signal can accurately reflect the real-time rotation speed, rotation direction and rotation speed change trend of each wheel, providing basic data support for the subsequent precise control of the tank turn. Subsequently, the control system processes and analyzes the collected wheel speed signals using a pre-set algorithm. On one hand, it calculates and determines the vehicle's current reference speed by combining the average speed of each wheel and parameters such as the wheel rolling radius. This reference speed objectively reflects the overall driving state of the vehicle and serves as an important benchmark for judging wheel slippage. On the other hand, by identifying information such as the vehicle's steering direction and wheel position, it accurately locates the inner rear wheel that requires braking force when performing a tank turn. Then, it filters the real-time speed data of the inner rear wheel from the collected wheel speed signals to determine the actual speed of the inner rear wheel. This provides targeted real-time data for subsequent calculation of slip ratio and adjustment of braking force, ensuring that the braking torque of the inner rear wheel can be accurately controlled during the tank turn, thereby establishing a reasonable speed difference between the left and right drive wheels and ensuring the smooth completion of the tank turn.

[0025] Specifically, the steps of determining the vehicle's reference speed and the actual speed of the inner rear wheel based on the rotational speed signal include: The rotation speed signal is filtered and denoised, and the wheel speed of each wheel of the vehicle is determined based on the wheel speed signal; The reference speed is obtained by adjusting the speed of the outer rear wheel based on the speed of the outer rear wheel and taking into account the overall vehicle driving conditions.

[0026] First, the system will perform special filtering and noise reduction on the raw wheel speed signal collected in real time from the ABS wheel speed sensor. Specific signal processing algorithms can be used here, such as Kalman filtering algorithm or moving average filtering algorithm, to effectively filter out noise signals and instantaneous abnormal data generated by factors such as electromagnetic interference, sensor operation error, road bumps and impacts during signal transmission. After completing the filtering and noise reduction process, and combining the inherent parameters such as the rolling radius of the vehicle wheels, the real-time wheel speed of each of the four wheels of the vehicle is accurately calculated through a specific wheel speed calculation algorithm example. This provides accurate and reliable basic data support for the subsequent determination of the reference vehicle speed and the extraction of the actual rotation speed of the inner rear wheel. Subsequently, when determining the reference speed, the system prioritizes the wheel speed of the outer rear wheel as the core benchmark. This is because during a tank turn, the outer rear wheel does not require braking intervention, and its wheel speed can more accurately reflect the actual driving state of the vehicle, avoiding the problem of wheel speed distortion caused by the application of subsequent braking force on the inner wheel. Then, it combines multiple vehicle driving state parameters such as the current driving posture of the whole vehicle (e.g., body tilt angle, steering angle), power output status (e.g., engine output power, drive torque), and road feedback information (e.g., road friction coefficient, bumpiness) to dynamically correct the wheel speed of the outer rear wheel through correction algorithms (e.g., proportional integral correction algorithm or fuzzy PID correction algorithm). This effectively eliminates wheel speed deviations caused by factors such as road surface undulations, power output fluctuations, and changes in steering posture, ultimately obtaining a reference speed that objectively and accurately reflects the overall driving state of the vehicle, providing a reliable benchmark for subsequent slip ratio calculation and braking force adjustment. Meanwhile, after completing the wheel speed calculation for each wheel, the system will accurately locate the inner rear wheel that needs to apply braking force during the tank's turn by recognizing relevant information such as the vehicle's steering direction signal and wheel installation position markings. Then, from the real-time wheel speed data of the four wheels after filtering and noise reduction, the system will accurately filter out the rotational speed data corresponding to the inner rear wheel and finally determine the actual rotational speed of the inner rear wheel.

[0027] Step S11: Determine the vehicle's slip ratio based on the reference vehicle speed and the actual rotation speed of the inner rear wheel; determine the current terrain of the vehicle based on the all-terrain mode selection switch signal; and obtain the slip ratio deviation based on the slip ratio and the target slip ratio corresponding to the current terrain of the vehicle.

[0028] First, based on the obtained reference vehicle speed and the actual rotational speed of the inner rear wheel, the actual slip ratio of the vehicle is accurately calculated using a preset slip ratio calculation algorithm. This actual slip ratio can truly reflect the motion state of the inner rear wheel during the tank's turn, and intuitively show the degree of slip between the inner rear wheel and the ground. In specific implementation, the calculated actual slip ratio can also be limited, and an anti-shake threshold can be set to avoid control malfunctions caused by instantaneous signal fluctuations, thus ensuring the reliability of the slip ratio feedback signal.

[0029] For example, the formula for calculating slip ratio is: ; in, This represents the actual slip ratio. For reference speed, This represents the actual rotational speed of the inner rear wheel.

[0030] Subsequently, the system will collect the all-terrain mode selection switch signal in real time. The switch can be manually switched by the driver according to the actual driving conditions, or automatically switched by the vehicle control system according to the road feedback. Different switch signals correspond to different terrain modes (such as snow mode, mud mode, gravel mode, paved road mode, etc.). By identifying the specific type of the switch signal, the system can accurately determine the terrain environment in which the vehicle is currently located. Meanwhile, the vehicle control system has pre-stored target slip ratio parameters for different terrains (for example, the target slip ratio is set to 5%-10% for paved roads, 10%-15% for gravel roads, 15%-20% for muddy roads, and 20%-25% for snow roads. This target slip ratio is the optimal slip ratio range that has been verified by a large number of tests and can take into account the tank's turning performance, road adaptability and chassis durability). After determining the current terrain, the system will automatically call up the target slip ratio corresponding to that terrain. Finally, by calculating the difference between the calculated actual slip ratio of the vehicle and the slip ratio of the current terrain target, the slip ratio deviation can be obtained. In specific implementation, , For slip ratio deviation, For the target slip ratio, This represents the actual slip ratio.

[0031] For example, the steps to obtain the target slip ratio corresponding to the terrain where the vehicle is currently located include: Based on the preset vehicle model parameters, a benchmark dynamic model of the slip ratio of the inner rear wheel tank turn target is built. Combined with the vehicle braking and transmission matching dynamic simulation, the critical constraint value of the inner rear wheel brake lock-up and the critical value of the transmission system impact tolerance are solved to determine the initial theoretical range threshold of the target slip ratio. Based on the initial theoretical interval threshold, bench calibration tests and multi-road condition vehicle calibration tests were carried out respectively. The theoretical deviation of the benchmark dynamic model was corrected through bench calibration. Through vehicle calibration corresponding to different terrain modes, measured data of tank turning radius, tire wear, transmission shock and brake thermal load were collected. The optimal correction coefficient of target slip ratio corresponding to each terrain condition was iteratively optimized. The target slip ratio values ​​corresponding to each terrain after calibration and iterative optimization are solidified to generate the all-terrain target slip ratio MAP solidification curve built into the vehicle stability control system. The MAP solidification curve uses the all-terrain mode selection switch signal as a one-dimensional query index and the real-time reference vehicle speed as a two-dimensional compensation variable to achieve dynamic adaptive matching of the target slip ratio. The system collects all-terrain mode selection switch signals in real time and identifies the current terrain conditions. Based on the reference vehicle speed, it finds the corresponding target slip ratio in the target slip ratio MAP fixed curve.

[0032] In this embodiment of the invention, a target slip ratio benchmark model for the inner rear wheel is established based on vehicle dynamics parameters, and a fixed MAP curve is formed through bench calibration and real vehicle calibration. First, a baseline dynamic model of the inner rear wheel's target slip ratio for a tank turn needs to be built based on the pre-defined vehicle's basic parameters (including core parameters such as wheel rolling radius, vehicle mass, braking system parameters, and transmission system stiffness). This model can simulate the force state, trajectory, and interaction with the ground of the inner rear wheel during a tank turn. Then, combined with vehicle braking and transmission matching dynamics simulation, the braking effect of the inner rear wheel and the force situation of the transmission system under different slip ratios are simulated to solve for the critical constraint value of the inner rear wheel's brake lock-up (i.e., when the slip ratio reaches this value, the inner rear wheel will lock up, affecting steering performance and chassis durability) and the critical value of the transmission system's impact tolerance (i.e., the upper limit of the impact force that the transmission system can withstand due to excessive slip ratio deviation). Combining these two critical values, the initial theoretical range threshold of the target slip ratio is initially determined. This range threshold is the basis for subsequent calibration and optimization, ensuring that the initial range meets the vehicle's hardware characteristics and the basic requirements of a tank turn. Next, based on the initially determined initial theoretical range threshold, bench calibration tests and multi-road condition vehicle calibration tests were carried out. The bench calibration tests were conducted on a professional test bench. By simulating different slip ratio conditions, the test data was compared with the theoretical calculation data of the benchmark dynamic model to correct theoretical deviations in the model and improve the model's accuracy. The multi-road condition vehicle calibration tests were carried out for different terrain modes (such as paved roads, gravel roads, muddy roads, snow roads, etc.). Under each terrain, the tank's turning action was simulated, and real-time measured data such as the tank's turning radius, tire wear, transmission system impact force, and brake thermal load were collected. By analyzing the correspondence between these data and different slip ratio values, it was determined whether the current slip ratio takes into account steering flexibility, road adaptability, and chassis durability. Then, the optimal correction coefficient of the target slip ratio corresponding to each terrain condition was iteratively optimized, gradually narrowing the target slip ratio range, and finally determining the optimal target slip ratio value under each terrain condition. Then, the target slip ratio values ​​corresponding to each terrain after iterative optimization through bench calibration and real vehicle calibration are solidified to generate the all-terrain target slip ratio MAP solidified curve built into the vehicle stability control system. The MAP solidified curve adopts two-dimensional mapping logic, using the all-terrain mode selection switch signal as a one-dimensional query index (i.e., different switch signals correspond to different MAP curve branches for different terrains), and the real-time reference vehicle speed as a two-dimensional compensation variable (i.e., under the same terrain, different reference vehicle speeds correspond to different target slip ratio fine-tuning values), to ensure that the target slip ratio can be dynamically and adaptively adjusted according to changes in vehicle speed, avoiding excessive slip ratio deviation due to vehicle speed fluctuations; Finally, when the vehicle actually performs a tank turn, the system collects the all-terrain mode selection switch signal in real time. By identifying the specific type of the switch signal (such as corresponding to snow mode, gravel mode, etc.), the system determines the current terrain conditions of the vehicle. Combined with the real-time calculated vehicle reference speed, the system accurately finds the target slip ratio corresponding to the current terrain and current speed in the preset target slip ratio MAP solidification curve. This target slip ratio will serve as the core benchmark for subsequent calculation of slip ratio deviation and adjustment of EPB clamping force, ensuring that the slip state of the inner rear wheel is always within the optimal range during the tank turn, taking into account steering performance, road adaptability, and chassis system durability.

[0033] In addition, in specific implementation, for low-adhesion road surfaces (sand, mud, snow, ice, etc.): due to the low road adhesion coefficient and small tire wear, the target slip ratio is set to a higher range, so that the inner rear wheel is close to locking up, in order to obtain the maximum difference in speed between the inner and outer wheels and achieve the minimum turning radius; for medium-high adhesion / complex bad roads (mountain roads, gravel roads, pothole roads, etc.): due to the high road adhesion coefficient and large tire wear, the target slip ratio is appropriately reduced, so that the inner rear wheel maintains controllable slip and does not lock up completely, thereby reducing the turning radius while avoiding impact on the transmission system, brake overload and excessive local tire wear.

[0034] Step S12: PID calculation is performed based on the slip ratio deviation to obtain the clamping force control quantity. The clamping force control quantity is then converted into a drive signal for the EPB motor, driving the motor of the EPB electronic caliper to rotate, thereby achieving dynamic adjustment of the clamping force.

[0035] After obtaining the slip ratio deviation, the system uses this deviation as the core input parameter to perform PID calculations to obtain a precise clamping force control quantity. A PID control algorithm (proportional-integral-derivative control algorithm) can be used here. The proportional term directly outputs the corresponding control quantity based on the magnitude of the slip ratio deviation, quickly responding to deviation changes. The integral term is used to eliminate long-term steady-state deviations, preventing the continuous accumulation of slip ratio deviations from affecting the control effect. The derivative term predicts the deviation trend in advance based on the rate of change of the slip ratio deviation, achieving proactive adjustment and reducing fluctuations during the control process. Through the synergistic effect of these three terms, the PID calculation module can output a precise and stable clamping force control quantity. This control quantity is a specific numerical signal that directly corresponds to the clamping force that the EPB electronic caliper needs to apply, ensuring the accuracy of clamping force adjustment. In a specific implementation of this invention, the proportional coefficient of the PID controller ( ), integral coefficient ( ), differential coefficients ( The control effect is directly determined by the vehicle parameters, EPB actuator characteristics, and all-terrain conditions. Precise calibration and optimization are required. Specific calibration principles are as follows: 1. Proportionality coefficient ( ): Primarily used for rapid response to deviations, reducing the magnitude of slip ratio deviations. If the value is too large, it will cause the clamping force to be adjusted too abruptly, resulting in slip ratio oscillation, EPB action impact, and even instantaneous wheel lock-up; If the value is too small, it will lead to a slow control response, making it difficult to quickly reduce the slip ratio deviation and making it impossible to quickly track the target slip ratio.

[0036] 2. Integral coefficient ( ): Primarily used to eliminate steady-state deviations, ensuring that the actual slip ratio can remain stable near the target slip ratio, and avoiding steady-state errors of "approaching the target but failing to reach it". If the value is too large, it will lead to integral saturation, excessive adjustment of clamping force, and slip ratio overshoot; If the value is too small, it cannot effectively eliminate steady-state deviation, affecting control accuracy. In this scheme, A piecewise integration strategy is adopted to reduce the slip ratio deviation when it is large. To avoid overshoot due to excessively rapid integration; when the slip ratio deviation is small, increase the value. The value is selected to quickly eliminate steady-state deviation; 3. Differential coefficients ( ): Primarily used to suppress the rate of change of slip ratio, reduce control oscillations, and improve control stability. If the value is too large, it will inhibit the adjustment speed of the clamping force, resulting in a slow response. If the value is too small, it cannot effectively suppress oscillations, resulting in a slip ratio that fluctuates greatly.

[0037] Through bench tests and real vehicle road tests, the PID parameters under different road surface modes are calibrated and iteratively optimized to form a fixed parameter MAP table. The controller automatically calls the corresponding parameters according to the all-terrain mode to ensure that the optimal control effect can be obtained under different working conditions.

[0038] Subsequently, the system uses a preset signal conversion module to convert the obtained clamping force control quantity (analog or digital signal) into a drive signal that the EPB motor can recognize and execute. This drive signal contains key commands such as motor rotation direction, rotation speed, and rotation angle. The rotation direction determines whether the clamping force increases or decreases (forward rotation increases clamping force, reverse rotation decreases clamping force), while the rotation speed and angle correspond to the rate and amplitude of clamping force adjustment, ensuring a smooth and controllable adjustment process. After the drive signal is transmitted to the motor of the EPB electronic caliper, it directly drives the motor to... As instructed, the motor rotates, driving the brake piston of the electronic caliper to move. This, in turn, pushes the brake pads against the brake disc, generating clamping force. When the clamping force needs to be increased, the motor rotates forward, pushing the brake pads to further press against the brake disc, increasing the braking torque to suppress slippage of the inner rear wheel. When the clamping force needs to be reduced, the motor rotates in the reverse direction, loosening the contact between the brake pads and the brake disc, reducing the braking torque to increase slippage of the inner rear wheel. This achieves dynamic adjustment of the clamping force, ensuring that the slip ratio of the inner rear wheel is always maintained within the target slip ratio range corresponding to the current terrain.

[0039] Step S13: Reacquire the wheel speed signal collected in real time by the ABS wheel speed sensor, determine the clamping force control amount under the current wheel speed, and realize the continuous dynamic adjustment of the clamping force based on the clamping force control amount.

[0040] When the EPB performs the clamping action, the speed of the inner rear wheel changes. The ABS wheel speed sensor collects the new wheel speed signal in real time, repeats the above slip ratio calculation process, obtains the new actual slip ratio, and compares it with the target slip ratio to calculate the deviation, forming a closed loop to realize continuous tracking of slip ratio and dynamic correction of clamping force.

[0041] In summary, the all-terrain tank turning method in the above embodiments of the present invention, when detecting that a tank needs to turn, acquires the wheel speed signal collected in real time by the ABS wheel speed sensor, determines the reference vehicle speed and the actual speed of the inner rear wheel based on the speed signal; determines the vehicle's slip ratio based on the reference vehicle speed and the actual speed of the inner rear wheel, determines the current terrain of the vehicle based on the all-terrain mode selection switch signal, and obtains the slip ratio deviation based on the slip ratio and the target slip ratio corresponding to the current terrain; performs PID calculation based on the slip ratio deviation to obtain the clamping force control quantity, converts the clamping force control quantity into a drive signal for the EPB motor, drives the motor of the EPB electronic caliper to rotate, and realizes dynamic adjustment of the clamping force; reacquires the wheel speed signal collected in real time by the ABS wheel speed sensor, determines the clamping force control quantity at the current wheel speed, and realizes continuous dynamic adjustment of the clamping force based on the clamping force control quantity. By using wheel slip ratio as feedback, and adjusting the EPB clamping force in real time through a PID controller, high-precision closed-loop servo control of the inner rear wheel slip ratio is achieved. This ensures that the vehicle maintains the optimal slip ratio under different road conditions, guaranteeing a minimum turning radius while avoiding system impact and component damage caused by complete wheel lock-up, ultimately achieving adaptability to different terrains. This solves the problems of existing tank turning technologies that mostly use open-loop fixed torque control without closed-loop adjustment, resulting in poor road adaptability and difficulty in balancing steering performance and chassis durability.

[0042] Example 2 This embodiment also proposes a method for tank turning around in all terrains. The difference between the tank turning around method in this embodiment and the tank turning around method in Embodiment 1 is as follows: The step of obtaining the clamping force control quantity by performing PID calculation based on the slip ratio deviation includes: The system acquires the actual rotational speed signal of the inner rear wheel in real time, and performs differential processing on the rotational speed signals of multiple consecutive control cycles to obtain the instantaneous angular acceleration of the inner rear wheel. ; Based on instantaneous angular acceleration Moment of inertia of the inner rear wheel Calculate the dynamic torque fluctuation energy of the current transmission system. ; Determine the energy of dynamic torque fluctuation Trend of change: If If the transmission system exhibits a divergent trend and exceeds the preset transmission tolerance threshold, it is determined that there is a risk of resonance. When a resonance risk is determined, the differential coefficients in the PID calculation are... Perform negative dynamic attenuation, while adjusting the scaling factor. Perform small positive compensation to maintain system response speed; The adjusted and Substituting into the PID calculation formula, the clamping force control quantity for the current control cycle is calculated. This is to suppress transmission system impact and maintain a stable slip ratio.

[0043] The determination of dynamic torque fluctuation energy Trend of change: If If the transmission system exhibits a divergent trend and exceeds a preset transmission tolerance threshold, the steps to determine if there is a risk of resonance include: Calculate dynamic torque fluctuation energy The first derivative with respect to time yields the energy dissipation rate of the current transmission system. ; Build with For the horizontal axis, The two-dimensional phase plane is the vertical axis, and is based on the current point. , Based on the historical points of the previous cycle, the tangential vector direction of the phase trajectory is fitted and predicted; If the tangential vector points into the phase plane The increased area, and If the absolute value of the signal shows an increasing trend, it is determined that the transmission system is in a divergent and unstable state, and there is a risk of resonance. If the tangential vector points towards the origin of the phase plane, the transmission system is determined to be in a stable attenuation state.

[0044] In this embodiment of the invention, a transmission system resonance risk identification and suppression mechanism is added based on PID control to ensure that the slip ratio remains stable during the tank's turning process, while avoiding resonance in the transmission system caused by torque fluctuations and resulting component damage. The specific implementation method is as follows: First, the system will collect the actual speed signal of the inner rear wheel in real time, and perform differential processing on the speed signal of multiple consecutive control cycles (for example, the control cycle can be set to 10ms, that is, the speed signal is collected once every 10ms, and 5-10 cycles are collected continuously). The differential processing here can use the exemplary first-order difference algorithm, that is, through the formula (in The speed of the rear wheel in the current cycle. (where T is the control cycle and T is the rotational speed of the previous cycle) is used to calculate the instantaneous angular acceleration α of the inner rear wheel; Next, based on the calculated instantaneous angular acceleration α and the moment of inertia J of the inner rear wheel (the moment of inertia J of the inner rear wheel refers to the magnitude of the inertia of the inner rear wheel when it rotates around its own axis, the unit is kg·m², it is an inherent parameter of the vehicle model, which can be pre-calibrated through bench testing, and an exemplary value can be set to 1.2 kg·m²), the formula is used to... Calculate the dynamic torque fluctuation energy of the current transmission system. ; Next, we proceed to the resonance risk assessment stage, which requires first determining the dynamic torque fluctuation energy. The changing trend, if If the transmission exhibits a divergent trend and exceeds the preset transmission tolerance threshold, the transmission system is deemed to have a resonance risk; the specific judgment steps are as follows: First, calculate the dynamic torque ripple energy. The first derivative with respect to time yields the energy dissipation rate of the current transmission system. For example, the calculation can be performed using the first-order finite difference method, i.e. T is the control period; Next, construct with For the horizontal axis, The two-dimensional phase plane is defined by the vertical axis. A linear fitting algorithm is used to fit and predict the tangential vector direction of the phase trajectory. The tangential vector direction of the phase trajectory refers to the direction of movement of the coordinate points on the phase plane, which can be calculated from the coordinates of two points. Finally, the system state is determined based on the direction of the tangential vector: if the tangential vector points into the phase plane... The region that increases (i.e., the vector horizontal axis component is positive), and If the absolute value of Evib shows a continuous increasing trend (the Evib value increases for three or more consecutive control cycles), the transmission system is determined to be in a divergent and unstable state, with a risk of resonance. If the tangential vector points towards the origin of the phase plane (i.e., both the horizontal and vertical components of the vector are negative, and the coordinate points gradually approach the origin), the transmission system is determined to be in a stable decay state, with no risk of resonance. When a risk of resonance is determined, in order to avoid exacerbating the resonance of the transmission system and protect the chassis components, the core parameters in the PID calculation need to be dynamically adjusted: the derivative coefficient Kd in the PID calculation is negatively and dynamically decayed, which can be done linearly to reduce the adjustment force of the derivative link and suppress the torque fluctuation of the transmission system; at the same time, the proportional coefficient Kp is slightly positively compensated to maintain the system's response speed to slip ratio deviation and avoid system response lag due to Kd decay.

[0045] In addition, in some optional embodiments of the present invention, after the step of driving the motor of the EPB electronic caliper to rotate and realize the dynamic adjustment of the clamping force, the method further includes: Synchronously start the fault counter and fault timer to begin real-time counting and timing; When the system experiences any of the following faults: mechanical jamming of the caliper, damage to the EPB motor, communication interruption between the controller and the actuator, or inability to establish clamping force, the inner wheel cannot reach the target slip ratio. The controller drives the caliper to enter repeated clamping attempts. Each time a clamping action is performed, the counter is decremented by 1. When the counter equals zero, the EPB clamping action is immediately terminated, the motor drive signal is cut off, a fault code is reported, and the fault indicator light is illuminated; or When the timer reaches ≥t seconds, the EPB clamping action is immediately forcibly stopped, the motor drive signal is cut off, a fault code is reported through the fault diagnosis module, the instrument fault indicator light is illuminated, and the tank turning function is prevented from being reactivated until the fault is resolved.

[0046] To ensure system safety in the event of EPB actuator failure, this embodiment of the invention employs a dual fault determination strategy that combines counter-limited protection and timer timeout protection, completely avoiding secondary damage caused by ineffective repeated clamping. Specifically: Counter operation limit protection: Initialize the fault counter: initial value = n. This initial value is determined through actual vehicle calibration, which can avoid misjudgment caused by momentary faults (such as momentary road slippage) and prevent invalid actions when the fault continues. The counter starts synchronously at the moment the tank turns around and clamps in, and begins real-time counting. Counting rules: When the system experiences faults such as mechanical jamming of the caliper, damage to the EPB motor, communication interruption between the controller and the actuator, or failure to establish clamping force, the inner wheel cannot reach the target slip ratio. The controller will drive the caliper to enter repeated clamping attempts. Each time a clamping action is performed, the counter is decremented by 1. Fault determination: When the counter decreases to 0, it is determined to be a permanent fault (cannot be recovered by repeated clamping). The clamping output is stopped immediately, the EPB motor drive signal is cut off, and the fault code is reported through the fault diagnosis module. At the same time, the instrument fault indicator light is illuminated to remind the driver to carry out maintenance.

[0047] Timer timeout forced protection: Initialize fault timer: Total allowable duration = t seconds. This duration is combined with the EPB clamping force build-up time and slip ratio response time calibration to ensure that there is sufficient response time for normal clamping action and timely identification of faults. Timing start timing: The timer starts synchronously at the moment the clamping command is initiated, and real-time timing begins. Timeout determination: If the actual slip ratio still does not reach the allowable range of the target slip ratio within t seconds, it is determined that the fault cannot be recovered, the EPB clamping action is immediately terminated, the motor drive signal is cut off, the fault code is reported and the fault indicator light is lit. Redundancy protection: The counter and timer operate independently and are redundant with each other. Regardless of which condition is met first, the system immediately enters the fail-safe state, ensuring the reliability of fault identification and preventing missed or false faults.

[0048] In summary, the all-terrain tank turning method in the above embodiments of the present invention, when detecting that a tank needs to turn, acquires the wheel speed signal collected in real time by the ABS wheel speed sensor, determines the reference vehicle speed and the actual speed of the inner rear wheel based on the speed signal; determines the vehicle's slip ratio based on the reference vehicle speed and the actual speed of the inner rear wheel, determines the current terrain of the vehicle based on the all-terrain mode selection switch signal, and obtains the slip ratio deviation based on the slip ratio and the target slip ratio corresponding to the current terrain; performs PID calculation based on the slip ratio deviation to obtain the clamping force control quantity, converts the clamping force control quantity into a drive signal for the EPB motor, drives the motor of the EPB electronic caliper to rotate, and realizes dynamic adjustment of the clamping force; reacquires the wheel speed signal collected in real time by the ABS wheel speed sensor, determines the clamping force control quantity at the current wheel speed, and realizes continuous dynamic adjustment of the clamping force based on the clamping force control quantity. By using wheel slip ratio as feedback, and adjusting the EPB clamping force in real time through a PID controller, high-precision closed-loop servo control of the inner rear wheel slip ratio is achieved. This ensures that the vehicle maintains the optimal slip ratio under different road conditions, guaranteeing a minimum turning radius while avoiding system impact and component damage caused by complete wheel lock-up, ultimately achieving adaptability to different terrains. This solves the problems of existing tank turning technologies that mostly use open-loop fixed torque control without closed-loop adjustment, resulting in poor road adaptability and difficulty in balancing steering performance and chassis durability.

[0049] Example 3 Please see Figure 2 The figure shows a tank turn-around system for all terrains proposed in the third embodiment of the present invention. It is applied to a vehicle stability control system integrating EPB software. The vehicle stability control system is communicatively connected to the ABS wheel speed sensor, the all-terrain mode selection switch, and the EPB electronic caliper. The system includes: The acquisition module 100 is used to acquire the wheel rotation speed signal collected in real time by the ABS wheel speed sensor when the vehicle needs to perform a tank turn, and to determine the reference vehicle speed and the actual rotation speed of the inner rear wheel based on the rotation speed signal. The determination module 200 is used to determine the slip ratio of the vehicle based on the reference vehicle speed and the actual rotation speed of the inner rear wheel, determine the current terrain of the vehicle based on the all-terrain mode selection switch signal, and obtain the slip ratio deviation based on the slip ratio and the target slip ratio corresponding to the current terrain of the vehicle. The calculation module 300 is used to perform PID calculation based on the slip ratio deviation to obtain the clamping force control quantity, and convert the clamping force control quantity into the drive signal of the EPB motor to drive the motor of the EPB electronic caliper to rotate, thereby realizing the dynamic adjustment of the clamping force. The adjustment module 400 is used to reacquire the wheel speed signal collected in real time by the ABS wheel speed sensor, determine the clamping force control amount at the current wheel speed, and realize continuous dynamic adjustment of the clamping force based on the clamping force control amount.

[0050] The functions or operation steps implemented by the above modules are largely the same as those in the above method embodiments, and will not be repeated here.

[0051] Example 4 In another aspect, the present invention provides a readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the steps of the method described in any one of Embodiments 1 to 2 above.

[0052] Example 5 In another aspect, the present invention provides an electronic device, the electronic device including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of any one of the methods described in Embodiments 1 to 2 above.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] Those skilled in the art will understand that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable storage medium" can mean any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0055] More specific examples (a non-exhaustive list) of computer-readable storage media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable storage media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0056] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0057] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for achieving tank turning around in all terrains, characterized in that, The method, applied in a vehicle stability control system integrating EPB software, wherein the vehicle stability control system is communicatively connected to the ABS wheel speed sensor, the all-terrain mode selection switch, and the EPB electronic caliper, includes: When it is detected that the vehicle needs to perform a tank turn, the rotational speed signal of the wheels is acquired in real time by the ABS wheel speed sensor, and the reference speed of the vehicle and the actual rotational speed of the inner rear wheel are determined based on the rotational speed signal. The vehicle's slip ratio is determined based on the reference vehicle speed and the actual rotation speed of the inner rear wheel. The current terrain of the vehicle is determined based on the all-terrain mode selection switch signal. The slip ratio deviation is obtained based on the slip ratio and the target slip ratio corresponding to the current terrain of the vehicle. The clamping force control quantity is obtained by PID calculation based on the slip ratio deviation. The clamping force control quantity is then converted into a drive signal for the EPB motor, which drives the motor of the EPB electronic caliper to rotate, thereby realizing the dynamic adjustment of the clamping force. The wheel speed signal collected in real time by the ABS wheel speed sensor is reacquired to determine the clamping force control amount at the current wheel speed, and the clamping force is continuously and dynamically adjusted based on the clamping force control amount.

2. The method for achieving tank turning around in all terrains according to claim 1, characterized in that, The steps for determining the vehicle's reference speed and the actual speed of the inner rear wheel based on the speed signal include: The rotation speed signal is filtered and denoised, and the wheel speed of each wheel of the vehicle is determined based on the wheel speed signal; The reference speed is obtained by adjusting the speed of the outer rear wheel based on the speed of the outer rear wheel and taking into account the overall vehicle driving conditions. The steps for determining the vehicle's slip ratio based on the reference vehicle speed and the actual rotational speed of the inner rear wheel include: ； in, This represents the actual slip ratio. For reference speed, This represents the actual rotational speed of the inner rear wheel.

3. The method for achieving tank turning around in all terrains according to claim 1, characterized in that, The step of obtaining the clamping force control quantity by performing PID calculation based on the slip ratio deviation includes: ； ； in, This is the proportionality coefficient. The integral coefficient is... These are the differential coefficients. For slip ratio deviation, For the target slip ratio, This represents the actual slip ratio.

4. The method for achieving tank turning around in all terrains according to claim 1, characterized in that, The steps to obtain the target slip ratio corresponding to the terrain where the vehicle is currently located include: Based on the preset vehicle model parameters, a benchmark dynamic model of the slip ratio of the inner rear wheel tank turn target is built. Combined with the vehicle braking and transmission matching dynamic simulation, the critical constraint value of the inner rear wheel brake lock-up and the critical value of the transmission system impact tolerance are solved to determine the initial theoretical range threshold of the target slip ratio. Based on the initial theoretical interval threshold, bench calibration tests and multi-road condition vehicle calibration tests were carried out respectively. The theoretical deviation of the benchmark dynamic model was corrected through bench calibration. Through vehicle calibration corresponding to different terrain modes, measured data of tank turning radius, tire wear, transmission shock and brake thermal load were collected. The optimal correction coefficient of target slip ratio corresponding to each terrain condition was iteratively optimized. The target slip ratio values ​​corresponding to each terrain after calibration and iterative optimization are solidified to generate the all-terrain target slip ratio MAP solidification curve built into the vehicle stability control system. The MAP solidification curve uses the all-terrain mode selection switch signal as a one-dimensional query index and the real-time reference vehicle speed as a two-dimensional compensation variable to achieve dynamic adaptive matching of the target slip ratio. The system collects all-terrain mode selection switch signals in real time and identifies the current terrain conditions. Based on the reference vehicle speed, it finds the corresponding target slip ratio in the target slip ratio MAP fixed curve.

5. The method for achieving tank turning around in all terrains according to claim 3, characterized in that, After the step of driving the motor of the EPB electronic caliper to rotate and achieve dynamic adjustment of the clamping force, the following steps are also included: Synchronously start the fault counter and fault timer to begin real-time counting and timing; When the system experiences any of the following faults: mechanical jamming of the caliper, damage to the EPB motor, communication interruption between the controller and the actuator, or inability to establish clamping force, the inner wheel cannot reach the target slip ratio. The controller drives the caliper to enter repeated clamping attempts. Each time a clamping action is performed, the counter is decremented by 1. When the counter equals zero, the EPB clamping action is immediately terminated, the motor drive signal is cut off, a fault code is reported, and the fault indicator light is illuminated; or When the timer reaches ≥t seconds, the EPB clamping action is immediately forcibly stopped, the motor drive signal is cut off, a fault code is reported through the fault diagnosis module, the instrument fault indicator light is illuminated, and the tank turning function is prevented from being reactivated until the fault is resolved.

6. The method for achieving tank turning around in all terrains according to claim 3, characterized in that, The step of obtaining the clamping force control quantity by performing PID calculation based on the slip ratio deviation includes: The system acquires the actual rotational speed signal of the inner rear wheel in real time, and performs differential processing on the rotational speed signals of multiple consecutive control cycles to obtain the instantaneous angular acceleration of the inner rear wheel. ; Based on instantaneous angular acceleration Moment of inertia of the inner rear wheel Calculate the dynamic torque fluctuation energy of the current transmission system. ; Determine the energy of dynamic torque fluctuation Trend of change: If If the transmission system exhibits a divergent trend and exceeds the preset transmission tolerance threshold, it is determined that there is a risk of resonance. When a resonance risk is determined, the differential coefficients in the PID calculation are... Perform negative dynamic attenuation, while adjusting the scaling factor. Perform small positive compensation to maintain system response speed; The adjusted and Substituting into the PID calculation formula, the clamping force control quantity for the current control cycle is calculated. This is to suppress transmission system impact and maintain a stable slip ratio.

7. The method for achieving tank turning around in all terrains according to claim 6, characterized in that, The determination of dynamic torque fluctuation energy Trend of change: If If the transmission system exhibits a divergent trend and exceeds a preset transmission tolerance threshold, the steps to determine if there is a risk of resonance include: Calculate dynamic torque fluctuation energy The first derivative with respect to time yields the energy dissipation rate of the current transmission system. ; Build with For the horizontal axis, The two-dimensional phase plane is the vertical axis, and is based on the current point. , Based on the historical points of the previous cycle, the tangential vector direction of the phase trajectory is fitted and predicted; If the tangential vector points into the phase plane The increased area, and If the absolute value of the signal shows an increasing trend, it is determined that the transmission system is in a divergent and unstable state, and there is a risk of resonance. If the tangential vector points towards the origin of the phase plane, the transmission system is determined to be in a stable attenuation state.

8. A tank turning system for all terrains, characterized in that, The system is applied in a vehicle stability control system integrating EPB software. The vehicle stability control system is communicatively connected to the ABS wheel speed sensor, all-terrain mode selection switch, and EPB electronic caliper. The system includes: The acquisition module is used to acquire the wheel speed signals collected in real time by the ABS wheel speed sensors when the vehicle needs to perform a tank turn. Based on the speed signals, the reference vehicle speed and the actual speed of the inner rear wheel are determined respectively. The determination module is used to determine the vehicle's slip ratio based on the reference vehicle speed and the actual rotation speed of the inner rear wheel, determine the current terrain of the vehicle based on the all-terrain mode selection switch signal, and obtain the slip ratio deviation based on the slip ratio and the target slip ratio corresponding to the current terrain of the vehicle. The calculation module is used to perform PID calculations based on the slip ratio deviation to obtain the clamping force control quantity, and convert the clamping force control quantity into a drive signal for the EPB motor to drive the motor of the EPB electronic caliper to rotate, thereby realizing dynamic adjustment of the clamping force. The adjustment module is used to reacquire the wheel speed signal collected in real time by the ABS wheel speed sensor, determine the clamping force control amount at the current wheel speed, and realize continuous dynamic adjustment of the clamping force based on the clamping force control amount.

9. A readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 1 to 7.

10. An electronic device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor, when executing the program, implements the steps of the method as described in any one of claims 1 to 7.

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