Vehicle control method and vehicle

Abstract

The application relates to a vehicle control method and a vehicle, and belongs to the field of vehicle braking. The method comprises the following steps: acquiring braking parameters, running state parameters and power transmission system parameters of a vehicle; determining a braking level of the vehicle based on the braking parameters and the running state parameters, wherein different braking levels are configured with corresponding torque management strategies; calculating a predicted value of a net torque borne by a driving shaft of the vehicle after a preset time based on the braking parameters and the power transmission system parameters; identifying whether the predicted value of the net torque meets a preset trigger condition, and if yes, acquiring the torque management strategy corresponding to the braking level, and executing a corresponding braking action based on the torque management strategy. The braking level identification, driving shaft net torque prediction and torque management strategy execution are combined, so that the technical defects of independent control and lack of cooperation between a traditional vehicle power system and a braking system are solved. The front protection of the transmission system torque overload is realized, and the hysteresis of passive feedback control is avoided.

Description

Technical Field

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

[0002] As the modern automotive industry rapidly develops towards electrification, intelligence, and connectivity, the integration and control precision of vehicle powertrain systems are constantly improving. Simultaneously, users' demands for vehicle driving safety, ride comfort, power responsiveness, and overall vehicle durability are becoming increasingly stringent. During actual vehicle operation, braking is one of the most frequent and complex driving conditions. Especially in typical scenarios such as congested urban traffic, continuous downhill driving in mountainous areas, emergency high-speed maneuvers, and rapid acceleration followed by rapid deceleration, the vehicle's transmission system simultaneously experiences torque from various factors. The superposition of torques from multiple dimensions on the transmission components easily creates instantaneous peak torque. When this peak torque exceeds the material yield strength, fatigue durability limit, or design safety threshold of the transmission system components, it directly leads to problems such as impact vibration, abnormal noise, premature wear, plastic deformation, and even fracture failure in the transmission components, seriously affecting vehicle lifespan and driving safety.

[0003] Currently, traditional vehicle control systems typically employ either simply increasing the mechanical strength of the drive shaft or using a single system control approach, which leads to performance defects. The first approach, increasing drive shaft size and material strength to improve load-bearing capacity, results in increased vehicle weight and manufacturing costs, and fails to address the complexity of dynamic loads, potentially causing damage due to excessive impact torque during emergency braking. The second approach uses mechanical protection devices such as clutches, but suffers from slow response speed and low protection accuracy. The response time of mechanical protection devices is typically on the order of seconds, while the torque impact during emergency braking occurs within milliseconds, causing the protection devices to fail to respond in time. Therefore, existing technologies cannot simultaneously meet the power transmission requirements of normal driving and the overload protection requirements of emergency braking, resulting in insufficient protection of the transmission system or protection measures that interfere with normal driving during emergency braking. Summary of the Invention

[0004] This application aims to provide a vehicle control method and a vehicle, which calculates the braking characteristic coefficient and determines the braking level by real-time acquisition and analysis of braking parameters and driving state parameters. Through braking level judgment and multi-level strategy execution, it achieves precise matching between protection measures and braking urgency, solves the technical problems of transmission system protection lag, low accuracy and impact on normal driving in the prior art, and achieves the technical objective of effectively preventing transmission system damage while maintaining vehicle power performance.

[0005] To achieve the above objectives, in a first aspect, this application provides a vehicle control method applied to a power control system, the method comprising: Obtain vehicle braking parameters, driving status parameters, and powertrain system parameters; The braking level of the vehicle is determined based on the braking parameters and driving state parameters, wherein different braking levels are configured with corresponding torque management strategies. Based on the braking parameters and the powertrain system parameters, calculate the predicted net torque value of the vehicle drive bearing after a preset time. If the net torque prediction value meets the preset triggering conditions, then the torque management strategy corresponding to the braking level is obtained, and the corresponding braking action is executed based on the torque management strategy.

[0006] The aforementioned technical solution combines braking level identification, drive shaft net torque prediction, and torque management strategy execution, addressing the technical shortcomings of traditional vehicle powertrain and braking systems being controlled independently and lacking coordination. By first determining the braking level, then predicting the net torque, and finally triggering the corresponding strategy, proactive protection against torque overload in the transmission system is achieved, avoiding the lag inherent in traditional passive feedback control. Simultaneously, matching different braking levels with corresponding torque management strategies makes the control actions more targeted, balancing vehicle braking performance, driving safety, and transmission system durability. This approach is applicable to various vehicle powertrain control scenarios, enhancing the versatility and practicality of the control method.

[0007] In some embodiments of this application, determining the braking level of the vehicle based on the braking parameters and driving state parameters includes: Based on the braking parameters and the driving state parameters, the vehicle braking control characteristics and the vehicle driving dynamic characteristics are obtained. The braking characteristic coefficient is determined based on the vehicle braking control characteristics and the vehicle driving dynamic characteristics. The braking characteristic coefficient is compared with a plurality of preset braking thresholds, and the braking level of the vehicle is determined by judging the relationship between the braking characteristic coefficient and the braking thresholds.

[0008] In the above technical solution, feature values ​​are extracted by analyzing braking parameters and driving state parameters, and then braking feature coefficients are calculated. Compared with the traditional method of judging braking intensity by a single signal, the accuracy of braking level identification is significantly improved. By comparing the braking feature coefficients with preset multiple thresholds to determine the braking level, the gradient differentiation of braking conditions is realized, avoiding mismatch of control strategies caused by misjudgment or omission of braking levels. This provides a reliable basis for the subsequent execution of differentiated torque management strategies and further improves the rationality and stability of vehicle control.

[0009] In some embodiments of this application, vehicle braking control characteristics and vehicle driving dynamic characteristics are obtained based on the braking parameters and the driving state parameters, and braking characteristic coefficients are determined based on the vehicle braking control characteristics and vehicle driving dynamic characteristics, including: The brake master cylinder pressure and brake pedal travel in the braking parameters are calculated to obtain the maximum brake pressure rise rate and pedal aggression. The driving wheel speed, maximum vehicle deceleration, and throttle opening in the driving state parameters are calculated to obtain the driving wheel speed change rate, maximum vehicle deceleration, and throttle opening change rate. The braking characteristic coefficient is obtained by weighting the vehicle's maximum deceleration, throttle opening rate of change, maximum braking pressure rise rate, pedal aggression, and wheel speed change rate.

[0010] In the above technical solution, feature values ​​are extracted from multiple dimensions such as braking operation (maximum braking pressure rise rate, pedal action intensity), vehicle deceleration state (wheel speed change rate, vehicle maximum deceleration), and power linkage (throttle opening change rate), comprehensively covering key indicators reflecting braking intensity. This solves the problem of traditional feature extraction being singular and unable to fully characterize braking conditions. By calculating the braking feature coefficient through multi-feature value weighting, the advantages of signals from various dimensions are effectively integrated, reducing the impact of single signal fluctuations on braking level identification. This further improves the accuracy and reliability of the braking feature coefficient, providing solid support for the accurate classification of braking levels.

[0011] In some embodiments of this application, when the braking characteristic coefficient is greater than or equal to a first braking threshold and less than a second braking threshold, the vehicle is determined to be of the first braking level. When the braking characteristic coefficient is greater than or equal to the second braking threshold and less than the third braking threshold, the vehicle is determined to be at the second braking level. When the braking characteristic coefficient is greater than or equal to the third braking threshold, the vehicle is determined to be at the third braking level.

[0012] In the above technical solution, by setting specific classification standards for multiple braking levels and comparing the braking characteristic coefficient with multiple preset thresholds, the working conditions corresponding to various braking intensities are clearly defined, making the classification of braking levels more operable and standardized. The design of the multi-level braking level classification is adapted to most braking scenarios during vehicle operation, providing a clear basis for the matching of subsequent differentiated torque management strategies, avoiding the problems of single and rigid control strategies, and enabling precise control under different braking conditions.

[0013] In some embodiments of this application, identifying whether the net torque prediction value meets a preset triggering condition includes: Obtain the safe torque threshold of the drive shaft, and determine whether the net torque prediction value reaches the safe torque threshold. If so, the net torque prediction value is identified as meeting the preset triggering conditions.

[0014] In the above technical solution, by comparing the predicted net torque value with the safe torque threshold of the drive shaft, the overload risk of the transmission system is accurately identified, which solves the problems of no clear triggering standard, false triggering or missed triggering in traditional control. The torque management strategy is triggered only when the net torque prediction value reaches the safe threshold, which not only ensures that the transmission system can be protected in time when overloaded, but also avoids the impact of frequent triggering of the strategy on the normal driving of the vehicle, improves the stability and rationality of the control method, and provides a quantitative standard for transmission system protection.

[0015] In some embodiments of this application, the predicted net torque value of the vehicle drive bearing after a preset time is calculated based on the braking parameters and the powertrain system parameters, including: Based on the braking parameters of the vehicle, calculate the braking torque of the vehicle after a preset time; Based on the powertrain system parameters, calculate the vehicle's inertial torque and engine-transmitted torque after a preset time. Retrieve the preset torque compensation value; The inertial torque, braking torque, engine transmitted torque, and torque compensation value are summed to obtain the predicted net torque value of the vehicle drive shaft after the preset time.

[0016] In the above technical solution, the net torque prediction value is obtained by summing four components: inertial torque, braking torque, engine transmitted torque, and torque compensation value. This comprehensively covers all sources of torque in the vehicle drive shaft and solves the problems of incomplete net torque calculation and low prediction accuracy in traditional methods. By summing the four torque components, the net torque prediction value can be accurately predicted after a preset time. This provides an accurate basis for the advance judgment of transmission system overload risk, enabling torque management strategies to be activated in advance and effectively preventing damage to the transmission system due to instantaneous overload.

[0017] In some embodiments of this application, calculating the braking torque of the vehicle after a preset time based on the vehicle's braking parameters includes: Obtain the brake master cylinder pressure from the braking parameters; Obtain the vehicle's braking friction coefficient, effective braking radius, braking area, braking efficiency coefficient, and number of braking wheels; The braking torque is calculated based on the master cylinder pressure, braking friction coefficient, effective braking radius, braking area, braking efficiency coefficient, and number of braking wheels.

[0018] In the above technical solution, the braking torque calculation model takes the master cylinder pressure as the core and combines key parameters such as the braking friction coefficient and the effective braking radius to accurately calculate the braking torque, thus solving the problem of rough and large error in traditional braking torque estimation. In this way, the structural parameters and working state of the braking system can be fully considered, significantly improving the calculation accuracy of the braking torque, thereby improving the accuracy of the drive shaft net torque prediction. This provides reliable data support for the precise execution of subsequent torque management strategies, ensuring that the coordinated control of the braking system and the power system is more targeted.

[0019] In some embodiments of this application, the different braking levels are configured with corresponding torque management strategies, including: The torque management strategy corresponding to the first braking level is a prevention strategy. The prevention strategy is used to control the vehicle's braking system to enter a pre-response state and adjust the operating parameters of the vehicle's power system. The torque management strategy corresponding to the second braking level is an intervention strategy. The intervention strategy is used to control the vehicle's braking system to redistribute the braking force according to a preset ratio and to perform torque unloading action on the vehicle's power system. The torque management strategy corresponding to the third braking level is a protection strategy. The protection strategy is used to control the vehicle's braking system to limit the front axle braking force output and to perform torque cut-off or power transmission interruption control operations on the vehicle's power system.

[0020] In the above technical solution, a three-level torque management strategy corresponding to different braking levels achieves a gradient and differentiated design of the control strategy, solving the problem of traditional control strategies being singular and unable to adapt to different braking conditions. The prevention strategy targets low-intensity braking, making control preparations in advance and improving response speed; the intervention strategy targets medium-intensity braking, suppressing torque peaks through coordinated adjustment of the power and braking systems; and the protection strategy targets high-intensity braking, implementing extreme protection to avoid damage to the transmission system. The three-level strategy is progressively strengthened, ensuring braking performance and ride comfort under different braking conditions while achieving full-condition protection of the transmission system, significantly improving vehicle driving safety and transmission system durability.

[0021] In some embodiments of this application, the vehicle control method further includes: The number of times each torque management strategy is triggered is statistically analyzed. When the number of triggers reaches a preset threshold, a prompt message is sent through the vehicle terminal.

[0022] In the above technical solution, by statistically analyzing the number of times the torque management strategy is triggered, a prompt function is activated when the number of triggers exceeds a preset value, thus solving the problem of the lack of status monitoring and early warning mechanisms in traditional control methods. By statistically analyzing the number of triggers for each strategy, abnormal vehicle operating conditions can be identified in a timely manner, and prompts can be sent to the driver through the vehicle terminal, reminding the driver to reasonably control driving behavior and check the vehicle status in a timely manner. At the same time, this function provides data support for subsequent vehicle maintenance and inspection, making it easier to detect potential faults in the transmission system and braking system in a timely manner, further improving the vehicle's safety, maintainability, and reliability.

[0023] In addition, this application also provides a vehicle that employs the above-described vehicle control method.

[0024] In the above technical solution, the vehicle provided by this application using the above control method solves the problem of traditional vehicles lacking a pre-emptive protection mechanism for torque overload in the transmission system. By adopting the above control method, the vehicle can achieve accurate identification of braking level, advanced prediction of drive shaft net torque, and precise execution of torque management strategy, effectively avoiding damage to the transmission system due to instantaneous overload, while taking into account braking performance, driving stability, and ride comfort. In addition, configuring this control method through an electronic control unit facilitates mass production and adaptation to different vehicle models, enhancing the industrial application value of this control method and expanding its scope of application.

[0025] As can be seen from the above technical solutions, additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of a vehicle control method according to an embodiment of this application; Figure 2 This is a schematic diagram of the process for determining the braking level of a vehicle according to an embodiment of this application; Figure 3 This is a flowchart illustrating the determination of a torque management strategy according to an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0028] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0029] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0030] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0031] It is important to note that in the automotive industry, as the integration and control precision of vehicle powertrain systems continue to improve, user demands for vehicle safety, ride comfort, power responsiveness, and overall vehicle durability are becoming increasingly stringent. During actual driving, braking is one of the most frequent and complex driving conditions. Especially in typical scenarios such as congested urban traffic, continuous downhill driving in mountainous areas, emergency high-speed maneuvers, and rapid acceleration followed by rapid deceleration, the vehicle's transmission system simultaneously experiences torque from various factors. The superposition of torques from multiple dimensions on the transmission components easily creates instantaneous peak torque. When this peak torque exceeds the material yield strength, fatigue durability limit, or design safety threshold of the transmission system components, it directly leads to problems such as impact vibration, abnormal noise, premature wear, plastic deformation, and even fracture failure, severely impacting vehicle lifespan and driving safety.

[0032] However, current traditional vehicle control systems typically employ either simply increasing the mechanical strength of the drive shaft or using a single system control approach. This approach can lead to performance defects in the vehicle. The first method increases load-bearing capacity through mechanical means such as increasing drive shaft size and strengthening materials, but this increases vehicle weight and manufacturing costs, and fails to address the complexity of dynamic loads. Furthermore, it may still cause damage due to excessive impact torque during emergency braking. The second method uses mechanical protection devices such as clutches, but suffers from slow response speed and low protection accuracy. The response time of mechanical protection devices is typically on the order of seconds, while the torque impact during emergency braking occurs within milliseconds, causing the protection devices to fail to respond in time. Therefore, existing technologies cannot simultaneously meet the power transmission requirements of normal driving and the overload protection requirements of emergency braking, resulting in insufficient protection of the transmission system or protection measures that interfere with normal driving during emergency braking.

[0033] Based on this, this application proposes a vehicle control method and a vehicle, applicable to scenarios where the transmission system is protected against torque overload during emergency braking. This system can monitor the vehicle's braking status in real time, predict the torque load on the transmission system, and execute a graded protection strategy according to the severity of braking, effectively preventing damage to transmission components such as the drive shaft due to overload.

[0034] In the following, embodiments of this application will be described in detail with reference to the accompanying drawings.

[0035] Please refer to all the accompanying drawings. In one illustrative embodiment of the vehicle control method and vehicle of this application, the method can be applied to a power control system, and the method includes: Step S110: Obtain the vehicle's braking parameters, driving status parameters, and powertrain system parameters. Determine the vehicle's braking level based on the braking parameters and driving status parameters. Different braking levels are configured with corresponding torque management strategies.

[0036] Specifically, the collected signals are mainly divided into braking-related parameters, driving state-related parameters, and powertrain system parameters. Braking parameters include brake master cylinder pressure signals and brake pedal travel signals. Driving state parameters include drive wheel speed signals, vehicle longitudinal acceleration or deceleration signals, and throttle opening signals. Powertrain system parameters can include the sum of the rotational inertia of all rotating components of the vehicle, angular acceleration, engine output torque, transmission gear ratios, and final drive ratios. Braking characteristic coefficients are calculated from the braking parameters and driving state parameters. The braking level of the vehicle at that moment is determined based on the comparison between the braking characteristic coefficients and preset thresholds. Corresponding torque management strategies are configured according to different braking levels.

[0037] This allows for precise identification of braking conditions of varying intensities, avoiding misjudgments or omissions caused by relying on a single signal to determine braking intent, thus improving the accuracy and adaptability of vehicle control. Through tiered control, graded and progressive torque management can be achieved, employing differentiated control strategies for different scenarios to better suit actual operating conditions. This makes the coordinated control of the powertrain and braking systems more targeted, providing progressive protection for the transmission system while ensuring braking performance, thus balancing ride comfort, driving safety, and transmission system durability. It avoids overly simplistic or rigid control strategies, preventing excessive intervention that could affect smoothness during low-intensity braking, and insufficient protection that could lead to component damage during high-intensity braking.

[0038] In some embodiments, determining the vehicle's braking level based on braking parameters and driving state parameters includes: Based on braking parameters and driving state parameters, vehicle braking control characteristics and vehicle driving dynamic characteristics are obtained. Based on vehicle braking control characteristics and vehicle driving dynamic characteristics, braking characteristic coefficients are determined. The braking characteristic coefficients are compared with multiple preset braking thresholds. By judging the relationship between the braking characteristic coefficients and the braking thresholds, the vehicle's braking level is determined.

[0039] Because vehicles are affected by a variety of factors during actual driving, such as uneven road surfaces, sensor noise, wiring harness transmission interference, and electromagnetic radiation inside the vehicle, the raw signals directly acquired usually have a certain degree of random fluctuations, instantaneous jumps, and static offsets. If the unprocessed raw signals are used directly for calculation and judgment, it is easy to cause problems such as feature value extraction deviation, misjudgment of braking level, and distortion of torque prediction. Therefore, after receiving the raw signals, the electronic control unit will first perform systematic preprocessing operations on the signals to provide a stable, reliable, and unified data foundation for subsequent multi-feature weighted calculations, thereby ensuring the accuracy and stability of the entire braking level recognition and torque control process.

[0040] The control system collects vehicle braking and driving status parameters in real time and performs comprehensive analysis on the collected operating parameters to extract multiple characteristic parameters (vehicle braking control characteristics and vehicle driving dynamic characteristics) that reflect braking intensity, vehicle deceleration state, and power linkage changes. The electronic control unit fuses these multiple characteristic parameters according to pre-calibrated weights to obtain a braking characteristic coefficient that uniformly represents the magnitude of vehicle braking intensity. This braking characteristic coefficient is then compared in real time with pre-set multi-level braking thresholds. Based on the comparison results, the current braking level of the vehicle is determined, thereby accurately distinguishing different operating conditions. This provides a stable and reliable basis for subsequent graded execution of corresponding torque management strategies, enabling the vehicle to achieve reasonable and precise control responses in various driving scenarios.

[0041] By analyzing braking parameters and driving state parameters to obtain multiple features, and calculating braking characteristic coefficients from these features, the system can comprehensively reflect the vehicle's current braking intensity and the driver's braking intention. Compared to traditional methods of judging braking intensity using a single signal, this significantly improves the accuracy of braking level identification, avoiding the errors and limitations caused by relying on a single parameter, and enhancing the accuracy and reliability of braking condition identification. By comparing the braking characteristic coefficients with multiple preset braking thresholds and determining the vehicle's braking level based on their magnitude relationships, the system enables a gradient and refined classification of braking intensity. This allows the vehicle to distinguish between different levels of braking conditions, providing an accurate basis for subsequent graded execution of corresponding torque management strategies and achieving precise protection of the transmission system.

[0042] In some embodiments, vehicle braking control characteristics and vehicle driving dynamic characteristics are obtained based on braking parameters and driving state parameters. Braking characteristic coefficients are determined based on vehicle braking control characteristics and vehicle driving dynamic characteristics, including: calculating the brake master cylinder pressure and brake pedal travel in the braking parameters to obtain the maximum brake pressure rise rate and pedal action intensity; calculating the drive wheel speed, vehicle maximum deceleration, and throttle opening in the driving state parameters to obtain the drive wheel speed change rate, vehicle maximum deceleration, and throttle opening change rate; and performing a weighted calculation based on the vehicle maximum deceleration, throttle opening change rate, maximum brake pressure rise rate, pedal action intensity, and wheel speed change rate to obtain braking characteristic coefficients.

[0043] Specifically, after the vehicle completes power-on initialization, system self-test, and communication establishment between various control units, the core electronic control unit begins to continuously and cyclically collect signals from external sensors and internal communication data at a fixed high-frequency sampling period. External sensors may include wheel speed sensors, brake sensors, acceleration sensors, and throttle sensors. Wheel speed sensors are located at the four wheels of the vehicle, measuring the wheel speeds of the right front wheel, left front wheel, left rear wheel, and right rear wheel, respectively. The drive wheel speed is determined by collecting the wheel speed signals from the four wheels (left front, right front, left rear, and right rear) to identify whether the vehicle is front-wheel drive, rear-wheel drive, or four-wheel drive, and then calculating the average wheel speed. Brake sensors include a brake pedal travel sensor and a brake master cylinder pressure sensor. The brake pedal travel sensor is mounted on the brake pedal shaft and measures the displacement of the brake pedal; the brake master cylinder pressure sensor is installed at the brake master cylinder outlet and measures the brake hydraulic pressure. Acceleration sensors are installed at the vehicle's center of gravity to measure the vehicle's longitudinal acceleration. It should be noted that when the acceleration is negative, it is the deceleration of the vehicle; the throttle sensor is installed on the throttle pedal assembly, which collects the throttle opening signal in real time and outputs the current throttle opening percentage signal (0% to 100%) in real time.

[0044] For example, the brake master cylinder pressure measured by the brake master cylinder pressure sensor is first calculated digitally to obtain the characteristic value F1 of the maximum brake pressure rise rate. The specific formula is as follows:

[0045] Where mcp is the brake master cylinder pressure (ESP_MasterCylBrkPress), and t is the current time. The time interval (i.e., the sampling period, such as...) =1ms).

[0046] This characteristic value can intuitively reflect the urgency and urgency of the driver's braking operation. The faster the rate of increase in braking pressure, the stronger the driver's braking intention and the higher the vehicle's braking intensity.

[0047] Secondly, the displacement of the brake pedal measured by the brake pedal travel sensor is calculated to obtain the characteristic value F2 of the pedal action intensity. The specific formula is as follows:

[0048] Where Ln is the current pedal travel and L0 is the total travel of the brake pedal.

[0049] The pedal action intensity F2 is used to characterize the urgency and intensity of the driver's braking operation. The faster the pedal action and the greater the travel, the higher the corresponding pedal action intensity.

[0050] Next, the vehicle's acceleration in the longitudinal direction is acquired from the vehicle's acceleration sensor. It should be noted that a negative acceleration value corresponds to deceleration. In other words, the vehicle's speed during braking is acquired in real-time, and the maximum deceleration during braking is selected as the vehicle's maximum deceleration characteristic value F3, denoted as:

[0051] Where Acc_X is the maximum longitudinal deceleration of the vehicle.

[0052] Then, the decrease in the drive wheel speed within a preset time period is calculated to obtain the characteristic value F4 of the drive wheel speed change rate, which specifically includes:

[0053] in, The change in wheel speed of the drive wheel within a preset time period ( (It can be 50ms). The time interval (i.e., the sampling period, such as...) =1ms).

[0054] The rate of change of drive wheel speed can be used to directly reflect the intensity of the actual braking effect on the wheel; the faster the wheel speed decreases, the more obvious the braking effect.

[0055] Finally, the characteristic value F5 of the rate of change of throttle opening is calculated in real time. The throttle opening signal is collected in real time by the throttle sensor, and the current throttle opening percentage signal (0%~100%) is output in real time. The rate of change of throttle opening is used to determine whether the driver has a synchronous power cancellation or power interruption behavior during braking. Under high-intensity braking conditions, the throttle opening usually drops back to zero quickly. The rate of change of throttle opening can effectively help identify whether the vehicle is in emergency braking or high-intensity braking conditions.

[0056] After extracting and calculating the above five feature values, the electronic control unit performs a weighted summation of each feature value based on the weighting coefficients obtained in advance through various experiments and actual vehicle calibration. Finally, it obtains the braking feature coefficients that can comprehensively and fully characterize the overall braking strength of the vehicle. The weighting coefficients can be adaptively calibrated according to the vehicle chassis structure, transmission system configuration, braking system specifications, and overall vehicle tuning style to ensure stable and reliable braking strength identification under different vehicle models, different loads, and different road surface adhesion conditions.

[0057] When calculating the braking characteristic coefficient by weighting the vehicle's maximum deceleration, throttle opening rate of change, maximum brake pressure rise rate, pedal aggression, and wheel speed change rate, the weights are as follows: maximum brake pressure rise rate F1 can have a weight of 0.3, pedal aggression F2 a weight of 0.25, maximum vehicle deceleration F3 a weight of 0.2, vehicle drive wheel speed change rate F4 a weight of 0.15, and throttle opening rate of change F5 a weight of 0.1. The maximum brake pressure rise rate has the highest weight because it directly reflects the intensity of the braking operation; pedal aggression has the second highest weight, reflecting the driver's braking intention; maximum vehicle deceleration has a weight of 0.2, reflecting the braking effect; wheel speed change rate has a weight of 0.15, reflecting changes in wheel condition; and throttle opening rate of change has a weight of 0.1, reflecting the state of the powertrain.

[0058] The specific formula for calculating the braking characteristic coefficient F is as follows: F=0.3×F1+0.25×F2+0.2×F3+0.15×F4+0.1×F5 By extracting feature values ​​from multiple dimensions such as braking operation (rate of increase of maximum braking pressure, intensity of pedal action), vehicle deceleration state (rate of change of wheel speed, maximum vehicle deceleration), and power linkage (rate of change of throttle opening), the key indicators reflecting braking intensity are comprehensively covered, solving the problem of traditional feature extraction being singular and unable to fully characterize braking conditions. By calculating the braking feature coefficients through weighted multi-feature value calculation, the advantages of signals from various dimensions are effectively integrated, reducing the impact of single signal fluctuations on braking level identification, further improving the accuracy and reliability of braking feature coefficients, and providing solid support for the accurate classification of braking levels.

[0059] In some embodiments, when the braking characteristic coefficient is greater than or equal to a first braking threshold and less than a second braking threshold, the vehicle is determined to be in a first braking level; when the braking characteristic coefficient is greater than or equal to a second braking threshold and less than a third braking threshold, the vehicle is determined to be in a second braking level; and when the braking characteristic coefficient is greater than or equal to a third braking threshold, the vehicle is determined to be in a third braking level.

[0060] For example, after calculating the braking characteristic coefficient F, the braking level identification step is entered. The braking level determination module of the electronic control unit compares the calculated braking characteristic coefficient F with three pre-existing braking thresholds to clearly define the current braking level of the vehicle. The braking thresholds can be the first braking threshold of 0.3, the second braking threshold of 0.65, and the third braking threshold of 0.85. This threshold division standard is also determined based on a large number of real vehicle experiments and simulation experiments. It can accurately adapt to most braking scenarios during vehicle operation, providing a clear and standardized basis for the subsequent matching of differentiated torque management strategies. It effectively avoids the problem of single and rigid control strategies caused by ambiguity in braking state judgment in traditional control strategies, and realizes accurate graded control under different braking conditions.

[0061] The specific braking level classification criteria are as follows: When the calculated braking characteristic coefficient F < 0.3, the vehicle is determined to be in normal operating condition, meaning the vehicle is not performing braking operations or only performing very slight braking operations. At this time, there is no risk of torque overload in the transmission system, and no torque management strategy is required; the vehicle's power system and braking system maintain normal operating conditions. When the braking characteristic coefficient F satisfies 0.3 ≤ F < 0.65, the vehicle is determined to be in the first braking level, i.e., the preventative operating condition. At this time, the vehicle is performing general braking operations. Although the current braking intensity is low, there is a potential risk of torque overload in the transmission system, requiring the implementation of corresponding preventative torque management strategies and advance protective measures. When the braking characteristic coefficient F satisfies 0.65 ≤ F < 0.85, the vehicle is determined to be in the second braking level. The first braking level, or intervention condition, indicates that the vehicle is performing pre-emergency braking, with significantly increased braking intensity. The peak torque of the transmission system shows a clear upward trend. If intervention is not taken in time, torque overload is likely to occur. It is necessary to implement corresponding intervention-type torque management strategies to actively control the rise in peak torque. When the braking characteristic coefficient F ≥ 0.85, the vehicle is determined to be in the third braking level, or protection condition. At this time, the vehicle is performing emergency braking, with the braking intensity reaching its maximum. The transmission system faces a serious risk of torque overload. If extreme protective measures are not taken immediately, the transmission system will be damaged due to the superposition of excessive reverse impact torque and inertial load. It is necessary to implement corresponding protective torque management strategies, and extreme measures can be taken to limit the torque of the drive shaft to prevent damage to transmission system components.

[0062] By setting specific criteria for multi-level braking, and comparing braking characteristic coefficients with multiple preset thresholds, the operating conditions corresponding to various braking intensities are clearly defined, making the classification of braking levels more operable and standardized. Through the aforementioned quantified threshold classification criteria, the vehicle's braking conditions can be clearly divided into normal conditions and three different braking intensities. Each braking level corresponds to a specific range of braking characteristic coefficients, making braking level identification highly operable and standardized. The electronic control unit can quickly and accurately determine the vehicle's braking level based on the calculated braking characteristic coefficient F, laying the foundation for precise matching of subsequent torque management strategies. The design of multi-level braking is adapted to most braking scenarios during vehicle operation, providing a clear basis for matching subsequent differentiated torque management strategies, avoiding the problems of a single, rigid control strategy, and enabling precise control under different braking conditions.

[0063] Step S120: Calculate the predicted net torque value of the vehicle drive bearing after a preset time based on braking parameters and power transmission system parameters.

[0064] Based on collected braking parameters, vehicle structural parameters, and powertrain system parameters, the electronic control unit predicts the net torque that the vehicle's drive axle will experience after a preset time Δt. This value is a vector value; a positive value represents positive driving torque (vehicle acceleration), and a negative value represents reverse braking torque (vehicle deceleration). During emergency braking, this value is typically a large negative value, which can easily exceed the drive axle's safety limit. The preset time can be flexibly calibrated based on the vehicle control response speed, actuator action delay, and system calculation cycle. This setting ensures that control commands are sent to the actuators before the actual torque peak arrives, thus achieving true proactive control rather than traditional passive feedback control. It should be noted that in this embodiment, the preset time Δt is 5ms. Of course, in other embodiments, the preset time Δt can be other values, which are not specifically limited here.

[0065] In some embodiments, calculating the predicted net torque of the vehicle drive bearing after a preset time based on braking parameters and powertrain system parameters includes: calculating the braking torque of the vehicle after a preset time based on the vehicle's braking parameters; calculating the inertial torque and engine-transmitted torque of the vehicle after a preset time based on the powertrain system parameters; retrieving a preset torque compensation value; and summing the inertial torque, braking torque, engine-transmitted torque, and torque compensation value to obtain the predicted net torque of the vehicle drive shaft after a preset time.

[0066] Understandably, the predicted net torque of the drive shaft... It is not a torque from a single source, but a composite torque formed by the superposition of multiple components at the drive shaft position, specifically including inertial torque. Braking torque Engine torque transmission and torque compensation value Four parts. Therefore, an engine torque sensor can also be installed inside the vehicle; the engine torque sensor is installed on the engine output shaft to measure the engine's output torque.

[0067] Inertial torque primarily reflects the inertial moment resulting from changes in the vehicle's motion state and is one of the main torque components experienced by the drive bearing during braking. The torque term, representing the conversion of vehicle kinetic energy, is calculated using the following formula:

[0068] in, It is the sum of the moments of inertia of all rotating parts of the vehicle (engine, gearbox, drive shaft, wheels, etc.); This represents the angular acceleration of the rotating components of the vehicle (negative for angular deceleration).

[0069] In some embodiments, calculating the braking torque of a vehicle after a preset time based on the vehicle's braking parameters includes: obtaining the master cylinder pressure in the braking parameters; obtaining the vehicle's braking friction coefficient, effective braking radius, braking area, braking efficiency coefficient, and number of braking wheels; and calculating the braking torque based on the master cylinder pressure, braking friction coefficient, effective braking radius, braking area, braking efficiency coefficient, and number of braking wheels.

[0070] Specifically, braking torque The external torque applied to the braking system is determined by the system's own parameters, including the master cylinder pressure, the working area of ​​the brake piston, the coefficient of friction between the brake pads and the brake disc, the effective braking radius, the braking efficiency coefficient, and the number of braking wheels. It is the main reverse torque applied to the drive shaft by the braking system and has the most significant impact on the transmission system.

[0071] Its braking torque The calculation formula is:

[0072] in, For braking friction coefficient, For the brake master cylinder pressure, The equivalent radius of the braking friction force. For the brake piston area, For braking efficiency coefficient, This refers to the number of wheels that are engaged in braking.

[0073] It should be noted that the braking friction coefficient Related to the materials of the brake pads and discs, these are fixed performance parameters of the braking system. They can be specifically set according to different vehicle models and are pre-stored in the electronic control unit. They can also be appropriately adjusted based on the wear condition of the braking system; brake master cylinder pressure. The brake master cylinder pressure sensor collects data in real time, which is the core variable for calculating the braking torque; the equivalent radius of the braking friction force. This parameter is a fixed structural parameter of the braking system, reflecting the location of the braking friction force. It can be specifically set according to different vehicle models and is pre-stored in the electronic control unit; brake piston area. Similarly, these are fixed structural parameters of the braking system, which can be specifically set according to different vehicle models and are pre-stored in the electronic control unit; braking efficiency coefficient This parameter reflects the energy transfer efficiency of the braking system, taking into account factors such as brake line pressure loss and brake component friction loss. It is an empirical value, pre-stored in the electronic control unit after being determined based on a large number of experiments, but can also be specifically set according to different vehicle models, including the number of wheels subjected to braking. The number of wheels currently engaged in braking is determined by the operating status of the braking system, which the electronic control unit can obtain in real time based on the signals from the braking system.

[0074] The above-mentioned braking torque calculation model can comprehensively consider the structural parameters, working state parameters, and performance parameters of the braking system, and achieve accurate calculation of braking torque. This significantly improves the calculation accuracy of braking torque, thereby effectively improving the accuracy of the net torque prediction of the drive shaft. It provides reliable data support for the precise execution of subsequent torque management strategies, and ensures that the coordinated control of the braking system and the power system is more targeted.

[0075] Engine transmits torque The torque transmitted from the engine to the drive shaft is calculated using the following formula:

[0076] in, For engine output torque, For the gearbox ratio, The main deceleration is determined by n, where n is the number of drive wheels of the vehicle. For example, if the vehicle is a four-wheel drive vehicle, n=4.

[0077] The torque transmitted by the engine is the actual output of the engine or drive motor, which is transmitted to the drive shaft end through transmission components such as the gearbox, main reducer, and differential. Its magnitude directly affects the superposition of positive torque on the drive shaft.

[0078] Torque compensation value For the remaining unquantified torque compensation items, a fixed value of 50 Nm is used in this embodiment to ensure the comprehensiveness of the net torque calculation. Of course, in subsequent implementations, other values ​​can be selected according to the actual vehicle model, and this is not limited here. The torque compensation value is used to compensate for torque deviations caused by various non-ideal factors such as transmission system mechanical losses, tire slippage, temperature changes, differences in lubrication conditions, assembly clearances, and system calculation errors, which can effectively improve the accuracy of net torque prediction.

[0079] Therefore, based on the various torque values ​​mentioned above, the electronic control unit predicts the net torque that the vehicle drive shaft will experience after a preset time Δt (Δt is 5ms in this embodiment). The net torque prediction value is calculated by summing all the components of the drive shaft torque to achieve an accurate prediction of the net torque value after a preset time. The calculation formula is as follows:

[0080] Therefore, the electronic control unit algebraically sums the four torque components to obtain the predicted net torque value of the drive shaft after a preset time. This proactive prediction method enables a shift from traditional passive feedback control to active pre-emptive protection control, suppressing peak torque in the transmission system at its source and significantly improving protection. The net torque prediction value is obtained by summing the four components: inertial torque, braking torque, engine-transmitted torque, and torque compensation value. This comprehensively covers all sources of torque on the vehicle's drive shaft, solving the problems of incomplete net torque calculation and low prediction accuracy in traditional methods. By summing the four torque components, accurate prediction of the net torque value after a preset time is achieved, providing an accurate basis for pre-judgment of transmission system overload risk. This allows torque management strategies to be activated in advance, effectively preventing damage to the transmission system due to instantaneous overload.

[0081] Step S130: Identify whether the net torque prediction value meets the preset triggering conditions. If so, obtain the torque management strategy corresponding to the braking level and execute the corresponding braking action based on the torque management strategy.

[0082] After obtaining the predicted net torque value of the drive shaft, the electronic control unit needs to determine whether the predicted net torque value meets the preset trigger conditions. These preset trigger conditions are torque judgment conditions calibrated in advance based on the vehicle's transmission system's safe load-bearing capacity, braking characteristics, and dynamic control requirements. Specifically, the predicted net torque value is compared in real time with a pre-calibrated safe torque threshold. When the predicted net torque value reaches or exceeds the corresponding safe torque threshold, the preset trigger conditions are deemed met. Furthermore, the safe torque threshold is determined comprehensively based on the material strength, fatigue life, design safety factor, and vehicle durability test results of key components in the transmission system, such as the drive shaft, gearbox input shaft, differential, drive shaft, and half-shafts. In other words, the safe torque threshold is the maximum torque value that the drive shaft can withstand, and it is the core basis for determining whether to activate the torque management strategy. When the predicted net torque value reaches or exceeds the safe torque threshold, the electronic control unit determines that the triggering conditions for the torque management strategy are met. It then automatically invokes the corresponding torque management strategy based on the currently identified braking level and sends unified, coordinated control commands to the actuators of the powertrain and braking systems. If the predicted net torque value does not reach the safe torque threshold, it indicates that there is no significant overload risk in the transmission system under the current operating conditions. The system maintains the vehicle's normal control mode, does not trigger additional torque management actions, and ensures the vehicle's power, economy, and ride comfort during normal driving. By combining torque prediction with threshold judgment, this invention can ensure control effectiveness while avoiding frequent false triggering of strategies, improving the smoothness, stability, and reliability of the overall vehicle control.

[0083] By combining braking level identification, drive shaft net torque prediction, and torque management strategy execution, this approach addresses the technical shortcomings of traditional vehicle powertrain and braking systems, which operate independently and lack coordination. The logic of first determining the braking level, then predicting the net torque, and finally triggering the corresponding strategy achieves proactive protection against torque overload in the transmission system, avoiding the lag inherent in traditional passive feedback control. Simultaneously, matching different braking levels with corresponding torque management strategies makes control actions more targeted, balancing vehicle braking performance, driving safety, and transmission system durability. This approach is applicable to various vehicle powertrain control scenarios, enhancing the versatility and practicality of the control method.

[0084] In some embodiments, identifying whether the net torque prediction value meets a preset trigger condition includes: Obtain the safe torque threshold of the drive shaft and determine whether the net torque prediction value reaches the safe torque threshold; if so, identify that the net torque prediction value meets the preset triggering conditions.

[0085] For example, the electronic control unit pre-obtains a safe torque threshold for the vehicle's drive shaft. The predicted net torque value With safety torque threshold In contrast, when ≤1.1× When predicting the net torque value, if the net torque value meets the preset triggering conditions, there is a significant risk of torque overload in the transmission system, requiring immediate activation of the corresponding torque management strategy. If the standard is not met, it is determined that there is no overload risk in the current transmission system, and the vehicle's current braking state is maintained without executing any additional torque management actions. By using quantified triggering standards, false or missed triggering of the strategy is avoided, ensuring the stability and rationality of the control method.

[0086] The trigger condition setting, based on the drive shaft's safe torque threshold, provides a certain safety margin. This effectively avoids transmission system overload caused by net torque calculation errors or sudden changes in vehicle operating conditions, while also preventing frequent strategy triggering due to overly stringent trigger conditions, which could affect the vehicle's normal driving and braking performance. By quantitatively comparing the predicted net torque value with the drive shaft's safe torque threshold, the overload risk of the transmission system can be accurately identified. This solves the problem of false or missed triggering of strategies caused by the lack of clear triggering standards and reliance on experience in traditional control methods. Furthermore, this method only triggers the torque management strategy when the net torque value reaches the safe threshold. This ensures timely protection of the transmission system in the event of overload risk while avoiding the impact of frequent torque management strategy triggering on normal vehicle driving and braking. This effectively improves the stability and rationality of the control method and provides a clear and quantifiable triggering standard for transmission system protection.

[0087] Once the electronic control unit determines that the net torque value meets the preset trigger conditions, it will immediately enter the torque management strategy matching and execution phase. The electronic control unit will quickly retrieve the corresponding torque management strategy pre-stored in the internal memory based on the previously identified vehicle braking level, and send precise execution commands to each actuator of the vehicle via the bus. After receiving the commands, each actuator will coordinate to execute the corresponding braking action and power adjustment action within milliseconds to achieve precise protection of the transmission system.

[0088] In some embodiments, different braking levels are configured with corresponding torque management strategies, including: The torque management strategy corresponding to the first braking level is a preventive strategy. The preventive strategy is used to control the vehicle's braking system to perform preload actions in order to shorten the braking intervention time and adjust the operating parameters of the vehicle's power system so that the power system is in an early response state.

[0089] The first braking level is a preventative condition, and the corresponding torque management strategy is a preventative strategy. Its core control objective is to prevent potential torque overload risks, prepare the braking system and power system in advance, improve the system's response speed, and lay the groundwork for potentially stronger braking operations in the future. This strategy mainly performs pre-loading actions on the braking system and adjusts the configuration of the vehicle's power system.

[0090] The preloading process of the braking system includes hydraulic prefilling, booster prefilling, and Electronic Stability Program (ESP) standby. Hydraulic prefilling refers to the electronic control unit (ECU) issuing a command to the braking system, causing the hydraulic control module to immediately prefill the brake calipers with a small amount of brake fluid, eliminating the gap between the calipers and discs through hydraulic pressure. Booster prefilling refers to the ECU slightly pre-pressuring the booster under the command of the ECU, putting it in an energy-storing state so that it can quickly provide braking assistance when the driver applies stronger braking force, further reducing brake travel and improving the braking system's response speed. ESP standby refers to the ECU issuing a command to the ESP system, switching it from a normal standby state to a rapid response state. The ESP system's sensors and control modules enter a high-sensitivity operating mode, enabling immediate intervention when the vehicle experiences abnormal driving conditions, ensuring vehicle stability.

[0091] Adjusting the operating parameters of a vehicle's powertrain involves three specific operations: increasing engine idle speed, adjusting throttle mapping, and setting transmission presets. Specifically, increasing engine idle speed means the engine control system, under the instruction of the electronic control unit (ECU), appropriately increases the engine's idle speed to reserve a certain torque capacity, allowing the engine to quickly adjust torque output when needed, thus improving the powertrain's responsiveness. Adjusting throttle mapping involves the ECU temporarily adjusting the engine's throttle mapping curve, appropriately reducing throttle sensitivity to prevent a sudden increase in engine torque due to driver error during braking, which could amplify the torque load on the transmission system. It also avoids minor throttle fluctuations interfering with the powertrain. Transmission presets, under the instruction of the ECU, prevent unnecessary downshifting, especially when the vehicle is in a low gear. This strictly maintains the current gear to prevent downshifting from increasing the gear ratio, amplifying engine braking effects, and increasing the torque load on the drive shaft. By stabilizing the gearbox, the transmission system's torque is kept stable, preventing potential torque overload risks.

[0092] Through the aforementioned series of operations for braking system preparation and power system optimization, the vehicle's braking and power systems can enter a protective preparation state in advance, effectively improving the system's response speed and preventing the risk of transmission system torque overload from the source. At the same time, these operations are all minor adjustments and will not have any negative impact on the vehicle's normal braking and driving, thus balancing protection and driving comfort.

[0093] The torque management strategy corresponding to the second braking level is an intervention strategy. The intervention strategy is used to control the vehicle's braking system to redistribute the braking force according to a preset ratio and to perform torque unloading action on the vehicle's power system to reduce the vehicle's braking torque.

[0094] The second braking level is an intervention condition, and the corresponding torque management strategy is also an intervention strategy. Its core control objective is to actively control the increase in peak torque of the drive shaft. This is achieved by performing torque unloading actions on the powertrain and redistributing braking force to the braking system according to a preset ratio, thereby reducing the vehicle's braking torque and effectively reducing the torque on the drive shaft. This avoids the overload risk caused by a continuous increase in peak torque. This strategy mainly involves rapid engine torque unloading, active transmission intervention, and braking system coordination. Rapid engine torque unloading is the core operation of this strategy. After the electronic control unit sends a torque unloading command to the engine control system, the engine will smoothly... The unloading strategy linearly reduces the engine's output torque at a rate of 800-1200 Nm / s. This unloading rate is determined based on extensive experiments. It can quickly reduce the torque transmitted from the engine to the drive shaft, effectively suppressing the rise of torque peak, and avoid problems such as sudden changes in engine speed and vehicle vibration caused by excessive torque unloading. This ensures the smooth operation of the power system and the driving comfort of the vehicle. During the torque unloading process, the engine torque sensor will collect the engine's output torque signal in real time and feed it back to the electronic control unit. The electronic control unit will adjust the unloading rate in real time according to the feedback signal to achieve precise and smooth torque unloading.

[0095] The active intervention operation of the transmission includes two specific actions: prohibiting downshifting and neutral preparation. Prohibiting downshifting means that the transmission control system, under the instruction of the electronic control unit, strictly prohibits the transmission from performing any downshifting operation, maintaining the current gear regardless of changes in vehicle speed and engine speed. This is because during braking, downshifting increases the gear ratio, significantly amplifying the engine braking effect and causing a sharp increase in the reverse torque on the drive bearing. Prohibiting downshifting effectively avoids this problem and maintains stable torque in the transmission system. Neutral preparation means that the transmission control system adjusts the transmission's shift mechanism to a preparatory position near neutral, entering a neutral preparation state, but does not immediately engage neutral. This operation is to cope with extreme situations where braking intensity suddenly increases. When the vehicle's braking condition suddenly deteriorates, entering the third braking level, the transmission can quickly engage neutral within milliseconds, cutting off torque transmission between the engine and drive shaft, providing stronger protection for the transmission system. Neutral preparation not only reserves operational space for subsequent extreme protection but also does not affect the current torque transmission of the transmission system.

[0096] The coordinated operation of the braking system includes two specific actions: optimized brake force distribution and early intervention of the anti-lock braking system (ABS). Optimized brake force distribution refers to the electronic control unit (ECU) sending a brake force distribution adjustment command to the braking system. The hydraulic control module of the braking system will appropriately increase the braking force ratio of the rear axle while correspondingly reducing the braking force ratio of the front axle. Through the redistribution of braking force, the reverse impact torque generated during front axle braking can be effectively reduced and transmitted to the drive axle, thereby reducing the total torque on the drive axle. At the same time, the increased braking force of the rear axle can effectively compensate for the overall braking force of the vehicle, ensuring that the overall braking performance of the vehicle is not affected. Early intervention of the anti-lock braking system (ABS) refers to the ECU sending a command to the ABS system to enable the ABS system to enter working state in advance. Before the wheels are about to lock up, the system will start adjusting the braking force to prevent sudden wheel speed changes caused by wheel lock-up. This avoids the transmission of instantaneous large torque caused by sudden wheel speed changes to the drive axle. At the same time, the early intervention of ABS can also ensure the vehicle's braking directional stability and prevent phenomena such as sideslip and fishtailing, thus taking into account both transmission system protection and vehicle driving safety.

[0097] Through the coordinated operation of rapid engine torque unloading, active transmission intervention, and braking system coordination, the torque of the drive shaft can be precisely intervened in the three core aspects of power output, torque transmission, and braking torque. This effectively controls the rise of torque peak and keeps the torque of the drive shaft within a safe range, avoiding overload of the transmission system. At the same time, each operation has been precisely designed and coordinated, ensuring vehicle braking performance and driving stability while achieving torque intervention, thus balancing protection, braking, and comfort.

[0098] The torque management strategy corresponding to the third braking level is a protection strategy. The protection strategy is used to control the vehicle's braking system to limit the front axle braking force output and to perform torque cut-off or power transmission interruption control operations on the vehicle's power system to prevent the transmission system from being damaged due to overload.

[0099] The third braking level is a protection condition, and the corresponding torque management strategy is a protection strategy. Its core control objective is to prevent damage to transmission system components due to overload. In response to the extremely large reverse torque on the drive bearing under emergency braking conditions, a series of extreme torque control and braking adjustment measures are taken to quickly and significantly reduce the torque load on the drive shaft while ensuring the vehicle's basic braking performance and driving safety. This strategy mainly performs extreme torque suppression actions on the power system and adjusts the vehicle's braking system to limit the braking force of the front axle and enhance the braking force of the rear axle. The extreme torque suppression action measures are the core of this strategy, including three specific operations: engine fuel cut-off, forced upshift, and forced clutch slippage. Engine fuel cut-off refers to the electronic control unit issuing an emergency fuel cut-off command to the engine control system. The engine immediately cuts off the fuel supply and stops fuel injection, reducing the engine's output torque to a minimum in a very short time. This quickly cuts off the torque transmitted from the engine to the drive shaft, which is the most extreme measure to reduce the torque output of the power system and can effectively reduce the torque load on the drive bearing. Forced upshift operation refers to the transmission control system, under the command of the electronic control unit, forcibly shifting the transmission into a higher gear. By increasing the gear ratio, it significantly reduces the reverse torque caused by engine braking. If the braking conditions are extremely severe and the torque on the drive shaft still exceeds the safety threshold, the transmission will directly shift into neutral (N), completely cutting off the engine torque. The torque transmission path between the engine and the drive shaft ensures that the drive shaft no longer bears any torque transmitted by the engine, fundamentally eliminating the torque load from the power system. Forced clutch slippage refers to the electronic control unit issuing a command to the clutch control system to put the clutch in a semi-engaged state, allowing partial clutch slippage. By slipping the clutch, excess energy in the transmission system is consumed, and some torque is converted into heat energy for release, thereby effectively reducing the net torque on the drive bearing. This operation can quickly consume the instantaneous large torque of the transmission system and prevent the continuous accumulation of torque from damaging transmission system components. During clutch slippage, the electronic control unit will monitor the clutch temperature and slippage degree in real time to avoid clutch damage due to excessive slippage.

[0100] Adjusting the vehicle's braking system to limit the braking force of the front axle and enhance the braking force of the rear axle involves two specific actions: limiting the braking force of the front axle and enhancing the braking force of the rear axle. The core is to minimize the reverse torque transmitted from the braking system to the drive axle by significantly adjusting the braking force while ensuring the overall braking force of the vehicle. Front axle braking force limiting operation refers to the electronic control unit issuing a command to the braking system, causing the hydraulic control module of the braking system to actively and significantly reduce the braking pressure on the front axle, thereby reducing the braking force on the front axle and effectively reducing the reverse impact torque generated during front axle braking, and significantly reducing the braking torque on the drive bearing. Rear axle braking force enhancing operation refers to the braking system significantly increasing the braking pressure on the rear axle while reducing the front axle braking force, thus enhancing the braking force on the rear axle. By significantly enhancing the rear axle braking force, the loss of overall vehicle braking force caused by the reduction in front axle braking force is fully compensated, ensuring that the vehicle still has sufficient braking efficiency while taking protective measures, and can quickly reduce vehicle speed, avoiding driving safety problems caused by insufficient braking efficiency. The coordinated operation of front axle braking force limiting and rear axle braking force enhancing achieves the dual goals of protecting the transmission system and ensuring braking efficiency, taking into account both the durability of the transmission system and the driving safety of the vehicle.

[0101] The aforementioned torque management strategy, corresponding to three braking levels, achieves a gradient and differentiated design of the control strategy, solving the problem of traditional control strategies being singular and unable to adapt to different braking conditions. The prevention strategy prepares for low-intensity braking in advance, improving response speed; the intervention strategy targets medium-intensity braking, suppressing torque peaks through coordinated adjustment of the power and braking systems; and the protection strategy targets high-intensity braking, implementing extreme protection to prevent damage to the transmission system. These three strategies, progressively strengthened, ensure braking performance and ride comfort under different braking conditions while achieving full-condition protection for the transmission system, significantly improving vehicle driving safety and transmission system durability.

[0102] In some embodiments, the vehicle control method further includes: counting the number of triggers for each torque management strategy by category; and issuing a prompt message through the vehicle terminal when the number of triggers reaches a preset threshold.

[0103] For example, after the execution of the multi-level torque management strategy is completed, this method for preventing torque overload of the transmission system also sets up a strategy trigger count statistics and vehicle warning steps, which can realize real-time monitoring of the status of the vehicle's transmission system and braking system, issue timely warnings to the driver, remind the driver to regulate driving behavior and check the vehicle status in a timely manner, and also provide important data support for the subsequent maintenance and inspection of the vehicle, further improving the vehicle's safety, maintainability and reliability.

[0104] Specifically, the counting and statistics module inside the electronic control unit can count the number of times each torque management strategy is triggered. It can be understood that the electronic control unit counts each type of torque management strategy separately. Taking the third braking level as an example, the number of times the corresponding protection strategy is triggered is counted in real time and continuously. Of course, in other embodiments, each torque management strategy can be counted, or only the number of times the protection strategy corresponding to the third braking level is counted. This is because the strategy corresponding to the third braking level is only triggered when the vehicle is under emergency braking or the transmission system is facing a serious overload risk. Its trigger count can directly reflect the frequency of the vehicle encountering emergency braking conditions, and can also indirectly reflect the working status of the transmission system and the braking system. If the protection strategy is triggered frequently, it may mean that the driver's driving behavior is relatively aggressive and frequently performs emergency braking, or it may mean that there is a potential fault in the vehicle's transmission system or braking system, resulting in an abnormal increase in the torque load of the transmission system.

[0105] The electronic control unit (ECU) activates the counting mechanism of the third-level braking protection strategy. After each trigger event of the third-level braking protection strategy, the counter inside the ECU automatically increments by 1. This counting mechanism provides data support for subsequent on-board terminal warnings. By statistically analyzing the number of triggers of the extreme protection strategy, abnormal operating conditions of the vehicle and potential changes in the transmission system can be identified in a timely manner. The ECU has a preset threshold for the number of triggers. In this embodiment, the preset threshold is set to 30 times. Of course, in other embodiments, it can be other values. When the counter accumulates 30 triggers of the third-level braking protection strategy, the ECU will immediately issue a warning command to the on-board instrument terminal. After receiving the command, the on-board instrument terminal will clearly display the prompt message "Please check the vehicle transmission system" on the display screen. This prompt message will continue to be displayed until the driver checks the vehicle and clears the prompt using a dedicated device. Through this on-board warning function, the driver can be promptly reminded to pay attention to the status of the vehicle's transmission system.

[0106] Thus, by statistically analyzing the number of times the torque management strategy is triggered, a prompt function is activated when the number of triggers exceeds a preset value, solving the problem of the lack of status monitoring and early warning mechanisms in traditional control methods. By statistically analyzing the trigger counts of each strategy, abnormal vehicle operating conditions can be identified in a timely manner, and prompts can be sent to the driver via the onboard terminal. This guides the driver to regulate driving behavior, reduce the number of emergency brakings, and lower the risk of overload in the transmission system. It also reminds the driver to promptly take the vehicle to a repair shop for professional inspection and maintenance, facilitating timely detection of potential faults in the transmission and braking systems, such as brake system wear, excessive transmission system clearance, and decreased sensor accuracy. Timely repair and replacement are then carried out to prevent further deterioration of potential faults that could lead to transmission system damage or traffic accidents. Furthermore, the electronic control unit records and stores relevant data such as the trigger time of the third braking level protection strategy, the vehicle operating conditions at the time of triggering, the net torque value, and the braking level. This data can be read through the vehicle's diagnostic interface, providing detailed and accurate information for fault diagnosis and repair by maintenance personnel. This facilitates the timely detection of potential faults in the transmission and braking systems, making maintenance work more targeted and effectively improving vehicle maintainability.

[0107] In addition, this application also provides a vehicle that employs the aforementioned vehicle control method.

[0108] The vehicle employing the above-described method for preventing transmission system torque overload can be any type of motor vehicle, such as a fuel vehicle, a new energy pure electric vehicle, or a hybrid vehicle. The vehicle may have an electronic control unit (ECU) installed inside, and the ECU is configured with the protection method for preventing transmission system torque overload described in any of the above embodiments. That is, the ECU pre-stores all the calculation formulas, preset thresholds, torque management strategies, and other data of this method, and has all the functional modules required by this method, and can independently complete all tasks such as signal processing, braking level identification, net torque prediction, trigger condition judgment, strategy matching and command issuance, and counting statistics.

[0109] This vehicle, by incorporating a protection method to prevent torque overload in the transmission system, achieves deep coordinated control between the braking and power systems. This effectively solves the problem of transmission system overload damage caused by the superposition of reverse impact torque and inertial loads during emergency braking in traditional vehicles. During emergency braking, it can actively and precisely limit the peak reverse torque on the drive bearing, protecting the safety of transmission system components. Compared to traditional transmission system protection measures, this vehicle does not need to increase the load-bearing capacity by simply increasing the size of the drive shaft, effectively avoiding the problems of increased vehicle weight, increased manufacturing costs, and decreased fuel / energy economy caused by increased drive shaft size. It also eliminates the need for additional protective components such as clutches, avoiding problems such as slow system response, low protection accuracy, and structural complexity caused by adding clutches. While achieving effective protection of the transmission system, it ensures the vehicle's lightweight, low cost, and high economy. This vehicle achieves quantitative judgment of the urgency of vehicle braking through multi-dimensional and comprehensive signal acquisition and processing; provides a clear basis for matching differentiated torque management strategies through clear and standardized braking level classification; realizes advance judgment of transmission system overload risk through accurate and comprehensive drive shaft net torque prediction; achieves accurate and efficient protection of the transmission system through gradient and differentiated multi-level torque management strategies; and realizes real-time monitoring and timely warning of vehicle status through strategy trigger count statistics and on-board warnings, effectively solving the technical defects of traditional protection methods such as control lag, single strategy, low protection accuracy, and poor compatibility.

[0110] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A vehicle control method, characterized in that, Applied to a power control system, the method includes: The vehicle's braking parameters, driving status parameters, and powertrain system parameters are acquired, and the vehicle's braking level is determined based on the braking parameters and driving status parameters. Different braking levels are configured with corresponding torque management strategies. Based on the braking parameters and the powertrain system parameters, calculate the predicted net torque value of the vehicle drive bearing after a preset time. If the net torque prediction value meets the preset triggering conditions, then the torque management strategy corresponding to the braking level is obtained, and the corresponding braking action is executed based on the torque management strategy.

2. The vehicle control method according to claim 1, characterized in that, Determining the braking level of the vehicle based on the braking parameters and driving status parameters includes: Based on the braking parameters and the driving state parameters, the vehicle braking control characteristics and the vehicle driving dynamic characteristics are obtained. The braking characteristic coefficient is determined based on the vehicle braking control characteristics and the vehicle driving dynamic characteristics. The braking characteristic coefficient is compared with a plurality of preset braking thresholds, and the braking level of the vehicle is determined by judging the relationship between the braking characteristic coefficient and the braking thresholds.

3. The vehicle control method according to claim 2, characterized in that, Based on the braking parameters and the driving state parameters, vehicle braking control characteristics and vehicle driving dynamic characteristics are obtained. Based on the vehicle braking control characteristics and vehicle driving dynamic characteristics, braking characteristic coefficients are determined, including: The brake master cylinder pressure and brake pedal travel in the braking parameters are calculated to obtain the maximum brake pressure rise rate and pedal aggression. The driving wheel speed, maximum vehicle deceleration, and throttle opening in the driving state parameters are calculated to obtain the driving wheel speed change rate, maximum vehicle deceleration, and throttle opening change rate. The braking characteristic coefficient is obtained by weighting the vehicle's maximum deceleration, throttle opening rate of change, maximum braking pressure rise rate, pedal aggression, and wheel speed change rate.

4. The vehicle control method according to claim 3, characterized in that, When the braking characteristic coefficient is greater than or equal to the first braking threshold and less than the second braking threshold, the vehicle is determined to be at the first braking level. When the braking characteristic coefficient is greater than or equal to the second braking threshold and less than the third braking threshold, the vehicle is determined to be at the second braking level. When the braking characteristic coefficient is greater than or equal to the third braking threshold, the vehicle is determined to be at the third braking level.

5. The vehicle control method according to any one of claims 1 to 4, characterized in that, Identifying whether the predicted net torque value meets preset trigger conditions includes: Obtain the safe torque threshold of the drive shaft, and determine whether the net torque prediction value reaches the safe torque threshold. If so, the net torque prediction value is identified as meeting the preset triggering conditions.

6. The vehicle control method according to any one of claims 1 to 4, characterized in that, Based on the braking parameters and the powertrain system parameters, the predicted net torque value of the vehicle drive bearing after a preset time is calculated, including: Based on the braking parameters of the vehicle, calculate the braking torque of the vehicle after a preset time; Based on the powertrain system parameters, calculate the vehicle's inertial torque and engine-transmitted torque after a preset time. Retrieve the preset torque compensation value; The inertial torque, braking torque, engine transmitted torque, and torque compensation value are summed to obtain the predicted net torque value of the vehicle drive shaft after the preset time.

7. The vehicle control method according to claim 6, characterized in that, Calculating the braking torque of the vehicle after a preset time, based on the vehicle's braking parameters, includes: Obtain the brake master cylinder pressure from the braking parameters; Obtain the vehicle's braking friction coefficient, effective braking radius, braking area, braking efficiency coefficient, and number of braking wheels; The braking torque is calculated based on the master cylinder pressure, braking friction coefficient, effective braking radius, braking area, braking efficiency coefficient, and number of braking wheels.

8. The vehicle control method according to claim 4, characterized in that, The different braking levels are configured with corresponding torque management strategies, including: The torque management strategy corresponding to the first braking level is a prevention strategy. The prevention strategy is used to control the vehicle's braking system to perform a pre-loading action and adjust the operating parameters of the vehicle's power system. The torque management strategy corresponding to the second braking level is an intervention strategy. The intervention strategy is used to control the vehicle's braking system to redistribute the braking force according to a preset ratio and to perform torque unloading action on the vehicle's power system. The torque management strategy corresponding to the third braking level is a protection strategy. The protection strategy is used to control the vehicle's braking system to limit the front axle braking force output and to perform torque cut-off or power transmission interruption control operations on the vehicle's power system.

9. The vehicle control method according to claim 1, characterized in that, The vehicle control method further includes: The number of times each torque management strategy is triggered is statistically analyzed. When the number of triggers reaches a preset threshold, a prompt message is sent through the vehicle terminal.

10. A vehicle, characterized in that, The vehicle employs the vehicle control method described in any one of claims 1 to 9.

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