A stable control method, device, equipment and storage medium

Abstract

The present application relates to a stability control method, device, equipment and storage medium. The stability control method includes: calculating the longitudinal allowable torque at the axle end when the vehicle is slipping; judging whether the vehicle is at risk of instability based on the longitudinal allowable torque at the axle end; if it is determined that there is a risk of instability and the vehicle body stability system is not activated, limiting the target torque at the axle end using the longitudinal allowable torque at the axle end, and attenuating the torque gradient based on the requested torque at the axle end to reduce the risk of instability and the abrupt feeling generated after the vehicle body stability system is activated. By implementing the stability control method provided by the present application, the risk of vehicle instability can be reduced, the probability of triggering the vehicle body stability system can be reduced, and the abrupt feeling generated after the vehicle body stability system is activated can be reduced, thereby greatly improving the user experience.

Description

Technical Field

[0001] The present application relates to the field of automotive technology, and in particular to a stability control method, device, equipment, and storage medium. Background Art

[0002] The vehicle stability system is an active safety system, such as the Electronic Stability Controller (ESC). This system is activated after the vehicle becomes unstable on low-adhesion surfaces such as icy or snowy roads, and achieves stability control by intervening and adjusting the vehicle's power output.

[0003] Although the body stability system can achieve body stability control for the car, it will not be activated until the car has become unstable. Moreover, after the body stability system is activated, in order to stabilize the car as quickly as possible, the body stability system may immediately limit the car's torque to a very small amount, causing the car to feel very abrupt, resulting in a poor user experience. Summary of the Invention

[0004] Based on this, the present application provides a stability control method, device, equipment and storage medium, which can reduce the risk of vehicle instability, reduce the probability of triggering the body stability system, and reduce the abruptness caused by the activation of the body stability system, thereby greatly improving the user experience.

[0005] In the first aspect, the present application provides a stability control method, which includes: calculating the longitudinal allowable torque at the axle end when the vehicle slips; judging whether the vehicle is at risk of instability based on the longitudinal allowable torque at the axle end; if it is determined that the vehicle is at risk of instability and the body stability system is not activated, limiting the axle end target torque using the longitudinal allowable torque at the axle end, and attenuating the torque gradient according to the axle end requested torque to reduce the risk of instability and the abrupt feeling caused by the activation of the body stability system.

[0006] In combination with the first aspect, in the first possible implementation of the first aspect, the aforementioned step of attenuating the torque gradient according to the shaft-end requested torque includes: obtaining a first mapping relationship, wherein the first mapping relationship records the mapping relationship between different shaft-end requested torques and shaft-end longitudinal allowable torques and attenuation coefficients, and as the absolute value of the shaft-end requested torque is larger and the absolute value of the shaft-end longitudinal allowable torque is smaller, the attenuation coefficient is smaller and the degree of attenuation is greater; based on the shaft-end requested torque and the shaft-end longitudinal allowable torque, the corresponding attenuation coefficient is searched in the first mapping relationship, and the torque gradient is attenuated using the attenuation coefficient to improve the stability of the vehicle.

[0007] In combination with the first aspect, in a second possible implementation manner of the first aspect, after calculating the allowable longitudinal torque at the axle end, the method further includes: calculating the difference between the control torque of the vehicle body stability system and the allowable longitudinal torque at the axle end; judging whether the vehicle is currently fully utilizing adhesion based on the difference; if the vehicle is currently not fully utilizing adhesion, using the difference to correct the allowable longitudinal torque at the axle end to fully utilize adhesion, thereby improving driving efficiency.

[0008] In combination with the second possible implementation method of the first aspect, in the third possible implementation method of the first aspect, the aforementioned step of correcting the allowable longitudinal torque of the shaft end using the difference includes: obtaining a second mapping relationship, wherein the second mapping relationship records a mapping relationship between different differences and adjustment ratios, the adjustment ratio is less than one, and the adjustment ratio increases as the absolute value of the difference increases; based on the difference, searching for the corresponding adjustment ratio in the second mapping relationship; and correcting the allowable longitudinal torque of the shaft end using the product of the adjustment ratio and the difference.

[0009] In combination with the first aspect, in a fourth possible implementation manner of the first aspect, after calculating the longitudinal allowable torque at the shaft end, the stability control method further includes: calculating the difference between the longitudinal allowable torque at the shaft end and the actual torque at the shaft end; when the vehicle has no slipping characteristics, judging whether the vehicle is currently fully utilizing the adhesion based on the difference; if the vehicle is currently not fully utilizing the adhesion, restoring the longitudinal allowable torque at the shaft end based on the difference to fully utilize the adhesion, thereby improving driving efficiency.

[0010] In combination with the fourth possible implementation method of the first aspect, in the fifth possible implementation method of the first aspect, the aforementioned step of restoring the allowable longitudinal torque of the shaft end based on the difference includes: obtaining a third mapping relationship, wherein the third mapping relationship records the mapping relationship between different vehicle speeds and adhesion coefficients and the recovery gradient, and the recovery gradient becomes smaller as the vehicle speed increases and the adhesion coefficient becomes smaller; based on the current vehicle speed and adhesion coefficient, searching for the corresponding recovery gradient in the third mapping relationship; and restoring the allowable longitudinal torque of the shaft end according to the recovery gradient.

[0011] In combination with the first aspect, in a sixth possible implementation manner of the first aspect, after calculating the allowable longitudinal torque at the shaft end, the stabilization control method further includes: monitoring the slip characteristics, and triggering the slip characteristic flag when the slip characteristics are detected; and correcting the allowable torque at the shaft end according to the number of times the slip characteristic flag is triggered.

[0012] On the second aspect, the present application also provides a stability control device, which includes: a calculation unit for calculating the longitudinal allowable torque of the shaft end when the vehicle slips; a judgment unit for judging whether the vehicle has a risk of instability based on the longitudinal allowable torque of the shaft end; a limitation unit for limiting the shaft end target torque using the longitudinal allowable torque of the shaft end if it is determined that the vehicle has a risk of instability and the body stability system is not activated, and attenuating the torque gradient according to the shaft end requested torque, so as to reduce the risk of instability and the abrupt feeling after the body stability system is activated.

[0013] In combination with the second aspect, in the first possible implementation manner of the second aspect, the limiting unit is specifically used to: obtain a first mapping relationship, wherein the first mapping relationship records the mapping relationship between different shaft-end requested torques and shaft-end longitudinal allowable torques and attenuation coefficients, and as the absolute value of the shaft-end requested torque is larger and the absolute value of the shaft-end longitudinal allowable torque is smaller, the attenuation coefficient is smaller and the degree of attenuation is greater; based on the shaft-end requested torque and the shaft-end longitudinal allowable torque, the corresponding attenuation coefficient is searched in the first mapping relationship, and the attenuation coefficient is used to attenuate the torque gradient to improve the stability of the vehicle.

[0014] In combination with the second aspect, in a second possible implementation manner of the second aspect, the stability control device also includes a correction unit, which is used to: calculate the difference between the control torque of the vehicle body stability system and the longitudinal allowable torque of the axle end; determine whether the vehicle is currently fully utilizing the adhesion based on the difference; if the vehicle is currently not fully utilizing the adhesion, use the difference to correct the longitudinal allowable torque of the axle end to fully utilize the adhesion, thereby improving driving efficiency.

[0015] In combination with the second possible implementation method of the second aspect, in the third possible implementation method of the second aspect, the correction unit is specifically used to: obtain a second mapping relationship, wherein the second mapping relationship records the mapping relationship between different differences and adjustment ratios, the adjustment ratio is less than one, and as the absolute value of the difference increases, the adjustment ratio increases; based on the difference, search for the corresponding adjustment ratio in the second mapping relationship; and use the product of the adjustment ratio and the difference to correct the allowable longitudinal torque of the shaft end.

[0016] In combination with the second aspect, in a fourth possible implementation manner of the second aspect, the stability control device further includes a recovery unit, which is used to: calculate the difference between the longitudinal allowable torque at the shaft end and the actual torque at the shaft end; when the vehicle has no slipping characteristics, determine whether the vehicle is currently fully utilizing the adhesion based on the difference; if the vehicle is currently not fully utilizing the adhesion, restore the longitudinal allowable torque at the shaft end based on the difference to fully utilize the adhesion, thereby improving driving efficiency.

[0017] In combination with the fourth possible implementation method of the second aspect, in the fifth possible implementation method of the second aspect, the recovery unit is specifically used to: obtain a third mapping relationship, wherein the third mapping relationship records the mapping relationship between different vehicle speeds and adhesion coefficients and the recovery gradient, and as the vehicle speed increases and the adhesion coefficient decreases, the recovery gradient decreases; based on the current vehicle speed and adhesion coefficient, search for the corresponding recovery gradient in the third mapping relationship; and restore the longitudinal allowable torque of the shaft end according to the recovery gradient.

[0018] In combination with the second aspect, in a sixth possible implementation manner of the second aspect, the stabilization control device further includes a correction unit, which is used to: monitor the slip characteristics and trigger the slip characteristic flag when the slip characteristics are detected; and correct the allowable torque of the shaft end according to the number of times the slip characteristic flag is triggered.

[0019] In a third aspect, the present application also provides a stabilization control device, which includes a processor and a memory, and the processor and the memory are connected via a bus; the processor is used to execute multiple instructions; the memory is used to store multiple instructions, and the instructions are suitable for being loaded and executed by the processor as a stabilization control method such as the first aspect or any one embodiment of the first aspect.

[0020] In a fourth aspect, the present application further provides a computer-readable storage medium, in which a plurality of instructions are stored, and the instructions are suitable for being loaded and executed by a processor, such as the stabilization control method of the first aspect or any one embodiment of the first aspect.

[0021] In summary, the present application provides a stability control method, apparatus, device and storage medium, wherein, when the vehicle slips, the stability control device determines whether the vehicle is at risk of instability based on the longitudinal allowable torque at the axle end, and when there is a risk of instability and the ESC is not activated, the longitudinal allowable torque at the axle end is used to limit the target torque at the axle end, and the torque gradient is attenuated according to the requested torque at the axle end, so that the target torque at the axle end will not be too large and the torque change will not be too large, thereby reducing the risk of vehicle instability and the probability of triggering the body stability system, and even after the vehicle is unstable and the body stability system is activated, it will not suddenly drop from a large torque to a small torque, thereby reducing the abrupt feeling after the body stability system is activated, thereby greatly improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic flow chart of a stabilization control method in an embodiment of the present application;

[0023] Figure 2 is a schematic flow chart of a stabilization control method in another embodiment of the present application;

[0024] Figure 3is a schematic flow chart of a stabilization control method in another embodiment of the present application;

[0025] Figure 4 is a schematic flow chart of a stabilization control method in another embodiment of the present application;

[0026] Figure 5 is a schematic block diagram of a stability control device in an embodiment of the present application;

[0027] Figure 6 This is a structural block diagram of a stabilization control device in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0029] At present, since the body control system is not activated until the car loses stability, and the car will produce a large abrupt feeling after activating the body stability system, the user experience is poor. In this regard, the present application provides a stability control method, which determines whether the car is at risk of instability by the longitudinal allowable torque at the axle end when the car slips, and then, when the car is at risk of instability and the body stability system is not activated, the longitudinal allowable torque at the axle end is used to limit the target torque at the axle end, and the torque gradient is attenuated according to the requested torque at the axle end.

[0030] It should be noted that the shaft-end target torque is the torque requested by the driver. After the driver issues the shaft-end target torque, the stability control device requests the engine to use the shaft-end target torque as the target, and gradually changes the current shaft-end request torque to be output according to the torque gradient, so that the car changes from the current actual output shaft-end torque to the shaft-end target torque. Therefore, the present application can reduce the output torque of the car and the size of the torque change by limiting the shaft-end target torque and attenuating the torque gradient, thereby reducing the risk of car instability and reducing the abruptness caused by the activation of the body stability system.

[0031] It should also be noted that the stability control device and stability control equipment proposed in this application can be a vehicle control unit (VCU) or an electronic control unit (ECU), and this application does not limit this. In addition, the stability control device and stability control equipment can exchange data with other controllers or terminal devices, and execute the stability control method proposed in this application.

[0032] In order to better understand the stability control method of this application, Figure 1 As shown, this application provides an embodiment of a stabilization control method. Next, this application uses a stabilization control device as the execution subject to Figure 1 The stability control method described is explained in detail:

[0033] 100: Calculate the permissible longitudinal torque at the shaft end when the vehicle is slipping;

[0034] 200: Determine whether the vehicle is at risk of instability based on the longitudinal allowable torque at the axle end;

[0035] 300: If the vehicle is determined to be at risk of instability and the vehicle stability system is not activated, the axle end target torque is limited using the axle end longitudinal allowable torque, and the torque gradient is attenuated according to the axle end request torque to reduce the risk of instability and the abrupt feeling caused by the vehicle stability system being activated;

[0036] Because a severe vehicle skid can lead to instability, the stability control system calculates the permitted longitudinal torque during a skid to determine whether the vehicle is at risk of instability. The permitted longitudinal torque represents the maximum traction the vehicle can achieve in the longitudinal, driving, and regenerating directions. If a risk of instability is determined and the ESC system is not activated, the stability control function flag is activated. This allows the permitted longitudinal torque to be used to limit the target torque and the torque gradient to be attenuated according to the requested torque, ensuring that the target torque is less than or equal to the permitted longitudinal torque. This minimizes excessive torque output and reduces torque variations by attenuating the torque gradient according to the requested torque. For example, the degree of torque gradient attenuation can be proportional to the requested torque; as the requested torque increases, the attenuation increases, and the torque gradient decreases. Overall, by limiting the target torque and attenuating the torque gradient, the stability control system reduces the risk of instability and the perceived abruptness of vehicle stability system activation, thereby improving the user experience.

[0037] It should be noted that, in order to effectively reduce the risk of instability, this application requires both limiting the shaft end target torque and attenuating the torque gradient. This is because if the shaft end longitudinal allowable torque is not calculated accurately, the vehicle may become unstable before reaching the limited shaft end target torque. In other words, if the torque gradient is attenuated, the torque changes more slowly as the shaft end request torque increases. It may previously take 1 minute to increase to the shaft end target torque, but now it takes 3 minutes. Therefore, slowing the rate at which the vehicle changes from the shaft end actual torque to the shaft end target torque can effectively reduce the risk of instability and improve the vehicle's stability.

[0038] For step 200, the present application provides a specific implementable manner. The stability control device can compare the longitudinal allowable torque at the shaft end with the target torque or the actual torque at the shaft end to determine whether the vehicle has a risk of instability. Specifically, the stability control device calculates the difference between the target torque or the actual torque at the shaft end and the longitudinal allowable torque at the shaft end. If, in the driving scenario, the difference is greater than the corresponding threshold (as shown in Formula 1), or in the recovery scenario, the difference is less than the corresponding threshold (as shown in Formula 2), it is determined that the vehicle has a risk of instability;

[0039] Formula 1: T AxleTarget -T Axleallow >TH1, or, T AxleAct- T Axleallow >TH2;

[0040] Formula 2: T AxleTarget- T Axleallow <TH1, or, T AxleAct -T Axleallow <TH2;

[0041] Where, T AxleTarget represents the target torque at the shaft end, and the target torque at the shaft end is used to represent the torque requested by the driver. T Axleallow represents the longitudinal allowable torque at the shaft end. T AxleAct represents the actual torque at the shaft end, and the actual torque at the shaft end is the torque actually output by the vehicle currently;

[0042] Where, TH1 represents the first threshold, and TH2 represents the second threshold. The first threshold and the second threshold can be the same or different, and the first threshold and the second threshold can be equal to zero or greater than zero.

[0043] In a specific implementable manner, the first threshold and the second threshold are equal to zero, making it easier for the vehicle to be determined as unstable and activating the function flag bit earlier, thereby further reducing the risk of instability.

[0044] It should be noted that when the first threshold and the second threshold are equal to zero, although the risk of instability can be further reduced, it also increases the risk of misjudgment and reduces the driving efficiency. For example, in the driving scenario, if the driver suddenly steps on the accelerator and then immediately releases it, it will cause the requested torque at the shaft end to increase as the target torque at the shaft end rises, but the target torque at the shaft end will immediately fall back. At this time, the requested torque at the shaft end has increased, resulting in an increase in the actual torque at the shaft end of the vehicle. In fact, since the driver has released the accelerator, the risk of instability at this time is relatively small. In this regard, by setting the first threshold and the second threshold to values greater than zero and delaying the activation of the function flag bit, the risk of misjudgment can be reduced, thereby improving the driving efficiency.

[0045] In another specific implementable manner, the first threshold and the second threshold are greater than zero, and the first threshold and the second threshold are equal to the torque increment of the shaft end requested torque or the shaft end actual torque within the driver's reaction time, so as to reduce the risk of misjudgment and improve driving efficiency. For example, assuming that the driver's reaction time is t unit time, and the torque gradient per unit time is n, then TH1 and TH2 are equal to tn.

[0046] In one specific implementation, the stability control method provided herein is specifically applied in low-adhesion scenarios. Low-adhesion scenarios refer to situations where a vehicle is traveling on a low-adhesion surface, such as an icy or snowy road. In such situations, the surface offers low adhesion, causing the vehicle to continuously slip, thereby easily triggering the vehicle stability system. Specifically, in this implementation, the stability control device monitors whether the wheel is slipping before executing step 110. If the wheel is slipping, the stability control device verifies whether the vehicle is traveling on a low-adhesion surface based on the maximum adhesion provided by the surface. If the vehicle is determined to be traveling on low-adhesion surface, then the vehicle is determined to be slipping.

[0047] Among them, the stability control device can consider the presence of slip characteristics when the wheel acceleration and / or slip rate are respectively greater than the corresponding thresholds, thereby determining that the wheel end is slipping. Otherwise, it is considered that there is no slip feature, and the tire is stable at this time, and the wheel end is not slipping. Wheel end slip is caused by a variety of reasons, which may be temporary slip caused by potholes or speed bumps, or continuous slip caused by the car driving on low-adhesion ground. In order to reduce false triggering in non-adhesion scenarios, the stability control device determines whether the car is driving on low-adhesion ground by judging whether the actual torque at the shaft end is close to the maximum adhesion, thereby judging whether the car is slipping due to low-adhesion ground. For example:

[0048] First, the absolute value of the difference between the actual torque at the shaft end and the maximum adhesion is calculated. Then, the absolute value is compared with the set value to determine whether the vehicle is driving on a low-adhesion surface. When the absolute value is less than the set value (as shown in Formula 3), it is determined that the vehicle is driving on a low-adhesion surface. When the absolute value is greater than or equal to the set value (as shown in Formula 4), it is determined that the vehicle is driving on a non-low-adhesion surface.

[0049] Formula 3: |T AxleAct -μFr|<σ; Formula 4: |T AxleAct -μFr|≥σ;

[0050] Where μ represents the adhesion coefficient, r represents the tire rolling radius, F represents the wheel end load, and T AxleAct Indicates the actual torque at the shaft end.

[0051] It should be noted that the stability control method provided in this application can achieve better stability control effects when applied in low-adhesion scenarios. This is because a car's slippage on potholes or speed bumps is relatively brief, and the probability of triggering the body stability system is low. Limiting the axle end target torque in these situations may limit the car's driving efficiency. Conversely, a car's slippage on low-adhesion surfaces is relatively persistent, and the probability of triggering the body stability system is high. Limiting the axle end target torque in these situations can better achieve the invention's stability control objectives.

[0052] In a specific practicable manner, the present application further provides a method for calculating the longitudinal allowable torque at the axle end. In the event of vehicle slippage, the stability control device calculates the longitudinal allowable acceleration based on the adhesion coefficient, as shown in Formula 5; calculates the longitudinal allowable torque of each wheel based on the longitudinal allowable acceleration and the wheel end load, as shown in Formula 6; and takes twice the smaller value of the longitudinal allowable torque of the left and right wheels as the longitudinal allowable torque at the axle end.

[0053] Formula 5:

[0054] Among them, a xallow represents the longitudinal allowable acceleration, μ represents the adhesion coefficient, g represents the acceleration due to gravity, μg represents the road allowable acceleration, a y represents the lateral acceleration;

[0055] Formula 6: T = F × a xallow ×r;

[0056] Among them, a xallow represents the longitudinal allowable torque, F represents the wheel end load, and r represents the tire rolling radius.

[0057] In a specific practicable manner, the present application further provides a specific method for calculating wheel-end loads. The stability control device may further calculate the wheel-end loads of each wheel based on the longitudinal acceleration and the lateral acceleration, as shown in the following formula for example:

[0058]

[0059]

[0060]

[0061]

[0062] Among them, F fl 、F fr 、F rl and F rr They represent the wheel end loads of the left front wheel, right front wheel, left rear wheel and right rear wheel respectively, m represents the mass of the vehicle, ax represents the longitudinal acceleration, a y represents lateral acceleration, a represents the distance from the front axle to the center of mass, b represents the distance from the rear axle to the center of mass, d1 represents the front axle track, d2 represents the rear axle track, l represents the wheelbase, and h represents the center of mass height.

[0063] With respect to step 300, the present application provides a specific implementation method, wherein when the stability control device attenuates the torque gradient, the torque gradient is attenuated according to the shaft-end requested torque and the shaft-end longitudinal allowable torque to improve the vehicle's stability. Specifically, a first mapping relationship is obtained, wherein the first mapping relationship records the mapping relationship between different shaft-end requested torques and shaft-end longitudinal allowable torques and attenuation coefficients. As the absolute value of the shaft-end requested torque increases and the absolute value of the shaft-end longitudinal allowable torque decreases, the attenuation coefficient decreases and the degree of attenuation increases. Based on the shaft-end requested torque and the shaft-end longitudinal allowable torque, the corresponding attenuation coefficient is searched in the first mapping relationship, and the attenuation coefficient is used to attenuate the torque gradient to improve the vehicle's stability, wherein the torque gradient includes a torque rise gradient and a torque fall gradient.

[0064] The stability control device can first obtain the attenuation coefficient corresponding to the shaft end request torque and the shaft end longitudinal allowable torque from a first mapping relationship. It then calculates the product of the attenuation coefficient and the standard torque gradient or the torque gradient after the previous attenuation to obtain the attenuated torque gradient. Finally, it torque-up or torque-down the shaft end request torque according to the attenuated torque gradient. The first mapping relationship can be obtained through actual vehicle testing and calibration, with the goal of improving vehicle stability.

[0065] For example, in a driving scenario, the first mapping relationship is shown in Table 1. As the permitted longitudinal torque at the axle end decreases, the attenuation coefficient gradually decreases to improve smoothness on low-adhesion surfaces. As the requested torque at the axle end increases, the attenuation coefficient gradually decreases to improve smoothness when the user presses the accelerator. Furthermore, the attenuation coefficients corresponding to other values can be interpolated from the first mapping relationship to achieve a linear change in the attenuation coefficient, further improving vehicle smoothness.

[0066]

[0067] Table 1 First mapping relationship

[0068] In addition, while this application uses the longitudinal permissible torque at the shaft end to limit the target torque at the shaft end, while reducing the risk of vehicle instability, it may also result in insufficient utilization of adhesion. This is because the adhesion coefficient, lateral acceleration, and longitudinal acceleration, etc., obtained when calculating the longitudinal permissible torque at the shaft end are obtained based on measurement data, and because measurement errors are inevitable, the calculated longitudinal permissible torque at the shaft end may be inaccurate, resulting in the shaft end target torque being limited to a very small value, failing to fully utilize adhesion, affecting the vehicle's driving efficiency, and resulting in a poor user experience.

[0069] In this regard, the present application also proposes to correct and restore the longitudinal allowable torque of the end according to at least one of the control torque of the vehicle body stability system and the actual torque of the end of the shaft, so that the longitudinal allowable torque of the end of the shaft is more in line with the road surface to fully utilize the adhesion. Figure 2 and Figure 3 As shown, the present application also provides two other embodiments of the stabilization control method, specifically:

[0070] In the first embodiment, since the vehicle stability system outputs a control torque to restore the vehicle to stability after being activated, the present application can obtain the control torque when the vehicle stability system was last exited and use the control torque as a reference data to correct the end longitudinal allowable torque to improve the accuracy of the end longitudinal allowable torque and make full use of the adhesion, such as Figure 2 As shown, specifically:

[0071] 411: After calculating the longitudinal permissible torque at the axle end, calculate the difference between the control torque of the vehicle stability system and the longitudinal permissible torque at the axle end;

[0072] 412: Determine whether the vehicle currently fully utilizes adhesion based on the aforementioned difference;

[0073] 413: If the vehicle is not currently making full use of adhesion, the difference is used to correct the longitudinal permissible torque at the axle end to make full use of adhesion, thereby improving driving efficiency.

[0074] To fully utilize adhesion and ensure driving efficiency, the stability control device determines whether the vehicle is currently fully utilizing adhesion based on the difference between the control torque and the longitudinal allowable torque at the axle end. Specifically, in a driving scenario, the device determines whether the difference between the control torque and the longitudinal allowable torque at the axle end is greater than zero. Alternatively, in a recovery scenario, the device determines whether the difference between the control torque and the longitudinal allowable torque at the axle end is less than zero. If either determination result is yes, it indicates that adhesion is not fully utilized, and the longitudinal allowable torque at the axle end is corrected using the control torque. Otherwise, no correction is made.

[0075] In a specific implementable manner, the stability control device may assign the value of the control torque to the longitudinal allowable torque of the shaft end to achieve correction of the longitudinal allowable torque of the shaft end.

[0076] It should be noted that although the above-mentioned correction method can improve the utilization of adhesion, the control torque is not the value that best fits the road surface under the current road conditions. Therefore, the direct assignment method still has a certain risk of instability. In this regard, this application also provides another specific and implementable method.

[0077] In another specific implementable manner, the stability control device can also appropriately adjust the longitudinal allowable torque of the shaft end according to the control torque, so as to reduce the risk of instability while fully utilizing the adhesion. Specifically, the aforementioned step of correcting the longitudinal allowable torque of the shaft end using the difference includes: obtaining a second mapping relationship, wherein the second mapping relationship records the mapping relationship between different differences and adjustment ratios, the adjustment ratio is less than one and greater than zero, and the adjustment ratio increases as the absolute value of the difference increases; based on the difference, searching for the corresponding adjustment ratio in the second mapping relationship; and correcting the longitudinal allowable torque of the shaft end using the product of the adjustment ratio and the difference.

[0078] The stability control device can first obtain the adjustment ratio corresponding to the difference from the second mapping relationship, then calculate the product of the difference and the adjustment ratio to obtain the adjusted difference. Finally, the adjusted difference and the allowable longitudinal torque at the axle end are summed to correct the allowable longitudinal torque at the axle end. This allows the allowable longitudinal torque at the axle end to be appropriately adjusted within the difference range, and the adjustment amplitude is less than the absolute value of the difference. This can fully utilize adhesion while reducing the risk of instability. The second mapping relationship can be obtained through actual vehicle testing and calibration, with the goal of fully utilizing the adhesion coefficient.

[0079] For example, in a driving scenario, the second mapping relationship is shown in Table 2. A larger difference indicates a less accurate longitudinal torque tolerance and lower adhesion utilization. Therefore, as the difference increases, the adjustment ratio increases, bringing the corrected longitudinal torque tolerance closer to the control torque, improving correction accuracy and further leveraging adhesion to ensure driving efficiency. Furthermore, based on the second mapping relationship, the adjustment ratios corresponding to other difference values can be calculated using the parabolic point difference method, achieving linear variation in the adjustment ratio and thus fully utilizing adhesion.

[0080] Difference 50 100 Adjust the ratio 0.6 0.8 Adjusted difference 30 80

[0081] Table 2 Second mapping relationship

[0082] In summary, this embodiment corrects the end longitudinal permissible torque according to the control torque of the vehicle body stability system, so that the axle end longitudinal permissible torque is more closely aligned with the road surface, thereby fully utilizing the adhesion.

[0083] In the second embodiment, the present application also recovers the end longitudinal allowable torque according to the actual torque of the shaft end to further improve the accuracy of the end longitudinal allowable torque, such as Figure 3 , specifically:

[0084] 421: After calculating the allowable longitudinal torque at the shaft end, calculate the difference between the allowable longitudinal torque at the shaft end and the actual torque at the shaft end;

[0085] 422: When the car has no slipping characteristics, determine whether the car is currently fully utilizing the adhesion based on the difference;

[0086] 423: If the vehicle is not currently making full use of adhesion, the longitudinal permissible torque at the axle end is restored based on the difference to fully utilize adhesion, thereby improving driving efficiency;

[0087] Among them, when the vehicle has no slip characteristics, if the actual shaft end torque is close to the longitudinal allowable shaft end torque, and in the driving scenario, the actual shaft end torque is less than the longitudinal allowable shaft end torque, or, in the recovery scenario, the actual shaft end torque is greater than the longitudinal allowable shaft end torque, then it is determined that the actual shaft end torque output by the vehicle at this time is about to reach the limit value, but has not slipped, so the adhesion is not fully utilized and the longitudinal allowable shaft end torque needs to be restored. Otherwise, no recovery is required.

[0088] In a specific implementable manner, the aforementioned step of restoring the allowable longitudinal torque of the shaft end based on the difference includes: obtaining a third mapping relationship, wherein the third mapping relationship records the mapping relationship between different vehicle speeds and adhesion coefficients and the recovery gradient, and as the vehicle speed increases and the adhesion coefficient decreases, the recovery gradient decreases; based on the current vehicle speed and adhesion coefficient, searching for the corresponding recovery gradient in the third mapping relationship; and restoring the allowable longitudinal torque of the shaft end according to the recovery gradient.

[0089] The instability control device first obtains the recovery gradient corresponding to vehicle speed and adhesion coefficient from a third mapping relationship. It then restores the longitudinal permissible torque at the axle end according to the recovery gradient, ensuring that the maximum permissible longitudinal torque at the axle end is consistent with the user's requested target torque. This reduces restrictions on driving efficiency and fully utilizes adhesion. This third mapping relationship can be obtained through actual vehicle testing and calibration, with the goal of improving vehicle stability.

[0090] For example, the third mapping relationship is shown in Table 3. As the adhesion coefficient decreases, the restoration gradient gradually decreases to improve stability on low-adhesion surfaces; as the vehicle speed increases, the restoration gradient gradually decreases to improve stability under high-speed conditions. Furthermore, the restoration gradients corresponding to other values can be interpolated from the third mapping relationship to achieve a linear change in the restoration gradient, further improving vehicle stability.

[0091]

[0092] Table 3 The third mapping relationship

[0093] In summary, this embodiment restores the longitudinal allowable torque at the end according to the actual torque at the shaft end, so that the longitudinal allowable torque at the shaft end is more closely aligned with the road surface, thereby fully utilizing the adhesion.

[0094] In addition, if the car still experiences wheel slip after limiting the longitudinal allowable torque of the shaft end, it means that the longitudinal allowable torque of the shaft end is not limited enough. In this regard, the present application also proposes another embodiment of the stability control method. The stability control device can also correct the longitudinal allowable torque of the shaft end according to the number of wheel end slips to further reduce the risk of vehicle instability. Next, the present application will combine Figure 4 This embodiment is described in detail, specifically:

[0095] 431: After calculating the longitudinal allowable torque at the shaft end, the slip feature is monitored and the slip feature flag is triggered when the slip feature is detected;

[0096] 432: According to the number of times the slip feature flag is triggered, the allowable torque of the shaft end is corrected;

[0097] Among them, each time the stability control device detects a slip feature, it triggers a slip feature flag. The more times it is triggered, the more accurate the longitudinal allowable torque at the shaft end is and the torque limit is insufficient. Therefore, the stability control corrects the allowable torque at the shaft end according to the number of times the slip feature flag is triggered.

[0098] In a specific practicable manner, the mathematical expression for correcting the allowable torque at the shaft end includes: T' Axleallow =(1-n×AM)T Axleallow ; Among them, T' Axleallow Indicates the corrected allowable longitudinal torque at the shaft end, T Axleallow It represents the permissible longitudinal torque of the shaft end before correction, n represents the number of triggers, and AM represents the correction amplitude, which may be 0.05, for example.

[0099] In another specific practicable manner, in order to further improve the correction efficiency, the mathematical expression for correcting the allowable torque at the shaft end includes: Axleallow =(1-AM) n T Axleallow ; Among them, T' Axleallow Indicates the corrected allowable longitudinal torque at the shaft end, T Axleallow It represents the permissible longitudinal torque of the shaft end before correction, n represents the number of triggers, and AM represents the correction amplitude, which may be 0.05, for example.

[0100] In addition, the present application also provides a stabilization control device, such as Figure 5 As shown. The embodiment of the present application can divide the functional modules of the device according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. Specifically, as Figure 5 As shown, the stability control device includes: a calculation unit 510, which is used to calculate the longitudinal allowable torque of the shaft end in the case of vehicle slippage; a judgment unit 520, which is used to judge whether the vehicle has an instability risk based on the longitudinal allowable torque of the shaft end; a limiting unit 530, which is used to limit the shaft end target torque using the longitudinal allowable torque of the shaft end if it is determined that the vehicle has an instability risk and the body stability system is not activated, and to attenuate the torque gradient according to the shaft end request torque, so as to reduce the instability risk and the abrupt feeling caused by the activation of the body stability system.

[0101] In another practicable manner, the limiting unit 530 is specifically used to: obtain a first mapping relationship, wherein the first mapping relationship records the mapping relationship between different shaft-end requested torques and shaft-end longitudinal allowable torques and attenuation coefficients, and as the absolute value of the shaft-end requested torque is larger and the absolute value of the shaft-end longitudinal allowable torque is smaller, the attenuation coefficient is smaller and the degree of attenuation is greater; based on the shaft-end requested torque and the shaft-end longitudinal allowable torque, the corresponding attenuation coefficient is searched in the first mapping relationship, and the attenuation coefficient is used to attenuate the torque gradient to improve the stability of the vehicle.

[0102] In another practicable embodiment, the stability control device further includes a correction unit 540, which is used to: calculate the difference between the control torque of the vehicle body stability system and the longitudinal allowable torque at the axle end; determine whether the vehicle is currently fully utilizing the adhesion based on the difference; if the vehicle is currently not fully utilizing the adhesion, use the difference to correct the longitudinal allowable torque at the axle end to fully utilize the adhesion, thereby improving driving efficiency.

[0103] In another practicable manner, the correction unit 540 is specifically used to: obtain a second mapping relationship, wherein the second mapping relationship records a mapping relationship between different differences and adjustment ratios, the adjustment ratio is less than one, and as the absolute value of the difference increases, the adjustment ratio increases; based on the difference, search for the corresponding adjustment ratio in the second mapping relationship; and use the product of the adjustment ratio and the difference to correct the allowable longitudinal torque at the shaft end.

[0104] In another practicable embodiment, the stability control device further includes a recovery unit 550, which is used to: calculate the difference between the longitudinal allowable torque at the shaft end and the actual torque at the shaft end; when the vehicle has no slipping characteristics, determine whether the vehicle is currently fully utilizing the adhesion based on the difference; if the vehicle is currently not fully utilizing the adhesion, restore the longitudinal allowable torque at the shaft end based on the difference to fully utilize the adhesion, thereby improving driving efficiency.

[0105] In another feasible manner, the recovery unit 550 is specifically used to: obtain a third mapping relationship, wherein the third mapping relationship records the mapping relationship between different vehicle speeds and adhesion coefficients and the recovery gradient, and as the vehicle speed increases and the adhesion coefficient decreases, the recovery gradient decreases; based on the current vehicle speed and adhesion coefficient, search for the corresponding recovery gradient in the third mapping relationship; and restore the longitudinal allowable torque of the shaft end according to the recovery gradient.

[0106] In another practicable embodiment, the stability control device further includes a correction unit 540, which is used to: monitor the slip feature and trigger the slip feature flag when the slip feature is detected; and correct the allowable torque at the shaft end according to the number of times the slip feature flag is triggered.

[0107] In addition, this application also provides a stabilization control device, see Figure 6 .like Figure 6 The stability control device in this embodiment may include a processor 610 and a memory 620. The processor 610 and the memory 620 are connected via a bus 630. The processor 610 is configured to execute multiple instructions, while the memory 620 is configured to store multiple instructions suitable for being loaded by the processor 610 and executed by the stability control method in the above embodiment.

[0108] The processor 610 may be an electronic control unit (ECU), a central processing unit (CPU), a general-purpose processor, a coprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The processor 610 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of an 5SP and a microprocessor, and the like. In this embodiment, the processor 610 may be a single-chip microcomputer (MCU), which can be programmed to implement various control functions. The processor has the advantages of strong computing power and fast processing speed. Specifically, the processor 610 is used to execute the calculation unit 510, which is used to calculate the longitudinal allowable torque of the shaft end when the car slips; the processor 610 is also used to execute the function of the judgment unit 520, which is used to determine whether the car has an instability risk based on the longitudinal allowable torque of the shaft end; the processor 610 is also used to execute the function of the limitation unit 530, which is used to limit the shaft end target torque using the longitudinal allowable torque of the shaft end if it is determined that the car has an instability risk and the body stability system is not activated, and to attenuate the torque gradient according to the shaft end requested torque, so as to reduce the instability risk and the abrupt feeling after the body stability system is activated.

[0109] In another practicable manner, the processor 610 is specifically used to: obtain a first mapping relationship, wherein the first mapping relationship records the mapping relationship between different shaft-end requested torques and shaft-end longitudinal allowable torques and attenuation coefficients, and as the absolute value of the shaft-end requested torque is larger and the absolute value of the shaft-end longitudinal allowable torque is smaller, the attenuation coefficient is smaller and the degree of attenuation is greater; based on the shaft-end requested torque and the shaft-end longitudinal allowable torque, search for the corresponding attenuation coefficient in the first mapping relationship, and use the attenuation coefficient to attenuate the torque gradient to improve the stability of the vehicle.

[0110] In another practicable embodiment, the processor 610 is further configured to execute the functions of the correction unit 540, which is configured to: calculate the difference between the control torque of the vehicle body stability system and the longitudinal allowable torque at the axle end; determine whether the vehicle is currently making full use of the adhesion based on the difference; if the vehicle is currently not making full use of the adhesion, use the difference to correct the longitudinal allowable torque at the axle end to make full use of the adhesion, thereby improving driving efficiency.

[0111] In another practicable manner, the processor 610 is specifically used to: obtain a second mapping relationship, wherein the second mapping relationship records a mapping relationship between different differences and adjustment ratios, the adjustment ratio is less than one, and as the absolute value of the difference increases, the adjustment ratio increases; based on the difference, search for the corresponding adjustment ratio in the second mapping relationship; and use the product of the adjustment ratio and the difference to correct the allowable longitudinal torque at the shaft end.

[0112] In another practicable embodiment, the processor 610 is also used to execute the functions of the recovery unit 550, which is used to: calculate the difference between the longitudinal allowable torque at the shaft end and the actual torque at the shaft end; when the vehicle has no slipping characteristics, determine whether the vehicle is currently fully utilizing the adhesion based on the difference; if the vehicle is currently not fully utilizing the adhesion, restore the longitudinal allowable torque at the shaft end based on the difference to fully utilize the adhesion, thereby improving driving efficiency.

[0113] In another practicable manner, the processor 610 is specifically used to: obtain a third mapping relationship, wherein the third mapping relationship records the mapping relationship between different vehicle speeds and adhesion coefficients and the recovery gradient, and as the vehicle speed increases and the adhesion coefficient decreases, the recovery gradient decreases; based on the current vehicle speed and adhesion coefficient, search for the corresponding recovery gradient in the third mapping relationship; and restore the longitudinal allowable torque of the shaft end according to the recovery gradient.

[0114] In another practicable embodiment, the processor 610 is also used to execute the functions of the correction unit 540, which is used to: monitor the slip feature and trigger the slip feature flag when the slip feature is detected; and correct the allowable torque of the shaft end according to the number of times the slip feature flag is triggered.

[0115] In one embodiment, the present application further provides a computer-readable storage medium storing a plurality of instructions suitable for being loaded by a processor and executing the method of any of the aforementioned embodiments. The processor is configured to execute the plurality of instructions; the memory is configured to store the plurality of instructions, which are loaded by the processor and executed by the stability control method of the aforementioned embodiment.

[0116] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The above embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A stabilization control method, characterized in that: include: Calculate the permissible longitudinal torque at the axle end when the vehicle is slipping; determining whether the vehicle has an instability risk based on the longitudinal allowable torque at the shaft end; If it is determined that the vehicle is at risk of instability and the body stability system is not activated, the shaft end target torque is limited using the shaft end longitudinal allowable torque, and the torque gradient is attenuated according to the shaft end requested torque to reduce the risk of instability and the abrupt feeling caused by the activation of the body stability system.

2. The method according to claim 1, characterized in that The torque gradient is attenuated according to the shaft end request torque, including: Obtaining a first mapping relationship, wherein the first mapping relationship records mapping relationships between different shaft end requested torques, shaft end longitudinal allowable torques, and attenuation coefficients, wherein as the absolute value of the shaft end requested torque increases and the absolute value of the shaft end longitudinal allowable torque decreases, the attenuation coefficient decreases and the degree of attenuation increases; Based on the shaft end requested torque and the shaft end longitudinal allowable torque, a corresponding attenuation coefficient is searched in the first mapping relationship, and the attenuation coefficient is used to attenuate the torque gradient to improve the stability of the vehicle.

3. The method according to claim 1, characterized in that After calculating the allowable longitudinal torque at the shaft end, the method further includes: Calculate the difference between the control torque of the vehicle stability system and the longitudinal allowable torque at the axle end; determining whether the vehicle currently fully utilizes adhesion based on the difference; If the vehicle currently does not fully utilize the adhesion, the difference is used to correct the permissible longitudinal torque at the axle end to fully utilize the adhesion, thereby improving driving efficiency.

4. The method according to claim 3, characterized in that The difference is used to correct the allowable longitudinal torque of the shaft end, including: Obtaining a second mapping relationship, wherein the second mapping relationship records a mapping relationship between different difference values and adjustment ratios, the adjustment ratio is less than one, and as the absolute value of the difference increases, the adjustment ratio increases; Based on the difference, searching for a corresponding adjustment ratio in the second mapping relationship; The permissible longitudinal torque at the shaft end is corrected by multiplying the adjustment ratio by the difference.

5. The method according to claim 1, wherein After calculating the allowable longitudinal torque at the shaft end, the method further includes: Calculate the difference between the allowable longitudinal torque at the shaft end and the actual torque at the shaft end; When the vehicle has no slipping characteristics, determining whether the vehicle is currently fully utilizing adhesion based on the difference; If the vehicle currently does not fully utilize the adhesion, the longitudinal permissible torque at the axle end is restored according to the difference to fully utilize the adhesion, thereby improving driving efficiency.

6. The method according to claim 5, characterized in that Restoring the allowable longitudinal torque of the shaft end according to the difference includes: Obtaining a third mapping relationship, wherein the third mapping relationship records a mapping relationship between different vehicle speeds and adhesion coefficients and restoration gradients, wherein the restoration gradient decreases as the vehicle speed increases and the adhesion coefficient decreases; Based on the current vehicle speed and adhesion coefficient, searching for a corresponding restoration gradient in a third mapping relationship; The permissible longitudinal torque at the shaft end is restored according to the restoration gradient.

7. The method according to claim 1, characterized in that After calculating the allowable longitudinal torque at the shaft end, the method further includes: Monitor the slip feature and trigger the slip feature flag when the slip feature is detected; The allowable torque at the shaft end is corrected according to the number of times the slip feature flag is triggered.

8. A stability control device, characterized in that: The stability control device comprises: A calculation unit, used to calculate the permissible longitudinal torque at the shaft end in the event of vehicle slippage; a judgment unit, configured to judge whether the vehicle has an instability risk based on the longitudinal allowable torque of the shaft end; The limiting unit is used to limit the axle-end target torque using the axle-end longitudinal allowable torque if it is determined that the vehicle has an instability risk and the body stability system is not activated, and to attenuate the torque gradient according to the axle-end requested torque, so as to reduce the instability risk and the abrupt feeling caused by the activation of the body stability system.

9. A stability control device, characterized in that: The stabilization control device includes a processor and a memory, which are connected via a bus; the processor is used to execute multiple instructions; the memory is used to store the multiple instructions, and the instructions are suitable for being loaded by the processor and executing the stabilization control method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the stabilization control method according to any one of claims 1 to 7.

Images