Vehicle slip control method and device, vehicle and storage medium

Abstract

The invention provides a vehicle slip control method and device, a vehicle and a storage medium, the method is applied to the technical field of vehicles, and the method comprises the steps that when it is judged that the vehicle slips based on the current wheel speed and the current reference vehicle speed, a first torque reduction gradient is determined according to the first difference value of the current wheel speed and the current reference vehicle speed, and reducing the output torque of the driving motor to a first target intervention torque based on the first torque reduction gradient, determining a target gradient according to the current request torque of the motor, the wheel speed after falling and the reference vehicle speed after falling when the current wheel speed has a falling trend, and adjusting the output torque of the driving motor based on the target gradient. And until the vehicle meets the slip control quitting condition. According to the method, the control algorithm can be integrated in the motor controller to monitor the wheel slipping state in real time, torque intervention can be conducted in advance, the output torque of the driving motor is dynamically adjusted so as to reduce the situation that the wheels slip again, and then stable output of the vehicle driving force is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a vehicle slip control method, device, vehicle and storage medium in the field of vehicle technology. Background Art

[0002] In new energy vehicles, traction control system is one of the key technologies to ensure vehicle driving safety and performance. Its main function is to prevent excessive wheel rotation by adjusting the output torque of the drive motor when the wheel slips, thereby maintaining the stability and handling of the vehicle.

[0003] In the related technology, when the wheel slips, the ESC (Electronic Stability Control) is mainly relied on to feed back the intervention request and intervention torque to the HCU (Hybrid Control Unit), and then the HCU sends the intervention torque to the MCU (Motor Control Unit) through the CAN (Controller Area Network) bus based on the intervention request, and the MCU performs torque reduction to reduce wheel slip.

[0004] However, the above method requires multi-level signal transmission for the intervention torque and the ESC has a large window for identifying tire slippage. This will lead to a long communication delay and a too-fast response of the MCU, causing the tire to slip earlier, resulting in a serious drop in wheel-end power and even loss of control, which urgently needs to be solved. Summary of the invention

[0005] The present application provides a vehicle slip control method, device, vehicle and storage medium. The method can integrate a control algorithm in a motor controller to monitor the wheel slip status in real time, and can perform torque intervention in advance, thereby dynamically adjusting the output torque of the drive motor to reduce the occurrence of wheel slippage, thereby ensuring the stable output of vehicle driving force.

[0006] In a first aspect, a vehicle slip control method is provided, the method comprising: obtaining a current wheel speed and a current reference vehicle speed of the vehicle; when determining that the vehicle is slipping based on the current wheel speed and the current reference vehicle speed, determining a first torque reduction gradient according to a first difference between the current wheel speed and the current reference vehicle speed, and based on the first torque reduction gradient, reducing the output torque of the drive motor to a first target intervention torque, and judging whether the current wheel speed has a downward trend; if the current wheel speed has the downward trend, determining a target gradient according to the current requested torque of the motor, the wheel speed after the decline and the reference vehicle speed after the decline, and based on the target gradient, adjusting the output torque of the drive motor until the vehicle meets the conditions for exiting slip control.

[0007] Through the above technical solution, a control algorithm can be integrated into the motor controller to monitor the wheel slip status in real time, and torque intervention can be performed in advance, so as to dynamically adjust the output torque of the drive motor to reduce the recurrence of wheel slippage, thereby ensuring the stable output of vehicle driving force.

[0008] In combination with the first aspect, in some possible implementations, after obtaining the current wheel speed and the current reference vehicle speed of the vehicle, it also includes: determining whether a first difference between the current wheel speed and the current reference vehicle speed is greater than a first speed difference threshold; if the first difference between the current wheel speed and the current reference vehicle speed is greater than the first speed difference threshold, it is determined that the vehicle is slipping.

[0009] Through the above technical solution, by comparing the difference between the current wheel speed and the current reference vehicle speed with the first speed difference threshold, it is determined whether the vehicle is slipping, so as to improve slip control.

[0010] In combination with the first aspect and the above implementations, in some possible implementations, the first speed difference threshold is obtained by looking up a table based on the difference between the current left wheel speed and the current right wheel speed of the vehicle.

[0011] Through the above technical solution, the first speed difference threshold is limited.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target gradient is determined according to the current requested torque of the motor, the wheel speed after the drop and the reference vehicle speed after the drop, and based on the target gradient, the output torque of the drive motor is adjusted, including: judging whether the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold; if the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold, determining the target gradient based on the second difference, and continuing to reduce the output torque of the drive motor to the first target intervention torque based on the target gradient.

[0013] Through the above technical scheme, when the current wheel speed has a downward trend, the difference between the wheel speed after the decline and the vehicle speed after the decline and the target gradient corresponding to the difference are further determined, so as to reduce and increase the output torque of the motor according to different target gradients to improve the slip control accuracy.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the second difference between the wheel speed after the fall and the vehicle speed after the fall is greater than the second speed difference threshold, it also includes: if the second difference between the wheel speed after the fall and the vehicle speed after the fall is less than or equal to the second speed difference threshold, then determining the target gradient based on the current requested torque of the motor, and restoring the output torque of the drive motor to the second target intervention torque based on the target gradient.

[0015] Through the above technical solution, when the current wheel speed has a downward trend, and the second difference between the wheel speed after the decline and the vehicle speed after the decline is less than or equal to the second speed difference threshold, the torque increase operation is further performed to gradually restore the driving force while ensuring safety, avoiding power loss caused by excessive intervention.

[0016] In combination with the first aspect and the above-mentioned implementation manner, in some possible implementation manners, when restoring the output torque of the drive motor to the second target intervention torque based on the target gradient, it also includes: calculating the third difference between the wheel speed after the fall and the vehicle speed after the fall; judging whether the third difference between the wheel speed after the fall and the vehicle speed after the fall is less than or equal to the third speed difference threshold; if the third difference is less than or equal to the third speed difference threshold, obtaining the current left wheel speed and the current right wheel speed of the vehicle, and judging whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; if the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, determining the target gradient based on the first gradient table according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed; otherwise, determining the target gradient based on the second gradient table according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed; and restoring the output torque of the drive motor to the third target intervention torque based on the target gradient.

[0017] Through the above technical solution, the current wheel speed is in a downward trend, and the third difference between the wheel speed after the decline and the vehicle speed after the decline is less than or equal to the third speed difference threshold. At this time, it means that the slippage has been controlled. In order to meet the driver's needs, it is necessary to obtain the corresponding torque reduction gradient based on the motor requested torque and the left and right wheel speed difference at this time to control the drive motor torque to return to the driver's required torque.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the third difference between the current wheel speed and the current actual vehicle speed is less than or equal to the third speed difference threshold, it also includes: if the third difference is greater than the third speed difference threshold, then determining whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; if the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, then determining the target gradient according to the third difference based on the third gradient table, otherwise, determining the target gradient according to the third difference based on the fourth gradient table; and reducing the output torque of the drive motor to the first target intervention torque based on the target gradient.

[0019] Through the above technical solution, the current wheel speed is in a downward trend, and the third difference between the wheel speed after the decline and the vehicle speed after the decline is greater than the third speed difference threshold. This indicates that slippage occurs again and intervention is required based on the first target intervention torque to prevent safety hazards.

[0020] In a second aspect, a vehicle slip control device is provided, which includes: an acquisition module for acquiring a current wheel speed and a current reference vehicle speed of the vehicle; a torque reduction module for determining a first torque reduction gradient according to a first difference between the current wheel speed and the current reference vehicle speed when it is determined that the vehicle is slipping based on the current wheel speed and the current reference vehicle speed, and based on the first torque reduction gradient, reducing the output torque of the drive motor to a first target intervention torque, and judging whether the current wheel speed has a downward trend; an adjustment module for determining a target gradient according to the current requested torque of the motor, the wheel speed after the decline and the reference vehicle speed after the decline if the current wheel speed has the downward trend, and adjusting the output torque of the drive motor based on the target gradient until the vehicle meets the conditions for exiting slip control.

[0021] In combination with the second aspect, in some possible implementations, after obtaining the current wheel speed and the current reference vehicle speed of the vehicle, the acquisition module also includes: a first judgment unit, used to judge whether the first difference between the current wheel speed and the current reference vehicle speed is greater than a first speed difference threshold; a judgment unit, used to judge that the vehicle is slipping if the first difference between the current wheel speed and the current reference vehicle speed is greater than the first speed difference threshold.

[0022] In combination with the second aspect and the above implementations, in some possible implementations, the first speed difference threshold is obtained by looking up a table based on the difference between the current left wheel speed and the current right wheel speed of the vehicle.

[0023] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the adjustment module includes: a second judgment unit, used to judge whether the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold; a torque reduction unit, used to determine the target gradient based on the second difference if the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold, and continue to reduce the output torque of the drive motor to the first target intervention torque based on the target gradient.

[0024] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the second difference between the wheel speed after the fall and the vehicle speed after the fall is greater than the second speed difference threshold, the second judgment unit also includes: a torque increase unit, which is used to determine the target gradient based on the current requested torque of the motor if the second difference between the wheel speed after the fall and the vehicle speed after the fall is less than or equal to the second speed difference threshold, and restore the output torque of the drive motor to the second target intervention torque based on the target gradient.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, when the output torque of the drive motor is restored to the second target intervention torque based on the target gradient, the torque increasing unit also includes: a calculation component for calculating a third difference between the wheel speed after the drop and the vehicle speed after the drop; a first judgment component for judging whether the third difference between the wheel speed after the drop and the vehicle speed after the drop is less than or equal to a third speed difference threshold; a second judgment component for obtaining the current left wheel speed and the current right wheel speed of the vehicle if the third difference is less than or equal to the third speed difference threshold, and judging whether the current left wheel speed and the current right wheel speed are equal. Whether the current right wheel speed difference is less than or equal to the first speed difference threshold; a determination component, used to determine the target gradient based on the first gradient table according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed if the current left wheel speed difference is less than or equal to the first speed difference threshold; otherwise, based on the second gradient table, determine the target gradient according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed; a torque increase component, used to restore the output torque of the drive motor to a third target intervention torque based on the target gradient.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the third difference between the current wheel speed and the current actual vehicle speed is less than or equal to the third speed difference threshold, the first judgment component also includes: a judgment sub-component, used to determine whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold if the third difference is greater than the third speed difference threshold; a determination sub-component, used to determine the target gradient based on the third difference based on the third gradient table if the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; otherwise, determine the target gradient based on the third difference based on the fourth gradient table; a torque reduction sub-component, used to reduce the output torque of the drive motor to the first target intervention torque based on the target gradient.

[0027] In a third aspect, a vehicle is provided, comprising the vehicle slip control method described in the above embodiment.

[0028] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0029] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A flow chart of a vehicle skidding control method provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of the main execution process of vehicle skidding control according to an embodiment of the present application;

[0032] Figure 3 A block diagram of a vehicle skid control device provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the structure of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0035] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0036] With the global emphasis on environmental protection and sustainable development, new energy vehicles have become an important development direction of the automotive industry. In new energy vehicles, the traction control system is one of the key technologies to ensure vehicle driving safety and performance. Its main function is to prevent excessive wheel rotation by adjusting the output torque of the drive motor when the wheel slips, thereby maintaining the stability and controllability of the vehicle, especially on low-adhesion roads, such as slippery, ice-covered and snow-covered roads. Good traction control can significantly improve driving safety and comfort.

[0037] When a vehicle encounters wheel slip during driving, traditional technology mainly relies on ESC to detect abnormal conditions and feed back intervention requests and intervention torque to HCU via the CAN bus. Then, based on the intervention request, HCU sends the intervention torque to MCU via the CAN bus, and MCU performs specific torque adjustment actions to reduce wheel slip. However, this method has the following problems: (1) The torque intervention transmission time is long. Since the signal needs to be transmitted through multiple levels from ESC to HCU and then to MCU, the MCU will then execute the intervention torque. This will cause a long communication delay during the signal transmission process, making the system unable to respond to wheel slip in time; (2) The existing ESC has a large window for identifying tire slip, which means that the intervention mechanism can only be triggered after the tire has obviously started to slip. This delayed identification can easily cause the MCU to respond too quickly, causing the tire to slip earlier, which in turn causes a serious drop in wheel-end power or even loss of control. Therefore, based on the above-mentioned problems, it is necessary to separately develop a set of wheel slip status monitoring and intervention torque control algorithms and integrate them directly into the MCU, which can identify the tire slip status earlier than the ESC, thereby directly intervening the MCU to perform precise torque reduction, thereby effectively reducing wheel slip and improving the vehicle's driving safety and stability under complex road conditions.

[0038] Figure 1 It is a schematic flow chart of a vehicle skidding control method provided in an embodiment of the present application.

[0039] For example, Figure 1 As shown, the method includes:

[0040] In step S101 , the current wheel speed and the current reference vehicle speed of the vehicle are obtained.

[0041] Specifically, when a vehicle is driving on complex road conditions, such as wet or snowy roads, the wheels are prone to slipping due to insufficient friction, thereby increasing the vehicle's driving safety hazards. Therefore, when a vehicle is driving on complex road conditions, effective vehicle slip control is required to reduce the risk of accidents.

[0042] Specifically, first, it is necessary to obtain the current wheel speed and current reference speed of the vehicle, wherein the current wheel speed of the vehicle is the single-axle wheel speed, i.e., the front axle wheel speed or the rear axle wheel speed, and the current reference speed is the actual driving speed of the vehicle. For two-wheel drive models, the current reference speed can take the non-driving wheel speed as the reference speed, and for four-wheel drive models, the current reference speed can be obtained by the maximum wheel speed method, the difference method, the reference speed calculation method based on the brake wheel cylinder pressure, the Kalman filter method, the recursive method, the vehicle dynamics method and the like; secondly, the ESC is used to generate a target gradient according to the real-time monitored current wheel speed, the current reference speed and the changes in the current requested torque of the motor, and based on the target gradient, the output torque of the drive motor is dynamically adjusted to ensure the optimal performance of the vehicle under different adhesion conditions, thereby reducing wheel slip and ensuring the driving force of the wheel.

[0043] In step S102, when it is determined that the vehicle is slipping based on the current wheel speed and the current reference vehicle speed, a first torque reduction gradient is determined according to a first difference between the current wheel speed and the current reference vehicle speed, and based on the first torque reduction gradient, the output torque of the drive motor is reduced to a first target intervention torque, and at the same time, it is determined whether the current wheel speed has a downward trend.

[0044] Optionally, in one embodiment of the present application, after obtaining the current wheel speed and the current reference speed of the vehicle, it also includes: determining whether a first difference between the current wheel speed and the current reference speed is greater than a first speed difference threshold; if the first difference between the current wheel speed and the current reference speed is greater than the first speed difference threshold, it is determined that the vehicle is slipping.

[0045] The first target intervention torque may be set by those skilled in the art according to actual test requirements, or may be obtained through a limited number of calculation simulations, which is not specifically limited herein.

[0046] Specifically, if Figure 2As shown, after obtaining the current wheel speed and the current actual vehicle speed of the vehicle, first, the wheel slip detection window is set to the first slip detection window, and the first difference between the current wheel speed and the current reference vehicle speed is calculated. If the first difference between the current wheel speed and the current reference vehicle speed is greater than the first speed difference threshold (i.e., speed difference threshold 1), for example, the first speed difference threshold may be 10kmh, that is, when the first difference between the current wheel speed and the current reference vehicle speed is greater than 10kmh, it indicates that the vehicle is slipping (e.g., Figure 2 S1 in: wheel speed ab), so torque intervention is required in advance to reduce the rotation speed of the wheel and prevent the wheel from excessively slipping. Therefore, when the wheel slips, the slip torque intervention flag needs to be activated first. Since the torque reduction corresponding to the highest point of wheel speed b is the largest, the first target intervention torque can be set at this time, and then the first torque reduction gradient (i.e. gradient 1) is determined according to the first difference between the current wheel speed and the current reference vehicle speed. That is, when the first difference between the current wheel speed and the current reference vehicle speed is input, the corresponding first torque reduction gradient can be obtained, so as to reduce the output torque of the drive motor to the first target intervention torque (i.e. torque threshold 1) based on the first torque reduction gradient. For example, the first The target intervention torque can be set to 0Nm, indicating that the target value of the slip intervention torque is 0Nm. At this time, the drive motor will quickly reduce the output torque of the drive motor according to the first torque reduction gradient. The current wheel speed will quickly reduce the slip trend and show a downward trend as the motor torque decreases, so that the wheel can quickly restore grip, thereby ensuring the smooth operation of the vehicle and avoiding sudden loss of driving force for the vehicle; secondly, in the process of gradually reducing the output torque of the drive motor to the first target intervention torque based on the first torque reduction gradient, it is necessary to further detect whether the current wheel speed has a downward trend, so as to generate different target gradients according to the current wheel speed detection results, and thus adjust the output torque of the drive motor accordingly.

[0047] Among them, the first slip detection window is specifically matched and calibrated with the actual vehicle debugging result, the first target intervention torque can be matched and calibrated by comprehensively considering indicators such as wheel slip, drivability, and power, and the first speed difference threshold can be obtained by looking up the table according to the wheel speed difference between the left and right wheels of the vehicle. Different wheel speed differences can output different first speed difference thresholds. At the same time, since the first torque reduction gradient is related to the first difference between the current wheel speed and the current reference vehicle speed, the larger the first difference, the larger the corresponding output first torque reduction gradient, which indicates that the output torque of the drive motor decreases faster.

[0048] In step S103, if the current wheel speed has a downward trend, the target gradient is determined according to the current requested torque of the motor, the wheel speed after the decline and the reference vehicle speed after the decline, and based on the target gradient, the output torque of the drive motor is adjusted until the vehicle meets the conditions for exiting slip control.

[0049] Optionally, in one embodiment of the present application, a target gradient is determined based on the current requested torque of the motor, the wheel speed after the drop and the reference vehicle speed after the drop, and based on the target gradient, the output torque of the drive motor is adjusted, including: judging whether the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than a second speed difference threshold; if the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold, determining the target gradient based on the second difference, and continuing to reduce the output torque of the drive motor to the first target intervention torque based on the target gradient.

[0050] Optionally, in one embodiment of the present application, after determining whether the second difference between the wheel speed after the fall and the vehicle speed after the fall is greater than the second speed difference threshold, it also includes: if the second difference between the wheel speed after the fall and the vehicle speed after the fall is less than or equal to the second speed difference threshold, then determining the target gradient based on the current requested torque of the motor, and restoring the output torque of the drive motor to the second target intervention torque based on the target gradient.

[0051] Specifically, Figure 2 As shown, in the embodiment of the present application, if it is detected that the current wheel speed has a downward trend, it means that the friction between the wheel and the ground is gradually increasing, the grip has begun to recover, and the slipping situation has been initially controlled, but there may still be a potential risk of slipping. Therefore, it is necessary to further determine the target gradient based on the wheel speed after the decline and the reference vehicle speed after the decline. The target gradient is multiple, corresponding to Figure 2 That is to say, the corresponding target gradient can be determined according to the difference between the wheel speed after the drop and the reference vehicle speed after the drop, so as to adjust the output torque of the drive motor based on the target gradient until the vehicle meets the conditions for exiting the slip control.

[0052] Specifically, first, if the current wheel speed has a downward trend, the wheel slip detection window is switched to the second slip detection window, and it is determined whether the second difference between the wheel speed after the decline and the vehicle speed after the decline is greater than the second speed difference threshold (i.e., speed difference threshold 3). For example, the second speed difference threshold is 12kmh. If the second difference between the wheel speed after the decline and the vehicle speed after the decline is greater than the second speed difference threshold, it means that the vehicle is still slipping (e.g., Figure 2 S2: wheel speed bc), a small torque reduction can be performed. At this time, the corresponding target gradient is determined based on the second difference, that is, the target gradient at this time is gradient 2, so that the output torque of the drive motor is further reduced to the first target intervention torque based on gradient 2, wherein the second speed difference threshold is obtained according to the second difference between the wheel speed after the drop and the vehicle speed after the drop. The larger the second difference, the larger the corresponding output gradient 2, indicating that the faster the drive motor torque drops, that is, when the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than 12kmh, the corresponding output gradient 2 is used at this time, so that the output torque of the drive motor is further reduced to 0Nm based on gradient 2.

[0053] Secondly, if the second difference between the wheel speed after the drop and the vehicle speed after the drop is less than or equal to the second speed difference threshold, that is, the second difference is less than or equal to 12 kmh, it means that the wheel further recovers the grip (such as Figure 2 S3 in the figure: wheel speed cd). If the strong torque reduction action is continued when the grip has been gradually restored, that is, the first target intervention torque is executed, it may cause unnecessary power loss, thereby affecting the vehicle's driving performance and driving experience. Therefore, the torque intervention strategy may be appropriately adjusted to start increasing the torque to prevent the current reference vehicle speed from dropping too much, that is, to set the second target intervention torque (that is, torque threshold 2). For example, the second target intervention torque may be set to 100 Nm. At this time, the corresponding target gradient is determined based on the current requested torque of the motor, that is, the target gradient at this time is gradient 3, so that the output torque of the drive motor is restored to the second target intervention torque based on gradient 3, so that the wheel state can be monitored more accurately to prevent the wheel from slipping again and better balance safety. The second speed difference threshold is obtained according to the second difference between the wheel speed after the drop and the vehicle speed after the drop. The larger the second difference is, the larger the corresponding output gradient 3 is, which indicates that the torque of the drive motor rises faster. That is, when the second difference between the wheel speed after the drop and the vehicle speed after the drop is less than or equal to 12 kmh, the corresponding output gradient 3 is output at this time, so that the output torque of the drive motor is restored to 100 Nm based on gradient 3.

[0054] Optionally, in one embodiment of the present application, when restoring the output torque of the drive motor to the second target intervention torque based on the target gradient, it also includes: calculating the third difference between the wheel speed after the fall and the vehicle speed after the fall; judging whether the third difference between the wheel speed after the fall and the vehicle speed after the fall is less than or equal to the third speed difference threshold; if the third difference is less than or equal to the third speed difference threshold, obtaining the current left wheel speed and the current right wheel speed of the vehicle, and judging whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; if the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, determining the target gradient based on the first gradient table according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed, otherwise, determining the target gradient based on the second gradient table according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed; and restoring the output torque of the drive motor to the third target intervention torque based on the target gradient.

[0055] Optionally, in one embodiment of the present application, after determining whether the third difference between the current wheel speed and the current actual vehicle speed is less than or equal to the third speed difference threshold, it also includes: if the third difference is greater than the third speed difference threshold, determining whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; if the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, based on the third gradient table, determining the target gradient according to the third difference; otherwise, based on the fourth gradient table, determining the target gradient according to the third difference; based on the target gradient, reducing the output torque of the drive motor to the first target intervention torque.

[0056] Specifically, during the process of reducing the output torque of the driving motor, the third difference between the wheel speed after the decrease and the vehicle speed after the decrease (eg Figure 2 S4 in the figure: wheel speed de), if the third difference is less than or equal to the third speed difference threshold (i.e., speed difference threshold 2), for example, the third speed difference threshold may be 6 kmh, and when the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, it means that the left and right wheel speeds are the same, based on the first gradient table, the corresponding target gradient is determined according to the difference between the current requested torque of the motor, the current left wheel speed, and the current right wheel speed, and the target gradient is gradient 4 at this time, so that the output torque of the drive motor is restored to the third target intervention torque (i.e., torque threshold 3) based on the target gradient, and the third target intervention torque is the driver's required torque, that is, when the third difference is less than or equal to 6kmh, and when the difference between the current left wheel speed and the current right wheel speed is less than or equal to 10kmh, the output torque of the drive motor can be adjusted to the requested output torque of the vehicle controller for the drive motor according to gradient 4, that is, the torque output under normal driving conditions is restored until the requested output torque of the vehicle controller for the drive motor is reached, that is, the torque required by the driver is reached. At this time, it is explained that the wheels have fully recovered their grip, the slippage has been effectively controlled, and the vehicle meets the conditions for exiting the slippage control, so that the driving force of the vehicle can be restored to the maximum extent under the premise of ensuring safety to avoid unnecessary power loss, while maintaining driving stability and comfort.

[0057] Furthermore, if the difference between the current left wheel speed and the current right wheel speed is greater than the first speed difference threshold, this indicates that during the process of reducing the output torque of the drive motor, the left and right wheel speeds are inconsistent. For example, the left wheel is on a low adhesion coefficient road surface and the right wheel is on a high adhesion coefficient road surface. At this time, slippage will occur again. Therefore, based on the first gradient table, the target gradient is determined according to the difference between the current requested torque of the motor, the current left wheel speed and the current right wheel speed. At this time, the target gradient is gradient 5, so that the output torque of the drive motor is restored to the third target intervention torque based on the target gradient. That is to say, when the third difference is less than or equal to 6kmh and the difference between the current left wheel speed and the current right wheel speed is greater than 10kmh, the output torque of the drive motor is restored to the driver's required torque based on gradient 5.

[0058] Among them, the third speed difference threshold can be obtained by looking up the table according to the difference between the current left wheel speed and the current right wheel speed of the vehicle. Different wheel speed differences can output different third speed difference thresholds. At the same time, since the target gradient is related to the motor requested torque and the difference between the current left wheel speed and the current right wheel speed, the larger the difference between the current left wheel speed and the current right wheel speed, the smaller the corresponding output target gradient is, and the slower the drive motor torque rises. The larger the motor requested torque is, the larger the corresponding output target gradient is, and the faster the drive motor torque rises.

[0059] It should be noted that the difference between the current left wheel speed and the current right wheel speed is larger when the working conditions are different. Therefore, the difference between the current left wheel speed and the current right wheel speed when they are in different working conditions is greater than the difference between the current left wheel speed and the current right wheel speed when they are in the same working condition.

[0060] Furthermore, if the third difference is greater than the third speed difference threshold, it means that slippage occurs again during the process of reducing the output torque of the drive motor (eg Figure 2 S5: wheel speed ef), at this time, it is necessary to continue to reduce the torque. If the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, that is, the difference between the current left wheel speed and the current right wheel speed is less than or equal to 10kmh, it means that the current left wheel speed and the current right wheel speed have the same working condition. Then, based on the third gradient table, the target gradient can be determined according to the third difference. At this time, the target gradient is gradient 6, so that the output torque of the drive motor is reduced to the first target intervention torque according to the gradient 6. That is to say, when the third difference is greater than 6kmh and the difference between the current left wheel speed and the current right wheel speed is less than or equal to 10kmh, the output torque of the drive motor is reduced to 0Nm according to the gradient 6. At the same time, it is also necessary to avoid the third difference from exceeding the first slip detection window as much as possible through calibration optimization.

[0061] Further, if the difference between the current left wheel speed and the current right wheel speed is greater than the first speed difference threshold, that is, the difference between the current left wheel speed and the current right wheel speed is greater than 10 kmh, it means that the current left wheel speed and the current right wheel speed are in different working conditions. At this time, the target gradient can be determined based on the third difference based on the fourth gradient table. At this time, the target gradient is gradient 7, so that the output torque of the drive motor is quickly reduced to the first target intervention torque according to gradient 7. That is to say, when the third difference is greater than 6 kmh and the difference between the current left wheel speed and the current right wheel speed is greater than 10 kmh, the output torque of the drive motor is reduced to 0 Nm according to gradient 7. Among them, since the target gradient is related to the third difference between the wheel speed after the drop and the vehicle speed after the drop, the larger the third difference between the wheel speed after the drop and the vehicle speed after the drop, the larger the corresponding output target gradient is, and the faster the drive motor torque drops.

[0062] It should be noted that if Figure 2 As shown, during the torque recovery in stage S4 and the torque reduction in stage S5, the embodiment of the present application distinguishes and calibrates based on the left and right wheel speed difference, so as to reduce the excess of the current wheel speed over the second slip detection window. During the torque recovery in stage S4, if the current wheel speed is closer to the boundary of the second slip detection window, the torque rises more slowly, and even when it approaches the boundary of the second slip detection window, the torque no longer increases. In addition, the left and right wheel speed conditions of the vehicle are determined (for example, the left wheel is on a low adhesion coefficient road surface, and the right wheel is on a high adhesion coefficient road surface) and calibrated separately. The specific implementation method is discussed in the above embodiment and will not be described in detail here to avoid redundancy.

[0063] Therefore, based on the specific discussion of the above embodiments, the present application can achieve the following beneficial effects:

[0064] (1) Shorten the response time: This application integrates the slip state monitoring and intervention torque control algorithm into the drive motor, reducing the CAN bus communication time from the ESC to the vehicle controller, and from the vehicle controller to the motor controller, thereby significantly shortening the time from detecting slip to actually executing torque adjustment, and improving the response speed;

[0065] (2) Earlier skid intervention: Compared with the vehicle stability control system (ESC), the present invention has an earlier skid intervention timing, which can intervene the wheel torque in advance, prevent excessive tire slippage from causing power loss, and maintain the power output at the wheel end;

[0066] (3) Dynamic adjustment of torque output: To deal with tire slip on low-adhesion roads, the target intervention torque can be dynamically adjusted based on the real-time monitoring of wheel speed and vehicle speed changes to ensure optimal vehicle performance under different adhesion conditions, reduce tire burnout, increase tire service life, and ensure vehicle driving safety.

[0067] In summary, according to the vehicle slip control method of the embodiment of the present application, when it is determined that the vehicle is slipping based on the current wheel speed and the current reference speed, the first torque reduction gradient is determined based on the first difference between the current wheel speed and the current reference speed, and the output torque of the drive motor is reduced to the first target intervention torque based on the first torque reduction gradient. At the same time, when the current wheel speed has a downward trend, the target gradient is determined based on the current motor request torque, the wheel speed after the decline, and the reference speed after the decline, and the output torque of the drive motor is adjusted based on the target gradient until the vehicle meets the exit slip control condition. This method can integrate a control algorithm in the motor controller to monitor the wheel slip state in real time, and can perform torque intervention in advance, so as to dynamically adjust the output torque of the drive motor to reduce the wheel slipping again, thereby ensuring the stable output of the vehicle driving force.

[0068] Figure 3 It is a structural schematic diagram of a vehicle skid control device provided in an embodiment of the present application.

[0069] For example, Figure 3 As shown, the device 10 may include: an acquisition module 100 , a torque reduction module 200 and an adjustment module 300 .

[0070] The acquisition module 100 is used to acquire the current wheel speed and the current reference vehicle speed of the vehicle;

[0071] The torque reduction module 200 is used to determine a first torque reduction gradient according to a first difference between the current wheel speed and the current reference vehicle speed when the vehicle is judged to be slipping based on the current wheel speed and the current reference vehicle speed, and to reduce the output torque of the drive motor to a first target intervention torque based on the first torque reduction gradient, and to judge whether the current wheel speed has a downward trend;

[0072] The adjustment module 300 is used to determine the target gradient according to the current requested torque of the motor, the wheel speed after the decline and the reference vehicle speed after the decline if the current wheel speed has a downward trend, and based on the target gradient, adjust the output torque of the drive motor until the vehicle meets the conditions for exiting the slip control.

[0073] Optionally, in one embodiment of the present application, after obtaining the current wheel speed and the current reference vehicle speed of the vehicle, the obtaining module 100 further includes:

[0074] A first judging unit, used for judging whether a first difference between a current wheel speed and a current reference vehicle speed is greater than a first speed difference threshold;

[0075] The determination unit is used to determine that the vehicle is slipping if a first difference between a current wheel speed and a current reference vehicle speed is greater than a first speed difference threshold.

[0076] Optionally, in one embodiment of the present application, the first speed difference threshold is obtained by looking up a table based on the difference between the current left wheel speed and the current right wheel speed of the vehicle.

[0077] Optionally, in one embodiment of the present application, the adjustment module 300 includes:

[0078] A second judgment unit, used for judging whether a second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than a second speed difference threshold;

[0079] The torque reduction unit is used to determine a target gradient based on the second difference between the wheel speed after the drop and the vehicle speed after the drop, and further reduce the output torque of the drive motor to the first target intervention torque based on the target gradient if the second difference between the wheel speed after the drop is greater than the second speed difference threshold.

[0080] Optionally, in one embodiment of the present application, after determining whether the second difference between the wheel speed after the fall and the vehicle speed after the fall is greater than the second speed difference threshold, the second determination unit further includes:

[0081] The torque increasing unit is used to determine a target gradient based on the current requested torque of the motor if a second difference between the wheel speed after the drop and the vehicle speed after the drop is less than or equal to a second speed difference threshold, and to restore the output torque of the drive motor to a second target intervention torque based on the target gradient.

[0082] Optionally, in one embodiment of the present application, when the output torque of the drive motor is restored to the second target intervention torque based on the target gradient, the torque increasing sub-unit further includes:

[0083] A calculation part, used for calculating a third difference between the wheel speed after the fall and the vehicle speed after the fall;

[0084] A first judgment element, used to judge whether a third difference between the wheel speed after the drop and the vehicle speed after the drop is less than or equal to a third speed difference threshold;

[0085] a second judgment component, for obtaining the current left wheel speed and the current right wheel speed of the vehicle and judging whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold value if the third difference is less than or equal to the third speed difference threshold value;

[0086] a determination member for determining a target gradient based on a first gradient table according to a current requested torque of the motor, a difference between a current left wheel speed and a current right wheel speed if the difference between a current left wheel speed and a current right wheel speed is less than or equal to a first speed difference threshold, and otherwise determining a target gradient based on a second gradient table according to a difference between a current requested torque of the motor, a difference between a current left wheel speed and a current right wheel speed;

[0087] The torque increasing member is used for restoring the output torque of the driving motor to a third target intervention torque based on the target gradient.

[0088] Optionally, in one embodiment of the present application, after determining whether the third difference between the current wheel speed and the current actual vehicle speed is less than or equal to the third speed difference threshold, the first determination element further includes:

[0089] a judgment sub-component, for judging whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold value if the third difference value is greater than the third speed difference threshold value;

[0090] a determination subcomponent, for determining a target gradient according to a third difference based on a third gradient table if the difference between the current left wheel speed and the current right wheel speed is less than or equal to a first speed difference threshold, and otherwise determining a target gradient according to the third difference based on a fourth gradient table;

[0091] The torque reduction component is used to reduce the output torque of the driving motor to a first target intervention torque based on the target gradient.

[0092] In summary, according to the vehicle skidding control device of the embodiment of the present application, when it is determined that the vehicle is skidding based on the current wheel speed and the current reference speed, the first torque reduction gradient is determined based on the first difference between the current wheel speed and the current reference speed, and the output torque of the drive motor is reduced to the first target intervention torque based on the first torque reduction gradient. At the same time, when the current wheel speed has a downward trend, the target gradient is determined based on the current motor request torque, the wheel speed after the decline, and the reference speed after the decline, and the output torque of the drive motor is adjusted based on the target gradient until the vehicle meets the conditions for exiting the skidding control. This method can integrate a control algorithm in the motor controller to monitor the wheel slip state in real time, and can perform torque intervention in advance, so as to dynamically adjust the output torque of the drive motor to reduce the wheel slipping again, thereby ensuring the stable output of the vehicle driving force.

[0093] Figure 4 A schematic structural diagram of a vehicle provided in an embodiment of the present application.

[0094] It should be understood that the above-described method can be applied to Figure 4 In a vehicle of the structure shown.

[0095] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute the vehicle slip control method provided by the embodiment of the present application.

[0096] Furthermore, the device also includes: a communication interface 403 for communication between the memory 401 and the processor 402 .

[0097] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0098] It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0099] It should be understood that the device provided in this embodiment is used to execute the above-mentioned vehicle slip control method, and thus can achieve the same effect as the above-mentioned implementation method.

[0100] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing mutual program codes, etc.

[0101] The processing module may be a processor 402 or a controller, which may implement or execute various exemplary logic blocks, modules and circuits disclosed in the present application. The processor 402 may also be a combination that implements a computing function, such as a combination of one or more microprocessors, a combination of a digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory 401.

[0102] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor 402 and a memory 401; wherein the memory 401 is used to store instructions, and when the processor calls and executes the instructions, the chip can execute the vehicle slip control method provided in the above embodiments.

[0103] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement a vehicle slip control method provided by the above embodiment.

[0104] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a vehicle skidding control method provided by the above-mentioned embodiment.

[0105] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0106] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0107] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0108] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A vehicle skidding control method, characterized in that: The method comprises: Get the vehicle's current wheel speed and current reference speed; When it is determined that the vehicle is slipping based on the current wheel speed and the current reference vehicle speed, a first torque reduction gradient is determined according to a first difference between the current wheel speed and the current reference vehicle speed, and based on the first torque reduction gradient, the output torque of the drive motor is reduced to a first target intervention torque, and at the same time, it is determined whether the current wheel speed has a downward trend; If the current wheel speed has the downward trend, the target gradient is determined according to the current requested torque of the motor, the wheel speed after the decline and the reference vehicle speed after the decline, and based on the target gradient, the output torque of the drive motor is adjusted until the vehicle meets the conditions for exiting slip control.

2. The method according to claim 1, characterized in that After obtaining the current wheel speed and current reference speed of the vehicle, it also includes: Determining whether a first difference between the current wheel speed and the current reference vehicle speed is greater than a first speed difference threshold; If a first difference between the current wheel speed and the current reference vehicle speed is greater than the first speed difference threshold, it is determined that the vehicle is slipping.

3. The method according to claim 2, characterized in that The first speed difference threshold is obtained by looking up a table according to the difference between the current left wheel speed and the current right wheel speed of the vehicle.

4. The method according to claim 1, characterized in that: The step of determining the target gradient according to the current requested torque of the motor, the wheel speed after the drop, and the reference vehicle speed after the drop, and adjusting the output torque of the drive motor based on the target gradient includes: Determine whether a second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than a second speed difference threshold; If a second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold, the target gradient is determined based on the second difference, and the output torque of the drive motor is further reduced to the first target intervention torque based on the target gradient.

5. The method according to claim 4, characterized in that After determining whether the second difference between the wheel speed after the drop and the vehicle speed after the drop is greater than the second speed difference threshold, the method further includes: If a second difference between the post-fall wheel speed and the post-fall vehicle speed is less than or equal to the second speed difference threshold, the target gradient is determined based on the current requested torque of the motor, and the output torque of the drive motor is restored to a second target intervention torque based on the target gradient.

6. The method according to claim 5, characterized in that When the output torque of the driving motor is restored to the second target intervention torque based on the target gradient, the method further includes: Calculating a third difference between the wheel speed after the drop and the vehicle speed after the drop; Determining whether a third difference between the wheel speed after the drop and the vehicle speed after the drop is less than or equal to a third speed difference threshold; If the third difference is less than or equal to the third speed difference threshold, obtaining the current left wheel speed and the current right wheel speed of the vehicle, and determining whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; If the difference between the current left wheel speed and the current right wheel speed is less than or equal to a first speed difference threshold, the target gradient is determined based on a first gradient table according to the current requested torque of the motor, the difference between the current left wheel speed and the current right wheel speed; otherwise, the target gradient is determined based on a second gradient table according to the current requested torque of the motor, the difference between the current left wheel speed and the current right wheel speed; The output torque of the driving motor is restored to a third target intervention torque based on the target gradient.

7. The method according to claim 6, characterized in that After determining whether the third difference between the current wheel speed and the current actual vehicle speed is less than or equal to a third speed difference threshold, the method further includes: If the third difference is greater than the third speed difference threshold, determining whether the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold; If the difference between the current left wheel speed and the current right wheel speed is less than or equal to the first speed difference threshold, then based on a third gradient table, the target gradient is determined according to the third difference; otherwise, based on a fourth gradient table, the target gradient is determined according to the third difference; The output torque of the drive motor is reduced to the first target intervention torque based on the target gradient.

8. A vehicle skid control device, characterized in that: The device comprises: An acquisition module, used to acquire the current wheel speed and current reference vehicle speed of the vehicle; a torque reduction module, configured to, when it is determined based on the current wheel speed and the current reference vehicle speed that the vehicle is slipping, determine a first torque reduction gradient according to a first difference between the current wheel speed and the current reference vehicle speed, and based on the first torque reduction gradient, reduce the output torque of the drive motor to a first target intervention torque, and at the same time determine whether the current wheel speed has a downward trend; The regulating module is used to determine a target gradient according to the current requested torque of the motor, the wheel speed after the decline and the reference vehicle speed after the decline if the current wheel speed has the downward trend, and based on the target gradient, regulate the output torque of the drive motor until the vehicle meets the conditions for exiting the slip control.

9. A vehicle, characterized in that: The vehicle comprises: a vehicle slip control method as described in any one of claims 1-7 above.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

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