A vehicle torque control method, vehicle and storage medium

Abstract

The present application provides a torque control method for a vehicle, a vehicle and a storage medium, the method is applied to a vehicle, the vehicle includes a first axle and a second axle, the power source of the first axle includes a first motor and an engine, the power source of the second axle includes a second motor, the first axle is connected to a first wheel, the method includes: if it is detected that the slip rate of the first wheel is greater than a preset first threshold, then determine the current driving mode of the vehicle; if the driving mode is a hybrid mode, then obtain the target torque reduction value corresponding to the first axle and the maximum torque reduction value currently supported by the first motor; if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, then control the first motor to reduce torque so that the first wheel stops slipping. The method can shorten the torque control transmission link, thereby reducing the response time of the torque control.

Description

Technical Field

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

[0002] At present, there are three main types of power systems for automobiles, namely fuel power systems, pure electric power systems and hybrid systems. Compared with traditional fuel power systems and pure electric power systems, when hybrid systems output torque, since there are at least two power sources, the engine and the motor, the output mode of the power system torque is complex. Under different working conditions, its output mode varies greatly. The traction control of multiple power sources requires secondary torque distribution through the power domain controller, which leads to an increase in the torque control transmission link and an increase in the response time of the torque control. Summary of the invention

[0003] The present application provides a vehicle torque control method, a vehicle and a storage medium, which can shorten the torque control transmission link and thus reduce the response time of the torque control.

[0004] In a first aspect, a torque control method for a vehicle is provided, wherein the vehicle comprises a first axle and a second axle, the power source of the first axle comprises a first motor and an engine, the power source of the second axle comprises a second motor, and the first axle is connected to a first wheel, the method comprising: if it is detected that the slip rate of the first wheel is greater than a preset first threshold, determining a current driving mode of the vehicle; if the driving mode is a hybrid mode, obtaining a target torque reduction value corresponding to the first axle and a maximum torque reduction value currently supported by the first motor; wherein the target torque reduction value corresponding to the first axle is a torque value required to reduce the power source of the first axle in order to stop the first wheel from slipping; if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, controlling the first motor to reduce torque so that the first wheel stops slipping.

[0005] In the above technical solution, when the slip rate of the first wheel is greater than the preset first threshold and the driving mode of the vehicle is the hybrid mode, it is necessary to obtain the target torque reduction value corresponding to the first axle and the maximum torque reduction value currently supported by the first motor. The above target torque reduction value is used to stop the first wheel from slipping. At this time, the size of the target torque reduction value and the maximum torque reduction value is judged. If the target torque reduction value is less than or equal to the maximum torque reduction value, it means that the maximum torque reduction capacity of the first motor can meet the needs of the first axle. Since the response speed and accuracy of the motor are higher than those of the engine when outputting torque, the torque of the first motor is reduced, and there is no need to reduce the torque of the engine or perform secondary distribution of torque, which reduces the slip time of the first wheel and can stop the slip of the first wheel faster. By reducing the torque of the motor, the link of torque control transmission can be shortened, thereby reducing the response time of torque control, improving the response speed of the first wheel to torque control, and stopping the slip of the first wheel as soon as possible.

[0006] In combination with the first aspect, in some possible implementations, if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, the first motor is controlled to reduce torque so that the first wheel stops slipping, including: if the target torque reduction value corresponding to the first axle is equal to the maximum torque reduction value, the first motor is controlled to reduce torque according to the maximum torque reduction value so that the first wheel stops slipping; if the target torque reduction value corresponding to the first axle is less than the maximum torque reduction value, the first motor is controlled to reduce torque according to the target torque reduction value corresponding to the first axle so that the first wheel stops slipping.

[0007] In the above technical solution, if the target torque reduction value is equal to the maximum torque reduction value, it means that the torque reduction capacity of the first motor just meets the needs of the first axle, therefore, the first wheel can be stopped from slipping by controlling the first motor to reduce torque according to the maximum torque reduction value; if the target torque reduction value is less than the maximum torque reduction value, it means that the torque reduction capacity of the first motor is higher than the needs of the first axle, therefore, the first wheel can be stopped from slipping by controlling the first motor to reduce torque according to the target torque reduction value. Since the motor has a fast response speed, when the torque reduction capacity of the first motor is sufficient to meet the needs of the first axle, only the first motor is subjected to torque control, so that the first wheel stops slipping as soon as possible, thereby improving driving safety.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, if the target torque reduction value corresponding to the first axle is greater than the maximum torque reduction value, the target torque reduction value corresponding to the first axle minus the maximum torque reduction value is calculated to obtain a first difference torque; the first motor is controlled to reduce torque according to the maximum torque reduction value, and the engine is controlled to reduce torque according to the first difference torque, so that the first wheel stops slipping.

[0009] In the above technical solution, if the target torque reduction value is greater than the maximum torque reduction value, it means that the torque reduction capacity of the first motor is insufficient to meet the needs of the first axle. Therefore, while controlling the first motor to reduce torque according to the maximum torque reduction value, the engine also needs to reduce torque to make up for the part that the first motor cannot complete, that is, the above-mentioned first difference torque. Through the above solution, the first motor is first reduced in torque. If the torque reduction capacity of the first motor is insufficient, the engine is then reduced in torque to make up for it. Although this method is also a distribution of torque, since the motor has a higher response speed to torque control than the engine, the first motor is given priority to reduce torque to the maximum extent, which can improve the response speed of the first wheel to torque control to a certain extent, reduce the time of slipping of the first wheel, and make the first wheel stop slipping as soon as possible, thereby improving driving safety.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, controlling the first motor to reduce torque according to the maximum torque reduction value includes: obtaining the current output torque of the first motor; calculating the second difference torque obtained by subtracting the maximum torque reduction value from the current output torque of the first motor; and controlling the first motor to output the second difference torque.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, controlling the engine to reduce torque according to the first differential torque includes: obtaining the current output torque of the engine; calculating the third differential torque obtained by subtracting the first differential torque from the current output torque of the engine; and controlling the engine to output the third differential torque.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the second axle is connected to the second wheel, and if the drive mode is a hybrid four-wheel drive mode or a pure electric four-wheel drive mode, the method also includes: if the slip rate of the second wheel is greater than a preset second threshold, obtaining a target torque reduction value of the second motor; wherein the target torque reduction value of the second motor is the torque value required to reduce the second motor to stop the second wheel from slipping; controlling the second motor to reduce torque according to the target torque reduction value of the second motor to stop the second wheel from slipping.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, if the driving mode is a pure electric mode, the target torque reduction value of the first motor is obtained; wherein the target torque reduction value of the first motor is the torque value required to reduce the first motor in order to stop the first wheel from slipping; the first motor is controlled to reduce the torque according to the target torque reduction value of the first motor so that the first wheel stops slipping.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, obtaining the target torque reduction value corresponding to the first axle includes: obtaining the current output torque of the first motor, the current output torque of the engine, and the target torque value corresponding to the first axle; wherein the target torque value corresponding to the first axle is the torque value required to be output by the power source of the first axle to stop the first wheel from slipping; calculating the current output torque of the first motor plus the current output torque of the engine to obtain the torque sum; and subtracting the target torque value corresponding to the first axle from the torque sum to obtain the target torque reduction value corresponding to the first axle.

[0015] In a second aspect, a torque control device for a vehicle is provided, wherein the vehicle comprises a first axle and a second axle, the power source of the first axle comprises a first motor and an engine, the power source of the second axle comprises a second motor, and the first axle is connected to a first wheel, the device comprising: a determination module, for determining a current driving mode of the vehicle if it is detected that a slip rate of the first wheel is greater than a preset first threshold; an acquisition module, for acquiring a target torque reduction value corresponding to the first axle and a maximum torque reduction value currently supported by the first motor if the driving mode is a hybrid mode; wherein the target torque reduction value corresponding to the first axle is a torque value required to reduce the power source of the first axle in order to stop the first wheel from slipping; and a control module, for controlling the first motor to reduce torque if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value so as to stop the first wheel from slipping.

[0016] In a third aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method in the first aspect or any possible implementation of the first aspect.

[0017] 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.

[0018] 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

[0019] Figure 1 is a schematic flow chart of a vehicle torque control method provided in an embodiment of the present application;

[0020] Figure 2 is a schematic flow chart of another vehicle torque control method provided in an embodiment of the present application;

[0021] Figure 3 is a schematic flow chart of a torque control method in a pure electric rear-drive mode provided in an embodiment of the present application;

[0022] Figure 4 is a schematic flow chart of a torque control method for a hybrid front-drive mode provided in an embodiment of the present application;

[0023] Figure 5 is a schematic flow chart of a torque control method of a pure electric front-drive mode provided in an embodiment of the present application;

[0024] Figure 6 is a schematic structural diagram of a torque control device for a vehicle provided in an embodiment of the present application;

[0025] Figure 7 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] 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.

[0027] 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.

[0028] At present, there are three main types of power systems for automobiles, namely fuel power systems, pure electric power systems and hybrid systems. Compared with traditional fuel power systems and pure electric power systems, when hybrid systems output torque, since there are at least two power sources, namely the engine and the motor, the output mode of the power system torque is complex, and its output mode varies greatly under different working conditions. The traditional traction control function can only limit the torque of a single power source, while the traction control of multiple power sources requires secondary torque distribution through the power domain controller, which leads to an increase in the torque control transmission link and an increase in the response time of the torque control.

[0029] Currently, the process of secondary torque distribution will lead to the growth of the torque control transmission link. The torque that was originally directly output by the power source now needs to be calculated and distributed by the power domain controller before it can be output. In this process, due to the increase in the torque transmission links, additional delays and errors may be introduced. Therefore, the growth of the torque control transmission link may lead to a decrease in response speed: due to the increase in torque transmission and conversion links, the power domain controller's response speed to torque may decrease, which may cause the vehicle to respond to torque control in dynamic processes such as acceleration and braking. Delayed, affecting driving safety. The growth of the torque control transmission link may also lead to a decrease in accuracy: errors may be introduced in the secondary distribution and transmission of torque, resulting in a deviation between the actual torque output of the power source and the expected value. This deviation may affect the stability of the vehicle.

[0030] In addition, when the power domain controller performs the task of secondary torque distribution, sometimes only the torque output of the engine needs to be adjusted, and sometimes the torque output of multiple power sources needs to be adjusted at the same time. However, since the response speed of the engine is slower than that of the motor, when the torque output adjustment mainly depends on the engine, the power system may face the problem of slow torque output response speed.

[0031] In order to at least solve the above technical problems, the embodiment of the present application provides a torque control method for a vehicle, which is applied to a vehicle, wherein the vehicle includes a first axle and a second axle, the power source of the first axle includes a first motor and an engine, the power source of the second axle includes a second motor, and the first axle is connected to a first wheel, and the second axle is connected to a second wheel. Among the first axle and the second axle, one is a front axle and the other is a rear axle.

[0032] In one possible implementation, the first axle is the front axle, in which case the first motor is the front motor and the first wheel is the front wheel; the second axle is the rear axle, in which case the second motor is the rear motor and the second wheel is the rear wheel.

[0033] In another possible implementation, the first axle is the rear axle, in which case the first motor is the rear motor, the first wheel is the rear wheel, and the second axle is the front axle, in which case the second motor is the front motor, and the second wheel is the front wheel.

[0034] Under the premise that the power source of the front axle or the rear axle is an engine and a motor, the vehicle model is a hybrid vehicle. Generally, a multi-power source traction control system (MPTC) is equipped in the hybrid vehicle. The torque control method in this embodiment can be specifically applied to the MPTC in the vehicle. The MPTC includes a brake control system and a power control system.

[0035] The brake control system determines whether to activate the traction control function by monitoring the wheel slip rate, the torque output of the power system, and the driver's torque request status. The wheel slip rate includes the front wheel slip rate and / or the rear wheel slip rate. If the traction function activation threshold is met, the brake control system sends the target shaft speed of the front axle and / or the rear axle to the power system controller to achieve precise control of the wheel speed. In order to respond to the needs of the traction control function more quickly, the brake control system can integrate the torque calculation part of the traction control function into the motor control unit (MCU) to achieve faster torque control.

[0036] The power control system includes: Vehicle Control Unit (VCU), motor controller MCU and Engine Control Module (ECM). When MPTC activates the traction control function, the power control system responds to the shaft speed control of the braking function system, and the MCU, ECM and VCU jointly complete the torque control.

[0037] Figure 1 It is a schematic flow chart of a vehicle torque control method provided in an embodiment of the present application.

[0038] For example, Figure 1 As shown, the method 100 includes:

[0039] Step 101: If it is detected that the slip rate of the first wheel is greater than a preset first threshold, the current driving mode of the vehicle is determined.

[0040] Step 102, if the driving mode is a hybrid mode, obtain the target torque reduction value corresponding to the first axle and the maximum torque reduction value currently supported by the first motor; wherein the target torque reduction value corresponding to the first axle is the torque value required to reduce the power source of the first axle to stop the first wheel from slipping.

[0041] Step 103: If the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, the first motor is controlled to reduce the torque so that the first wheel stops slipping.

[0042] In the embodiment of the present application, when the slip rate of the first wheel is greater than the preset first threshold and the driving mode of the vehicle is the hybrid mode, it is necessary to obtain the target torque reduction value corresponding to the first axle and the maximum torque reduction value currently supported by the first motor. The above target torque reduction value is used to stop the first wheel from slipping. At this time, the size of the target torque reduction value and the maximum torque reduction value is judged. If the target torque reduction value is less than or equal to the maximum torque reduction value, it means that the maximum torque reduction capacity of the first motor can meet the needs of the first axle. Since the response speed and accuracy of the motor are higher than those of the engine when outputting torque, the torque of the first motor is reduced, and there is no need to reduce the torque of the engine or perform secondary distribution of torque, which reduces the slip time of the first wheel and enables the first wheel to stop slipping faster. By reducing the torque of the motor, the link of torque control transmission can be shortened, the response speed of torque control can be increased, and the vehicle performance can be improved.

[0043] Below Figure 1 The implementation method of each step in the embodiment shown is specifically described:

[0044] As for step 101, it can be understood that the wheel slip rate is used to measure the relative slip degree between the tire and the road surface when the vehicle is braking or accelerating, and is intended to measure whether the vehicle is accelerating and slipping. If the slip rate of the first wheel is greater than the preset first threshold, it is determined that the first wheel is slipping at this time. The above-mentioned first wheel may include a first left wheel and a first right wheel. The slip rate of the above-mentioned first wheel may be the slip rate of the first left wheel, or the slip rate of the first right wheel, or the average slip rate between the slip rate of the first left wheel and the slip rate of the first right wheel. In other words, the above-mentioned judgment of whether the slip rate of the first wheel is greater than the preset first threshold is equivalent to judging whether the slip rate of the first left wheel is greater than the preset first threshold, or judging whether the slip rate of the first right wheel is greater than the preset first threshold, or judging whether the above-mentioned average slip rate is greater than the preset first threshold. The above-mentioned preset first threshold can be calibrated in advance based on experience, and is intended to measure whether the first left wheel and / or the first right wheel are slipping. If the slip rate of the first wheel is less than or equal to the preset first threshold, the vehicle is driving normally and continues to judge.

[0045] The vehicle's current driving mode can be a hybrid mode or a pure electric mode, wherein the hybrid mode includes a hybrid two-wheel drive mode and a hybrid four-wheel drive mode, the hybrid two-wheel drive mode can include a hybrid front-wheel drive mode and a hybrid rear-wheel drive mode, and the pure electric mode includes a pure electric two-wheel drive mode and a pure electric four-wheel drive mode, the pure electric two-wheel drive mode can include a pure electric front-wheel drive mode and a pure electric rear-wheel drive mode.

[0046] For step 102, it can be understood that, under the premise that the driving mode of the vehicle is a hybrid two-wheel drive mode and the power output shaft of the vehicle is the first axle, or under the premise that the driving mode of the vehicle is a hybrid four-wheel drive mode, the target torque reduction value corresponding to the first axle and the maximum torque reduction value currently supported by the first motor are obtained. In other words, the hybrid mode in step 102 can be a hybrid two-wheel drive mode or a hybrid four-wheel drive mode.

[0047] The target torque reduction value corresponding to the first axle is: the torque value required to reduce the power source of the first axle to stop the first wheel from slipping, that is, how much the torque of the power source of the first axle needs to be reduced in order to stop the first wheel from slipping.

[0048] In some embodiments, obtaining a target torque reduction value corresponding to the first axle includes: obtaining a current output torque of the first motor, a current output torque of the engine, and a target torque value corresponding to the first axle; wherein the target torque value corresponding to the first axle is a torque value required to be output by a power source of the first axle to stop the first wheel from slipping; calculating the sum of the torques obtained by adding the current output torque of the first motor to the current output torque of the engine; and subtracting the target torque value corresponding to the first axle from the sum of the torques to obtain the target torque reduction value corresponding to the first axle.

[0049] It is understandable that the current output torque of the first motor can be obtained in a variety of ways, including but not limited to: formula calculation method, torque meter or torque meter measurement method, dynamic torque measurement method, rotary encoder method and electromagnetic measurement method. The current output torque of the engine can be obtained in a variety of ways, including but not limited to: torque meter measurement method, engine test bench measurement method and formula calculation method. The embodiment of the present application does not limit the method for obtaining the current output torque of the first motor and the engine.

[0050] The target torque value corresponding to the first axle is: the torque value expected to be achieved by the first axle to stop the first wheel from slipping. The target torque value corresponding to the first axle can be calculated based on the actual rotational speed of the first axle and the target rotational speed of the first axle.

[0051] When calculating the target speed of the first axle, the target slip rate of the first wheel may be obtained first, and the target slip rate of the first wheel may be less than or equal to a preset first threshold. When the actual slip rate of the first wheel is the target slip rate, the first wheel is in a non-slip state. According to the target slip rate and the current vehicle speed, the target speed of the first wheel is calculated, and finally the target speed of the first axle is obtained according to the target speed of the first wheel and the radius of the first wheel.

[0052] The maximum torque reduction value currently supported by the above-mentioned first motor represents the current maximum torque reduction capability of the first motor, which can be understood as: the difference between the current output torque of the first motor and the minimum torque that the first motor can support to output. The minimum torque that the first motor can support to output can be obtained by referring to the motor manual, or can be obtained through experimental test measurements.

[0053] In the parallel drive mode of the power system of some models, the engine and the motor are connected by a clutch. Before obtaining the minimum torque that the first motor can support output, the maximum load torque that the engine can bear, the maximum negative torque that the first motor can output, and the maximum load torque between the engine and the first motor can be obtained. Among them, the above-mentioned maximum load torque is the maximum torque value that the engine can output, the above-mentioned maximum negative torque is the maximum torque value that the first motor can output when reversing, the above-mentioned maximum load torque is the maximum torque value that can be transmitted between the first motor and the engine, and the above-mentioned maximum load torque between the engine and the first motor can be determined according to the physical capacity limit of the hard link between the engine and the first motor. After that, the absolute value of the maximum negative torque is taken, and after taking the absolute value, the maximum load torque, the maximum load torque and the maximum negative torque after taking the absolute value are compared to obtain the minimum value, and the minimum value is used as the maximum load that the first motor can apply to the engine. When the first motor applies the maximum load to the engine, the actual output torque of the first motor is a negative value, so the negative minimum value can be used as the minimum torque that the first motor can support output. When the first motor outputs a torque value lower than the minimum torque, it is equivalent to the engine being subjected to a load greater than the maximum load. At this time, the engine will stall or even fail. Therefore, the minimum torque that the first motor can support output determined by the above method can avoid failure of the first motor, engine and clutch caused by the first motor outputting a torque value lower than the minimum torque.

[0054] In some other embodiments, the target torque reduction value corresponding to the first axle can be determined based on the lateral acceleration of the vehicle and the yaw angular velocity of the vehicle, specifically including: when it is detected that the lateral acceleration exceeds the lateral acceleration threshold value or the yaw angular velocity exceeds the yaw angular velocity threshold value, querying a preset corresponding relationship based on the lateral acceleration and the yaw angular velocity to obtain the torque reduction rate; wherein the corresponding relationship is used to describe the relationship between different combinations of lateral acceleration and yaw angular velocity and the torque reduction rate; according to the torque reduction rate, determining the target torque reduction value corresponding to the first axle.

[0055] It can be understood that the above correspondence is a preset correspondence, which is used to describe the relationship between different combinations of lateral acceleration and yaw rate and the torque reduction rate. According to different combinations of lateral acceleration and yaw rate, different torque reduction rates can be obtained by querying the above correspondence. The above torque reduction rate generally refers to the ratio of the torque from a certain initial value to a certain final value.

[0056] In some embodiments, the target torque reduction value corresponding to the first axle is determined based on the current output torque of the first motor, the current output torque of the engine and the torque reduction rate, including: calculating the current output torque of the first motor plus the current output torque of the engine to obtain the sum of the torques; calculating the product of the sum of the torques and the torque reduction rate to obtain the target torque reduction value corresponding to the first axle.

[0057] In the above correspondence, when the lateral acceleration remains unchanged, the yaw angular velocity is positively correlated with the torque reduction rate; when the yaw angular velocity remains unchanged, the lateral acceleration is positively correlated with the torque reduction rate.

[0058] It can be understood that the above correspondence can be used to describe the relationship between different combinations of lateral acceleration and yaw rate and the torque reduction rate. In the above correspondence, when the lateral acceleration remains unchanged, the torque reduction rate gradually increases with the increase of yaw rate; when the yaw rate remains unchanged, the torque reduction rate also gradually increases with the increase of lateral acceleration.

[0059] If the vehicle's current lateral acceleration or yaw rate gradually increases, it means that the vehicle's yaw degree is relatively severe at this time. Therefore, it is necessary to reduce the output torque of the vehicle, that is, gradually increase the torque reduction rate, thereby reducing the driving force on the wheels, and then reduce the vehicle's lateral acceleration and yaw rate, so that the vehicle gradually stabilizes.

[0060] For step 103, it can be understood that the relationship between the target torque reduction value corresponding to the first axle and the maximum torque reduction value of the first motor is determined. When the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, it means that the maximum torque reduction capacity of the first motor is sufficient to meet the torque reduction demand of the first axle. At this time, it is only necessary to reduce the torque of the first motor to stop the first wheel from slipping.

[0061] In some embodiments, if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, the first motor is controlled to reduce torque so that the first wheel stops slipping, including: if the target torque reduction value corresponding to the first axle is equal to the maximum torque reduction value, the first motor is controlled to reduce torque according to the maximum torque reduction value so that the first wheel stops slipping.

[0062] It is understandable that if the target torque reduction value corresponding to the first axle is equal to the maximum torque reduction value, it means that the maximum torque reduction capacity of the first motor just meets the torque reduction requirement of the first axle. At this time, it is only necessary to control the first motor to reduce torque according to the maximum torque reduction value without controlling the engine to reduce torque, so that the first wheel can stop slipping. Controlling the first motor to reduce torque according to the maximum torque reduction value can be understood as: controlling the torque reduction amount of the first motor to be equal to the maximum torque reduction value.

[0063] In some embodiments, controlling the first motor to reduce torque according to the maximum torque reduction value includes: obtaining the current output torque of the first motor; calculating the second difference torque obtained by subtracting the maximum torque reduction value from the current output torque of the first motor; and controlling the first motor to output the second difference torque.

[0064] It can be understood that the above-mentioned second differential torque refers to the difference between the current output torque of the first motor and the maximum torque reduction value, which is used to indicate the torque that the first motor should output after the torque reduction. Under the premise that the target torque reduction value corresponding to the first axle is equal to the maximum torque reduction value, the first motor is controlled to output the second differential torque.

[0065] In some cases, the overall demand of the first axle cannot be met by simply reducing the torque of the first motor. In this case, the torque of the engine must be reduced to stop the first wheel from slipping.

[0066] In some embodiments, if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, the first motor is controlled to reduce torque so that the first wheel stops slipping, including: if the target torque reduction value corresponding to the first axle is less than the maximum torque reduction value, the first motor is controlled to reduce torque according to the target torque reduction value corresponding to the first axle so that the first wheel stops slipping.

[0067] It is understandable that if the target torque reduction value corresponding to the first axle is less than the maximum torque reduction value, it means that the maximum torque reduction capacity of the first motor is higher than the torque reduction requirement of the first axle. At this time, it is only necessary to control the first motor to reduce the torque according to the target torque reduction value without controlling the engine to reduce the torque, so that the first wheel can stop slipping. Controlling the first motor to reduce the torque according to the target torque reduction value can be understood as: controlling the torque reduction amount of the first motor to be equal to the target torque reduction value.

[0068] In some embodiments, controlling the first motor to reduce torque according to a target torque reduction value corresponding to the first axle includes: obtaining the current output torque of the first motor; calculating the fourth difference torque obtained by subtracting the target torque reduction value corresponding to the first axle from the current output torque of the first motor; and controlling the first motor to output the fourth difference torque.

[0069] It can be understood that the above-mentioned fourth differential torque refers to the difference between the current output torque of the first motor and the target torque reduction value corresponding to the first axle, which is used to indicate the torque that the first motor should output after the torque reduction. Under the premise that the target torque reduction value corresponding to the first axle is less than the maximum torque reduction value, the first motor is controlled to output the fourth differential torque.

[0070] In some embodiments, if the target torque reduction value corresponding to the first axle is greater than the maximum torque reduction value, the first difference torque is obtained by subtracting the maximum torque reduction value from the target torque reduction value corresponding to the first axle; the first motor is controlled to reduce torque according to the maximum torque reduction value, and the engine is controlled to reduce torque according to the first difference torque, so that the first wheel stops slipping.

[0071] It can be understood that the above-mentioned first difference torque refers to the difference between the target torque reduction value corresponding to the first axle and the maximum torque reduction value, which is used to represent the torque reduction value required by the engine.

[0072] If the target torque reduction value corresponding to the first axle is greater than the maximum torque reduction value, it means that the maximum torque reduction capacity of the first motor is not sufficient to meet the torque reduction demand of the first axle. At this time, on the basis of reducing the torque of the first motor, the torque difference that cannot be met by the first motor is calculated, and the engine is controlled to reduce the torque according to the torque difference, that is, the first motor is controlled to reduce the torque according to the maximum torque reduction value, and the first difference torque between the target torque reduction value and the maximum torque reduction value corresponding to the first axle needs to be calculated, and the engine is controlled to reduce the torque according to the first difference torque. Only then can the first wheel stop slipping.

[0073] In some embodiments, controlling the engine to reduce torque according to the first differential torque includes: obtaining the current output torque of the engine; calculating the third differential torque obtained by subtracting the first differential torque from the current output torque of the engine; and controlling the engine to output the third differential torque.

[0074] It can be understood that the above-mentioned third differential torque refers to the difference between the current output torque of the engine and the first differential torque, which is used to indicate the torque that the engine should output after torque reduction. On the premise that the target torque reduction value corresponding to the first axle is greater than the maximum torque reduction value, in addition to controlling the first motor to reduce the torque according to the maximum torque reduction value, the engine is controlled to output the third differential torque.

[0075] For example, assuming that the current output torque of the first motor is 600N·m and the current output torque of the engine is 1000N·m, the current output torque corresponding to the first axle is the sum of the current output torque of the first motor and the current output torque of the engine, that is, 600N·m plus 1000N·m. The current output torque corresponding to the first axle is equal to 1600N·m. Due to the physical capacity limitation of the first motor itself, assuming that the first motor can support the minimum output torque of -100N·m, therefore, the maximum torque reduction value currently supported by the first motor is the difference between the current output torque of the first motor and the minimum torque that the first motor can support output, that is, 600N·m minus -100N·m. The maximum torque reduction value currently supported by the first motor is equal to 700N·m. If you want to stop the first wheel from slipping, the following situations will occur:

[0076] Case 1: The target torque reduction value corresponding to the first axle is less than the maximum torque reduction value

[0077] Assume that if the first wheel needs to stop slipping, the current output torque corresponding to the first axle needs to be reduced to 1100N·m, then the target torque reduction value corresponding to the first axle is 1600N·m minus 1100N·m, which is equal to 500N·m. Since the maximum torque reduction value currently supported by the first motor is equal to 700N·m, the target torque reduction value corresponding to the first axle (500N·m) is less than the maximum torque reduction value currently supported by the first motor (700N·m), that is, the torque reduction capacity of the first motor is higher than the demand of the first axle, so by reducing the torque of the first motor, the first wheel can stop slipping, then, after the torque reduction, the output torque of the first motor is 600N·m minus 500N·m, which is equal to 100N·m, and since the engine still outputs at a torque of 1000N·m, the output torque corresponding to the first axle after the torque reduction is equal to 1100N·m, and the first wheel can stop slipping at this time.

[0078] Case 2: The target torque reduction value corresponding to the first axle is equal to the maximum torque reduction value

[0079] Assume that if the first wheel needs to stop slipping, the current output torque corresponding to the first axle needs to be reduced to 900N·m, then the target torque reduction value corresponding to the first axle is 1600N·m minus 900N·m, which is equal to 700N·m. Since the maximum torque reduction value currently supported by the first motor is equal to 700N·m, the target torque reduction value corresponding to the first axle (700N·m) is exactly equal to the maximum torque reduction value currently supported by the first motor (700N·m), that is, the torque reduction capacity of the first motor just meets the needs of the first axle, so by reducing the torque of the first motor, the first wheel can stop slipping, then, after the torque reduction, the output torque of the first motor is 600N·m minus 700N·m, which is equal to -100N·m, and since the engine still outputs at a torque of 1000N·m, the output torque corresponding to the first axle after the torque reduction is equal to 900N·m, and the first wheel can stop slipping at this time.

[0080] Case 3: The target torque reduction value corresponding to the first axle is greater than the maximum torque reduction value

[0081] Assume that, in order to stop the first wheel from slipping, the current output torque corresponding to the first axle needs to be reduced to 700 N·m, then the target torque reduction value corresponding to the first axle is 1600 N·m minus 700 N·m, which is equal to 900 N·m. Since the maximum torque reduction value currently supported by the first motor is equal to 700N·m, the target torque reduction value corresponding to the first axle (900N·m) is greater than the maximum torque reduction value currently supported by the first motor (700N·m). In other words, the torque reduction capacity of the first motor is insufficient to meet the needs of the first axle. Therefore, while reducing the torque of the first motor, the engine must also be reduced to stop the first wheel from slipping. However, the first motor must be controlled to reduce the torque first, and the part that cannot be met by the first motor will be executed by the engine. Therefore, after the torque reduction, the output torque of the first motor is 600N·m minus 700N·m, which is equal to -100N·m. The part that cannot be met by the first motor is 900N·m minus 700N·m, which is equal to 200N·m. The output torque of the engine after the torque reduction is 1000N·m minus 200N·m, which is equal to 800N·m. At this time, the output torque corresponding to the first axle after the torque reduction is equal to 700N·m, and the first wheel can stop slipping.

[0082] Under the premise that the driving mode of the vehicle is a hybrid two-wheel drive mode and the power output shaft of the vehicle is the second axle, or under the premise that the driving mode of the vehicle is a hybrid four-wheel drive mode, the specific torque control method for the second axle is as follows.

[0083] In some embodiments, the second axle is connected to the second wheel. If the drive mode is a hybrid four-wheel drive mode, the method also includes: if the slip rate of the second wheel is greater than a preset second threshold, obtaining a target torque reduction value of the second motor; wherein the target torque reduction value of the second motor is a torque value required to reduce the second motor to stop the second wheel from slipping; controlling the second motor to reduce torque according to the target torque reduction value of the second motor to stop the second wheel from slipping.

[0084] It can be understood that the second wheel can include a second left wheel and a second right wheel, and the slip rate of the second wheel can be the slip rate of the second left wheel, or the slip rate of the second right wheel, or the average slip rate between the slip rate of the second left wheel and the slip rate of the second right wheel. That is to say, the above judgment of whether the slip rate of the second wheel is greater than the preset second threshold is equivalent to judging whether the slip rate of the second left wheel is greater than the preset second threshold, or judging whether the slip rate of the second right wheel is greater than the preset second threshold, or judging whether the average slip rate is greater than the preset second threshold. The above preset second threshold can be calibrated in advance based on experience, aiming to measure whether the second left wheel and / or the second right wheel is slipping. If the slip rate of the second wheel is less than or equal to the preset second threshold, the vehicle drives normally and continues to judge. The above preset first threshold and the preset second threshold can be equal or different, and this embodiment does not limit this.

[0085] The target torque reduction value of the second motor is: the torque value required to be reduced by the second motor to stop the second wheel from slipping, that is, how much the torque of the second motor needs to be reduced in order to stop the second wheel from slipping.

[0086] The current output torque of the second motor can be obtained in a variety of ways, including but not limited to: formula calculation method, torque meter or torque meter measurement method, dynamic torque measurement method, rotary encoder method and electromagnetic measurement method. The present embodiment of the application does not limit the method for obtaining the current output torque of the second motor.

[0087] The above-mentioned controlling the second motor to reduce torque according to the target torque reduction value of the second motor includes: obtaining the current output torque of the second motor; calculating the fifth difference torque obtained by subtracting the target torque reduction value of the second motor from the current output torque of the second motor; and controlling the second motor to output the fifth difference torque.

[0088] The fifth difference torque can also be understood as the target torque of the second motor, which can be calculated based on the actual speed of the second motor and the target speed of the second motor. When calculating the target speed of the second motor, the target speed of the second wheel can be calculated based on the target slip rate of the second wheel and the current vehicle speed, and then the target speed of the second motor can be calculated based on the target speed of the second wheel and the radius of the second wheel. The target slip rate of the second wheel is less than or equal to the preset second threshold. When the actual slip rate of the second wheel is the target slip rate, the second wheel is in a non-slip state.

[0089] It can be understood that the above-mentioned fifth differential torque refers to the difference between the current output torque of the second motor and the target torque reduction value of the second motor, which is used to indicate the torque that the second motor should output after the torque reduction, and controls the second motor to output the fifth differential torque after the torque reduction.

[0090] Under the premise that the vehicle's driving mode is a pure electric two-wheel drive mode and the vehicle's power output shaft is the first axle, or under the premise that the vehicle's driving mode is a pure electric four-wheel drive mode, the specific torque control method for the first axle is as follows.

[0091] In some other embodiments, the target torque reduction value corresponding to the second axle can be determined based on the lateral acceleration of the vehicle and the yaw angular velocity of the vehicle, specifically including: when it is detected that the lateral acceleration exceeds the lateral acceleration threshold value or the yaw angular velocity exceeds the yaw angular velocity threshold value, querying a preset corresponding relationship based on the lateral acceleration and the yaw angular velocity to obtain the torque reduction rate; wherein the corresponding relationship is used to describe the relationship between different combinations of lateral acceleration and yaw angular velocity and the torque reduction rate; according to the torque reduction rate, determining the target torque reduction value corresponding to the second axle.

[0092] In some embodiments, the target torque reduction value corresponding to the second axle is determined based on the current output torque of the second motor and the torque reduction rate, including: calculating the product of the current output torque of the second motor and the torque reduction rate to obtain the target torque reduction value corresponding to the second axle.

[0093] It can be understood that by multiplying the current output torque of the second motor by the torque reduction rate, the torque value required to reduce the power source of the second axle in order to stop the vehicle from swaying can be obtained, that is, the target torque reduction value corresponding to the second axle.

[0094] In some embodiments, if the driving mode is a pure electric mode, the target torque reduction value of the first motor is obtained; wherein the target torque reduction value of the first motor is the torque value required to reduce the first motor in order to stop the first wheel from slipping; the first motor is controlled to reduce the torque according to the target torque reduction value of the first motor so as to stop the first wheel from slipping.

[0095] It can be understood that the target torque reduction value of the first motor is: the torque value required to be reduced by the first motor to stop the first wheel from slipping, that is, how much the torque of the first motor needs to be reduced in order to stop the first wheel from slipping.

[0096] The above-mentioned controlling the first motor to reduce torque according to the target torque reduction value of the first motor includes: obtaining the current output torque of the first motor; calculating the sixth difference torque obtained by subtracting the target torque reduction value of the first motor from the current output torque of the first motor; and controlling the first motor to output the sixth difference torque.

[0097] It can be understood that the above-mentioned sixth differential torque refers to the difference between the current output torque of the first motor and the target torque reduction value of the first motor, which is used to indicate the torque that the first motor should output after the torque reduction, and controls the first motor to output the sixth differential torque after the torque reduction.

[0098] The sixth differential torque can also be understood as the target torque of the first motor, which can be calculated based on the actual speed of the first motor and the target speed of the first motor. When calculating the target speed of the first motor, the target speed of the first wheel can be calculated based on the target slip rate of the first wheel and the current vehicle speed, and then the target speed of the first motor can be calculated based on the target speed of the first wheel and the radius of the first wheel. The target slip rate of the first wheel is less than or equal to the preset first threshold. When the actual slip rate of the first wheel is the target slip rate, the first wheel is in a non-slip state.

[0099] Under the premise that the vehicle's driving mode is a pure electric two-wheel drive mode and the vehicle's power output shaft is the second axle, or under the premise that the vehicle's driving mode is a pure electric four-wheel drive mode, the specific torque control method for the second axle is the same as the torque control method when the above-mentioned vehicle is in a hybrid two-wheel drive mode and the vehicle's power output shaft is the second axle, and will not be repeated here.

[0100] If the driving mode of the vehicle is the pure electric four-wheel drive mode, the torque control is performed on the first axle and the second axle according to the torque control method in the pure electric mode.

[0101] The above introduces the torque control method of the vehicle in different driving modes. The following will take the engine front decoupling four-wheel drive hybrid model as an example to introduce the above scheme in detail.

[0102] Figure 2 It is a schematic flow chart of another vehicle torque control method provided in an embodiment of the present application.

[0103] For four-wheel drive hybrid models, the vehicle has different driving modes, which can be specifically divided into four-wheel drive mode, front-wheel drive mode and rear-wheel drive mode; among them, the four-wheel drive mode can drive the front axle and the rear axle at the same time, the front-wheel drive mode can include front axle drive or front axle drive and rear axle power generation, the rear-wheel drive mode can include rear axle drive or front axle power generation, and the power generation mode refers to converting the power source of the front axle or the rear axle into the power generation mode, thereby recovering the vehicle's kinetic energy for subsequent use.

[0104] Different power sources have different working modes. In the engine front decoupled four-wheel drive hybrid model, for the rear axle, the power source is only the motor, which is relatively simple, so the working mode of the motor is also relatively simple, which can be divided into motor drive mode and motor power generation mode. For the front axle, the power source includes both the engine and the motor, so the working mode of the power source is also relatively complex, which can be divided into engine drive mode and motor drive mode, engine drive mode and motor power generation mode, engine stop mode and motor drive mode, and engine stop mode and motor stop mode.

[0105] MPTC's torque control method is different in different working modes. Since the power source of the rear axle is the motor, the torque control method for the rear axle is the same regardless of whether it is in hybrid mode or pure electric mode, as long as the vehicle's current drive mode is rear-wheel drive mode or four-wheel drive mode. And since there are multiple power sources on the front axle, the torque control of the front axle is related to the vehicle's current drive mode. If the vehicle's current drive mode is hybrid mode, the front axle is subject to torque control in hybrid mode; if the vehicle's current drive mode is pure electric mode, the front axle is subject to torque control in pure electric mode.

[0106] Exemplarily, the first axle is a front axle, the second axle is a rear axle, the first wheel is a front wheel, the second wheel is a rear wheel, the first motor is a front motor, and the second motor is a rear motor. Figure 2 As shown, the method 200 includes:

[0107] Step 201, determining that the vehicle is accelerating and skidding.

[0108] It is understandable that, whether the vehicle is skidding is determined based on the wheel slip rate, and if the front wheel slip rate exceeds the front wheel threshold value and / or the rear wheel slip rate exceeds the rear wheel threshold value, it can be determined that the vehicle is skidding. The front wheel slip rate is equivalent to the slip rate of the first wheel, the front wheel threshold value is equivalent to the preset first threshold, the rear wheel slip rate is equivalent to the slip rate of the second wheel, and the rear wheel threshold value is equivalent to the preset second threshold.

[0109] In two-wheel drive mode, the wheel slip rate can be the slip rate of a single wheel on the front axle or rear axle, or the average slip rate of two wheels on the front axle or rear axle; in four-wheel drive mode, the wheel slip rate can be the slip rate of one of the four wheels, or the slip rate of two of the wheels, or the average slip rate of all four wheels.

[0110] Step 202, determining the current driving mode of the vehicle.

[0111] It can be understood that when the braking control system monitors that the front wheel slip rate exceeds the front wheel threshold value and / or the rear wheel slip rate exceeds the rear wheel threshold value, the braking control system interacts with the power control system to determine the vehicle's current driving mode information and confirm the vehicle's current driving mode.

[0112] Step 203: The vehicle is currently in two-wheel drive mode.

[0113] Step 204 , performing torque control on the rear axle in pure electric mode.

[0114] Step 205: The vehicle is currently in four-wheel drive mode.

[0115] Step 206 , determine whether it is the front-wheel drive mode. If yes, execute step 211 , otherwise execute step 207 .

[0116] Step 207: The vehicle is currently in pure electric rear-wheel drive mode.

[0117] It is understandable that since the power source of the rear axle is the motor, this driving mode in which the engine does not participate in the driving and only relies on the motor to participate in the driving is called the pure electric mode. And since the power output shaft of the current vehicle is not the front axle, the driving mode of the vehicle at this time is the pure electric rear-wheel drive mode.

[0118] Step 208 , performing torque control on the front axle in the hybrid mode.

[0119] Step 209: The vehicle is currently in hybrid four-wheel drive mode.

[0120] Step 210, determine whether the engine is driven. If yes, execute step 209, otherwise execute step 215.

[0121] It is understandable that the power source of the front axle includes at least the engine and the motor, so it is necessary to determine whether the engine is in the driving mode to determine the driving mode of the vehicle. If the engine is in the driving mode, the driving mode of the vehicle is the hybrid four-wheel drive mode; if the engine is in the stop mode, the driving mode of the vehicle is the pure electric four-wheel drive mode.

[0122] Step 211, determine whether the engine is driven. If yes, execute step 216, otherwise execute step 212.

[0123] Step 212: The vehicle is currently in pure electric front-wheel drive mode.

[0124] Step 213, determine whether the rear wheel slip rate exceeds the rear wheel threshold value. If yes, execute step 218, otherwise execute step 208.

[0125] Step 214, determine whether the front wheel slip rate exceeds the front wheel threshold value. If yes, execute step 213, otherwise execute step 219.

[0126] It is understandable that, since both the front and rear axles are power output shafts in the four-wheel drive mode, the rear axle slip rate must be determined after determining the front wheel slip rate. If only the front wheel slip rate exceeds the front wheel threshold value, torque control is performed on the front wheels; if only the rear wheel slip rate exceeds the rear wheel threshold value, torque control is performed on the rear wheels; if the front wheel slip rate exceeds the front wheel threshold value and the rear wheel slip rate exceeds the rear wheel threshold value, torque control is performed on both the front and rear wheels.

[0127] Step 215, the vehicle is currently in pure electric four-wheel drive mode.

[0128] Step 216: The vehicle is currently in hybrid front-wheel drive mode.

[0129] Step 217, performing torque control on the front axle in pure electric mode.

[0130] Step 218 , performing torque control on the front axle and the rear axle in hybrid mode.

[0131] Step 219, performing torque control on the rear axle in pure electric mode.

[0132] Step 220, determine whether the front wheel slip rate exceeds the front wheel threshold value. If yes, execute step 223, otherwise execute step 219.

[0133] Step 221, performing torque control on the front axle in hybrid mode.

[0134] Step 222, performing torque control on the front axle and the rear axle simultaneously in pure electric mode.

[0135] Step 223, determine whether the rear wheel slip rate exceeds the rear wheel threshold value. If yes, execute step 222, otherwise execute step 217.

[0136] Figure 3 It is a schematic flow chart of a torque control method for a pure electric rear-wheel drive mode provided in an embodiment of the present application.

[0137] For example, Figure 3 As shown, the method 300 is used to specifically explain the implementation process of the above step 209, and the method 300 includes:

[0138] Step 301 : The brake control system calculates a target speed of the rear motor according to a target slip ratio of the rear wheel, and sends the target speed of the rear motor to a rear motor controller.

[0139] It can be understood that, since the vehicle's driving mode is in pure electric rear-wheel drive mode at this time, the speed that the rear motor needs to reach, that is, the target speed of the rear motor, can be calculated according to the target slip rate of the rear wheel, so as to stop the rear wheel from slipping, and the target speed of the rear motor is sent to the rear motor controller (Rear Motor Controller Unit, RMCU).

[0140] Step 302 : The rear motor controller forwards the current speed of the rear motor and the target speed of the rear motor to a brake system logic block integrated in the rear motor controller.

[0141] It can be understood that the RMCU forwards the current speed of the rear motor and the target speed of the rear motor to the braking system logic block integrated in the RMCU through the CAN signal.

[0142] Step 303 : The brake system logic block calculates the target torque of the rear motor based on the current speed of the rear motor and the target speed of the rear motor.

[0143] It can be understood that the above-mentioned target torque of the rear motor represents the torque that the rear motor needs to output after the rear motor is torque-reduced according to the target torque-reduction value of the above-mentioned second motor.

[0144] The braking control system logic block can calculate the target torque of the rear motor based on the current speed of the rear motor and the target speed of the rear motor. In addition, other auxiliary signals can be combined in the process of calculating the target torque of the rear motor, such as throttle torque, etc. The embodiment of the present application is not limited to this.

[0145] Step 304 : The rear motor controller performs operations according to the rear motor target torque. That is, the rear motor controller controls the rear motor to output according to the rear motor target torque.

[0146] Step 305: The brake control system detects the rear wheel slip rate. When the rear wheel slip rate is lower than the rear wheel threshold value, the rear wheel stops slipping.

[0147] It can be understood that when RMCU outputs according to the target torque of the rear motor, the braking control system detects the rear wheel slip rate again. If the rear wheel slip rate is lower than the rear wheel threshold value and lasts for a period of time, it means that the rear wheels of the vehicle have stopped slipping. The rear motor is then controlled to output according to the torque required by the current rear wheels of the vehicle.

[0148] Figure 4 It is a schematic flow chart of a torque control method for a hybrid front-wheel drive mode provided in an embodiment of the present application.

[0149] For example, Figure 4 As shown, the method 400 is used to specifically explain the implementation process of the above step 210, and the method 400 includes:

[0150] Step 401 : The brake control system calculates a front axle target speed according to a target slip ratio of the front wheels, and sends the front axle target speed to a front motor controller.

[0151] It can be understood that, since the vehicle's driving mode is in the hybrid front-wheel drive mode at this time, the speed that the front axle needs to reach, that is, the front axle target speed, can be calculated based on the target slip rate of the front wheels, so as to stop the front wheels from slipping, and the front axle target speed is sent to the front motor controller (Front Motor Controller Unit, FMCU).

[0152] Step 402 : The front motor controller forwards the current speed of the front axle and the target speed of the front axle to a brake system logic block integrated in the front motor controller.

[0153] It can be understood that the FMCU forwards the current front axle speed and the front axle target speed to the brake system logic block integrated inside the FMCU via the CAN signal.

[0154] Step 403 , the brake system logic block calculates the front axle target overall torque reduction value based on the front axle current speed and the front axle target speed, and sends the front axle target overall torque reduction value to the front motor controller.

[0155] It can be understood that the above-mentioned target overall torque reduction value of the front axle is equivalent to the target torque reduction value corresponding to the above-mentioned first axle.

[0156] Step 404 : The front motor controller determines the maximum torque reduction value that can be supported according to the physical capacity limitation of the front motor itself.

[0157] It can be understood that the above-mentioned maximum torque reduction value refers to the difference between the current output torque of the front motor and the minimum torque that the front motor can support output. The minimum torque that the front motor can support output needs to be determined based on the physical capacity limitations of the front motor itself.

[0158] Step 405 , the front motor controller determines the maximum torque reduction value and the front axle target overall torque reduction value, and executes the smaller one.

[0159] In step 406 , the front motor controller sends the maximum torque reduction value and the front axle target overall torque reduction value to the vehicle controller.

[0160] It can be understood that the FMCU sends the maximum torque reduction value and the front axle target overall torque reduction value to the VCU via the CAN signal.

[0161] Step 407: The vehicle controller receives the front axle target overall torque reduction value and the maximum torque reduction value, and calculates the difference between the two to obtain a first differential torque.

[0162] Step 408 , determining whether the first difference torque is greater than 0. If yes, executing step 409 , otherwise executing step 412 .

[0163] Step 409: The vehicle controller sends the first difference torque to the engine control module.

[0164] In step 410 , the engine control module controls the engine to reduce torque according to the first difference torque.

[0165] Step 411: The braking system detects the front wheel slip rate. When the front wheel slip rate is less than the front wheel threshold value, the front wheel stops slipping.

[0166] It can be understood that after the engine and the front motor complete the torque reduction, the braking control system detects the front wheel slip rate again. If the front wheel slip rate is lower than the front wheel threshold value and lasts for a period of time, it means that the front wheels of the vehicle have stopped slipping. The engine and motor will be controlled to output the torque required by the current front wheels of the vehicle.

[0167] Step 412: When the first difference torque is less than or equal to 0, the vehicle controller does not need to perform additional torque coordination, and the front motor controller controls the front motor to reduce torque.

[0168] It can be understood that when the first difference torque is equal to 0, it means that the target overall torque reduction value of the front axle is equal to the maximum torque reduction value. At this time, the front motor controller controls the front motor to reduce the torque according to the maximum torque reduction value; when the first difference torque is less than 0, it means that the target overall torque reduction value of the front axle is less than the maximum torque reduction value. At this time, the front motor controller controls the front motor to reduce the torque according to the target overall torque reduction value of the front axle.

[0169] Figure 5 It is a schematic flow chart of a torque control method for a pure electric front-wheel drive mode provided in an embodiment of the present application.

[0170] For example, Figure 5 As shown, the method 500 is used to specifically explain the implementation process of the above step 214, and the method 500 includes:

[0171] Step 501 : The braking control system calculates a target speed of the front motor according to a target slip ratio of the front wheels, and sends the target speed of the front motor to a front motor controller.

[0172] It can be understood that the above-mentioned front motor is equivalent to the above-mentioned first motor. Since the driving mode of the vehicle is in the pure electric front-wheel drive mode at this time, the speed that the front motor needs to reach can be calculated according to the target slip rate of the front wheel, that is, the target speed of the front motor, so as to achieve the purpose of stopping the front wheel from slipping, and the target speed of the front motor is sent to the FMCU.

[0173] Step 502 : The front motor controller forwards the current speed of the front motor and the target speed of the front motor to a brake system logic block integrated in the front motor controller.

[0174] It can be understood that the FMCU forwards the current speed of the front motor and the target speed of the front motor to the brake system logic block integrated in the FMCU through the CAN signal.

[0175] Step 503 : The brake system logic block calculates the target torque of the front motor based on the current speed of the front motor and the target speed of the front motor.

[0176] It can be understood that the above-mentioned front motor target torque represents the torque that the front motor needs to output after the front motor is torque-reduced according to the target torque-reduction value of the above-mentioned first motor.

[0177] The braking control system logic block can calculate the target torque of the front motor based on the current speed of the front motor and the target speed of the front motor. In addition, other auxiliary signals can be combined in the process of calculating the target torque of the front motor, such as throttle torque, etc. The embodiment of the present application is not limited to this.

[0178] Step 504 , the front motor controller is executed according to the front motor target torque, that is, the front motor is controlled to output according to the front motor target torque.

[0179] Step 505: The braking control system detects the front wheel slip rate. When the front wheel slip rate is lower than the front wheel threshold value, the front wheel stops slipping.

[0180] It can be understood that when the FMCU outputs according to the target torque of the front motor, the braking control system detects the rear front wheel slip rate again. If the front wheel slip rate is lower than the front wheel threshold value and lasts for a period of time, it means that the front wheels of the vehicle have stopped slipping. The front motor is controlled to output according to the torque required by the current vehicle.

[0181] If the driving mode of the vehicle is the hybrid four-wheel drive mode at this time, method 400 is executed on the front axle, and method 300 is executed on the rear axle.

[0182] If the driving mode of the vehicle is the hybrid front-wheel drive mode at this time, method 400 is executed on the front axle.

[0183] If the driving mode of the vehicle is the pure electric four-wheel drive mode at this time, method 500 is executed on the front axle, and method 300 is executed on the rear axle.

[0184] If the driving mode of the vehicle is the pure electric front-wheel drive mode at this time, method 500 is executed on the front axle.

[0185] If the driving mode of the vehicle is the pure electric rear-wheel drive mode at this time, method 300 is executed on the rear axle.

[0186] Figure 6 It is a structural schematic diagram of a torque control device for a vehicle provided in an embodiment of the present application.

[0187] For example, Figure 6 As shown, the device 600 includes:

[0188] The determination module 601 is configured to determine the current driving mode of the vehicle if it is detected that the slip rate of the first wheel is greater than a preset first threshold.

[0189] The acquisition module 602 is used to obtain the target torque reduction value corresponding to the first axle and the maximum torque reduction value currently supported by the first motor if the driving mode is the hybrid mode; wherein the target torque reduction value corresponding to the first axle is the torque value required to reduce the power source of the first axle to stop the first wheel from slipping.

[0190] The control module 603 is configured to control the first motor to reduce torque if the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, so as to stop the first wheel from slipping.

[0191] Figure 7 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0192] For example, Figure 7 As shown, the vehicle 700 includes: a memory 701 and a processor 702, wherein the memory 701 stores an executable program code 7011, and the processor 702 is used to call and execute the executable program code 7011 to perform a vehicle torque control method.

[0193] 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 a vehicle torque control method provided in an embodiment of the present application.

[0194] 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.

[0195] In the case of dividing each functional module according to each function, the device may also include a determination module, an acquisition module, a control module, etc. 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.

[0196] It should be understood that the device provided in this embodiment is used to execute the above-mentioned torque control method for a vehicle, and thus can achieve the same effect as the above-mentioned implementation method.

[0197] 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 related program codes, etc.

[0198] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in combination with the contents disclosed in this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0199] 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 and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a vehicle torque control method provided in the above embodiments.

[0200] 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 torque control method provided in the above embodiment.

[0201] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement a vehicle torque control method provided in the above embodiment.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] 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 method for controlling torque of a vehicle, characterized in that: The vehicle comprises a first axle and a second axle, the power source of the first axle comprises a first motor and an engine, the power source of the second axle comprises a second motor, the first axle is connected to a first wheel, and the method comprises: If it is detected that the slip rate of the first wheel is greater than a preset first threshold, determining the current driving mode of the vehicle; If the driving mode is a hybrid mode, a target torque reduction value corresponding to the first axle and a maximum torque reduction value currently supported by the first motor are obtained; wherein the target torque reduction value corresponding to the first axle is a torque value required to reduce the power source of the first axle in order to stop the first wheel from slipping; If the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, controlling the first motor to reduce torque so that the first wheel stops slipping; If the target torque reduction value corresponding to the first axle is greater than the maximum torque reduction value, a first difference torque is obtained by subtracting the maximum torque reduction value from the target torque reduction value corresponding to the first axle; The first motor is controlled to reduce torque according to the maximum torque reduction value, and the engine is controlled to reduce torque according to the first differential torque, so that the first wheel stops slipping.

2. The method according to claim 1, characterized in that If the target torque reduction value corresponding to the first axle is less than or equal to the maximum torque reduction value, controlling the first motor to reduce torque so that the first wheel stops slipping, including: If the target torque reduction value corresponding to the first axle is equal to the maximum torque reduction value, controlling the first motor to reduce torque according to the maximum torque reduction value so that the first wheel stops slipping; If the target torque reduction value corresponding to the first axle is less than the maximum torque reduction value, the first motor is controlled to reduce torque according to the target torque reduction value corresponding to the first axle, so that the first wheel stops slipping.

3. The method according to claim 1 or 2, characterized in that: The controlling the first motor to reduce torque according to the maximum torque reduction value includes: Obtaining a current output torque of the first motor; Calculate a second difference torque obtained by subtracting the maximum torque reduction value from the current output torque of the first motor; The first motor is controlled to output the second difference torque.

4. The method according to claim 1, characterized in that The controlling the engine to reduce torque according to the first difference torque includes: Obtaining the current output torque of the engine; Calculate a third difference torque obtained by subtracting the first difference torque from the current output torque of the engine; The engine is controlled to output the third difference torque.

5. The method according to claim 1, characterized in that The second axle is connected to the second wheel. If the driving mode is a hybrid four-wheel drive mode or a pure electric four-wheel drive mode, the method further includes: If the slip rate of the second wheel is greater than a preset second threshold, a target torque reduction value of the second motor is obtained; wherein the target torque reduction value of the second motor is a torque value required to reduce the second motor in order to stop the second wheel from slipping; The second motor is controlled to reduce torque according to a target torque reduction value of the second motor so that the second wheel stops slipping.

6. The method according to claim 1, characterized in that After determining the current driving mode of the vehicle, the method further includes: If the driving mode is the pure electric mode, obtaining a target torque reduction value of the first motor; wherein the target torque reduction value of the first motor is a torque value required to reduce the first motor in order to stop the first wheel from slipping; The first motor is controlled to reduce torque according to a target torque reduction value of the first motor so that the first wheel stops slipping.

7. The method according to claim 1, characterized in that The obtaining of a target torque reduction value corresponding to the first axle includes: Acquire the current output torque of the first motor, the current output torque of the engine, and the target torque value corresponding to the first axle; wherein the target torque value corresponding to the first axle is the torque value required to be output by the power source of the first axle to stop the first wheel from slipping; Calculate the sum of the torques obtained by adding the current output torque of the first motor to the current output torque of the engine; The target torque value corresponding to the first axle is subtracted from the torque sum to obtain a target torque reduction value corresponding to the first axle.

8. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 7.

9. 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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