Vehicle, control method and control device thereof and computer readable storage medium

Abstract

The invention discloses a vehicle and a control method and device thereof and a computer readable storage medium, the vehicle comprises a front axle driving motor and a rear axle driving motor, and the control method comprises the steps that it is determined that the vehicle enters an escape mode; determining a front axle driving motor demand torque according to the front axle driving motor target rotating speed and the front axle driving motor actual rotating speed, and determining a rear axle driving motor demand torque according to the rear axle driving motor target rotating speed and the rear axle driving motor actual rotating speed; correcting the required torque of the front axle driving motor and the required torque of the rear axle driving motor according to the front wheel speed and the rear wheel speed so as to obtain the output torque of the front axle driving motor and the output torque of the rear axle driving motor; and front wheels and rear wheels are controlled according to the output torque of the front axle driving motor and the output torque of the rear axle driving motor. Therefore, the method realizes the closed-loop control of the rotating speed of the motor, shortens the information interaction time, and can effectively solve the problems of slipping and vehicle sinking under the sand working condition.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a vehicle control method, a vehicle control device, a computer-readable storage medium and a vehicle. Background Art

[0002] The surface of the sand is composed of finely crushed sand and gravel, with a loose structure, close to zero bonding force between sand particles, and a very small adhesion coefficient. When a vehicle is driving on sand, the sand layer is squeezed and deformed and constantly creeps backwards, which can easily cause the driving wheels to slip and sink, making driving difficult.

[0003] In the related technology, the vehicle is freed from the sandy conditions based on hardware optimization, specifically by equipping the vehicle with a front axle differential lock, a rear axle differential lock and a central differential lock, and forcibly connecting the four wheels together through the hardware structure, so that the four wheels are driven at the same time and the wheel speed is kept consistent to achieve the freeing. However, the application of the central differential lock in this technical solution greatly increases the production cost of the vehicle. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to propose a vehicle control method, which can be applied to vehicles not equipped with a central differential lock, calculate the motor required torque through the motor target speed and the motor actual speed, and correct the motor required torque in real time according to the wheel speed, thereby realizing closed-loop control of the motor speed and shortening the information interaction time, and effectively solving the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0005] A second object of the present invention is to provide a control device for a vehicle.

[0006] A third object of the present invention is to provide a computer-readable storage medium.

[0007] A fourth object of the present invention is to provide a vehicle.

[0008] To achieve the above-mentioned purpose, a first embodiment of the present invention proposes a vehicle control method, wherein the vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle, and the vehicle control method includes: determining that the vehicle enters an escape mode; determining the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and determining the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor; correcting the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor; and controlling the front wheels and the rear wheels according to the output torque of the front axle drive motor and the output torque of the rear axle drive motor.

[0009] According to the control method of the vehicle of the embodiment of the present invention, the vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheel of the vehicle, and the rear axle drive motor is configured to drive the rear wheel of the vehicle. The control method of the vehicle, first, determines that the vehicle enters the escape mode, and determines the front axle drive motor required torque according to the front axle drive motor target speed and the front axle drive motor actual speed, and determines the rear axle drive motor required torque according to the rear axle drive motor target speed and the rear axle drive motor actual speed, and corrects the front axle drive motor required torque and the rear axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque and the rear axle drive motor output torque, and controls the front wheel and the rear wheel according to the front axle drive motor output torque and the rear axle drive motor output torque. Therefore, the method can be applied to vehicles not equipped with a central differential lock, calculates the motor required torque by the motor target speed and the motor actual speed, and corrects the motor required torque in real time according to the wheel speed, realizes the motor speed closed-loop control, and shortens the information interaction time, and can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0010] In addition, the vehicle control method according to the above embodiment of the present invention may also have the following additional technical features:

[0011] According to one embodiment of the present invention, the required torque of the front axle drive motor and the required torque of the rear axle drive motor are corrected according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, including: when a first wheel speed difference between the minimum value of the front wheel speed and the maximum value of the rear wheel speed is greater than a preset vehicle speed threshold, a first torque reduction coefficient is determined according to the first wheel speed difference; when a second wheel speed difference between the minimum value of the rear wheel speed and the maximum value of the front wheel speed is greater than the preset vehicle speed threshold, a second torque reduction coefficient is determined according to the second wheel speed difference; the front axle drive required torque is corrected according to the first torque reduction coefficient to obtain the output torque of the front axle drive motor; the rear axle drive required torque is corrected according to the second torque reduction coefficient to obtain the output torque of the rear axle drive motor.

[0012] According to one embodiment of the present invention, the required torque of the front axle drive motor and the required torque of the rear axle drive motor are corrected according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, including: when a third wheel speed difference between the maximum value of the front wheel speed and the minimum value of the rear wheel speed is less than a preset vehicle speed threshold, determining a first torque increase coefficient according to the third wheel speed difference; when a fourth wheel speed difference between the maximum value of the rear wheel speed and the minimum value of the front wheel speed is less than a preset vehicle speed threshold, determining a second torque increase coefficient according to the fourth wheel speed difference; correcting the front axle drive required torque according to the first torque increase coefficient to obtain the front axle drive motor output torque; correcting the rear axle drive required torque according to the second torque increase coefficient to obtain the rear axle drive motor output torque.

[0013] According to one embodiment of the present invention, the required torque of the front axle drive motor is determined according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, including: obtaining the target speed of the vehicle; determining the target speed of the front axle drive motor according to the target speed, the transmission ratio of the front axle drive motor and the tire circumference of the front wheels; and performing PI control on the difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor to obtain the required torque of the front axle drive motor.

[0014] According to one embodiment of the present invention, determining the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor includes: acquiring a target vehicle speed; determining the target speed of the rear axle drive motor according to the target vehicle speed, the transmission ratio of the rear axle drive motor and the tire circumference of the rear wheel; and performing PI (Proportional Integral) control on the difference between the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor to obtain the required torque of the rear axle drive motor.

[0015] According to one embodiment of the present invention, the control method of the vehicle also includes: determining the external characteristic torque of the front axle drive motor according to the front axle drive motor speed and the front axle drive motor voltage value, and using the smaller value of the external characteristic torque of the front axle drive motor and the output torque of the front axle drive motor as the output torque of the front axle drive motor; determining the external characteristic torque of the front axle drive motor according to the rear axle drive motor speed and the rear axle drive motor voltage value, and using the smaller value of the external characteristic torque of the rear axle drive motor and the output torque of the rear axle drive motor as the output torque of the rear axle drive motor.

[0016] According to one embodiment of the present invention, the vehicle further comprises a front axle differential lock and a rear axle differential lock, and when the vehicle enters the escape mode, the front axle differential lock and the rear axle differential lock are in a locked state.

[0017] To achieve the above-mentioned purpose, a second embodiment of the present invention proposes a vehicle control device, the vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle, the vehicle control device includes: a first determination module, used to determine that the vehicle enters an escape mode; a second determination module, used to determine the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor; a third determination module, used to determine the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor; a calculation module, used to correct the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor; a first control module, used to control the front wheels according to the output torque of the front axle drive motor; a second control module, used to control the rear wheels according to the output torque of the rear axle drive motor.

[0018] According to the control device of a vehicle of an embodiment of the present invention, the vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle, the control device of the vehicle determines that the vehicle enters an escape mode through a first determination module, determines the required torque of the front axle drive motor according to a target speed of the front axle drive motor and an actual speed of the front axle drive motor through a second determination module, determines the required torque of the rear axle drive motor according to a target speed of the rear axle drive motor and an actual speed of the rear axle drive motor through a third determination module, corrects the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed through a calculation module to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, the first control module controls the front wheels according to the output torque of the front axle drive motor, and the second control module controls the rear wheels according to the output torque of the rear axle drive motor. Therefore, the device can be applied to vehicles that are not equipped with a central differential lock. The motor required torque is calculated by the motor target speed and the motor actual speed, and the motor required torque is corrected in real time according to the wheel speed, thereby realizing closed-loop control of the motor speed and shortening the information interaction time. It can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0019] To achieve the above-mentioned purpose, a third aspect of the present invention provides a computer-readable storage medium on which a vehicle control program is stored. When the vehicle control program is executed by a processor, the above-mentioned vehicle control method is implemented.

[0020] According to the computer-readable storage medium of an embodiment of the present invention, the above-mentioned vehicle control method is implemented when the vehicle control program is executed by the processor. Based on the above-mentioned vehicle control method, closed-loop control of the motor speed is realized, and at the same time, the information interaction time is shortened, which can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0021] To achieve the above-mentioned purpose, a fourth aspect of the present invention proposes a vehicle, comprising: a front axle drive motor, a front axle drive motor controller, a rear axle drive motor and a rear axle drive motor controller, wherein the front axle drive motor controller is configured to, when the vehicle is in an escape mode, determine the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and correct the required torque of the front axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor, and control the front wheels according to the output torque of the front axle drive motor; the rear axle drive motor controller is configured to, when the vehicle is in an escape mode, determine the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, and correct the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the rear axle drive motor, and control the rear wheels according to the output torque of the rear axle drive motor.

[0022] According to the vehicle of the embodiment of the present invention, when the vehicle is in the escape mode, the front axle drive motor controller determines the front axle drive motor required torque according to the front axle drive motor target speed and the front axle drive motor actual speed, and corrects the front axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque, and controls the front wheel according to the front axle drive motor output torque. When the vehicle is in the escape mode, the rear axle drive motor controller determines the rear axle drive motor required torque according to the rear axle drive motor target speed and the rear axle drive motor actual speed, and corrects the rear axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the rear axle drive motor output torque, and controls the rear wheel according to the rear axle drive motor output torque. Thus, the vehicle calculates the motor required torque through the motor target speed and the motor actual speed, and corrects the motor required torque in real time according to the wheel speed, realizing the motor speed closed-loop control, while shortening the information interaction time, and effectively solving the problem of slipping and getting stuck in sandy working conditions without increasing the vehicle production cost.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of a vehicle control method according to an embodiment of the present invention;

[0025] Figure 2 is a flow chart of a vehicle control method according to a specific embodiment of the present invention;

[0026] Figure 3 is a connection diagram of a control device for a vehicle according to an embodiment of the present invention;

[0027] Figure 4 FIG. 4 is a connection diagram of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] The following describes a vehicle control method, a vehicle control device, a computer-readable storage medium, and a vehicle according to embodiments of the present invention with reference to the accompanying drawings.

[0030] In the related art, there are two common methods for four-wheel drive vehicles to escape from trouble when driving in desert conditions:

[0031] ① Hardware optimization solution: The vehicle is equipped with a front axle differential lock, a rear axle differential lock, and a central differential lock. The four wheels are forcibly connected together through the hardware structure, so that the four wheels can be driven simultaneously and keep the wheel speed consistent to get out of trouble;

[0032] ②Software optimization solution: The vehicle is equipped with front axle differential lock and rear axle differential lock, but not central differential lock. ESP (Electronic Stability Program) calculates the vehicle slip rate and intervention torque through the four wheel speeds. VCU (Vehicle Control Unit) corrects the torque distributed to the front and rear axles according to the intervention torque. Then MCU (Motor Control Unit) controls the wheels according to the corrected front and rear axle distributed torque to avoid the front or rear wheels slipping for a long time and causing the vehicle to get stuck.

[0033] However, in the above hardware optimization solution, the solution of equipping the central differential lock will increase the vehicle production cost. In the above software optimization solution, although the central differential lock is not equipped, the solution of adjusting the front and rear axle torque through wheel speed → ESP → VCU → MCU has a long information exchange time and still has the problem of slipping and getting stuck in sandy conditions.

[0034] In order to solve the above technical problems, the present application proposes a vehicle control method, which can be applied to vehicles including front axle drive motors and rear axle drive motors. It does not need to be equipped with a central differential lock, and reduces the application cost compared with the above hardware optimization solution. At the same time, the motor required torque is calculated by the motor target speed and the motor actual speed, and the motor required torque is corrected in real time according to the wheel speed, thereby realizing closed-loop control of the motor speed and shortening the information interaction time. It can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0035] The vehicle control method of the present application is described in detail below with reference to the accompanying drawings.

[0036] Figure 1 4 is a flow chart of a vehicle control method according to an embodiment of the present invention.

[0037] In one embodiment of the present invention, a vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle.

[0038] like Figure 1 As shown, the vehicle control method of the embodiment of the present invention may include:

[0039] S1, determining that the vehicle enters an escape mode;

[0040] S2, determining the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and determining the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor;

[0041] S3, correcting the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor;

[0042] S4, controlling the front wheels and the rear wheels according to the output torque of the front axle drive motor and the output torque of the rear axle drive motor.

[0043] Specifically, the vehicle system may preset an escape mode and a corresponding trigger button, which may be a physical button or a touch screen button, without limitation. For example, when the vehicle is running in pure electric four-wheel drive mode, if the driver selects the escape mode through a physical button or touch screen, the escape mode is triggered and the vehicle enters the escape mode.

[0044] After the vehicle enters the escape mode, the target speed of the front axle drive motor and the target speed of the rear axle drive motor are determined, and the actual speed of the front axle drive motor and the actual speed of the rear axle drive motor are obtained based on the speed sensor. Specifically, the required torque of the front axle drive motor is determined according to the speed difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and the required torque of the rear axle drive motor is obtained according to the speed difference between the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor. For example, a mapping table between the speed difference and the required torque can be pre-set, and the required torque of the front axle drive motor and the required torque of the rear axle drive motor can be determined by looking up the table during operation, or the required torque of the front axle drive motor and the required torque of the rear axle drive motor can be obtained based on PI control or PID (Proportional Integral Derivative, proportional-integral-differential) control mode, without specific restrictions. In addition, the target speed of the front axle drive motor and the target speed of the rear axle drive motor can be looked up in the table and calculated according to parameters such as the target vehicle speed and the vehicle operation mode set by the user.

[0045] After determining the required torque of the front axle drive motor and the required torque of the rear axle drive motor, the front wheel speed and the rear wheel speed are obtained through the sensor. For a four-wheel drive vehicle, the front wheel speed includes the left front wheel speed and the right front wheel speed, and the rear wheel speed includes the left rear wheel speed and the right rear wheel speed. It is determined whether the front axle is slipping or the rear axle is slipping based on the front wheel speed and the rear wheel speed. For example, the average of the left front wheel speed and the right front wheel speed is used as the front wheel speed, and the average of the left rear wheel speed and the right rear wheel speed is used as the rear wheel speed. When the front wheel speed is greater than the rear wheel speed and the wheel speed difference exceeds the first wheel speed threshold, it is determined that the front axle is slipping; when the rear wheel speed is greater than the front wheel speed and the wheel speed difference exceeds the first wheel speed threshold, it is determined that the rear axle is slipping. Then, based on the slip situation, the torque required by the front axle drive motor and the rear axle drive motor are corrected to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor. For example, if the front axle slips, the torque required by the front axle drive motor is corrected to reduce torque, and the torque required by the rear axle drive motor is corrected to increase torque; if the rear axle slips, the torque required by the front axle drive motor is corrected to increase torque, and the torque required by the rear axle drive motor is corrected to reduce torque. Then, the front wheels of the vehicle are controlled with the corrected output torque of the front axle drive motor, and the rear wheels of the vehicle are controlled with the corrected output torque of the rear axle drive motor, thereby effectively suppressing the slip of the vehicle.

[0046] Therefore, this embodiment is applicable to vehicles without a central differential lock, and the motor required torque is calculated by the motor target speed and the motor actual speed, and the motor required torque is corrected based on the wheel speed. This can shorten the information interaction time and quickly adjust the motor output torque after the wheel slips, thereby avoiding the wheel slipping for a long time.

[0047] In one embodiment of the present invention, the required torque of the front axle drive motor is determined based on the target speed of the front axle drive motor and the actual speed of the front axle drive motor, including: obtaining the target speed of the vehicle; determining the target speed of the front axle drive motor based on the target speed, the transmission ratio of the front axle drive motor and the tire circumference of the front wheels; and performing PI control on the difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor to obtain the required torque of the front axle drive motor.

[0048] The target vehicle speed is the desired driving speed set by the driver or vehicle control system. The front axle drive motor ratio is the speed ratio between the input shaft and the output shaft of the front axle transmission. The speed of the drive motor is the number of revolutions per unit time, usually expressed in revolutions per minute (rpm). The tire circumference is calculated by the wheel diameter or radius, with the formula C=πd or C=2πr. The front axle drive motor ratio and the tire circumference of the front wheel can be predetermined and stored, and can be directly retrieved during application.

[0049] Specifically, the required torque of the front axle drive motor can be calculated by the following formula:

[0050] Front axle drive motor target speed = target vehicle speed ÷ 60 * 1000 ÷ front wheel tire circumference * front axle drive motor transmission ratio

[0051] △n=front axle drive motor target speed – front axle drive motor actual speed

[0052]

[0053] Among them, △n is the difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor, Kp is the proportional gain coefficient, Ki is the integral gain coefficient, Kp*△n is the proportional control modulation torque, is the integral control modulated torque, and t is the duration of speed control.

[0054] In one embodiment of the present invention, the rear axle drive motor required torque is determined according to the rear axle drive motor target speed and the rear axle drive motor actual speed, including: obtaining the target vehicle speed of the vehicle; determining the rear axle drive motor target speed according to the target vehicle speed, the rear axle drive motor transmission ratio and the tire circumference of the rear wheel; and performing PI control on the difference between the rear axle drive motor target speed and the rear axle drive motor actual speed to obtain the rear axle drive motor required torque. The rear axle drive motor transmission ratio is the speed ratio of the input shaft and the output shaft of the rear axle transmission.

[0055] Specifically, the transmission ratio of the rear axle drive motor and the tire circumference of the rear wheel can be predetermined and stored in advance, and directly retrieved during the application process.

[0056] For example, the required torque of the rear axle drive motor can be calculated by the following formula:

[0057] Rear axle drive motor target speed = target vehicle speed ÷ 60 * 1000 ÷ rear wheel tire circumference * rear axle drive motor transmission ratio

[0058] △n=rear axle drive motor target speed – rear axle drive motor actual speed

[0059]

[0060] Among them, △n is the difference between the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, Kp is the proportional gain coefficient, Ki is the integral gain coefficient, Kp*△n is the proportional control modulation torque, is the integral control modulated torque, and t is the duration of speed control.

[0061] Furthermore, in the related art, the conventional control method of motor torque is: VCU calculates the required torque of the whole vehicle through information such as vehicle speed, driving mode, accelerator pedal opening, slope, etc., and then calculates the distributed torque of the front axle drive motor and the rear axle drive motor according to the efficiency, driving mode and other information of the front axle drive motor and the rear axle drive motor. The front axle drive motor and the rear axle drive motor output torque according to the torque requested by VCU. The motor torque obtained by this control method does not refer to the motor speed, and the motor speed is in an open-loop state. After the motor speed soars and the wheels slip, the motor torque cannot be reduced in time to prevent slipping. On high-adhesion roads, the wheels are not easy to slip due to the large friction between the wheels and the ground. The above control method can meet the power and driving smoothness of the whole vehicle; but in sandy conditions, the wheels are very likely to slip due to the small friction between the wheels and the ground, and after slipping, the motor output torque cannot be reduced in time, causing the car to dig into a pit and get stuck.

[0062] When the vehicle enters the escape mode, this embodiment can calculate the motor required torque in real time based on the speed difference between the target speed and the actual speed of the motor. Then, when the speed difference is large, the motor outputs a larger torque to make the motor speed close to the target speed. When the speed difference is small, it means that the actual motor speed is close to the target speed, so the motor outputs a smaller torque to reduce the probability of wheel slippage. Therefore, even if the wheel slips, that is, when the actual motor speed exceeds the target speed, since the speed difference is a negative value, a negative torque can be output to quickly reduce the motor speed, so that the wheel quickly exits the slipping state. Therefore, this embodiment performs PI control based on the difference between the motor target speed and the actual motor speed to calculate the motor required torque, so that the motor speed is in a closed-loop control state, which can effectively suppress wheel slippage in sandy working conditions.

[0063] In one embodiment of the present invention, the front axle drive motor required torque and the rear axle drive motor required torque are corrected according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque and the rear axle drive motor output torque, including: when the first wheel speed difference between the minimum value of the front wheel speed and the maximum value of the rear wheel speed is greater than the preset vehicle speed threshold, the first torque reduction coefficient is determined according to the first wheel speed difference; when the second wheel speed difference between the minimum value of the rear wheel speed and the maximum value of the front wheel speed is greater than the preset vehicle speed threshold, the second torque reduction coefficient is determined according to the second wheel speed difference; the front axle drive required torque is corrected according to the first torque reduction coefficient to obtain the front axle drive motor output torque; the rear axle drive required torque is corrected according to the second torque reduction coefficient to obtain the rear axle drive motor output torque. Among them, the preset vehicle speed threshold can be set according to actual conditions, and there is no specific limitation.

[0064] Specifically, taking the preset vehicle speed threshold of 0 km / h as an example, the left front wheel speed, the right front wheel speed, the left rear wheel speed and the right rear wheel speed are obtained through the sensor, and the first torque reduction coefficient and the second torque reduction coefficient are determined based on the left front wheel speed, the right front wheel speed, the left rear wheel speed and the right rear wheel speed, specifically:

[0065] The minimum value of the front wheel speed is obtained by taking the smaller of the left front wheel speed and the right front wheel speed, and the maximum value of the rear wheel speed is obtained by taking the larger of the left rear wheel speed and the right rear wheel speed. The wheel speed difference between the minimum value of the front wheel speed and the maximum value of the rear wheel speed is calculated to obtain the first wheel speed difference. When the first wheel speed difference is greater than 0km / h, it is determined that the front axle is slipping, and the front axle should be subjected to a torque reduction operation, that is, the required torque of the front axle drive motor is reduced to avoid slipping. At this time, the first torque reduction coefficient should be within the range of (0, 1); when the first wheel speed difference is less than or equal to 0km / h, the required torque of the front axle motor remains unchanged, and the first torque reduction coefficient is always 1. For example, a mapping table between the first torque reduction coefficient and the first wheel speed difference (such as Table 1) can be pre-set. During the control process, the first torque reduction coefficient is determined by looking up the table based on the calculated first wheel speed difference; the function calculation formula between the torque reduction coefficient and the wheel speed difference can also be pre-set. During the control process, the first torque reduction coefficient is obtained by substituting the calculated first wheel speed difference into the preset function calculation formula. The specific application can be based on the actual situation. Then, the required torque of the front axle drive motor is corrected based on the first torque reduction coefficient, and the output torque of the front axle drive motor is obtained as follows: the output torque of the front axle drive motor=the required torque of the front axle drive*the first torque reduction coefficient.

[0066] Table 1

[0067] Wheel speed difference (km / h) … -20 -10 -5 0 5 10 15 20 25 … Torque reduction coefficient … 1 1 1 1 0.98 0.95 0.90 0.85 0.80 …

[0068] The smaller of the left rear wheel speed and the right rear wheel speed is taken to obtain the minimum rear wheel speed, the larger of the left front wheel speed and the right front wheel speed is taken to obtain the maximum front wheel speed, and the wheel speed difference between the minimum rear wheel speed and the maximum front wheel speed is calculated to obtain the second wheel speed difference. When the second wheel speed difference is greater than 0km / h, it is determined that the rear axle is in a slipping state, and the rear axle needs to be subjected to a torque reduction operation, that is, the required torque of the rear axle drive motor is reduced to avoid slipping. At this time, the second torque reduction coefficient should be within the range of (0, 1) and the larger the second wheel speed difference, the smaller the second torque reduction coefficient; when the second wheel speed difference is ≤0km / h, the required torque of the rear axle drive motor remains unchanged, that is, the second torque reduction coefficient is always 1. Referring to the method of obtaining the first torque reduction coefficient mentioned above, the second torque reduction coefficient can also be determined by looking up a table during the control process based on the calculated second wheel speed difference, or the obtained second wheel speed difference is substituted into a preset function calculation formula to calculate the second torque reduction coefficient, without specific limitation, and then the required torque of the rear axle drive motor is corrected by the second torque reduction coefficient to obtain the output torque of the rear axle drive motor = rear axle drive required torque * second torque reduction coefficient.

[0069] In one embodiment of the present invention, the required torque of the front axle drive motor and the required torque of the rear axle drive motor are corrected according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, including: when the third wheel speed difference between the maximum value of the front wheel speed and the minimum value of the rear wheel speed is less than a preset vehicle speed threshold, determining the first torque increase coefficient according to the third wheel speed difference; when the fourth wheel speed difference between the maximum value of the rear wheel speed and the minimum value of the front wheel speed is less than the preset vehicle speed threshold, determining the second torque increase coefficient according to the fourth wheel speed difference; correcting the front axle drive required torque according to the first torque increase coefficient to obtain the front axle drive motor output torque; correcting the rear axle drive required torque according to the second torque increase coefficient to obtain the rear axle drive motor output torque.

[0070] Specifically, taking the preset vehicle speed threshold of 0 km / h as an example, the left front wheel speed, the right front wheel speed, the left rear wheel speed and the right rear wheel speed are obtained through the sensor, and the first torque increase coefficient and the second torque increase coefficient are determined based on the left front wheel speed, the right front wheel speed, the left rear wheel speed and the right rear wheel speed, specifically:

[0071] The maximum value of the front wheel speed is obtained by taking the larger of the left front wheel speed and the right front wheel speed, and the minimum value of the rear wheel speed is obtained by taking the smaller of the left rear wheel speed and the right rear wheel speed. The wheel speed difference between the maximum value of the front wheel speed and the minimum value of the rear wheel speed is calculated to obtain the third wheel speed difference. When the third wheel speed difference is less than 0km / h, the required torque of the front axle drive motor should be increased, and the first torque increase coefficient should be in the range of (1, +∞); when the third speed difference is greater than or equal to 0km / h, the required torque of the front axle drive motor remains unchanged, and the first torque increase coefficient is always 1. For example, a mapping table between the first torque increase coefficient and the third wheel speed difference (such as Table 2) can be pre-set, and in the control process, the first torque increase coefficient is determined by looking up the table based on the calculated third wheel speed difference; the function calculation formula between the torque increase coefficient and the wheel speed difference can also be pre-set, and in the control process, the first torque increase coefficient is obtained by substituting the calculated third wheel speed difference into the preset function calculation formula, and it can be applied according to the actual situation. Then, the required torque of the front axle drive motor is corrected based on the first torque increase coefficient, and the output torque of the front axle drive motor is obtained as follows: the front axle drive required torque*the first torque increase coefficient.

[0072] Table 2

[0073] Speed ​​difference (km / h) … -25 -20 -15 -10 -5 0 5 10 15 … Torque coefficient … 1.20 1.15 1.10 1.05 1.02 1 1 1 1 …

[0074] The maximum value of the rear wheel speed is obtained by taking the larger of the left rear wheel speed and the right rear wheel speed, and the minimum value of the front wheel speed is obtained by taking the smaller of the left front wheel speed and the right front wheel speed, and the wheel speed difference between the maximum value of the rear wheel speed and the minimum value of the front wheel speed is calculated to obtain the fourth wheel speed difference. When the fourth wheel speed difference is less than 0km / h, the required torque of the rear axle drive motor should be increased, and the second torque increase coefficient should be within the range of (1, +∞); when the fourth speed difference is greater than or equal to 0km / h, the required torque of the rear axle drive motor remains unchanged, and the second torque increase coefficient is always 1. Referring to the acquisition method of the first torque increase coefficient, the second torque increase coefficient can also be determined by looking up a table according to the calculated fourth wheel speed difference during the control process, or the obtained fourth wheel speed difference is substituted into a preset function calculation formula to obtain the second torque increase coefficient, and the specific details are not limited, and then the required torque of the rear axle drive motor is corrected by the second torque increase coefficient to obtain the output torque of the rear axle drive motor = the required torque of the rear axle drive * the second torque increase coefficient.

[0075] Furthermore, in the related art, the conventional control method for suppressing vehicle skidding is: wheel speed → ESP calculates wheel slip rate → VCU adjusts the front and rear axle torque distribution → front and rear axle motor output torque, thereby suppressing wheel skidding. In this embodiment, the front and rear axle drive motor required torque correction coefficient (first torque reduction coefficient, first torque increase coefficient, second torque reduction coefficient and second torque increase coefficient) is determined by the wheel speed, and the front and rear drive motor required torque is corrected based on the coefficient to obtain the front and rear axle drive motor output torque, that is, the front axle drive motor output torque = front axle drive motor required torque * first torque reduction coefficient * first torque increase coefficient, the rear axle drive motor output torque = rear axle drive motor required torque * second torque reduction coefficient * second torque increase coefficient. This technical solution can shorten the information interaction time, and can quickly adjust the motor output torque after the wheel slips to avoid the wheel being in a slipping state for a long time.

[0076] In one embodiment of the present invention, the control method of the vehicle also includes: determining the external characteristic torque of the front axle drive motor according to the front axle drive motor speed and the front axle drive motor voltage value, and using the smaller value of the external characteristic torque of the front axle drive motor and the output torque of the front axle drive motor as the output torque of the front axle drive motor; determining the external characteristic torque of the front axle drive motor according to the rear axle drive motor speed and the rear axle drive motor voltage value, and using the smaller value of the external characteristic torque of the rear axle drive motor and the output torque of the rear axle drive motor as the output torque of the rear axle drive motor.

[0077] Specifically, the external characteristic torque of the front axle drive motor can be set based on the motor parameters of the front axle drive motor, and is used to characterize the maximum torque that the front axle drive motor is allowed to output at different speeds and voltages. The external characteristic torque of the rear axle drive motor can be set based on the motor parameters of the rear axle drive motor, and is used to characterize the maximum torque that the rear axle drive motor is allowed to output at different speeds and voltages. In actual application, a preset mapping table between motor speed-motor voltage value-motor external characteristic torque can be pre-set, and the external characteristic torque of the front axle drive motor and the external characteristic torque of the rear axle drive motor can be obtained by looking up the table during the control process. In addition, a preset calculation function between the motor speed, the motor voltage value and the motor external characteristic torque can also be pre-set, and the motor speed and motor voltage values ​​obtained during the control process are substituted into the preset calculation function to calculate the motor external characteristic torque, and there is no specific limitation.

[0078] The following is an example of determining the external characteristic torque of the front axle drive motor and the external characteristic torque of the rear axle drive motor by table lookup to illustrate the control method of the vehicle.

[0079] After the required torque of the front axle drive motor is corrected by the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor, the external characteristic torque of the front axle drive motor is obtained by looking up the table according to the front axle drive motor speed and the front axle drive motor voltage obtained by the sensor, and the smaller of the front axle drive motor output torque and the front axle drive motor external characteristic torque is taken to obtain the final front axle drive motor output torque for front wheel control.

[0080] After the rear axle drive motor demand torque is corrected by the front wheel speed and the rear wheel speed to obtain the rear axle drive motor output torque, the rear axle drive motor external characteristic torque is obtained by looking up the table according to the rear axle drive motor speed and the rear axle drive motor voltage value obtained by the sensor, and the rear axle drive motor output torque and the rear axle drive motor external characteristic torque are taken as the smaller to obtain the final rear axle drive motor output torque for rear wheel control.

[0081] This embodiment performs a smaller operation between the output torque and the external characteristic torque for wheel control to avoid a motor false alarm fault caused by the output torque exceeding a preset capacity range of the motor.

[0082] In one embodiment of the present invention, the vehicle further includes a front axle differential lock and a rear axle differential lock, and when the vehicle enters the escape mode, the front axle differential lock and the rear axle differential lock are in a locked state.

[0083] Specifically, the front axle differential lock is used to lock the wheels on both sides of the front axle. The rear axle differential lock is used to lock the wheels on both sides of the rear axle. When the vehicle enters the escape mode, the front axle differential lock and the rear axle differential lock are locked, so that the front axle differential lock locks the wheels on both sides of the front axle, and the rear axle differential lock locks the wheels on both sides of the rear axle, so as to prevent one side of the wheel from slipping due to snow, ice, mud or suspension, so that the vehicle can be easily escaped. As a specific embodiment of the present invention, the control method of the vehicle can be as follows: Figure 2 As shown, the following steps are included:

[0084] S101, determining that the vehicle enters an escape mode, and locking the front axle differential lock and the rear axle differential lock.

[0085] S102, obtaining the target speed of the vehicle, and then proceeding to steps S103 and S105 respectively.

[0086] S103, target speed of the front axle drive motor = target vehicle speed ÷ 60*1000 ÷ front wheel tire circumference * front axle drive motor transmission ratio.

[0087] S104, performing PI control on the difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor to obtain the required torque of the front axle drive motor. Execute step S107.

[0088] S105, rear axle drive motor target speed = target vehicle speed ÷ 60 * 1000 ÷ rear wheel tire circumference * rear axle drive motor transmission ratio.

[0089] S106: Perform PI control on the difference between the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor to obtain the required torque of the rear axle drive motor.

[0090] S107, obtaining the left front wheel speed, the right front wheel speed, the left rear wheel speed and the right rear wheel speed.

[0091] S108, determine the minimum value of the front wheel speed, the maximum value of the front wheel speed, the maximum value of the rear wheel speed and the minimum value of the rear wheel speed. Execute steps S109, S111, S117 and S119 respectively.

[0092] S109, first wheel speed difference = minimum value of front wheel speed - maximum value of rear wheel speed.

[0093] S110, obtaining a first torque reduction coefficient by looking up a table according to the first wheel speed difference.

[0094] S111, third wheel speed difference = maximum value of front wheel speed - minimum value of rear wheel speed.

[0095] S112, obtaining a first torque increase coefficient by looking up a table according to the third wheel speed difference.

[0096] S113, front axle drive motor output torque=front axle drive motor required torque*first torque reduction coefficient*first torque increase coefficient.

[0097] S114, determining the external characteristic torque of the front axle drive motor according to the front axle drive motor speed and the front axle drive motor voltage value.

[0098] S115, taking the smaller of the external characteristic torque of the front axle drive motor and the output torque of the front axle drive motor to obtain a final output torque of the front axle drive motor.

[0099] S116: Control the front wheels according to the final output torque of the front axle drive motor.

[0100] S117, second wheel speed difference = minimum value of rear wheel speed - maximum value of front wheel speed.

[0101] S118, obtaining a second torque reduction coefficient by looking up a table according to the second wheel speed difference.

[0102] S119, fourth wheel speed difference = maximum value of rear wheel speed - minimum value of front wheel speed;

[0103] S120, obtaining a second torque increase coefficient by looking up a table according to the fourth wheel speed difference.

[0104] S121, rear axle drive motor output torque=rear axle drive motor required torque*second torque reduction coefficient*second torque increase coefficient.

[0105] S122, determining the external characteristic torque of the rear axle drive motor according to the speed of the rear axle drive motor and the voltage value of the rear axle drive motor.

[0106] S123, taking the smaller of the external characteristic torque of the rear axle drive motor and the output torque of the rear axle drive motor to obtain a final output torque of the rear axle drive motor.

[0107] S124, controlling the rear wheels according to the final output torque of the rear axle drive motor.

[0108] In summary, according to the control method of a vehicle in an embodiment of the present invention, the vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle. The control method of the vehicle first determines that the vehicle enters an escape mode, and determines the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and determines the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, and corrects the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, and controls the front wheels and the rear wheels according to the output torque of the front axle drive motor and the output torque of the rear axle drive motor. Therefore, this method can be applied to vehicles that are not equipped with a central differential lock. The motor required torque is calculated by the motor target speed and the motor actual speed, and the motor required torque is corrected in real time according to the wheel speed, thereby realizing closed-loop control of the motor speed and shortening the information interaction time. It can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0109] Corresponding to the above embodiment, the present invention also proposes a vehicle control device.

[0110] According to one embodiment of the present invention, a vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle.

[0111] like Figure 3 As shown, the vehicle control device of the embodiment of the present invention may include: a first determination module 10 , a second determination module 20 , a third determination module 30 , a calculation module 40 , a first control module 50 and a second control module 60 .

[0112] Among them, the first determination module 10 is used to determine whether the vehicle enters the escape mode. The second determination module 20 is used to determine the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor. The third determination module 30 is used to determine the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor. The calculation module 40 is used to correct the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor. The first control module 50 is used to control the front wheels according to the output torque of the front axle drive motor. The second control module 60 is used to control the rear wheels according to the output torque of the rear axle drive motor.

[0113] According to one embodiment of the present invention, the calculation module 40 corrects the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, and is specifically used for: when a first wheel speed difference between the minimum value of the front wheel speed and the maximum value of the rear wheel speed is greater than a preset vehicle speed threshold, determining a first torque reduction coefficient according to the first wheel speed difference; when a second wheel speed difference between the minimum value of the rear wheel speed and the maximum value of the front wheel speed is greater than the preset vehicle speed threshold, determining a second torque reduction coefficient according to the second wheel speed difference; correcting the front axle drive required torque according to the first torque reduction coefficient to obtain the front axle drive motor output torque; correcting the rear axle drive required torque according to the second torque reduction coefficient to obtain the rear axle drive motor output torque.

[0114] According to one embodiment of the present invention, the calculation module 40 corrects the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, and is specifically used for: when the third wheel speed difference between the maximum value of the front wheel speed and the minimum value of the rear wheel speed is less than a preset vehicle speed threshold, determining the first torque increase coefficient according to the third wheel speed difference; when the fourth wheel speed difference between the maximum value of the rear wheel speed and the minimum value of the front wheel speed is less than the preset vehicle speed threshold, determining the second torque increase coefficient according to the fourth wheel speed difference; correcting the front axle drive required torque according to the first torque increase coefficient to obtain the front axle drive motor output torque; correcting the rear axle drive required torque according to the second torque increase coefficient to obtain the rear axle drive motor output torque.

[0115] According to one embodiment of the present invention, the second determination module 20 determines the required torque of the front axle drive motor based on the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and is specifically used for: obtaining the target speed of the vehicle; determining the target speed of the front axle drive motor based on the target speed, the transmission ratio of the front axle drive motor and the tire circumference of the front wheels; and performing PI control on the difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor to obtain the required torque of the front axle drive motor.

[0116] According to one embodiment of the present invention, the third determination module 30 determines the required torque of the rear axle drive motor based on the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, and is specifically used for: obtaining the target speed of the vehicle; determining the target speed of the rear axle drive motor based on the target speed, the transmission ratio of the rear axle drive motor and the tire circumference of the rear wheels; and performing PI control on the difference between the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor to obtain the required torque of the rear axle drive motor.

[0117] According to one embodiment of the present invention, the first control module 50 is also used to: determine the external characteristic torque of the front axle drive motor according to the front axle drive motor speed and the front axle drive motor voltage value, and use the smaller value of the external characteristic torque of the front axle drive motor and the output torque of the front axle drive motor as the output torque of the front axle drive motor; the second control module 60 is also used to: determine the external characteristic torque of the front axle drive motor according to the rear axle drive motor speed and the rear axle drive motor voltage value, and use the smaller value of the external characteristic torque of the rear axle drive motor and the output torque of the rear axle drive motor as the output torque of the rear axle drive motor.

[0118] According to one embodiment of the present invention, the vehicle further comprises a front axle differential lock and a rear axle differential lock, and when the vehicle enters the escape mode, the front axle differential lock and the rear axle differential lock are in a locked state.

[0119] It should be noted that for details not disclosed in the vehicle control device of the embodiment of the present invention, please refer to the details disclosed in the vehicle control method of the above-mentioned embodiment of the present invention, and the details will not be repeated here.

[0120] According to the control device of a vehicle of an embodiment of the present invention, the vehicle includes a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle, the control device of the vehicle determines that the vehicle enters an escape mode through a first determination module, determines the required torque of the front axle drive motor according to a target speed of the front axle drive motor and an actual speed of the front axle drive motor through a second determination module, determines the required torque of the rear axle drive motor according to a target speed of the rear axle drive motor and an actual speed of the rear axle drive motor through a third determination module, corrects the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed through a calculation module to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor, the first control module controls the front wheels according to the output torque of the front axle drive motor, and the second control module controls the rear wheels according to the output torque of the rear axle drive motor. Therefore, the device can be applied to vehicles that are not equipped with a central differential lock. The motor required torque is calculated by the motor target speed and the motor actual speed, and the motor required torque is corrected in real time according to the wheel speed, thereby realizing closed-loop control of the motor speed and shortening the information interaction time. It can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the vehicle production cost.

[0121] Corresponding to the above embodiment, the present invention also proposes a computer-readable storage medium.

[0122] The computer-readable storage medium of the embodiment of the present invention stores a vehicle control program thereon, and the vehicle control program implements the above-mentioned vehicle control method when executed by a processor.

[0123] According to the computer-readable storage medium of an embodiment of the present invention, the above-mentioned vehicle control method is implemented when the vehicle control program is executed by the processor. Based on the above-mentioned vehicle control method, closed-loop control of the motor speed is realized, and at the same time, the information interaction time is shortened, which can effectively solve the problem of slipping and getting stuck in sandy conditions without increasing the production cost of large vehicles.

[0124] Corresponding to the above embodiment, the present invention also provides a vehicle.

[0125] like Figure 4As shown, a vehicle 100 according to an embodiment of the present invention includes: a front axle drive motor 110, a front axle drive motor controller 120, a rear axle drive motor 130 and a rear axle drive motor controller 140, wherein the front axle drive motor controller 120 is configured to, when the vehicle is in an escape mode, determine the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and correct the required torque of the front axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the front axle drive motor, and control the front wheels according to the output torque of the front axle drive motor; the rear axle drive motor controller 140 is configured to, when the vehicle is in an escape mode, determine the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, and correct the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed to obtain the output torque of the rear axle drive motor, and control the rear wheels according to the output torque of the rear axle drive motor.

[0126] According to the vehicle of the embodiment of the present invention, when the vehicle is in the escape mode, the front axle drive motor controller determines the front axle drive motor required torque according to the front axle drive motor target speed and the front axle drive motor actual speed, and corrects the front axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque, and controls the front wheel according to the front axle drive motor output torque. When the vehicle is in the escape mode, the rear axle drive motor controller determines the rear axle drive motor required torque according to the rear axle drive motor target speed and the rear axle drive motor actual speed, and corrects the rear axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the rear axle drive motor output torque, and controls the rear wheel according to the rear axle drive motor output torque. Thus, the vehicle calculates the motor required torque through the motor target speed and the motor actual speed, and corrects the motor required torque in real time according to the wheel speed, thereby realizing the motor speed closed-loop control, and shortening the information interaction time, and effectively solving the problem of slipping and getting stuck in sandy working conditions without increasing production costs.

[0127] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0128] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0129] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0130] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0131] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0132] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A vehicle control method, characterized in that: The vehicle comprises a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle, and the method comprises: Determining that the vehicle enters an escape mode; Determine the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, and determine the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor; Correcting the front axle drive motor required torque and the rear axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque and the rear axle drive motor output torque; The front wheels and the rear wheels are controlled according to the output torque of the front axle drive motor and the output torque of the rear axle drive motor.

2. The vehicle control method according to claim 1, characterized in that: The front axle drive motor required torque and the rear axle drive motor required torque are corrected according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque and the rear axle drive motor output torque, including: When a first wheel speed difference between the minimum value of the front wheel speed and the maximum value of the rear wheel speed is greater than a preset vehicle speed threshold, determining a first torque reduction coefficient according to the first wheel speed difference; When a second wheel speed difference between the minimum value of the rear wheel speed and the maximum value of the front wheel speed is greater than a preset vehicle speed threshold, determining a second torque reduction coefficient according to the second wheel speed difference; Correcting the front axle drive required torque according to the first torque reduction coefficient to obtain the front axle drive motor output torque; The rear axle drive required torque is corrected according to the second torque reduction coefficient to obtain the rear axle drive motor output torque.

3. The vehicle control method according to claim 1, characterized in that: The front axle drive motor required torque and the rear axle drive motor required torque are corrected according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque and the rear axle drive motor output torque, including: When a third wheel speed difference between the maximum value of the front wheel speed and the minimum value of the rear wheel speed is less than a preset vehicle speed threshold, determining a first torque increase coefficient according to the third wheel speed difference; When a fourth wheel speed difference between the maximum value of the rear wheel speed and the minimum value of the front wheel speed is less than a preset vehicle speed threshold, determining a second torque increase coefficient according to the fourth wheel speed difference; Correcting the front axle drive required torque according to the first torque increase coefficient to obtain the front axle drive motor output torque; The rear axle drive required torque is corrected according to the second torque increase coefficient to obtain the rear axle drive motor output torque.

4. The vehicle control method according to claim 1, characterized in that: The required torque of the front axle drive motor is determined according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor, including: Obtaining a target speed of the vehicle; Determining a target rotation speed of the front axle drive motor according to the target vehicle speed, the transmission ratio of the front axle drive motor and the tire circumference of the front wheel; The difference between the target speed of the front axle drive motor and the actual speed of the front axle drive motor is subjected to PI control to obtain the required torque of the front axle drive motor.

5. The vehicle control method according to claim 1, characterized in that: The required torque of the rear axle drive motor is determined according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, including: Obtaining a target speed of the vehicle; Determining a target speed of the rear axle drive motor according to the target vehicle speed, the transmission ratio of the rear axle drive motor and the tire circumference of the rear wheel; The difference between the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor is subjected to PI control to obtain the required torque of the rear axle drive motor.

6. The vehicle control method according to any one of claims 1 to 5, characterized in that: The method further comprises: Determine the external characteristic torque of the front axle drive motor according to the front axle drive motor speed and the front axle drive motor voltage value, and use the smaller value of the external characteristic torque of the front axle drive motor and the output torque of the front axle drive motor as the output torque of the front axle drive motor; The external characteristic torque of the front axle drive motor is determined according to the rear axle drive motor speed and the rear axle drive motor voltage value, and the smaller value of the external characteristic torque of the rear axle drive motor and the output torque of the rear axle drive motor is used as the output torque of the rear axle drive motor.

7. The vehicle control method according to any one of claims 1 to 5, characterized in that: The vehicle further comprises a front axle differential lock and a rear axle differential lock, and when the vehicle enters an escape mode, the front axle differential lock and the rear axle differential lock are in a locked state.

8. A vehicle control device, characterized in that: The vehicle comprises a front axle drive motor and a rear axle drive motor, the front axle drive motor is configured to drive the front wheels of the vehicle, and the rear axle drive motor is configured to drive the rear wheels of the vehicle, and the device comprises: A first determination module, used for determining that the vehicle enters an escape mode; A second determination module is used to determine the required torque of the front axle drive motor according to the target speed of the front axle drive motor and the actual speed of the front axle drive motor; A third determination module is used to determine the required torque of the rear axle drive motor according to the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor; A calculation module, used for correcting the required torque of the front axle drive motor and the required torque of the rear axle drive motor according to the front wheel speed and the rear wheel speed, so as to obtain the output torque of the front axle drive motor and the output torque of the rear axle drive motor; A first control module, configured to control the front wheels according to the output torque of the front axle drive motor; The second control module is used to control the rear wheels according to the output torque of the rear axle drive motor.

9. A computer-readable storage medium, characterized in that: A vehicle control program is stored thereon, and when the vehicle control program is executed by a processor, a vehicle control method according to any one of claims 1 to 7 is implemented.

10. A vehicle, characterized in that: include: A front axle drive motor, a front axle drive motor controller, a rear axle drive motor and a rear axle drive motor controller, wherein: The front axle drive motor controller is configured to, when the vehicle is in an escape mode, determine the front axle drive motor required torque according to the front axle drive motor target speed and the front axle drive motor actual speed, and correct the front axle drive motor required torque according to the front wheel speed and the rear wheel speed to obtain the front axle drive motor output torque, and control the front wheels according to the front axle drive motor output torque; The rear axle drive motor controller is configured to, when the vehicle is in an escape mode, determine the required torque of the rear axle drive motor based on the target speed of the rear axle drive motor and the actual speed of the rear axle drive motor, and correct the required torque of the rear axle drive motor based on the front wheel speed and the rear wheel speed to obtain the output torque of the rear axle drive motor, and control the rear wheels based on the output torque of the rear axle drive motor.

Images