Anti-slip management method, system, vehicle-mounted device and vehicle for electric four-wheel drive vehicle

Abstract

The application discloses a method and system for preventing skidding of an electric four-wheel drive vehicle, a vehicle-mounted device and a vehicle. The method comprises the following steps: acquiring the number and positions of wheels of the electric four-wheel drive vehicle; activating a corresponding skid control mode according to the number of wheels, wherein the skid control mode comprises a first skid control mode, a second skid control mode, a third skid control mode and a fourth skid control mode; and preventing skidding of the wheels of the electric four-wheel drive vehicle according to the skid control mode and the positions of the wheels. In one aspect, the skid control mode is divided into four types according to the number of wheels, thereby realizing targeted adjustment of the skidding of the electric four-wheel drive vehicle. In another aspect, the skid control mode is adaptively regulated in combination with the positions of the wheels, thereby effectively improving the skid prevention effect and ensuring stable operation of the electric four-wheel drive vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile control technology, and particularly relates to a slip management method and system for an electric four-wheel drive vehicle, a vehicle-mounted device and a vehicle. BACKGROUND

[0002] The drive slip system of an automobile is used to prevent the drive wheels from slipping during driving, to ensure the safe and stable driving of the automobile, and to improve the utilization efficiency of the driving power of the automobile. A good drive slip system should have two advantages: on the one hand, the vehicle has the best possible acceleration, and on the other hand, the acceleration does not unnecessarily affect the driving stability of the vehicle.

[0003] For a traditional electric four-wheel drive vehicle, the central differential is used to avoid the problem of uncoordinated driving between the front and rear axles, and the inter-wheel differential is used to solve the problem of uncoordinated operation between the same shaft wheels. The engine power output is generally adjusted to apply braking to the drive wheels, and the central differential and inter-wheel differential means are used for drive slip. However, for an electric vehicle with independent driving of the front and rear axles, the slip processing method through the central differential and inter-wheel differential is no longer applicable. That is, it is difficult to achieve the target slip effect by using the central differential and inter-wheel differential means for drive slip of an electric four-wheel drive vehicle with independent driving of the front and rear axles, thereby causing the electric four-wheel drive vehicle to continuously slip during operation and difficult to maintain stability.

[0004] Therefore, in the prior art, the electric four-wheel drive vehicle has the problem of being difficult to maintain stable operation due to continuous slipping during operation. SUMMARY

[0005] Therefore, it is necessary to provide a slip management method and system for an electric four-wheel drive vehicle, a vehicle-mounted device and a vehicle to solve the problem of being difficult to maintain stable operation due to continuous slipping during operation of the electric four-wheel drive vehicle in the prior art.

[0006] To solve the above problems, the present application provides a slip management method for an electric four-wheel drive vehicle, comprising:

[0007] Obtaining the number and position of the slipping wheels of the electric four-wheel drive vehicle;

[0008] According to the number of slipping wheels, the corresponding slip control mode is activated, wherein the slip control mode includes a first slip control mode, a second slip control mode, a third slip control mode and a fourth slip control mode;

[0009] According to the slip control mode and the position of the slipping wheels, the wheels of the electric four-wheel drive vehicle are managed for slip prevention.

[0010] Further, the number and position of the slipping wheels of the electric four-wheel drive vehicle are acquired, comprising:

[0011] The slip ratios of the front left wheel, the front right wheel, the rear left wheel and the rear right wheel of the electric four-wheel drive vehicle are respectively acquired;

[0012] The slip ratios of the front left wheel, the front right wheel, the rear left wheel and the rear right wheel are respectively compared with the preset threshold value of the slip ratio to determine the number and position of the slipping wheels.

[0013] Further, according to the number of the slipping wheels, the corresponding slip control mode is activated, comprising:

[0014] If the number of the slipping wheels is one, the first slip control mode is activated;

[0015] If not, it is determined whether the number of the slipping wheels is two, if yes, the second slip control mode is activated;

[0016] If not, it is determined whether the number of the slipping wheels is three, if yes, the third slip control mode is activated;

[0017] If not, the fourth slip control mode is activated.

[0018] Further, the first slip control mode comprises:

[0019] If the slipping wheel is the front wheel, the drive torque of the slipping front wheel is reduced, and the drive torque of the other front wheel is increased;

[0020] If not, the wheel speeds of the two front wheels are adjusted to be equal, and the drive torque of the slipping rear wheel is reduced.

[0021] Further, the second slip control mode comprises:

[0022] If the slipping wheels are both the front wheels, the drive torques of the front left wheel and the front right wheel are reduced, the wheel speeds of the front left wheel and the front right wheel are adjusted to be equal and equal to the average wheel speed of the rear left wheel and the rear right wheel;

[0023] If not, it is determined whether the slipping wheels are both the rear wheels, if yes, the drive torques of the rear left wheel and the rear right wheel are reduced, and the slip ratios of the rear left wheel and the rear right wheel are respectively adjusted to the threshold value of the slip ratio;

[0024] If not, the vehicle speed is acquired, it is determined whether the vehicle speed is within the threshold value of the vehicle speed and the slipping wheels are on the same side, if yes, the slip ratios of the front left wheel and the front right wheel are respectively adjusted to the preset slip ratio, and the slip ratios of the rear left wheel and the rear right wheel are adjusted to the preset slip ratio;

[0025] If not, the wheel speed of the slipping front wheel is adjusted to the wheel speed of the non-slip front wheel, and the rotation speed and torque of the rear wheels are adjusted to make the wheel speeds of the left and right rear wheels equal to the wheel speed of the non-slip front wheel.

[0026] Further, the third slipping control mode comprises:

[0027] If yes, the wheel speeds of the left and right rear wheels are adjusted to the wheel speed of the non-slip front wheel, and the wheel speed of the slipping front wheel is adjusted to the wheel speed of the non-slip front wheel.

[0028] If not, the wheel speeds of the left and right front wheels are adjusted to the wheel speed of the non-slip rear wheel, and the wheel speed of the slipping rear wheel is adjusted to the wheel speed of the non-slip rear wheel.

[0029] Further, the fourth slipping control mode comprises:

[0030] The vehicle speed is obtained, and it is determined whether the vehicle speed is within a vehicle speed threshold. If yes, the slip ratios of the slipping left and right rear wheels are adjusted to a preset slip ratio, and the wheel speeds of the slipping left and right front wheels are adjusted to the average wheel speed of the left and right rear wheels.

[0031] If not, the slip ratios of the slipping left and right front wheels are adjusted to a slip ratio threshold, and the wheel speeds of the slipping left and right rear wheels are adjusted to the average wheel speed of the left and right front wheels.

[0032] To solve the above problems, the application further provides an anti-slip management system of an electric four-wheel drive vehicle, comprising:

[0033] A slipping wheel obtaining module is configured to obtain the number and position of the slipping wheels of the electric four-wheel drive vehicle.

[0034] A slipping control mode activating module is configured to activate a corresponding slipping control mode according to the number of the slipping wheels, wherein the slipping control mode comprises a first slipping control mode, a second slipping control mode, a third slipping control mode, and a fourth slipping control mode.

[0035] An anti-slip management module is configured to perform anti-slip management on the wheels of the electric four-wheel drive vehicle according to the slipping control mode and the position of the slipping wheels.

[0036] To solve the above problems, the application further provides a vehicle-mounted device comprising a processor and a memory, wherein the memory stores a computer program, and the computer program is executed by the processor to implement the anti-slip management method of the electric four-wheel drive vehicle as described above.

[0037] To solve the above problems, the application further provides a vehicle comprising the vehicle-mounted device as described above.

[0038] The beneficial effects of the above technical scheme are: the application provides a slip prevention management method, system, vehicle-mounted device and vehicle for an electric four-wheel drive vehicle, the method comprising: obtaining the number and position of the slipping wheels of the electric four-wheel drive vehicle; activating the corresponding slip control mode according to the number of the slipping wheels, wherein the slip control mode comprises a first slip control mode, a second slip control mode, a third slip control mode and a fourth slip control mode; and performing slip prevention management on the wheels of the electric four-wheel drive vehicle according to the slip control mode and the position of the slipping wheels. On the one hand, the slip control mode is divided into four types according to the number of the slipping wheels, so that the slipping condition of the electric four-wheel drive vehicle can be adjusted in a targeted manner; on the other hand, the slip control mode is adaptively regulated in combination with the position of the slipping wheels, so that the slip prevention effect can be effectively improved and the stable operation of the electric four-wheel drive vehicle can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A flowchart of an embodiment of the slip prevention management method for the electric four-wheel drive vehicle provided by the application;

[0040] Figure 2 A flowchart of an embodiment of the activation of the corresponding slip control mode provided by the application;

[0041] Figure 3 A flowchart of an embodiment of the second slip control mode provided by the application;

[0042] Figure 4 A structural diagram of an embodiment of the slip prevention management system for the electric four-wheel drive vehicle provided by the application;

[0043] Figure 5 A structural block diagram of an embodiment of the vehicle-mounted device provided by the application. DETAILED DESCRIPTION

[0044] The preferred embodiments of the application will be described in detail below with reference to the accompanying drawings, wherein the drawings constitute a part of this application and serve to explain the principles of the embodiments of the application, but are not used to limit the scope of the application.

[0045] Before the embodiments are described, the limited slip differential, the electric four-wheel drive vehicle and the open differential are described first:

[0046] The limited slip differential is an improved differential that limits the wheel slip, and its English name is Limited Slip Differential, abbreviated as LSD. The limited slip differential is a differential that allows the speed difference between the two drive wheels to be within a certain range to ensure normal driving performance such as turning, and is a non-electric control type, which can realize limited inter-wheel torque distribution ratio.

[0047] Among them, the active electronic limited slip differential in the application can realize a limit inter-wheel torque distribution ratio as high as 0:100, and is electrically controlled.

[0048] The electric four-wheel drive car is a pure electric car with four-wheel drive. Its working principle is to realize four-wheel drive through single motor + transmission shaft, double motor all-wheel drive, engine + motor combination structure. Compared with traditional fuel vehicles, the electric four-wheel drive car cancels the gearbox, transfer case and other parts, making the structure simpler and the transmission more efficient. On the other hand, it directly controls the motor of the front and rear axles to distribute power, with faster and more accurate response. However, the electric four-wheel drive car generally carries an open differential. Once a wheel slips, the motor power will be greatly reduced, making it difficult to escape.

[0049] The open differential is a differential used in cars, which is a differential that can work normally when the car turns without any restrictions. The planetary gear set has no locking device. If a four-wheel drive car is equipped with three open differentials in front, middle and rear, if one of the wheels slips, the entire power of the car will be wasted on this wheel, and the remaining three wheels cannot be powered.

[0050] That is, during the operation of the current electric four-wheel drive car, when the open differential is used to control the running speed, there is a problem of difficulty in maintaining stable operation due to continuous slipping.

[0051] In order to solve the above problems, the application provides a slip management method, system, vehicle-mounted equipment and vehicle for electric four-wheel drive car, which are described in detail below.

[0052] As shown in Figure 1 , the flowchart of an embodiment of the slip management method for electric four-wheel drive car provided by the application comprises: Figure 1

[0053] Step S101: obtaining the number of slipping wheels and the position of the slipping wheels of the electric four-wheel drive car.

[0054] Step S102: activating the corresponding slip control mode according to the number of slipping wheels, wherein the slip control mode includes first slip control mode, second slip control mode, third slip control mode and fourth slip control mode.

[0055] Step S103: managing the wheels of the electric four-wheel drive car according to the slip control mode and the position of the slipping wheels.

[0056] ​In this embodiment, firstly, the number and position of the slipping wheels of the electric four-wheel drive vehicle are determined according to the operating state of the electric four-wheel drive vehicle; then, the corresponding slip control mode is activated according to the number of the slipping wheels, wherein the corresponding slip control mode has four kinds in total since the electric four-wheel drive vehicle has four wheels; finally, after the slip control mode is activated, the slip control mode needs to be adaptively adjusted according to the position of the slipping wheels, so as to realize the anti-slip management of the electric four-wheel drive vehicle.

[0057] In this embodiment, on the one hand, the slip control mode is divided into four kinds according to the number of the slipping wheels, so as to realize the targeted adjustment of the slipping condition of the electric four-wheel drive vehicle; on the other hand, the slip control mode is adaptively regulated in combination with the position of the slipping wheels, so as to effectively improve the anti-slip effect and ensure the stable operation of the electric four-wheel drive vehicle.

[0058] It should be noted that, firstly, in order to ensure the normal work of the electric four-wheel drive vehicle, the vehicle control system is self-checked to ensure that the electric four-wheel drive vehicle is in the key on state; in addition, since the application does not involve anti-slip in the steering process, it is necessary to ensure that the front wheel angle δ = 0.

[0059] In a specific embodiment, the calculation formula of the slip ratio of the electric four-wheel drive vehicle is as follows:

[0060]

[0061] Wherein, λ is the slip ratio of the electric four-wheel drive vehicle, ω is the wheel speed of the electric four-wheel drive vehicle, r is the wheel rolling radius of the electric four-wheel drive vehicle, and V is the vehicle speed of the electric four-wheel drive vehicle.

[0062] In a specific embodiment, the vehicle speed is a commonly used vehicle parameter, which is received by the drive anti-slip control unit through the CAN bus. The wheel speed information of the four wheels is measured by the wheel speed sensor on each wheel and received by the drive anti-slip control unit.

[0063] As a preferred embodiment, in step S101, in order to obtain the number and position of the slipping wheels of the electric four-wheel drive vehicle, firstly, the front left wheel slip ratio, the front right wheel slip ratio, the rear left wheel slip ratio and the rear right wheel slip ratio of the electric four-wheel drive vehicle need to be obtained respectively, that is, the slip ratio of each wheel needs to be obtained in real time; then, the front left wheel slip ratio, the front right wheel slip ratio, the rear left wheel slip ratio and the rear right wheel slip ratio are compared with the slip ratio threshold preset value respectively to determine whether the slip ratio of each wheel is within the slip ratio threshold preset value, since the electric four-wheel drive vehicle preferentially provides power to the wheel without resistance, by obtaining the slip ratio of each wheel, it can be determined whether there is a slipping wheel, and since the slip ratio of each wheel is measured separately, the number of slipping wheels can be obtained at the same time, and the position of the slipping wheel can be determined, that is, the position of the slipping wheel is determined.

[0064] In a specific embodiment, the slip ratio threshold preset value is set to 0.3.

[0065] In other embodiments, the slip ratio preset value can also be set according to actual conditions and judgment needs.

[0066] As a preferred embodiment, in step S102, in order to activate the corresponding slip control mode, as shown in the flowchart of an embodiment of the application for activating the corresponding slip control mode, comprising: Figure 2 Figure 2 As a preferred embodiment, in step S102, in order to activate the corresponding slip control mode, as shown in the flowchart of an embodiment of the application for activating the corresponding slip control mode, comprising:

[0067] Step S121: Determine whether the number of slipping wheels is one, if yes, activate the first slip control mode.

[0068] Step S122: If no, determine whether the number of slipping wheels is two, if yes, activate the second slip control mode.

[0069] Step S123: If no, determine whether the number of slipping wheels is three, if yes, activate the third slip control mode.

[0070] Step S124: If no, activate the fourth slip control mode.

[0071] In this embodiment, by setting the slip control mode corresponding to the number of slipping wheels, after obtaining the number of slipping wheels, the electric four-wheel drive vehicle is activated to enter the corresponding slip control mode according to the number of slipping wheels. Since the electric four-wheel drive vehicle has a total of four wheels, the slip control mode has a total of four modes.

[0072] Further, in step S121, when there is only one slipping wheel, the electric four-wheel drive vehicle is activated to enter the first slip control mode. First, determine whether the slipping wheel is the front wheel, if the slipping wheel is the front wheel, the left and right wheel torque distribution function of the front axle active electronic limited slip differential is controlled to start, the torque ratio between the front left and right wheels is adjusted, the driving torque of the slipping front wheel is reduced, and the driving torque of the other non-slip front wheel is increased, so as to achieve the purpose of eliminating slip. However, there are special cases where the above operation cannot eliminate slip, but causes two front wheels to slip at the same time. Therefore, the second slip control mode needs to be activated, and the position of the slipping wheel is two front wheels.

[0073] In another embodiment, the brake of the slipping front wheel is controlled to brake, and the front limited slip differential is controlled to reduce the driving torque of the slipping front wheel.

[0074] ​If the slipping wheel is the rear wheel, that is, the judgment result is no, the coordination control opens the left and right wheel torque distribution function of the front active electronic limited slip differential, so that the wheel speeds of the two front wheels are equal, then the coordination control opens the left and right wheel torque distribution function of the rear active electronic limited slip differential, so as to reduce the driving torque of the slipping rear wheel. Similarly, the above operation may not only eliminate the current rear wheel slipping condition, but also cause the two rear wheels to slip at the same time, so that the number of slipping wheels is increased to two, and the second slipping control mode needs to be activated, and the positions of the slipping wheels are the two rear wheels.

[0075] In another embodiment, the brake of the front wheel is implemented by coordination control, and the front limited slip differential is matched, so that the wheel speeds of the two front wheels are equal, and the front wheel does not slip, then the brake of the slipping rear wheel is implemented by coordination control, and the rear limited slip differential is matched, so as to reduce the driving torque of the slipping rear wheel.

[0076] Further, in step S122, since the positions of the slipping wheels are uncertain, the anti-slip method is correspondingly provided with multiple methods, such as Figure 3 as shown, Figure 3 a flowchart of an embodiment of the second slipping control mode provided by the application, comprising:

[0077] Step S1221: judging whether the slipping wheels are all front wheels, if yes, reducing the driving torques of the front left wheel and the front right wheel, adjusting the wheel speeds of the front left wheel and the front right wheel to be equal and equal to the average wheel speed of the rear left wheel and the rear right wheel.

[0078] Step S1222: if no, judging whether the slipping wheels are all rear wheels, if yes, reducing the driving torques of the rear left wheel and the rear right wheel, and adjusting the slip ratios of the rear left wheel and the rear right wheel to the slip ratio threshold value, respectively.

[0079] Step S1223: if no, obtaining the vehicle speed, judging whether the vehicle speed is within the vehicle speed threshold value and whether the slipping wheels are on the same side, if yes, adjusting the slip ratios of the front left wheel and the front right wheel to the preset slip ratio, and adjusting the slip ratios of the rear left wheel and the rear right wheel to the preset slip ratio.

[0080] Step S1224: if no, adjusting the wheel speed of the slipping front wheel to the wheel speed of the non-slip front wheel, and adjusting the rotational speed and the torque of the rear wheel, so that the wheel speeds of the left and right rear wheels are equal to the wheel speed of the non-slip front wheel.

[0081] In this embodiment, first, the slipping condition needs to be divided into four kinds according to the positions of the slipping wheels, which are two front wheels slipping, two rear wheels slipping, one front wheel and one rear wheel slipping on the same side, and one front wheel and one rear wheel slipping on different sides; then, for the four conditions, the driving torque, the wheel speed, the slip ratio and other parameters of the wheels are adjusted, so as to eliminate the slipping condition.

[0082] In step S1221, when it is judged that two front wheels are slipping, then the left and right wheel torque distribution function of the front active electronic limited slip differential is opened and the output speed and torque of the front axle motor are controlled by coordinated control, on the one hand, the driving torque of the front left wheel and the front right wheel is reduced, on the other hand, the wheel speeds of the front left wheel and the front right wheel are adjusted to be equal, which is equal to the average wheel speed of the rear left wheel and the rear right wheel.

[0083] In another embodiment, the brakes of the two front wheels are implemented by coordinated control to brake and the output speed and torque of the front axle motor are controlled, and the front limited slip differential is matched to reduce the driving torque of the front left wheel and the front right wheel, and to make the wheel speeds of the front left wheel and the front right wheel equal, which is equal to the average wheel speed of the rear left wheel and the rear right wheel.

[0084] In step S1222, when it is judged that two rear wheels are slipping, then the left and right wheel torque distribution function of the rear active electronic limited slip differential is opened and the output speed and torque of the rear axle motor are controlled by coordinated control, on the one hand, the driving torque of the rear left wheel and the rear right wheel is reduced, on the other hand, the slip ratios of the rear left wheel and the rear right wheel are respectively adjusted to the slip ratio threshold.

[0085] In a specific embodiment, the slip ratio threshold is set to 0.02.

[0086] In another embodiment, the brakes of the two slipping rear wheels are implemented by coordinated control to brake and the output speed and torque of the rear axle motor are controlled, and the rear limited slip differential is matched to reduce the driving torque of the rear left wheel and the rear right wheel, and to adjust the slip ratios of the rear left wheel and the rear right wheel to the slip ratio threshold.

[0087] In step S1223, when it is judged that one front wheel and one rear wheel located at the same side are slipping, then the vehicle speed variable also needs to be considered, first, the vehicle speed is obtained, it is judged whether the vehicle speed is within the vehicle speed threshold, if yes, it means that the electric four-wheel drive vehicle is in a low-speed running state, therefore, first, the left and right wheel torque distribution function of the front active electronic limited slip differential is opened and the output speed and torque of the front axle motor are controlled by coordinated control, the slip ratio of the front left wheel is adjusted to the preset slip ratio, and the slip ratio of the front right wheel is adjusted to be equal to the slip ratio of the front left wheel, which is also equal to the preset slip ratio, and then, the slip ratio of the rear left wheel is adjusted to the preset slip ratio, and the slip ratio of the rear right wheel is adjusted to be equal to the slip ratio of the rear left wheel, that is, the slip ratios of all wheels are finally adjusted to be equal, and equal to the preset slip ratio.

[0088] In another embodiment, firstly, the brakes of the slipping front wheels are controlled to brake and the output speed and torque of the front motor are controlled to adjust the slip ratio of the front right wheel to be equal to the slip ratio of the front left wheel, which is also equal to the preset slip ratio, in coordination with the front limited slip differential; then, the brakes of the slipping rear wheels are controlled to brake and the output speed and torque of the rear motor are controlled to adjust the slip ratio of the rear left wheel to be equal to the slip ratio of the rear right wheel, which is also equal to the preset slip ratio, in coordination with the rear limited slip differential.

[0089] In step S1224, when it is judged that the vehicle speed is not within the vehicle speed threshold, i.e., the electric four-wheel drive vehicle is in a high-speed running state, or it is judged that one front wheel and one rear wheel on different sides are slipping, on one hand, the left and right wheel torque distribution functions of the front active electronic limited slip differential are controlled to be turned on, the output speed and torque of the front motor are controlled, and the wheel speed of the slipping front wheel is adjusted to be equal to the wheel speed of the non-slip front wheel; on the other hand, the left and right wheel torque distribution functions of the rear active electronic limited slip differential are controlled to be turned on, the output speed and torque of the rear motor are controlled, and the wheel speeds of the left and right rear wheels are adjusted to be equal to the wheel speed of the non-slip front wheel.

[0090] In another embodiment, the brakes of the slipping front wheels are controlled to brake and the output speed and torque of the front motor are controlled to adjust the wheel speed of the slipping front wheel to be equal to the wheel speed of the non-slip front wheel, in coordination with the front limited slip differential; then, the brakes of the slipping rear wheels are controlled to brake and the output speed and torque of the rear motor are controlled to adjust the wheel speeds of the two rear wheels to be equal to the wheel speed of the non-slip front wheel, in coordination with the rear limited slip differential.

[0091] In this embodiment, firstly, the two slipping wheels are divided into four cases, and then the parameters involved in each specific case are adaptively adjusted, so as to finally eliminate the slipping of the electric four-wheel drive vehicle and ensure stable running.

[0092] Further, in step S123, for the case that three wheels are slipping, i.e., only one wheel is not slipping, firstly, it is judged whether the non-slip wheel is a front wheel, if yes, firstly, the left and right wheel torque distribution functions of the rear active electronic limited slip differential are controlled to be turned on, the output speed and torque of the rear motor are controlled, and the wheel speeds of the rear left wheel and the rear right wheel are adjusted to be equal to the wheel speed of the non-slip front wheel, i.e., the wheel speeds of the two rear wheels are adjusted to be equal to the wheel speed of the non-slip wheel; then, the wheel speed of the slipping front wheel is adjusted to be equal to the wheel speed of the non-slip front wheel, so as to achieve the goal of eliminating the slipping.

[0093] In another embodiment, the slipping rear wheels can also be braked by coordinating the control of the brakes of the slipping rear wheels and the control of the output speed and torque of the rear motor, and the rear limited slip differential can be used to adjust the wheel speeds of the two rear wheels to the wheel speed of the non-slip wheel. Then, the slipping front wheels can be braked by coordinating the control of the brakes of the slipping front wheels and the control of the output speed and torque of the front motor, and the front limited slip differential can be used to adjust the wheel speeds of the front left wheel and the front right wheel to the wheel speed of the non-slip rear wheel. Then, the slipping rear wheels can be braked by coordinating the control of the brakes of the slipping rear wheels and the control of the output speed and torque of the rear motor, and the rear limited slip differential can be used to adjust the wheel speeds of the two rear wheels to the wheel speed of the non-slip wheel.

[0094] In addition, when the non-slip wheel is the rear wheel, i.e., the determination result is no, first, the left and right wheel torque distribution functions of the front active electronic limited slip differential are opened and the output speed and torque of the front motor are controlled to adjust the wheel speeds of the front left wheel and the front right wheel to the wheel speed of the non-slip rear wheel, i.e., to adjust the wheel speeds of the two front wheels to the wheel speed of the non-slip rear wheel. Then, the wheel speed of the slipping rear wheel is adjusted to the wheel speed of the non-slip rear wheel, thereby achieving the goal of eliminating the slip.

[0095] In another embodiment, the slipping rear wheels can also be braked by coordinating the control of the brakes of the slipping rear wheels and the control of the output speed and torque of the rear motor, and the rear limited slip differential can be used to adjust the wheel speeds of the two rear wheels to the wheel speed of the non-slip wheel. Then, the slipping front wheels can be braked by coordinating the control of the brakes of the slipping front wheels and the control of the output speed and torque of the front motor, and the front limited slip differential can be used to adjust the wheel speeds of the front left wheel and the front right wheel to the wheel speed of the non-slip rear wheel. Then, the slipping rear wheels can be braked by coordinating the control of the brakes of the slipping rear wheels and the control of the output speed and torque of the rear motor, and the rear limited slip differential can be used to adjust the wheel speeds of the two rear wheels to the wheel speed of the non-slip wheel.

[0096] In this embodiment, first, the wheel speeds of the two front / rear wheels in the slipping state are adjusted to the wheel speed of the non-slip rear / front wheel, so that three wheels can operate normally, and then the wheel speed of the last slipping wheel is adjusted to the wheel speed of the non-slip wheel. Not only can the slip be quickly eliminated to achieve stable operation of the electric four-wheel drive vehicle, but also the waste of energy of the electric four-wheel drive vehicle caused by providing the slipping wheel can be quickly reduced.

[0097] Further, in step S124, for the case where all four wheels are slipping, i.e., all wheels are slipping, first, the vehicle speed is obtained, and it is determined whether the vehicle speed is within the vehicle speed threshold. If yes, it indicates that the electric four-wheel drive vehicle is in a low-speed running state. Therefore, first, the left and right wheel torque distribution functions of the rear active electronic limited slip differential are opened and the output speed and torque of the rear motor are controlled to adjust the slip ratios of the slipping rear left wheel and the slipping rear right wheel to the preset slip ratio. Then, the left and right wheel torque distribution functions of the front active electronic limited slip differential are opened and the output speed and torque of the front motor are controlled to adjust the wheel speeds of the slipping front left wheel and the slipping front right wheel to be equal to the average wheel speed of the non-slip rear left wheel and the non-slip rear right wheel.

[0098] In another embodiment, the braking of the slipping rear wheels can also be implemented by coordinating the control of the brakes of the slipping rear wheels and the output speed and torque of the rear motor, and cooperating with the rear limited slip differential to adjust the slip ratio of the slipping rear left wheel and the slipping rear right wheel to the preset slip ratio, then the braking of the slipping front wheels can be implemented by coordinating the control of the brakes of the slipping front wheels and the output speed and torque of the front motor, and cooperating with the front limited slip differential to adjust the wheel speed of the slipping front left wheel and the slipping front right wheel to be equal, equal to the average wheel speed of the non-slip rear left wheel and the non-slip rear right wheel.

[0099] In a specific embodiment, when starting and accelerating, there is a situation that all four wheels are slipping, at this time, the vehicle center of gravity will move backward, and the rear axle load will increase, therefore, the slipping of the rear wheels should be controlled first, and the slip ratio of the rear wheels is controlled near the optimal value, that is, the wheels have relatively large longitudinal and lateral adhesion at the same time, at this time, the vehicle has good stability and traction, for example, the optimal value range is 0.1-0.2, such control is to make the vehicle have both stability and fast acceleration, and also save energy.

[0100] In a specific embodiment, the slip ratio threshold is set to 0.1-0.2.

[0101] If not, that is, the vehicle speed exceeds the vehicle speed threshold, indicating that the electric four-wheel drive vehicle is in a high-speed running state, first, the left and right wheel torque distribution functions of the front active electronic limited slip differential and the output speed and torque of the front motor are coordinated and controlled to adjust the slip ratio of the slipping front left wheel and the slip ratio of the slipping front right wheel to be equal, equal to the slip ratio threshold, then the left and right wheel torque distribution functions of the rear active electronic limited slip differential and the output speed and torque of the rear motor are coordinated and controlled to adjust the wheel speed of the slipping rear left wheel to be equal to the wheel speed of the slipping rear right wheel, both equal to the average wheel speed of the non-slip front left wheel and the non-slip front right wheel.

[0102] In a specific embodiment, the slip ratio threshold is set to 0.02.

[0103] In another embodiment, the braking of the slipping front wheels can also be implemented by coordinating the control of the brakes of the slipping front wheels and the output speed and torque of the front motor, and cooperating with the front limited slip differential to adjust the slip ratio of the slipping front left wheel and the slip ratio of the slipping front right wheel to be equal, both equal to the slip ratio threshold, then the braking of the slipping rear wheels can be implemented by coordinating the control of the brakes of the slipping rear wheels and the output speed and torque of the rear motor, and cooperating with the rear limited slip differential to adjust the wheel speed of the slipping rear left wheel to be equal to the wheel speed of the slipping rear right wheel, both equal to the average wheel speed of the non-slip front left wheel and the non-slip front right wheel.

[0104] In a specific embodiment, the vehicle speed exceeding the vehicle speed threshold belongs to a high-speed working condition, therefore, the control of stable vehicle running should be given priority, first, the slipping of the front wheels is eliminated, and then the wheel speed of the rear wheels is made consistent with the wheel speed of the front wheels.

[0105] In the above manner, the number of slipping wheels of the electric four-wheel drive vehicle is taken as a judgment basis to activate the slipping control mode of the electric four-wheel drive vehicle, and then the slipping control mode is refined in correspondence with the wheel speed, the slip rate, the vehicle speed and other information of the electric four-wheel drive vehicle, so that the slipping phenomenon of the electric four-wheel drive vehicle is accurately eliminated, and the stability of the electric four-wheel drive vehicle in operation is improved.

[0106] To solve the above problems, the application further provides an anti-slip management system of an electric four-wheel drive vehicle, as shown in Figure 4 Figure 4 The anti-slip management system of the electric four-wheel drive vehicle provided by the application is an embodiment of a structural schematic diagram, and the anti-slip management system 400 of the electric four-wheel drive vehicle comprises:

[0107] A slipping wheel acquisition module 401 is configured to acquire the number and position of the slipping wheels of the electric four-wheel drive vehicle.

[0108] A slipping control mode activation module 402 is configured to activate a corresponding slipping control mode according to the number of the slipping wheels, wherein the slipping control mode comprises a first slipping control mode, a second slipping control mode, a third slipping control mode and a fourth slipping control mode.

[0109] An anti-slip management module 403 is configured to perform anti-slip management on the wheels of the electric four-wheel drive vehicle according to the slipping control mode and the position of the slipping wheels.

[0110] The application further provides a vehicle-mounted device, as shown in Figure 5 Figure 5 The vehicle-mounted device provided by the application is an embodiment of a structural block diagram. The vehicle-mounted device 500 can be a mobile terminal, a desktop computer, a notebook computer, a palm computer, a server and other computing devices. The vehicle-mounted device 500 comprises a processor 501 and a memory 502, wherein the memory 502 stores an anti-slip management program 503 of an electric four-wheel drive vehicle.

[0111] ​​The memory 502 may, in some embodiments, be an internal storage unit of the computer device, such as a hard disk or a memory of the computer device. The memory 502 may, in other embodiments, also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 502 may also include both an internal storage unit and an external storage device of the computer device. The memory 502 is configured to store application software and various data installed in the computer device, such as program codes, etc. The memory 502 may also be configured to temporarily store data that has been output or is to be output. In an embodiment, the anti-slip management program 503 of the electric four-wheel drive vehicle can be executed by the processor 501, thereby implementing the anti-slip management method of the electric four-wheel drive vehicle according to the embodiments of the present application.

[0112] The processor 501 may, in some embodiments, be a central processing unit (CPU), a microprocessor or other data processing chip, configured to execute program codes or process data stored in the memory 502, such as executing the anti-slip management program of the electric four-wheel drive vehicle, etc.

[0113] The embodiment also provides a computer readable storage vehicle, including the vehicle-mounted device according to any of the above technical solutions.

[0114] The above description is merely preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed by the present application should be covered within the protection scope of the present application.

Claims

1. A method for managing the anti-slip of an electric four-wheel drive vehicle, characterized in that, The method comprises the following steps: acquiring the number and position of the slipping wheels of the electric four-wheel drive vehicle; activating a corresponding slip control mode according to the number of the slipping wheels, wherein the slip control mode comprises a first slip control mode, a second slip control mode, a third slip control mode and a fourth slip control mode; managing the wheels of the electric four-wheel drive vehicle according to the slip control mode and the position of the slipping wheels, wherein the second slip control mode comprises: determining whether the slipping wheels are all front wheels, if yes, reducing the driving torque of the front left wheel and the front right wheel, adjusting the wheel speeds of the front left wheel and the front right wheel to be equal and equal to the average wheel speed of the rear left wheel and the rear right wheel; if no, determining whether the slipping wheels are all rear wheels, if yes, reducing the driving torque of the rear left wheel and the rear right wheel, and adjusting the slip ratios of the rear left wheel and the rear right wheel to the slip ratio threshold value respectively; if no, acquiring the vehicle speed, determining whether the vehicle speed is within a vehicle speed threshold value and whether the slipping wheels are on the same side, if yes, adjusting the slip ratios of the front left wheel and the front right wheel to a preset slip ratio respectively, and adjusting the slip ratios of the rear left wheel and the rear right wheel to the preset slip ratio; if no, adjusting the wheel speed of the slipping front wheel to the wheel speed of the non-slip front wheel, and adjusting the wheel speed and torque of the rear wheel so that the wheel speeds of the left and right rear wheels are equal to the wheel speed of the non-slip front wheel.

2. The method of slip management for an electric all-wheel drive vehicle according to claim 1, characterized in that, The method for acquiring the number and position of the slipping wheels of the electric four-wheel drive vehicle comprises the following steps: respectively acquiring the front left wheel slip ratio, the front right wheel slip ratio, the rear left wheel slip ratio and the rear right wheel slip ratio of the electric four-wheel drive vehicle; comparing the front left wheel slip ratio, the front right wheel slip ratio, the rear left wheel slip ratio and the rear right wheel slip ratio with a preset slip ratio threshold value to determine the number and position of the slipping wheels.

3. The method of slip management for an electrically driven four-wheel drive vehicle according to claim 1, characterized by, The method for activating a corresponding slip control mode according to the number of the slipping wheels comprises the following steps: determining whether the number of the slipping wheels is one, if yes, activating the first slip control mode; if no, determining whether the number of the slipping wheels is two, if yes, activating the second slip control mode; if no, determining whether the number of the slipping wheels is three, if yes, activating the third slip control mode; if no, activating the fourth slip control mode.

4. The method of slip management for an electrically driven four-wheel drive vehicle according to claim 1, characterized by, The first slip control mode comprises the following steps: determining whether the slipping wheel is a front wheel, if yes, reducing the driving torque of the slipping front wheel and increasing the driving torque of the other front wheel; if no, adjusting the wheel speeds of the two front wheels to be equal, and reducing the driving torque of the slipping rear wheel.

5. The method of slip management for an electrically driven four-wheel drive vehicle according to claim 1, characterized by, The third slip control mode comprises the following steps: determining whether the non-slip wheel is a front wheel, if yes, adjusting the wheel speeds of the rear left wheel and the rear right wheel to the wheel speed of the non-slip front wheel, and adjusting the wheel speed of the slipping front wheel to the wheel speed of the non-slip front wheel; if no, adjusting the wheel speeds of the front left wheel and the front right wheel to the wheel speed of the non-slip rear wheel, and adjusting the wheel speed of the slipping rear wheel to the wheel speed of the non-slip rear wheel.

6. The method of slip management for an electric all-wheel drive vehicle according to claim 1, characterized in that, The fourth slip control mode comprises the following steps: acquiring a vehicle speed, judging whether the vehicle speed is within a vehicle speed threshold, if yes, adjusting slip ratios of left and right rear wheels to a preset slip ratio, and adjusting wheel speeds of left and right front wheels to average wheel speeds of the left and right rear wheels; if no, adjusting the slip ratios of the left and right front wheels to a slip ratio threshold, and adjusting wheel speeds of the left and right rear wheels to average wheel speeds of the left and right front wheels.

7. An anti-slip management system for an electric four-wheel drive vehicle, characterized by comprising: a slip wheel acquiring module, configured to acquire a number and positions of slip wheels of the electric four-wheel drive vehicle; a slip control mode activating module, configured to activate a corresponding slip control mode according to the number of the slip wheels, wherein the slip control mode comprises a first slip control mode, a second slip control mode, a third slip control mode and a fourth slip control mode; a slip prevention management module, configured to perform slip prevention management on the wheels of the electric four-wheel drive vehicle according to the slip control mode and the positions of the slip wheels, wherein the second slip control mode comprises: judging whether the slip wheels are all front wheels, if yes, reducing driving torques of the left and right front wheels, adjusting wheel speeds of the left and right front wheels to be equal and equal to average wheel speeds of left and right rear wheels; if no, judging whether the slip wheels are all rear wheels, if yes, reducing driving torques of the left and right rear wheels, and adjusting slip ratios of the left and right rear wheels to a slip ratio threshold, respectively; if no, acquiring a vehicle speed, judging whether the vehicle speed is within a vehicle speed threshold and whether the slip wheels are on the same side, if yes, adjusting slip ratios of the left and right front wheels to a preset slip ratio, and adjusting slip ratios of the left and right rear wheels to the preset slip ratio, respectively; if no, adjusting wheel speeds of the front wheels to wheel speeds of non-slip front wheels, and adjusting wheel speeds and torques of the rear wheels, so that wheel speeds of the left and right rear wheels are equal to the wheel speeds of the non-slip front wheels.

8. An in-vehicle device characterized by comprising: comprising a processor and a memory, wherein the memory stores a computer program, and the computer program is executed by the processor to implement the slip prevention management method of the electric four-wheel drive vehicle according to any one of claims 1-6.

9. A vehicle characterized by comprising: comprising the vehicle-mounted device according to claim 8.

Images