Electric vehicle driving control method and device and electric vehicle

Abstract

The invention discloses an electric vehicle driving control method and device and an electric vehicle. The speed control stability of the vehicle can be improved. The electric vehicle running control method comprises the steps that the total torque required by a vehicle is obtained based on the vehicle actual rotating speed and the vehicle target rotating speed; a first actual torque value of a front wheel motor and a second actual torque value of a rear wheel motor during starting control are obtained; based on the actual load ratio of the front wheel and the rear wheel, the torque distribution proportion of the front wheel and the rear wheel is determined; determining anti-skid compensation values of the front wheel and the rear wheel based on the speed difference of the front wheel and the rear wheel; determining output limit values of a front wheel motor and a rear wheel motor based on a preset torque limit value of the vehicle; according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution proportion of the front wheel and the rear wheel, the anti-skid compensation values of the front wheel and the rear wheel and the output limit values of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value, and the rear wheel motor is controlled to output the second torque value.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to an electric vehicle driving control method, device and electric vehicle. Background Art

[0002] With the increasing global awareness of environmental protection and the transformation of energy structure, electric vehicles, as representatives of new energy vehicles, have developed rapidly in recent years. When electric vehicles are applied to the field of road machinery, the existing technology is difficult to apply because the operating nature of the operating equipment is different from the operating habits of electric vehicles. For example, in the existing technology, dual-drive electric vehicles can achieve front and rear wheel torque distribution, but cannot maintain the vehicle speed while satisfying the torque distribution, which reduces the speed control stability of the vehicle. Summary of the invention

[0003] In order to solve the above technical problems, the present application is proposed. The embodiments of the present application provide an electric vehicle driving control method, device and electric vehicle, which can improve the speed control stability of the vehicle.

[0004] According to a first aspect of the present application, a method for controlling driving an electric vehicle is provided, comprising: obtaining a total torque required by the vehicle based on an actual vehicle speed and a target vehicle speed; wherein the vehicle comprises front wheels, rear wheels, a front-wheel motor and a rear-wheel motor; obtaining a first actual torque value of the front-wheel motor and a second actual torque value of the rear-wheel motor during starting control; determining a torque distribution ratio of the front wheels and the rear wheels based on an actual load ratio of the front wheels and the rear wheels; determining anti-skid compensation values ​​of the front wheels and the rear wheels based on a speed difference between the front wheels and the rear wheels; determining output limit values ​​of the front-wheel motor and the rear-wheel motor based on a preset torque limit value of the vehicle; and controlling the front-wheel motor to output a first torque value and controlling the rear-wheel motor to output a second torque value according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-skid compensation values ​​of the front wheels and the rear wheels, and the output limit values ​​of the front-wheel motor and the rear-wheel motor.

[0005] As a possible implementation method, the total torque required by the vehicle is obtained based on the actual vehicle speed and the target vehicle speed, including: obtaining the difference between the actual vehicle speed and the target vehicle speed; based on the difference between the actual vehicle speed and the target vehicle speed, searching for the corresponding proportional coefficient and integral coefficient in a preset table; based on the corresponding proportional coefficient and integral coefficient, performing proportional-integral adjustment on the difference between the actual vehicle speed and the target vehicle speed to obtain the total torque required by the vehicle.

[0006] As a possible implementation method, the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor during starting control are obtained, including: when entering starting control, the motor control performs a zero speed control mode and opens a brake release valve; when the brake release pressure of the vehicle is greater than the brake release opening value, it is determined that the starting control is completed; when the starting control is completed and the starting control is exited, the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor are read and recorded.

[0007] As a possible implementation method, according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value, and the rear wheel motor is controlled to output the second torque value, including: determining the driving road state of the vehicle according to the first actual torque value of the front wheel motor, the second actual torque value of the rear wheel motor and the preset torque; wherein the driving road state includes flat road driving and slope driving; when the driving road state of the vehicle is slope driving, the front wheel motor is controlled to output a first torque value greater than or equal to the first actual torque value, and the rear wheel motor is controlled to output a second torque value greater than or equal to the second actual torque value.

[0008] As a possible implementation, after determining the torque distribution ratio of the front wheels and the rear wheels based on the actual load ratio of the front wheels and the rear wheels, the electric vehicle driving control method includes: based on the torque distribution ratio of the front wheels and the rear wheels, allocating a first torque proportional coefficient to the front wheels and allocating a second torque proportional coefficient to the rear wheels; wherein, according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value and the rear wheel motor is controlled to output the second torque value, including: according to the total torque required by the vehicle, the first actual torque value, the first torque proportional coefficient, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value; according to the total torque required by the vehicle, the second actual torque value, the second torque proportional coefficient, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor, the rear wheel motor is controlled to output the second torque value.

[0009] As a possible implementation method, the anti-skid compensation values ​​of the front wheels and the rear wheels are determined based on the speed difference between the front wheels and the rear wheels, including: when a first speed difference between the front wheels and the rear wheels is greater than a preset speed difference, the slipping wheels and the non-slipping wheels are determined based on a first real-time speed value of the front wheels and a second real-time speed value of the rear wheels; and the anti-skid compensation value of the slipping wheels is calculated based on the minimum speed difference, the maximum speed difference, the maximum compensation value and the first speed difference between the front wheels and the rear wheels.

[0010] As a possible implementation method, the anti-skid compensation values ​​of the front wheels and the rear wheels are determined based on the speed difference between the front wheels and the rear wheels, and the method also includes: obtaining a second speed difference between the real-time speed value of the non-slipping wheel and the target speed of the vehicle; and calculating the anti-skid compensation value of the non-slipping wheel based on the anti-skid compensation value of the slipping wheel, the minimum speed difference between the front wheels and the rear wheels, the maximum speed difference, the maximum compensation value and the second speed difference.

[0011] As a possible implementation method, the anti-skid compensation value of the non-skidding wheel is calculated based on the anti-skid compensation value of the slipping wheel, the minimum speed difference, the maximum speed difference, the maximum compensation value and the second speed difference between the front wheels and the rear wheels, including: when the real-time speed value of the non-skidding wheel is less than the target speed of the vehicle, the anti-skid compensation value of the non-skidding wheel is the opposite of the anti-skid compensation value of the slipping wheel; when the real-time speed value of the non-skidding wheel is greater than or equal to the target speed of the vehicle, the anti-skid compensation value of the non-skidding wheel is related to the minimum speed difference, the maximum speed difference, the maximum compensation value and the second speed difference between the front wheels and the rear wheels.

[0012] According to a second aspect of the present application, there is provided an electric vehicle driving control device, comprising: a first acquisition module, for acquiring a total torque required by the vehicle based on an actual vehicle speed and a target vehicle speed; wherein the vehicle comprises front wheels, rear wheels, a front wheel motor and a rear wheel motor; a second acquisition module, for acquiring a first actual torque value of the front wheel motor and a second actual torque value of the rear wheel motor during starting control; a first determination module, for determining a torque distribution ratio of the front wheels and the rear wheels based on an actual load ratio of the front wheels and the rear wheels; a second determination module, for determining an anti-skid compensation value of the front wheels and the rear wheels based on a speed difference between the front wheels and the rear wheels; a third determination module, for determining an output limit value of the front wheel motor and the rear wheel motor based on a preset torque limit value of the vehicle; and a control module, for controlling the front wheel motor to output a first torque value and controlling the rear wheel motor to output a second torque value according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor.

[0013] According to the third aspect of the present application, an electric vehicle is provided, comprising: a front wheel motor and a rear wheel motor; an electric vehicle driving control device as described in the second aspect, the electric vehicle driving control device is electrically connected to the front wheel motor, and the electric vehicle driving control device is electrically connected to the rear wheel motor.

[0014] The electric vehicle driving control method, device and electric vehicle provided by the present application take into account the actual vehicle speed and the target vehicle speed during the control process to achieve closed-loop speed control. Based on the actual torque of the front and rear wheels during starting control, the starting output torque can be controlled to reduce the possibility of slipping at the start, and anti-skid compensation is performed considering the speed difference between the front and rear wheels to further improve the stability of wheel control. After proportional distribution, starting control, and drive anti-skid control, the front and rear wheel motors are controlled to output the corresponding target torque to achieve front and rear wheel torque distribution and closed-loop speed control, thereby improving the speed control stability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0016] Figure 1 It is a structural diagram of a control system of an electric vehicle provided by an exemplary embodiment of the present application.

[0017] Figure 2 It is a flowchart of an electric vehicle driving control method provided by an exemplary embodiment of the present application.

[0018] Figure 3 It is a schematic diagram of the calculation principle of the total torque required by the vehicle provided by an exemplary embodiment of the present application.

[0019] Figure 4 It is a flowchart of a start control provided by an exemplary embodiment of the present application.

[0020] Figure 5 It is a structural schematic diagram of an electric vehicle driving control device provided by an exemplary embodiment of the present application.

[0021] Figure 6 A structural diagram of an electronic device provided by an exemplary embodiment of the present application.

[0022] Explanation of the reference numerals: 11. handle; 12. vehicle controller; 131. front wheel motor controller; 132. rear wheel motor controller; 141. front wheel motor; 142. rear wheel motor; 151. front wheel reducer and steel wheel; 152. rear wheel reducer and steel wheel; 16. battery management system; 17. hydraulic parking system. DETAILED DESCRIPTION

[0023] Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the exemplary embodiments described here.

[0024] Application Overview

[0025] Distributed electric drive solutions usually use motors and reducers for direct drive, which are energy-saving, efficient, powerful, and have a simple transmission structure. They have become a hot topic in the current electric vehicle research field. However, when distributed electric drive solutions are applied to the field of road machinery, the existing technology cannot be directly applied because the operating nature of the operating equipment is different from the operating habits of electric vehicles. For example, a dual-drive electric roller uses a distributed electric drive solution, and the travel control may encounter the following difficult problems: 1. It is necessary to achieve torque distribution between the front and rear wheels to avoid uneven torque distribution or even confrontation; 2. Travel needs to solve the drive anti-skid and start anti-slip functions.

[0026] In order to solve the problem that distributed electric drive solutions cannot be adapted to the field of road machinery, the present application proposes an electric vehicle driving control method, device and electric vehicle. The difference between the actual vehicle speed and the target vehicle speed is obtained and adjusted to obtain the total torque required by the vehicle. After proportional distribution, starting control and drive anti-skid control, the front wheel motor and the rear wheel motor are controlled to output corresponding target torques respectively, thereby realizing front and rear wheel torque distribution and closed-loop control of vehicle speed. The method is suitable for low-speed working equipment that switches back and forth between forward and backward and needs to maintain speed.

[0027] Example Vehicles

[0028] The electric vehicle driving control method provided in the present application can be applicable to electric vehicles, which include: a front wheel motor and a rear wheel motor; such as the electric vehicle driving control device provided in the present application, the electric vehicle driving control device is electrically connected to the front wheel motor, and the electric vehicle driving control device is electrically connected to the rear wheel motor.

[0029] The electric vehicle driving control device is used to execute the electric vehicle driving control method, and the electric vehicle can be a road mechanical vehicle, such as a distributed dual-drive electric roller, a distributed dual-drive electric excavator, and a distributed dual-drive electric loader. The distributed dual-drive electric vehicle uses two or more motors to drive the vehicle together, and the distributed drive system can independently control the torque and speed of each wheel.

[0030] Figure 1 is a schematic diagram of a control system of an electric vehicle provided by an exemplary embodiment of the present application. Figure 1As shown, the control system of the electric vehicle includes a handle 11, a vehicle controller 12, a front wheel motor controller 131, a front wheel motor 141, a front wheel reducer and a steel wheel 151, a rear wheel motor controller 132, a rear wheel motor 142, a rear wheel reducer and a steel wheel 152, a battery management system 16 (BMS, Battery Management System), and a hydraulic parking system 17.

[0031] The handle 11 in an electric vehicle usually refers to the accelerator pedal and brake pedal and their related operating mechanisms. The function of the handle 11 is to convert the driver's acceleration and braking intentions into electrical signals and input them into the vehicle controller 12, thereby realizing the acceleration, deceleration and braking control of the vehicle. The vehicle controller 12 (VCU) is the core control component of the electric vehicle, responsible for the key tasks of controlling the entire vehicle. The vehicle controller 12 can be used for driving torque control. According to the driver's operating intention (such as the input of the accelerator pedal and the brake pedal), the output torque of the motor is controlled to achieve the acceleration and deceleration of the vehicle. It can also be used for braking energy optimization, energy management, network management and fault diagnosis. The front wheel motor controller 131 and the rear wheel motor controller 132 are control units that control the motor to drive the entire vehicle. They are core components of electric vehicles. The motor controller can be used to regulate motor operation, precise control, energy recovery and real-time monitoring. The front wheel motor 141 and the rear wheel motor 142 are the power sources of the electric vehicle, responsible for converting electrical energy into mechanical energy to drive the vehicle. The distributed dual-drive electric vehicle uses two or more motors to drive the vehicle together, so the front wheel motor 141 and the rear wheel motor 142 can be set to control the front wheel and the rear wheel respectively. The front wheel reducer and the rear wheel reducer convert the high-speed and low-torque output of the motor into a low-speed and high-torque output suitable for the wheels, ensuring that the vehicle has sufficient power when driving at low speed and starting. The steel wheel is the driving component of the electric vehicle, responsible for transmitting the driving force of the motor to the road surface, so that the vehicle can move forward, backward and turn. The battery management system 16 is used to monitor the working state and efficiency of the battery pack, realize the balanced management of the battery, perform heat dissipation and heating management, and perform safety assurance. The hydraulic parking system 17 is the parking brake device of the electric vehicle, and its main function is to provide sufficient braking force when the vehicle is parked to prevent the vehicle from sliding or rolling. The hydraulic parking system 17 usually has the characteristics of easy operation, large braking force, high reliability, etc., and can provide safe and reliable parking brakes for electric vehicles.

[0032] Exemplary Methods

[0033] In order to solve the problem that the distributed electric drive solution cannot be adapted to the field of road machinery, Figure 2 is a flow chart of an electric vehicle driving control method provided by an exemplary embodiment of the present application. Figure 2For example, the vehicle includes front wheels, rear wheels, front wheel motors and rear wheel motors. First, based on the actual speed of the vehicle and the target speed of the vehicle, the total torque required by the vehicle is obtained (see Figure 2 Then, the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor during the start control are obtained (see S100). Figure 2 The actual torque value during the start control is recorded, which can be used to control the start output torque to reduce the possibility of slipping at the start. Then, based on the actual load ratio of the front wheels and the rear wheels, the torque distribution ratio of the front wheels and the rear wheels is determined (see Figure 2 S300) calculates the distribution coefficient according to the real-time vehicle status such as the wheel load ratio, so that the front wheel motor and the rear wheel motor can output the torque corresponding to the distribution coefficient. Then, based on the speed difference between the front wheel and the rear wheel, the anti-skid compensation value of the front wheel and the rear wheel is determined (see Figure 2 When the front and rear wheel speeds are inconsistent and a speed difference is generated, negative compensation can be given to the slipping wheel to reduce torque distribution, and positive compensation can be given to the non-slipping wheel to increase torque to achieve drive anti-slip control. Next, based on the vehicle's preset torque limit value, the output limit values ​​of the front and rear wheel motors are determined (see Figure 2 S500 of the present invention) limits the torque of the front wheel motor and the rear wheel motor, which can protect the power system, improve driving safety and optimize energy use. Finally, according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front and rear wheels, the anti-slip compensation value of the front and rear wheels, and the output limit value of the front and rear wheel motors, the front wheel motor is controlled to output the first torque value and the rear wheel motor is controlled to output the second torque value (see Figure 2 S600), after considering the proportional distribution, starting control and driving anti-skid control, controls the front and rear wheel motors to output the corresponding target torque, realizes the front and rear wheel torque distribution and vehicle speed closed-loop control, and improves the vehicle control stability.

[0034] Combined with the following Figure 2 , a more detailed introduction is given to the electric vehicle driving control method provided in the embodiment of the present application.

[0035] In S100, the total torque required by the vehicle is obtained based on the actual vehicle speed and the target vehicle speed. The torque is adjusted by the actual vehicle speed and the target vehicle speed, so that the closed-loop control of the vehicle speed can be achieved.

[0036] A possible implementation method of S100 may be: obtaining the difference between the actual vehicle speed and the target vehicle speed; based on the difference between the actual vehicle speed and the target vehicle speed, searching for the corresponding proportional coefficient and integral coefficient in a preset table; based on the corresponding proportional coefficient and integral coefficient, performing proportional-integral adjustment on the difference between the actual vehicle speed and the target vehicle speed to obtain the total torque required by the vehicle.

[0037] Figure 3 FIG. 1 is a schematic diagram of the calculation principle of the total torque required by a vehicle provided by an exemplary embodiment of the present application, such as Figure 3 As shown, first obtain the actual vehicle speed, then obtain the vehicle target speed according to the handle opening, calculate the difference E between the actual vehicle speed and the target vehicle speed, and perform PI (proportional integral) control based on the difference E to obtain the total torque T required by the vehicle t . PI regulation, or proportional-integral regulation, is a controller widely used in industrial control systems. PI regulation combines two mechanisms, proportional control (P) and integral control (I). By adjusting these two parameters, precise control of the system output can be achieved. Proportional control amplifies the deviation between the input signal (here is the speed difference) and the set value to generate a control signal. The characteristic of proportional control is fast response speed, and the output of the system can be quickly adjusted to reduce the deviation. The role of integral control is to eliminate the steady-state error in proportional control. By integrating the deviation signal, the PI regulator generates a control signal that is proportional to the accumulated deviation. This signal accumulates over time until the deviation is completely eliminated and the integral control stops. In this way, integral control can improve the error-freeness of the system.

[0038] In addition, in some vehicles with complex working conditions, different speeds and different loads require different parameter adjustments. Therefore, different gears can be set according to different target speeds. For example, the working conditions of distributed dual-drive rollers are complex, and the load span is inconvenient to distinguish statistically. The difference between the target speed and the actual speed can be used to replace the load. The gears are set to low, medium, and high levels of load according to the difference between the target and actual speeds. Different KP (proportional coefficient) and KI (integral coefficient) are set to adjust to meet the speed response of complex working conditions. KP reflects the response speed and sensitivity of the controller to the deviation signal. When there is a deviation between the actual speed and the target speed, the KP parameter will determine how much adjustment the controller outputs to eliminate the deviation. The larger the deviation, the larger the adjustment amount, thereby speeding up the system response speed and making the actual speed approach the target speed as soon as possible. The KI parameter reflects the cumulative effect of the controller on the deviation signal. By accumulating the deviation signal, the integral adjustment can gradually eliminate the static error of the system and improve the control accuracy.

[0039] In some embodiments, the preset table may be set as Table 1:

[0040] Table 1

[0041]

[0042] In S200, a first actual torque value of the front wheel motor and a second actual torque value of the rear wheel motor during start control are obtained. The torque value during start control can help the vehicle not to slip when starting.

[0043] Figure 4 is a flowchart of a start control provided by an exemplary embodiment of the present application. Figure 4 For example, a possible implementation of S200 is: when entering the starting control, the motor control performs the zero speed control mode and opens the brake release valve (see Figure 4 S41 in ); determine whether the brake release pressure is greater than the brake release opening value (see Figure 4 When the brake release pressure of the vehicle is greater than the brake release opening value, the start control is determined to be completed; when the start control is completed and the start control is exited, the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor are read and recorded (see S42 in FIG. Figure 4 If the vehicle's brake release pressure is less than or equal to the brake release opening value, the brake release valve continues to open. A brake release pressure greater than the brake release opening value means that during the brake release process, the pressure generated inside the brake system exceeds the preset brake release opening value. This usually indicates that the brake system has completed the transition from the locked state to the released state, that is, the brake has been completely released. Zero speed control mode refers to a mode in which the system takes specific control measures when the motor speed is maintained at a certain set value (usually close to or equal to zero).

[0044] The torque recorded during the start control can be used to determine whether the vehicle is on a slope. For example, the vehicle's driving road state is determined based on the first actual torque value of the front-wheel motor, the second actual torque value of the rear-wheel motor, and the preset torque. The preset torque can be the torque recorded when the vehicle is on flat ground, or it can be a torque value set according to the torque recorded when the vehicle is on flat ground. The first actual torque value of the front-wheel motor, the second actual torque value of the rear-wheel motor, and the preset torque are compared to determine whether the vehicle is on a slope. When the vehicle's driving road state is a slope, the front-wheel motor is controlled to output a first torque value greater than or equal to the first actual torque value, and the rear-wheel motor is controlled to output a second torque value greater than or equal to the second actual torque value. The purpose is to control the starting output torque to be not less than the torque output in the zero-speed control mode to ensure that the vehicle does not slip when starting.

[0045] In some embodiments, after the brake release pressure is greater than the brake release opening value, a delay T 1S (set according to requirements) determines whether the start control is completed. When the brake release pressure exceeds the opening value, this usually means that the driver has expressed the intention to start. To ensure the clarity of this intention, the system needs a certain amount of time to confirm. Delayed determination can help the system more accurately judge whether the brake is fully released, avoiding triggering the exit from the start control due to misoperation or short-term pressure changes (when the brake is actually not released). In addition, after the brake release pressure is greater than the opening value, these systems need a certain amount of time to respond and reach a stable state. Delayed determination can ensure that the vehicle system has fully responded and is ready to start, thereby improving the smoothness and stability of the start.

[0046] In S300, based on the actual load ratio of the front and rear wheels, the torque distribution ratio of the front and rear wheels is determined. The actual load ratio of the front and rear wheels is affected by the attributes of the vehicle itself. For example, the total weight of the vehicle is the basis for determining the loads on the front and rear wheels. The position of the engine has a certain impact on the front and rear wheel load ratio. Vehicles with a front-mounted engine usually have a heavier front axle load, while vehicles with a rear-mounted engine have a heavier rear axle load. The driving habits of the driver, such as acceleration, braking, and turning, will all affect the load ratio of the front and rear wheels. Therefore, based on the attributes and operating conditions of each vehicle itself, the actual load ratio of the front and rear wheels of the vehicle is obtained. According to the actual load ratio, the torque distribution ratio of the front and rear wheels is determined.

[0047] In some embodiments, after S300, based on the torque distribution ratio of the front and rear wheels, a first torque ratio coefficient is assigned to the front wheel, and a second torque ratio coefficient is assigned to the rear wheel. According to the total torque required by the vehicle, the first actual torque value, the first torque ratio coefficient, the anti-skid compensation values of the front and rear wheels, and the output limit values of the front-wheel motor and the rear-wheel motor, the front-wheel motor is controlled to output a first torque value; according to the total torque required by the vehicle, the second actual torque value, the second torque ratio coefficient, the anti-skid compensation values of the front and rear wheels, and the output limit values of the front-wheel motor and the rear-wheel motor, the rear-wheel motor is controlled to output a second torque value.

[0048] For example, the sum of the first torque ratio coefficient of the front wheel and the second torque ratio coefficient of the rear wheel is 1, that is, a + b = 1, where a can represent the first torque ratio coefficient of the front wheel, b can represent the second torque ratio coefficient of the rear wheel, and 0 < a < 1, 0 < b < 1. In some ideal states, the loads on the front and rear wheels are close, so a:b = 1, a = 0.5, b = 0.5 can be set.

[0049] In S400, based on the speed difference between the front wheels and the rear wheels, the anti-skid compensation values ​​of the front wheels and the rear wheels are determined. After the torque distribution ratio is determined, the friction between the front and rear wheels may be different. When the driving force distributed to the wheels is greater than its friction, slippage will occur, which is manifested as the speed difference caused by the inconsistent rotation speed of the front and rear wheels. The anti-skid compensation torque of the front and rear wheels is calculated through anti-skid control, and negative compensation is given to the slipping wheel (high-speed wheel) to reduce torque distribution, and positive compensation is given to the non-slipping wheel (low-speed wheel) to increase torque, so as to achieve drive anti-skid control.

[0050] In some embodiments, a possible implementation method for realizing anti-skid compensation may be: when the first speed difference between the front wheel and the rear wheel is greater than the preset speed difference, the slipping wheel and the non-slipping wheel are determined based on the first real-time rotation speed value of the front wheel and the second real-time rotation speed value of the rear wheel; the anti-skid compensation value of the slipping wheel is calculated based on the minimum speed difference, maximum speed difference, maximum compensation value and first speed difference between the front wheel and the rear wheel. The second speed difference between the real-time rotation speed value of the non-slipping wheel and the target rotation speed of the vehicle is obtained; the anti-skid compensation value of the non-slipping wheel is calculated based on the anti-skid compensation value of the slipping wheel, the minimum speed difference, maximum speed difference, maximum compensation value and second speed difference between the front wheel and the rear wheel.

[0051] For example, first compare the rotation speeds of the front wheel and the rear wheel, and obtain the first speed difference SD between the front wheel and the rear wheel. 1 , determine the faster wheel as the slipping wheel, the slower wheel as the non-slipping wheel, and calculate the anti-skid compensation value of the slipping wheel: T a =map(SD min , S.D. max ,0,T amax , S.D. 1 ), where T a Indicates the anti-slip compensation value of the slipping wheel, SD min Indicates the minimum speed difference, SD max Indicates the maximum speed difference, T amax Indicates the maximum anti-slip compensation value, SD 1 After the slip compensation value of the slipping wheel is calculated, the real-time speed value of the non-slipping wheel is compared with the target speed of the vehicle to obtain the second speed difference SD. 2 , calculate the anti-skid compensation value of the non-slipping wheel. When the real-time speed value of the non-slipping wheel is less than the target speed of the vehicle, the anti-skid compensation value of the non-slipping wheel is the opposite of the anti-skid compensation value of the slipping wheel, such as T n1 =-T a When the real-time speed value of the non-slipping wheel is greater than or equal to the vehicle target speed, the anti-skid compensation value of the non-slipping wheel is related to the minimum speed difference between the front and rear wheels, the maximum speed difference, the maximum compensation value and the second speed difference, such as T n2 =map(SD min , S.D. max ,0,Tamax , S.D. 2 ), T n1 and T n2 Indicates the anti-slip compensation value of the non-slipping wheel at different speeds.

[0052] In S500, based on the preset torque limit value of the vehicle, the output limit value of the front wheel motor and the rear wheel motor is determined. If the motor torque needs to be limited, the minimum value can be taken from the rated torque of the vehicle motor and the fault limit torque as the maximum value of the output torque of the front wheel motor and the rear wheel motor, that is, the minimum limit torque. Limiting the torque of the front wheel motor and the rear wheel motor can prevent the power system from overloading, and in some extreme driving conditions, such as slippery roads or sudden acceleration, excessive torque may cause the vehicle to slip or lose control. By limiting the torque, the driving stability of the vehicle can be improved and driving safety can be ensured.

[0053] In S600, the front wheel motor is controlled to output the first torque value and the rear wheel motor is controlled to output the second torque value according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheel and the rear wheel, the anti-skid compensation value of the front wheel and the rear wheel, and the output limit value of the front wheel motor and the rear wheel motor. When controlling the output torque of the front wheel motor and the rear wheel motor, the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheel and the rear wheel, the anti-skid compensation value of the front wheel and the rear wheel, and the output limit value of the front wheel motor and the rear wheel motor are considered, so that the speed closed-loop control can be realized, and the possibility of slipping at the start is reduced, and the possibility of wheel slipping is reduced.

[0054] In some embodiments, the method for calculating the first torque value output by the front wheel motor may be: f =limit{-T max , max[T sf , (T t *a±T af )],T max}, where T f Represents the first torque value of the front wheel motor output, T max represents the minimum limit torque (i.e., output limit value) obtained in S500, T sf represents the first actual torque value of the front wheel motor during the start control obtained in S200, T t represents the total torque required by the vehicle obtained in S100, a represents the first torque proportional coefficient of the front wheel obtained in S300, T af Indicates the anti-skid compensation value obtained in S400. For example, when the front wheel is a slipping wheel, T af T a , T af The value is T a=map(SD min , S.D. max ,0,T amax , S.D. 1 ), if the front wheel is a non-slip wheel, then T af T n1 or T n2 , according to the front wheel speed and the vehicle target speed. When the start control is not on a slope, T sf The value can be 0. When the first speed difference between the front wheel and the rear wheel is less than or equal to the preset speed difference, T af The value can be 0.

[0055] In some other embodiments, the method for calculating the second torque value output by the rear wheel motor may be: r =limit{-T max , max[T sr , (T t *b±T ar )],T max}, where T r Represents the second torque value of controlling the output of the rear wheel motor, T max represents the minimum limit torque (i.e., output limit value) obtained in S500, T sr represents the second actual torque value of the rear wheel motor during the start control obtained in S200, T t represents the total torque required by the vehicle obtained in S100, b represents the second torque proportional coefficient of the rear wheels obtained in S300, T ar Indicates the anti-skid compensation value obtained in S400. For example, when the rear wheel is a slipping wheel, T ar T a , T ar The value is T a =map(SD min , S.D. max ,0,T amax , S.D. 1 ), if the rear wheel is a non-slip wheel, then T ar T n1 or T n2 , according to the rear wheel speed and the vehicle target speed. When the start control is not on a slope, T sr The value can be 0. When the first speed difference between the front wheel and the rear wheel is less than or equal to the preset speed difference, T ar The value can be 0.

[0056] Exemplary Devices

[0057] Figure 5 A schematic diagram of the structure of an electric vehicle driving control device provided by an exemplary embodiment of the present application is as follows: Figure 5 As shown, the electric vehicle driving control device 5 includes: a first acquisition module 51, which is used to acquire the total torque required by the vehicle based on the actual speed of the vehicle and the target speed of the vehicle; wherein the vehicle includes front wheels, rear wheels, front wheel motors and rear wheel motors; a second acquisition module 52, which is used to acquire the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor during starting control; a first determination module 53, which is used to determine the torque distribution ratio of the front wheels and the rear wheels based on the actual load ratio of the front wheels and the rear wheels; a second determination module 54, which is used to determine the anti-skid compensation value of the front wheels and the rear wheels based on the speed difference between the front wheels and the rear wheels; a third determination module 55, which is used to determine the output limit value of the front wheel motor and the rear wheel motor based on the preset torque limit value of the vehicle; and a control module 56, which is used to control the front wheel motor to output the first torque value and the rear wheel motor to output the second torque value according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor.

[0058] As a possible implementation method, the first acquisition module 51 can be configured to: obtain the difference between the actual vehicle speed and the target vehicle speed; based on the difference between the actual vehicle speed and the target vehicle speed, search for the corresponding proportional coefficient and integral coefficient in a preset table; based on the corresponding proportional coefficient and integral coefficient, perform proportional-integral adjustment on the difference between the actual vehicle speed and the target vehicle speed to obtain the total torque required by the vehicle.

[0059] As a possible implementation, the second acquisition module 52 may be configured as follows: when entering starting control, the motor control performs a zero speed control mode and opens the brake release valve; when the brake release pressure of the vehicle is greater than the brake release opening value, the starting control is determined to be completed; when the starting control is completed and the starting control is exited, the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor are read and recorded.

[0060] As a possible implementation, the control module 56 can be configured to: determine the driving road state of the vehicle based on the first actual torque value of the front-wheel motor, the second actual torque value of the rear-wheel motor and the preset torque; wherein the driving road state includes flat road driving and slope driving; when the driving road state of the vehicle is slope driving, the front-wheel motor is controlled to output a first torque value greater than or equal to the first actual torque value, and the rear-wheel motor is controlled to output a second torque value greater than or equal to the second actual torque value.

[0061] As a possible implementation method, the electric vehicle driving control device 5 can be configured as: based on the torque distribution ratio of the front wheels and the rear wheels, a first torque proportional coefficient is allocated to the front wheels, and a second torque proportional coefficient is allocated to the rear wheels; wherein the control module 56 can be configured as: according to the total torque required by the vehicle, the first actual torque value, the first torque proportional coefficient, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value; according to the total torque required by the vehicle, the second actual torque value, the second torque proportional coefficient, the anti-skid compensation value of the front wheels and the rear wheels, and the output limit value of the front wheel motor and the rear wheel motor, the rear wheel motor is controlled to output the second torque value.

[0062] As a possible implementation method, the second determination module 54 can be configured as follows: when the first speed difference between the front wheels and the rear wheels is greater than a preset speed difference, the slipping wheels and non-slipping wheels are determined based on the first real-time speed value of the front wheels and the second real-time speed value of the rear wheels; and the anti-skid compensation value of the slipping wheels is calculated based on the minimum speed difference, the maximum speed difference, the maximum compensation value and the first speed difference between the front wheels and the rear wheels.

[0063] As a possible implementation method, the second determination module 54 can also be configured to: obtain the second speed difference between the real-time speed value of the non-slipping wheel and the target speed of the vehicle; calculate the anti-slip compensation value of the non-slipping wheel based on the anti-slip compensation value of the slipping wheel, the minimum speed difference between the front and rear wheels, the maximum speed difference, the maximum compensation value and the second speed difference.

[0064] As a possible implementation method, the second determination module 54 can also be configured as follows: when the real-time speed value of the non-slipping wheel is less than the target speed of the vehicle, the anti-slip compensation value of the non-slipping wheel is the opposite of the anti-slip compensation value of the slipping wheel; when the real-time speed value of the non-slipping wheel is greater than or equal to the target speed of the vehicle, the anti-slip compensation value of the non-slipping wheel is related to the minimum speed difference, maximum speed difference, maximum compensation value and second speed difference between the front and rear wheels.

[0065] Exemplary Electronic Devices

[0066] An electronic device includes: a processor; a memory for storing instructions executable by the processor; and the processor is used to execute the electric vehicle driving control method described in the embodiment provided in the present application.

[0067] Below, reference Figure 6 The electronic device according to the embodiment of the present application is described. The electronic device may be any one or both of the first device and the second device, or a stand-alone device independent of them, and the stand-alone device may communicate with the first device and the second device to receive the collected input signal from them.

[0068] Figure 6A block diagram of an electronic device according to an embodiment of the present application is illustrated.

[0069] like Figure 6 As shown, the electronic device 60 includes one or more processors 61 and a memory 62 .

[0070] The processor 61 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 60 to perform desired functions.

[0071] The memory 62 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 61 may run the program instructions to implement the electric vehicle driving control method of each embodiment of the present application described above and / or other desired functions. Various contents such as input signals, signal components, noise components, etc. may also be stored in the computer-readable storage medium.

[0072] In one example, the electronic device 60 may further include: an input device 63 and an output device 64, and these components are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0073] When the electronic device is a stand-alone device, the input device 63 may be a communication network connector for receiving collected input signals from the first device and the second device.

[0074] In addition, the input device 63 may also include, for example, a keyboard, a mouse, etc.

[0075] The output device 64 can output various information to the outside, including the determined distance information, direction information, etc. The output device 64 can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto, and the like.

[0076] Of course, to simplify, Figure 6 Only some of the components related to the present application in the electronic device 60 are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application situations, the electronic device 60 may also include any other appropriate components.

[0077] The computer program product may be written in any combination of one or more programming languages ​​to write program codes for performing the operations of the embodiments of the present application, including object-oriented programming languages, such as Java, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0078] A computer-readable storage medium stores a computer program, and the computer program is used to execute the electric vehicle driving control method described in the embodiment provided in the present application.

[0079] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0080] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A driving control method for an electric vehicle, characterized in that: include: Based on the actual speed of the vehicle and the target speed of the vehicle, the total torque required by the vehicle is obtained; wherein the vehicle includes front wheels, rear wheels, front wheel motors and rear wheel motors; Acquire a first actual torque value of the front wheel motor and a second actual torque value of the rear wheel motor during start control; Determine the torque distribution ratio between the front wheels and the rear wheels based on the actual load ratio between the front wheels and the rear wheels; Determining anti-skid compensation values ​​of the front wheels and the rear wheels based on the speed difference between the front wheels and the rear wheels; Determining output limit values ​​of the front wheel motor and the rear wheel motor based on a preset torque limit value of the vehicle; According to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-slip compensation values ​​of the front wheels and the rear wheels, and the output limit values ​​of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value, and the rear wheel motor is controlled to output the second torque value.

2. The electric vehicle driving control method according to claim 1, characterized in that: Based on the actual vehicle speed and the target vehicle speed, the total torque required by the vehicle is obtained, including: Obtain the difference between the actual speed of the vehicle and the target speed of the vehicle; Based on the difference between the actual speed of the vehicle and the target speed of the vehicle, searching for the corresponding proportional coefficient and integral coefficient in the preset table; Based on the corresponding proportional coefficient and integral coefficient, the difference between the actual speed of the vehicle and the target speed of the vehicle is adjusted proportionally and integrally to obtain the total torque required by the vehicle.

3. The electric vehicle driving control method according to claim 1, characterized in that: Acquiring a first actual torque value of a front wheel motor and a second actual torque value of a rear wheel motor during start control, including: When entering the starting control, the motor control enters the zero speed control mode and opens the brake release valve; When the brake release pressure of the vehicle is greater than the brake release opening value, it is determined that the start control is completed; When the launch control is completed and the launch control is exited, the first actual torque value of the front wheel motor and the second actual torque value of the rear wheel motor are read and recorded.

4. The electric vehicle driving control method according to claim 3, characterized in that: According to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-slip compensation values ​​of the front wheels and the rear wheels, and the output limit values ​​of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value, and the rear wheel motor is controlled to output the second torque value, including: Determine the driving road state of the vehicle according to the first actual torque value of the front wheel motor, the second actual torque value of the rear wheel motor and the preset torque; wherein the driving road state includes flat road driving and slope driving; When the vehicle is traveling on a slope, the front wheel motor is controlled to output a first torque value greater than or equal to a first actual torque value, and the rear wheel motor is controlled to output a second torque value greater than or equal to a second actual torque value.

5. The electric vehicle driving control method according to claim 1, characterized in that: After determining the torque distribution ratio of the front wheels and the rear wheels based on the actual load ratio of the front wheels and the rear wheels, the electric vehicle driving control method includes: Based on the torque distribution ratio between the front wheels and the rear wheels, a first torque proportional coefficient is allocated to the front wheels, and a second torque proportional coefficient is allocated to the rear wheels; According to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-slip compensation values ​​of the front wheels and the rear wheels, and the output limit values ​​of the front wheel motor and the rear wheel motor, the front wheel motor is controlled to output the first torque value, and the rear wheel motor is controlled to output the second torque value, including: Controlling the front wheel motor to output the first torque value according to the total torque required by the vehicle, the first actual torque value, the first torque proportional coefficient, the anti-slip compensation values ​​of the front wheels and the rear wheels, and the output limit values ​​of the front wheel motor and the rear wheel motor; The rear wheel motor is controlled to output the second torque value according to the total torque required by the vehicle, the second actual torque value, the second torque proportional coefficient, the anti-slip compensation values ​​of the front and rear wheels, and the output limit values ​​of the front and rear wheel motors.

6. The electric vehicle driving control method according to claim 1, characterized in that: Based on the speed difference between the front wheels and the rear wheels, the anti-skid compensation values ​​of the front wheels and the rear wheels are determined, including: When a first speed difference between the front wheel and the rear wheel is greater than a preset speed difference, determining a slipping wheel and a non-slipping wheel based on a first real-time rotation speed value of the front wheel and a second real-time rotation speed value of the rear wheel; An anti-skid compensation value of the slipping wheel is calculated based on the minimum speed difference, the maximum speed difference, the maximum compensation value, and the first speed difference between the front wheel and the rear wheel.

7. The electric vehicle driving control method according to claim 6, characterized in that: Determining anti-skid compensation values ​​of the front wheels and the rear wheels based on the speed difference between the front wheels and the rear wheels, further comprising: Obtaining a second speed difference between the real-time rotation speed value of the non-slipping wheel and the target rotation speed of the vehicle; The anti-slip compensation value of the non-slipping wheel is calculated based on the anti-slip compensation value of the slipping wheel, the minimum speed difference between the front wheel and the rear wheel, the maximum speed difference, the maximum compensation value, and the second speed difference.

8. The electric vehicle driving control method according to claim 7, characterized in that: Calculating the anti-skid compensation value of the non-skidding wheel based on the anti-skid compensation value of the skidding wheel, the minimum speed difference between the front wheel and the rear wheel, the maximum speed difference, the maximum compensation value, and the second speed difference, includes: When the real-time speed value of the non-slipping wheel is less than the target speed of the vehicle, the anti-slip compensation value of the non-slipping wheel is the opposite of the anti-slip compensation value of the slipping wheel; When the real-time rotation speed value of the non-slipping wheel is greater than or equal to the vehicle target rotation speed, the anti-slip compensation value of the non-slipping wheel is related to the minimum speed difference, the maximum speed difference, the maximum compensation value and the second speed difference between the front and rear wheels.

9. An electric vehicle driving control device, characterized in that: include: A first acquisition module is used to acquire the total torque required by the vehicle based on the actual speed of the vehicle and the target speed of the vehicle; wherein the vehicle includes front wheels, rear wheels, front wheel motors and rear wheel motors; A second acquisition module, used for acquiring a first actual torque value of the front wheel motor and a second actual torque value of the rear wheel motor during start control; A first determination module, configured to determine a torque distribution ratio between the front wheels and the rear wheels based on an actual load ratio between the front wheels and the rear wheels; A second determination module, configured to determine anti-skid compensation values ​​of the front wheels and the rear wheels based on a speed difference between the front wheels and the rear wheels; A third determination module, configured to determine output limit values ​​of the front wheel motor and the rear wheel motor based on a preset torque limit value of the vehicle; The control module is used to control the front wheel motor to output a first torque value and control the rear wheel motor to output a second torque value according to the total torque required by the vehicle, the first actual torque value, the second actual torque value, the torque distribution ratio of the front wheels and the rear wheels, the anti-skid compensation values ​​of the front wheels and the rear wheels, and the output limit values ​​of the front wheel motor and the rear wheel motor.

10. An electric vehicle, characterized in that: Includes: Front wheel motor and rear wheel motor; The electric vehicle running control device as claimed in claim 9, wherein the electric vehicle running control device is electrically connected to the front wheel motor, and the electric vehicle running control device is electrically connected to the rear wheel motor.

Images