CN114475263A

CN114475263A - Control method, vehicle control unit, control system, electric vehicle and storage medium

Info

Publication number: CN114475263A
Application number: CN202210325048.4A
Authority: CN
Inventors: 陈森; 刘浩浩; 杨帆; 潘涛
Original assignee: Xuzhou Xugong Automobile Manufacturing Co ltd
Current assignee: Xuzhou Xugong Automobile Manufacturing Co ltd
Priority date: 2022-03-30
Filing date: 2022-03-30
Publication date: 2022-05-13
Anticipated expiration: 2042-03-30
Also published as: CN114475263B

Abstract

The disclosure provides a control method, a vehicle control unit, a control system, an electric vehicle and a storage medium. The control method comprises the following steps: judging whether the electric automobile meets the condition of starting an energy feedback mode or not according to the received accelerator pedal state signal, the received gear state signal, the speed information of the electric automobile and the battery management system information; if the electric automobile meets the condition of starting the energy feedback mode, determining the type of the energy feedback mode according to the received brake pedal state signal; under the condition that the brake pedal state signal indicates that the electric automobile is in a brake state, determining that the electric automobile enters a brake energy feedback mode, acquiring a first required torque under the brake energy feedback mode and outputting the first required torque to the motor controller; and under the condition that the brake pedal state signal indicates that the electric automobile is not in the brake state, determining that the electric automobile enters a sliding energy feedback mode, acquiring a second required torque in the sliding energy feedback mode and outputting the second required torque to the motor controller.

Description

Control method, vehicle control unit, control system, electric vehicle and storage medium

Technical Field

The disclosure relates to the technical field of control of electric vehicles, and in particular relates to a control method, a vehicle control unit, a control system, an electric vehicle and a storage medium.

Background

With the increasingly prominent energy crisis, the increasing price of fuel, and the great pressure brought by the problems of environmental pollution and carbon emission, the development of new energy electric vehicles is more and more emphasized. Currently, some vehicle enterprises have introduced new energy vehicle development plans. In an electric automobile, a braking energy feedback system can improve the driving range of the automobile, and different operating automobiles have different requirements on the braking energy feedback function. For example, the washing and sweeping vehicle needs to maintain a fixed vehicle speed for operation, and energy feedback should not be performed; when the muck truck and the mine truck are fully loaded and unloaded, the weight of the truck changes greatly, and dynamic requirements are provided for braking energy feedback force.

At present, the conventional electric commercial automobile has no braking energy feedback function or single function, is poor in driving experience and cannot comprehensively cover all types of automobile models.

Disclosure of Invention

The technical problem that this disclosure solved is: the control method for the electric automobile is provided, so that different energy feedback functions can be provided for the electric automobile, and the driving experience is improved.

According to an aspect of the present disclosure, there is provided a control method for an electric vehicle, including: receiving an accelerator pedal state signal, a gear state signal, a brake pedal state signal, the speed information of the electric automobile and the battery management system information; judging whether the electric automobile meets the condition of starting an energy feedback mode or not according to the accelerator pedal state signal, the gear state signal, the speed information of the electric automobile and the battery management system information; if the electric automobile meets the condition of starting an energy feedback mode, determining the type of the energy feedback mode according to the brake pedal state signal, wherein the energy feedback mode comprises the following steps: a braking energy feedback mode and a sliding energy feedback mode; under the condition that the brake pedal state signal indicates that the electric automobile is in a braking state, determining that the electric automobile enters a braking energy feedback mode, acquiring a first required torque under the braking energy feedback mode, and outputting the first required torque to a motor controller; and under the condition that the brake pedal state signal indicates that the electric automobile is not in a braking state, determining that the electric automobile enters a slip energy feedback mode, acquiring a second required torque in the slip energy feedback mode, and outputting the second required torque to the motor controller.

In some embodiments, the battery management system information comprises: the battery state of charge (SOC) value, the battery state of health (SOH) value, temperature information and the battery system fault state.

In some embodiments, the determining whether the electric vehicle satisfies a condition of turning on an energy feedback mode according to the accelerator pedal state signal, the gear state signal, the vehicle speed information of the electric vehicle, and the battery management system information includes: judging whether the electric automobile is in a fault state or not; if the electric automobile is in a fault state, the electric automobile enters a fault mode; and if the electric automobile is not in a fault state, determining that the electric automobile meets the condition of starting an energy feedback mode under the condition that the accelerator pedal state signal indicates that an accelerator pedal is not started, the gear state signal indicates that the current gear is in a forward gear, the speed information of the electric automobile is greater than a speed threshold value, and the SOC value of the battery is smaller than an allowable charging value.

In some embodiments, obtaining the first required torque in the braking energy feedback mode comprises: obtaining allowable feedback torque of a drive axle; according to the external characteristic curve data of the motor between the rotating speed of the motor and the generating torque of the motor, the maximum allowable braking feedback torque under the current rotating speed of the motor is obtained by a table look-up and interpolation method of a two-dimensional table; obtaining the allowable maximum feedback torque of the current finished automobile system by a method of table look-up and interpolation of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value; and selecting the minimum value of the allowable feedback torque of the drive axle, the maximum allowable braking feedback torque under the current motor rotating speed and the allowable maximum feedback torque of the current whole vehicle system, and calculating the product of the minimum value and the opening degree of a brake pedal to obtain the first required torque.

In some embodiments, obtaining the second required torque in the slip energy feedback mode comprises: obtaining allowable feedback torque of a drive axle; calculating an allowable sliding feedback torque under a constant power feedback condition according to a preset sliding feedback power when the motor operates; obtaining the maximum allowable braking feedback torque under the current motor rotating speed by a two-dimensional table lookup interpolation method according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a three-dimensional table lookup interpolation method according to the temperature information, the battery SOC value and the battery SOH value, and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current finished automobile system; calculating to obtain a deceleration value of the vehicle at the current moment by a discrete system differentiation method according to the vehicle speed information, obtaining an adjusting torque by a Proportional Integral Derivative (PID) algorithm according to the deceleration value, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback moment; and selecting the minimum value of the allowable drive axle feedback torque, the allowable sliding feedback torque under the constant power feedback condition, the sliding feedback torque of the current whole vehicle system and the regulation limit feedback torque as the second required torque.

In some embodiments, the two-dimensional table is a corresponding relation table between the motor rotating speed, the motor generating torque and the maximum allowable braking feedback torque; the three-dimensional table is a corresponding relation table among temperature information, a battery SOC value, a battery SOH value and the maximum allowable feedback torque of the whole vehicle system at present.

In some embodiments, the control method further comprises: receiving ABS state information and/or EBS state information of an anti-lock braking system; wherein, judging whether the electric automobile is in a fault state comprises: judging whether the accelerator pedal is in a fault state or not according to the accelerator pedal state signal; judging whether the gear shifting lever is in a fault state or not according to the gear state signal; judging whether the brake pedal is in a fault state or not according to the brake pedal state signal; judging whether the battery system is in a fault state or not according to the fault state of the battery system of the battery management system information; and judging whether the ABS system is in a fault state according to the ABS state information, and/or judging whether the EBS system is in a fault state according to the EBS state information.

In some embodiments, the control method further comprises: and judging whether the electric automobile has the fault of the whole automobile system in real time, and if the fault of the whole automobile system occurs, exiting the energy feedback mode.

According to another aspect of the present disclosure, there is provided a vehicle control unit including: the receiving unit is used for receiving an accelerator pedal state signal, a gear state signal, a brake pedal state signal, the speed information of the electric automobile and the battery management system information; a determining unit, configured to determine whether the electric vehicle meets a condition for turning on an energy feedback mode according to the accelerator pedal state signal, the gear state signal, the vehicle speed information of the electric vehicle, and the battery management system information, and determine a type of the energy feedback mode according to the brake pedal state signal if the electric vehicle meets the condition for turning on the energy feedback mode, where the energy feedback mode includes: a braking energy feedback mode and a sliding energy feedback mode; the first obtaining unit is used for determining that the electric automobile enters a braking energy feedback mode under the condition that the braking pedal state signal represents that the electric automobile is in a braking state, and obtaining a first required torque under the braking energy feedback mode; a second obtaining unit, configured to determine that the electric vehicle enters a slip energy feedback mode and obtain a second required torque in the slip energy feedback mode, when the brake pedal state signal indicates that the electric vehicle is not in a braking state; and an output unit for outputting the first required torque to a motor controller or outputting the second required torque to the motor controller.

In some embodiments, the battery management system information comprises: battery SOC value, battery SOH value, temperature information, and battery system fault status.

In some embodiments, the determining unit is configured to determine whether the electric vehicle is in a fault state, if the electric vehicle is in the fault state, the electric vehicle enters a fault mode, and if the electric vehicle is not in the fault state, it is determined that the electric vehicle satisfies a condition for turning on an energy feedback mode when the accelerator pedal state signal indicates that an accelerator pedal is not activated, the gear state signal indicates that a current gear is in a forward gear, the vehicle speed information of the electric vehicle is greater than a vehicle speed threshold, and the battery SOC value is less than an allowable charging value.

In some embodiments, the first obtaining unit is to: obtaining allowable feedback torque of a drive axle; according to the external characteristic curve data of the motor between the rotating speed of the motor and the generating torque of the motor, the maximum allowable braking feedback torque under the current rotating speed of the motor is obtained by a table look-up and interpolation method of a two-dimensional table; obtaining the allowable maximum feedback torque of the current finished automobile system by a method of table look-up and interpolation of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value; and selecting the minimum value of the allowable feedback torque of the drive axle, the maximum allowable braking feedback torque under the current motor rotating speed and the allowable maximum feedback torque of the current whole vehicle system, and calculating the product of the minimum value and the opening degree of a brake pedal to obtain the first required torque.

In some embodiments, the second obtaining unit is configured to: obtaining allowable feedback torque of a drive axle; calculating an allowable sliding feedback torque under a constant power feedback condition according to a preset sliding feedback power when the motor operates; obtaining the maximum allowable braking feedback torque under the current motor rotating speed by a two-dimensional table lookup interpolation method according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a three-dimensional table lookup interpolation method according to the temperature information, the battery SOC value and the battery SOH value, and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current finished automobile system; calculating to obtain a deceleration value of the vehicle at the current moment by a discrete system differentiation method according to the vehicle speed information, obtaining an adjusting torque by a Proportional Integral Derivative (PID) algorithm according to the deceleration value, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque; and selecting the minimum value of the allowable drive axle feedback torque, the allowable sliding feedback torque under the constant power feedback condition, the sliding feedback torque of the current whole vehicle system and the regulation limit feedback torque as the second required torque.

In some embodiments, the receiving unit is further configured to receive ABS status information and/or EBS status information; the judging unit is used for judging whether the accelerator pedal is in a fault state according to the accelerator pedal state signal, judging whether the gear lever is in a fault state according to the gear state signal, judging whether the brake pedal is in a fault state according to the brake pedal state signal, and judging whether the battery system is in a fault state according to the battery system fault state of the battery management system information; the judging unit is also used for judging whether the ABS system is in a fault state according to the ABS state information and/or judging whether the EBS system is in a fault state according to the EBS state information.

In some embodiments, the determining unit is further configured to determine whether the electric vehicle has a failure in a vehicle system in real time, and exit the energy feedback mode if the vehicle has the failure in the vehicle system.

According to another aspect of the present disclosure, there is provided a vehicle control unit including: a memory; and a processor coupled to the memory, the processor configured to perform the method as previously described based on instructions stored in the memory.

According to another aspect of the present disclosure, there is provided a control system for an electric vehicle, including: the vehicle control unit is as described above.

In some embodiments, the control system further comprises: the accelerator pedal is used for sending an accelerator pedal state signal to the vehicle controller; the gear shifting lever is used for sending a gear state signal to the vehicle control unit; the brake pedal is used for sending a brake pedal state signal to the vehicle control unit; the instrument control unit is used for sending the speed information of the electric automobile to the whole automobile controller; the battery management system is used for sending battery management system information to the vehicle control unit; and the motor controller is used for receiving the first required torque or the second required torque from the vehicle control unit and controlling the magnitude of the motor recharging current according to the first required torque or the second required torque.

According to another aspect of the present disclosure, there is provided an electric vehicle including: a control system as hereinbefore described.

According to another aspect of the present disclosure, there is provided a computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the method as previously described.

The control method can provide different energy feedback functions for the electric automobile, namely a braking energy feedback mode and a sliding energy feedback mode, and improves the driving experience. In addition, in the above method, the start determination of the energy feedback mode is performed before the execution of the energy feedback mode, so that the driving safety can be improved.

Other features of the present disclosure and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a flow chart illustrating a control method for an electric vehicle according to some embodiments of the present disclosure;

FIG. 2 is a flow chart illustrating a method of determining whether an electric vehicle meets a condition for turning on an energy feedback mode according to some embodiments of the present disclosure;

FIG. 3 is a schematic diagram illustrating operation of a hybrid vehicle controller according to some embodiments of the present disclosure;

FIG. 4 is a block diagram illustrating a vehicle control unit according to some embodiments of the present disclosure;

FIG. 5 is a block diagram illustrating a vehicle control unit according to further embodiments of the present disclosure;

FIG. 6 is a block diagram illustrating a vehicle control unit according to further embodiments of the present disclosure;

fig. 7 is a block diagram illustrating a control system for an electric vehicle according to some embodiments of the present disclosure.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Fig. 1 is a flowchart illustrating a control method for an electric vehicle according to some embodiments of the present disclosure. Fig. 3 is a schematic diagram illustrating the operation of a Vehicle Control Unit (VCU) according to some embodiments of the present disclosure. A control method for an electric vehicle according to some embodiments of the present disclosure is described in detail below with reference to fig. 1 and 3. The control method can be executed by a vehicle control unit.

As shown in fig. 1, in step S102, an accelerator pedal state signal, a gear state signal, a brake pedal state signal, vehicle speed information of the electric vehicle, and battery management system information are received.

For example, as shown in fig. 3, the hybrid controller 310 may receive an accelerator pedal state signal from an accelerator pedal (e.g., a sensor inside the accelerator pedal, not shown in fig. 3), a gear state signal from a shift lever (not shown in fig. 3), a brake pedal state signal from a brake pedal (e.g., a sensor inside the brake pedal, not shown in fig. 3), vehicle speed information of the electric vehicle from an instrument control unit 340, and Battery Management System information from a Battery Management System (BMS) 330.

In some embodiments, as shown in fig. 3, the battery management system information includes: a battery SOC (State Of Charge) value, a battery SOH (State Of Health) value, temperature information, and a battery system fault State. In other embodiments, the battery management system information may also include battery system operating modes, and the like.

As shown in fig. 3, the hybrid controller 310 may transmit battery energy request information to the battery management system 330 in addition to receiving the battery management system information from the battery management system 330.

In some embodiments, as shown in fig. 3, the method may further include: ABS (Antilock Brake System) status information and/or EBS (Electronic Brake System) status information is received. For example, the hybrid controller 310 may receive ABS status information from an ABS system and/or receive EBS status information from an EBS system.

Returning to fig. 1, in step S104, it is determined whether the electric vehicle satisfies the condition for turning on the energy feedback mode according to the accelerator pedal state signal, the gear state signal, the vehicle speed information of the electric vehicle, and the battery management system information. That is, as shown in fig. 3, the start determination of the energy feedback mode is performed.

A specific embodiment of this step S104 is described below in conjunction with fig. 2. Fig. 2 is a flowchart illustrating a method of determining whether an electric vehicle satisfies a condition for turning on an energy feedback mode according to some embodiments of the present disclosure. As shown in fig. 2, the method for determining whether the electric vehicle satisfies the condition for turning on the energy feedback mode includes steps S202 to S206, i.e., the step S104 includes steps S202 to S206.

In step S202, it is determined whether the electric vehicle is in a failure state. If so, the process advances to step S204; otherwise the process advances to step S206.

In some embodiments, this step S202 includes: and judging whether the accelerator pedal is in a fault state or not according to the accelerator pedal state signal. For example, an accelerator pedal status signal indicates that the accelerator pedal is malfunctioning, indicating that the accelerator pedal is in a fault condition. For another example, the accelerator pedal state signal indicates that the accelerator pedal is normal, indicating that the accelerator pedal is not in a fault condition.

In some embodiments, this step S202 further includes: and judging whether the gear shifting lever is in a fault state or not according to the gear state signal. For example, a gear state signal indicates a gear shift malfunction or failure of the shift lever, indicating that the shift lever is in a failure state. For another example, the gear state signal indicates that the shift position of the shift lever is normal, indicating that the shift lever is not in a failure state.

In some embodiments, this step S202 further includes: and judging whether the brake pedal is in a fault state or not according to the brake pedal state signal. For example, a brake pedal status signal indicates a brake pedal failure, indicating that the brake pedal is in a fault condition. For another example, the brake pedal status signal indicates that the brake pedal is normal, indicating that the brake pedal is not in a fault condition.

In some embodiments, this step S202 further includes: and judging whether the battery system is in a fault state or not according to the fault state of the battery system of the battery management system information. Here, the battery system fault state reflects whether the battery system is in fault, and thus, it is possible to determine whether the battery system is in fault based on the battery system fault state of the battery management system information.

In some embodiments, this step S202 further includes: and judging whether the ABS system is in a fault state according to the ABS state information, and/or judging whether the EBS system is in a fault state according to the EBS state information. Here, the ABS status information may reflect whether the ABS system has failed, and the EBS status information may reflect whether the EBS system has failed, and thus, whether the ABS system is in a failed state may be determined according to the ABS status information, and whether the EBS system is in a failed state may be determined according to the EBS status information.

Determining that the electric automobile is in a fault state under the condition that at least one of the components or the systems has faults; and under the condition that all the components or the systems are not in fault, determining that the electric automobile is not in a fault state.

In step S204, if the electric vehicle is in a failure state, the electric vehicle enters a failure mode. After entering a failure mode (such as the failure mode 313 shown in fig. 3), the electric vehicle may operate according to a failure handling manner in the related art, which is not described in detail herein.

In step S206, if the electric vehicle is not in the fault state, it is determined that the electric vehicle satisfies the condition of turning on the energy feedback mode when the accelerator pedal state signal indicates that the accelerator pedal is not activated, the gear state signal indicates that the current gear is in the forward gear, the vehicle speed information of the electric vehicle is greater than the vehicle speed threshold, and the battery SOC value is less than the allowable charging value.

Here, both the vehicle speed threshold value and the allowable charge value may be set according to actual needs, and the scope of the present disclosure is not limited to specific values of the vehicle speed threshold value and the allowable charge value.

For example, as shown in FIG. 3, the accelerator pedal state is not activated; the gear state is in a forward gear; the vehicle speed given by the instrument control unit 340 is greater than the vehicle speed threshold value, the battery SOC value given by the battery management system 330 is lower than the allowable charging value, no fault occurs in the whole vehicle system after the information is processed by the whole vehicle controller 310, and the vehicle is ready to be electrified at high voltage. If the above conditions are satisfied, the vehicle is allowed to start the energy feedback function.

Of course, if at least one of the conditions (conditions satisfied by the accelerator pedal state signal, the shift state signal, the vehicle speed information of the electric vehicle, and the battery SOC value) in step S206 cannot be satisfied, the energy feedback mode is not allowed to be turned on.

Thus, a method for determining whether the electric vehicle satisfies a condition for turning on the energy feedback mode is described in detail.

In other embodiments, as shown in fig. 3, the vehicle Control Unit 310 may further receive Motor controller fault information from a Motor Control Unit (MCU) 320, so as to determine whether the Motor controller is in a fault state. This can also be used to determine whether the electric vehicle is in a fault state. In addition, the hybrid controller 310 may also receive a motor speed signal from the motor controller 320.

In some embodiments, the vehicle controller 310 may send vehicle fault information to the meter control unit 340 to display that the electric vehicle is currently in a fault state.

Referring back to fig. 1, in step S106, if the electric vehicle satisfies a condition for turning on the energy feedback mode, the type of the energy feedback mode is determined according to the brake pedal state signal, wherein the energy feedback mode includes: a braking energy feedback mode and a sliding energy feedback mode.

In step S108, when the brake pedal state signal indicates that the electric vehicle is in the braking state, it is determined that the electric vehicle enters the braking energy feedback mode, a first required torque in the braking energy feedback mode is obtained, and the first required torque is output to the motor controller.

Here, the braking state means that the brake pedal is depressed and the brake pedal state signal is valid. For example, the brake pedal is depressed and the vehicle is in a decelerating state.

In some embodiments, obtaining the first requested torque in the braking energy feedback mode includes: obtaining allowable feedback torque of a drive axle; according to the external characteristic curve data of the motor between the rotating speed of the motor and the generating torque of the motor, the maximum allowable braking feedback torque under the current rotating speed of the motor is obtained by a table look-up and interpolation method of a two-dimensional table; obtaining the allowable maximum feedback torque of the current finished automobile system by a table look-up and interpolation method of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value; and selecting the minimum value of the allowable feedback torque of the drive axle, the maximum allowable braking feedback torque under the current motor rotating speed and the allowable maximum feedback torque of the current whole vehicle system, and calculating the product of the minimum value and the opening degree of the brake pedal to obtain the first required torque.

The method of obtaining the first required torque in the braking energy feedback mode 311 described above is specifically described below with reference to fig. 3.

(1) And obtaining the allowable feedback torque of the drive axle. For example, the transaxle allowable feedback torque may be set to 30% of the motor generation torque, and may be provided by a transaxle supplier or obtained through experiments. Of course, those skilled in the art will appreciate that the allowable axle reactive torque may be set based on the actual conditions.

(2) And obtaining the maximum allowable braking feedback torque at the current motor rotating speed by a table look-up and interpolation method of a two-dimensional table according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque.

Here, the motor external characteristic curve data may be provided by a motor manufacturer.

The two-dimensional table is a corresponding relation table among the motor rotating speed, the motor generating torque and the maximum allowable braking feedback torque. For example, in the two-dimensional table, the abscissa is the motor rotation speed, the ordinate is the motor power generation torque, and the elements in the two-dimensional table are the maximum allowable braking feedback torque at a certain motor rotation speed and a certain motor power generation torque. The two-dimensional table is a two-dimensional table provided in the prior art.

Here, the maximum allowable braking feedback torque at the current motor speed can be obtained by using a table lookup interpolation method. For example, for a certain motor speed, not shown in the two-dimensional table, but the two-dimensional table shows a motor speed (denoted as a first motor speed) which is closest to the motor speed and is less than the certain motor speed and another motor speed (denoted as a second motor speed) which is greater than the certain motor speed, assuming that the motor power generation torque corresponding to the certain motor speed exists in the two-dimensional table, a first maximum allowable braking feedback torque corresponding to the first motor speed and a second maximum allowable braking feedback torque corresponding to the second motor speed at the motor power generation torque can be searched, and then an appropriate allowable braking feedback torque is selected between the first maximum allowable braking feedback torque and the second maximum allowable braking feedback torque as the maximum allowable braking torque corresponding to the certain motor speed at the motor power generation torque, namely the maximum allowable braking feedback torque obtained by an interpolation method.

Here, a method of obtaining the maximum allowable braking feedback torque by interpolation assuming that the motor generation torque corresponding to the above-described certain motor rotation speed exists in the two-dimensional table is described. Of course, as will be understood by those skilled in the art, in the case where the motor generation torque corresponding to the above-described certain motor rotation speed (referred to as certain motor generation torque) does not exist in the two-dimensional table, the maximum allowable braking feedback torque can also be obtained by interpolation, as long as the maximum allowable braking feedback torque is obtained at the same time as the first motor speed and the second motor speed, a table is looked up to obtain a motor generating torque (denoted as a first motor generating torque) which is closest to the certain motor generating torque and is smaller than the certain motor generating torque and another motor generating torque (denoted as a second motor generating torque) which is larger than the certain motor generating torque, and then, the maximum allowable braking feedback torque is obtained by comprehensively analyzing the first motor rotating speed, the second motor rotating speed, the first motor generating torque and the second motor generating torque through a difference method, and the detailed description is omitted here.

(3) And obtaining the allowable maximum feedback torque of the current finished automobile system by a table look-up and interpolation method of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value.

The three-dimensional table is a corresponding relation table among temperature information, a battery SOC value and a battery SOH value in the battery management system information and the allowable maximum feedback torque of the current finished automobile system. For example, in the three-dimensional table, the x coordinate is temperature information, the y coordinate is a battery SOC value, the z coordinate is a battery SOH value, and the elements in the three-dimensional table are allowable maximum feedback torque of the vehicle system at a certain temperature, a certain battery SOC value and a certain battery SOH value. The three-dimensional table is a three-dimensional table provided in the prior art. The method for interpolating from a three-dimensional table is similar to the method for interpolating from a two-dimensional table as described above and will not be described in detail here.

Next, the minimum value of the torque in method (1) to the torque in method (3) is selected, and the minimum value is multiplied by the brake pedal opening degree (which can be obtained by the system pedal state signal), so that the first required torque can be obtained. The hybrid controller 310 may output the first required torque to the motor controller 320. The motor controller 320 may control the magnitude of the motor recharging current according to the magnitude of the first required torque, and thus, the motor controller may control the reverse current (i.e., the recharging current) generated by the motor to recharge the battery.

In step S110, in the case that the brake pedal state signal indicates that the electric vehicle is not in the braking state, it is determined that the electric vehicle enters the slip energy feedback mode, a second required torque in the slip energy feedback mode is obtained, and the second required torque is output to the motor controller.

In some embodiments, obtaining the second required torque in the slip energy feedback mode comprises: obtaining allowable feedback torque of a drive axle; calculating an allowable sliding feedback torque under a constant power feedback condition according to a preset sliding feedback power when the motor operates; obtaining the maximum allowable braking feedback torque under the current motor rotating speed by a two-dimensional table lookup interpolation method according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a three-dimensional table lookup interpolation method according to temperature information, a battery SOC value and a battery SOH value, and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current finished automobile system; calculating to obtain a deceleration value of the vehicle at the current moment by a discrete system differentiation method according to the vehicle speed information, obtaining an adjusting torque by a Proportional Integral Derivative (PID) algorithm according to the deceleration value, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque; and selecting the minimum value of the allowable drive axle feedback torque, the allowable sliding feedback torque under the constant power feedback condition, the sliding feedback torque of the current whole vehicle system and the regulation limit feedback torque as the second required torque.

The above method of obtaining the second required torque in the slip energy feedback mode 312 is described in detail with reference to fig. 3.

(a) And obtaining the allowable feedback torque of the drive axle. The allowable drive axle feedback torque is the same as or similar to the allowable drive axle feedback torque described in (1) above, and will not be described herein again.

(b) And calculating the allowable sliding feedback torque under the constant power feedback condition according to the preset sliding feedback power when the motor runs.

For example, the coasting feedback power (which may be a calibration value set manually, for example) when the motor operates may be obtained through experiments or calibration, and the allowable coasting feedback torque under the constant power feedback condition is calculated by using the formula T9549P/n. Here, T is the allowable coasting feedback torque, P is the coasting feedback power, and n is the motor speed.

In some embodiments, the feedback may be performed in a constant torque mode at low speeds and in a constant power mode at high speeds.

(c) According to the data of the external characteristic curve of the motor between the rotating speed of the motor and the generating torque of the motor, obtaining the maximum allowable braking feedback torque under the current rotating speed of the motor by a method of table look-up and interpolation of a two-dimensional table, and calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque; according to the temperature information, the SOC value and the SOH value of the battery, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a method of table lookup and interpolation of a three-dimensional table; and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current whole vehicle system.

Similarly, the two-dimensional table is a corresponding relation table among the rotating speed of the motor, the generating torque of the motor and the maximum allowable braking feedback torque, and the three-dimensional table is a corresponding relation table among temperature information, a battery SOC value, a battery SOH value and the allowable maximum feedback torque of the current finished automobile system. Here, the method for table lookup and interpolation of the two-dimensional table and the method for table lookup and interpolation of the three-dimensional table have been described above, and are not described herein again.

In the method, when the first coasting feedback torque is calculated, the maximum allowable braking feedback torque obtained by a table lookup and interpolation method of a two-dimensional table is multiplied by a predetermined protection coefficient to obtain the first coasting feedback torque. For example, the protection factor ranges from 0.3 to 0.7. And then, according to the temperature information, the SOC value of the battery and the SOH value of the battery, obtaining the allowable maximum feedback torque of the current whole vehicle system as a second sliding feedback torque by a method of table lookup and interpolation of a three-dimensional table. And then, comparing the first sliding feedback torque with the second sliding feedback torque, and taking the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current whole vehicle system.

(d) Calculating to obtain a deceleration value of the vehicle at the current moment (for example, after the vehicle loses power, the vehicle decelerates due to wind resistance, rolling resistance, friction and the like) according to the vehicle speed information by a discrete system differentiation method, obtaining an adjusting torque by a variable ratio coefficient Integral discrete PID (proportional Integral Differential) algorithm according to a target deceleration value calibrated by a test and the deceleration value at the current moment, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque.

Here, the deceleration value of the vehicle at the present time is calculated by a discrete system differentiation method based on the vehicle speed information. The deceleration value is then adjusted by the PID algorithm to be within the target value range, at which time an adjustment torque is obtained by the PID algorithm. For example, the target deceleration value-the current deceleration value is an adjustment amount, and then the adjustment torque can be obtained through a PID algorithm by using the adjustment amount, a known proportionality coefficient and an integral coefficient; the function of the adjusting torque is to control the deceleration of the vehicle to approach the set target deceleration value, so that the vehicle can decelerate at a constant deceleration and feed back energy no matter whether the vehicle is empty or full. The PID algorithm here is a prior art algorithm. And after the adjusting torque is obtained, performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque.

Next, the minimum value of the four of the torque in method (a) to the torque in method (d) is selected and taken as the second required torque. The hybrid controller 310 may output the second required torque to the motor controller 320. The motor controller 320 may control the magnitude of the motor recharging current according to the magnitude of the second required torque, and thus, the motor controller may control the reverse current generated by the motor to charge the battery.

The sliding energy feedback mode can avoid the change caused by the empty and full load of the vehicle, so that the vehicle is controlled in a certain deceleration range when sliding in the empty and full load, the driving range is increased, the energy utilization rate is increased, and the driving comfort of a driver is enhanced.

To this end, a control method for an electric vehicle according to some embodiments of the present disclosure is provided. The control method comprises the following steps: receiving an accelerator pedal state signal, a gear state signal, a brake pedal state signal, the speed information of the electric automobile and the battery management system information; judging whether the electric automobile meets the condition of starting an energy feedback mode or not according to the accelerator pedal state signal, the gear state signal, the speed information of the electric automobile and the battery management system information; if the electric automobile meets the condition of starting the energy feedback mode, determining the type of the energy feedback mode according to the brake pedal state signal, wherein the energy feedback mode comprises the following steps: a braking energy feedback mode and a sliding energy feedback mode; under the condition that the brake pedal state signal indicates that the electric automobile is in a brake state, determining that the electric automobile enters a brake energy feedback mode, obtaining a first required torque under the brake energy feedback mode, and outputting the first required torque to the motor controller; and under the condition that the brake pedal state signal indicates that the electric automobile is not in the brake state, determining that the electric automobile enters a slip energy feedback mode, acquiring a second required torque in the slip energy feedback mode, and outputting the second required torque to the motor controller. The control method can provide different energy feedback functions (namely a braking energy feedback mode and a sliding energy feedback mode) for the electric automobile, and improves the driving experience.

In addition, in the above method, the start determination of the energy feedback mode is performed before the execution of the energy feedback mode, so that the driving safety can be improved.

In the related art, once a fault occurs in a current electric vehicle, for example: when a transmission hard wire fails, a vehicle controller fails or communication between the vehicle controller and a motor controller fails, the vehicle may not normally exit a braking energy feedback state, and thus traffic accidents may occur.

In some embodiments of the present disclosure, the control method may further include: and judging whether the electric automobile has the fault of the whole automobile system in real time, and if the fault of the whole automobile system occurs, exiting the energy feedback mode. Whether the whole vehicle system fault occurs in the electric vehicle is monitored in real time, and then the energy feedback mode is quitted after the whole vehicle system fault occurs, so that the safety of the vehicle can be improved.

For example, the vehicle Controller processes the information including, but not limited to, a hardwire signal, a sensor signal, and a CAN (Controller Area Network) signal according to the collected vehicle information, and then determines that the vehicle is in a fault state, the vehicle enters a fault mode, and exits the braking energy feedback function.

Fig. 4 is a block diagram illustrating a vehicle control unit according to some embodiments of the present disclosure. As shown in fig. 4, the vehicle control unit includes: a receiving unit 402, a judging unit 404, a first obtaining unit 406, a second obtaining unit 408 and an output unit 410.

The receiving unit 402 is configured to receive an accelerator pedal state signal, a gear state signal, a brake pedal state signal, vehicle speed information of the electric vehicle, and battery management system information.

The determining unit 404 is configured to determine whether the electric vehicle satisfies a condition for turning on the energy feedback mode according to the accelerator pedal state signal, the gear state signal, the vehicle speed information of the electric vehicle, and the battery management system information, and determine a type of the energy feedback mode according to the brake pedal state signal if the electric vehicle satisfies the condition for turning on the energy feedback mode, where the energy feedback mode includes: a braking energy feedback mode and a sliding energy feedback mode.

The first obtaining unit 406 is configured to determine that the electric vehicle enters the braking energy feedback mode and obtain the first required torque in the braking energy feedback mode, when the braking pedal state signal indicates that the electric vehicle is in the braking state.

The second obtaining unit 408 is configured to determine that the electric vehicle enters the slip energy feedback mode and obtain the second required torque in the slip energy feedback mode, in a case where the brake pedal state signal indicates that the electric vehicle is not in the braking state.

The output unit 410 is configured to output the first required torque to the motor controller or output the second required torque to the motor controller.

To this end, a hybrid vehicle controller according to some embodiments of the present disclosure is provided. The vehicle control unit can provide different energy feedback (namely a braking energy feedback mode and a sliding energy feedback mode) for the electric vehicle, and driving experience is improved.

In some embodiments, the determining unit 404 is configured to determine whether the electric vehicle is in a fault state, if the electric vehicle is in the fault state, the electric vehicle enters a fault mode, and if the electric vehicle is not in the fault state, it is determined that the electric vehicle satisfies a condition for turning on the energy feedback mode in a case that the accelerator pedal state signal indicates that the accelerator pedal is not activated, the gear state signal indicates that the current gear is in the forward gear, the vehicle speed information of the electric vehicle is greater than the vehicle speed threshold, and the battery SOC value is less than the allowable charging value.

In some embodiments, the first obtaining unit 406 is configured to: obtaining allowable feedback torque of a drive axle; according to the external characteristic curve data of the motor between the rotating speed of the motor and the generating torque of the motor, the maximum allowable braking feedback torque under the current rotating speed of the motor is obtained by a table look-up and interpolation method of a two-dimensional table; obtaining the allowable maximum feedback torque of the current finished automobile system by a table look-up and interpolation method of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value; and selecting the minimum value of the allowable feedback torque of the drive axle, the maximum allowable braking feedback torque under the current motor rotating speed and the allowable maximum feedback torque of the current whole vehicle system, and calculating the product of the minimum value and the opening degree of the brake pedal to obtain the first required torque.

In some embodiments, the second obtaining unit 408 is configured to: obtaining allowable feedback torque of a drive axle; calculating an allowable sliding feedback torque under a constant power feedback condition according to a preset sliding feedback power when the motor operates; obtaining the maximum allowable braking feedback torque under the current motor rotating speed by a two-dimensional table lookup interpolation method according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a three-dimensional table lookup interpolation method according to temperature information, a battery SOC value and a battery SOH value, and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current finished automobile system; calculating to obtain a deceleration value of the vehicle at the current moment by a discrete system differentiation method according to the vehicle speed information, obtaining an adjusting torque by a Proportional Integral Derivative (PID) algorithm according to the deceleration value, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque; and selecting the minimum value of the allowable drive axle feedback torque, the allowable sliding feedback torque under the constant power feedback condition, the sliding feedback torque of the current whole vehicle system and the regulation limit feedback torque as the second required torque.

In some embodiments, the two-dimensional table is a corresponding relation table between the motor rotating speed, the motor generating torque and the maximum allowable braking feedback torque; the three-dimensional table is a corresponding relation table among temperature information, a battery SOC value, a battery SOH value and the allowable maximum feedback torque of the current finished automobile system.

In some embodiments, the receiving unit 402 may also be configured to receive ABS status information and/or EBS status information. The determining unit 404 is configured to determine whether the accelerator pedal is in a fault state according to the accelerator pedal state signal, determine whether the shift lever is in a fault state according to the gear state signal, determine whether the brake pedal is in a fault state according to the brake pedal state signal, and determine whether the battery system is in a fault state according to the battery system fault state of the battery management system information. The determining unit 404 may be further configured to determine whether the ABS system is in a failure state according to the ABS state information and/or determine whether the EBS system is in a failure state according to the EBS state information.

In some embodiments, the determining unit 404 may further be configured to determine whether the electric vehicle has a vehicle system fault in real time, and exit the energy feedback mode if the vehicle system fault occurs.

Fig. 5 is a block diagram illustrating a vehicle control unit according to further embodiments of the present disclosure. The hybrid controller includes a memory 510 and a processor 520. Wherein:

the memory 510 may be a magnetic disk, flash memory, or any other non-volatile storage medium. The memory is used for storing instructions in the embodiments corresponding to fig. 1 and/or fig. 2.

Processor 520 is coupled to memory 510 and may be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. The processor 520 is configured to execute the instructions stored in the memory, and may provide different energy feedback functions for the electric vehicle to improve driving experience.

In some embodiments, as also shown in fig. 6, vehicle control unit 600 includes a memory 610 and a processor 620. Processor 620 is coupled to memory 610 through a BUS 630. The hybrid controller 600 may be further coupled to an external storage device 650 via a storage interface 640 for external data access, and may be further coupled to a network or another computer system (not shown) via a network interface 660, which will not be described in detail herein.

In the embodiment, the data instructions are stored in the memory, and the instructions are processed by the processor, so that different energy feedback functions can be provided for the electric automobile, and the driving experience is improved.

In some embodiments, the vehicle control unit shown in fig. 4, 5, or 6 may be used as the vehicle control unit 310 in fig. 3.

In some embodiments of the present disclosure, a control system for an electric vehicle is also provided. The control system includes a vehicle control unit (e.g., the vehicle control unit shown in fig. 4, 5, or 6) as previously described.

As shown in fig. 7, the control system includes a vehicle control unit 710. For example, vehicle control unit 710 is a vehicle control unit as shown in fig. 4, 5, or 6.

In some embodiments, as shown in fig. 7, the control system may further include: accelerator pedal 720, gear selector 730, brake pedal 740, meter control unit 750, battery management system 760, and motor controller 770.

Accelerator pedal 720 is configured to send an accelerator pedal status signal to vehicle control unit 710.

The shift lever 730 is used to send a gear state signal to the vehicle control unit 710.

Brake pedal 740 is configured to send a brake pedal status signal to vehicle control unit 710.

The meter control unit 750 is configured to send vehicle speed information of the electric vehicle to the vehicle controller 710.

The battery management system 760 is configured to send battery management system information to the vehicle control unit 710.

The motor controller 770 is configured to receive the first required torque or the second required torque from the vehicle controller 710 and control the magnitude of the motor recharging current according to the first required torque or the second required torque.

In some embodiments, the control system may also include an ABS system and/or an EBS system. The ABS system is configured to transmit ABS status information to the vehicle control unit 710. The EBS system is configured to transmit EBS status information to the vehicle controller 710.

In some embodiments, the vehicle control unit is connected and communicated with each controller and component through a CAN network, and is communicated with a brake pedal and an accelerator pedal through analog quantity hard wires and data transmission. The vehicle controller integrally schedules an operation signal, an accelerator pedal signal, a brake signal (brake pedal state signal), a gear signal and an ABS/EBS system signal; and the signals are analyzed, and the vehicle is controlled to decelerate and recover energy according to the state of the whole vehicle and the operation and control requirements of a driver under the condition of meeting the brake energy feedback enabling condition. In other embodiments, the vehicle control unit may also monitor the state of each system controller of the vehicle in real time, analyze the fault, and perform energy recovery control or cancel energy recovery according to the fault level.

After the vehicle control unit is powered on, information from a motor controller and a battery management system is processed and diagnosed through self-checking, whether the gear state of the vehicle is a forward gear or not is diagnosed, whether a brake pedal is effective or not is diagnosed, whether systems such as an ABS/EBS system work normally or not is diagnosed, whether the vehicle control unit meets the condition of starting a brake energy feedback function or not is judged, and a vehicle speed variable obtained by an internal function operation module through data chain operation is sent to the vehicle control unit by an instrument control unit. And when the VCU vehicle control unit judges that the condition of starting the braking energy feedback function is met, the vehicle control unit starts an energy feedback permission function and enters a vehicle energy feedback state. Judging whether the driver steps on the brake pedal or not, and entering a braking energy feedback mode if the driver steps on the brake pedal and the state signal of the brake pedal is effective; if the driver does not press the brake pedal, the vehicle is in a sliding state, and the vehicle enters a sliding energy feedback mode.

There is also provided, in accordance with some embodiments of the present disclosure, an electric vehicle, including: a control system as previously described (e.g., a control system as shown in fig. 7).

In other embodiments, the present disclosure also provides a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) having stored thereon computer program instructions that, when executed by a processor, implement the steps of the method in the corresponding embodiments of fig. 1 and/or fig. 2. As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, apparatus, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Thus far, the present disclosure has been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. Those skilled in the art can now fully appreciate how to implement the teachings disclosed herein, in view of the foregoing description.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A control method for an electric vehicle, comprising:

receiving an accelerator pedal state signal, a gear state signal, a brake pedal state signal, the speed information of the electric automobile and the battery management system information;

judging whether the electric automobile meets the condition of starting an energy feedback mode or not according to the accelerator pedal state signal, the gear state signal, the speed information of the electric automobile and the battery management system information;

if the electric automobile meets the condition of starting an energy feedback mode, determining the type of the energy feedback mode according to the brake pedal state signal, wherein the energy feedback mode comprises the following steps: a braking energy feedback mode and a sliding energy feedback mode;

under the condition that the brake pedal state signal indicates that the electric automobile is in a braking state, determining that the electric automobile enters a braking energy feedback mode, acquiring a first required torque under the braking energy feedback mode, and outputting the first required torque to a motor controller; and

and under the condition that the brake pedal state signal indicates that the electric automobile is not in a braking state, determining that the electric automobile enters a slip energy feedback mode, acquiring a second required torque in the slip energy feedback mode, and outputting the second required torque to the motor controller.

2. The control method according to claim 1, wherein,

the battery management system information includes: the battery state of charge (SOC) value, the battery state of health (SOH) value, temperature information and the battery system fault state.

3. The control method according to claim 2, wherein the condition for determining whether the electric vehicle satisfies an on-energy-feedback mode according to the accelerator pedal state signal, the shift state signal, the vehicle speed information of the electric vehicle, and the battery management system information includes:

judging whether the electric automobile is in a fault state or not;

if the electric automobile is in a fault state, the electric automobile enters a fault mode;

and if the electric automobile is not in a fault state, determining that the electric automobile meets the condition of starting an energy feedback mode under the condition that the accelerator pedal state signal indicates that an accelerator pedal is not started, the gear state signal indicates that the current gear is in a forward gear, the speed information of the electric automobile is greater than a speed threshold value, and the SOC value of the battery is smaller than an allowable charging value.

4. The control method according to claim 2, wherein obtaining the first required torque in the braking energy feedback mode includes:

obtaining allowable feedback torque of a drive axle;

according to the external characteristic curve data of the motor between the rotating speed of the motor and the generating torque of the motor, the maximum allowable braking feedback torque under the current rotating speed of the motor is obtained by a table look-up and interpolation method of a two-dimensional table;

obtaining the allowable maximum feedback torque of the current finished automobile system by a method of table look-up and interpolation of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value; and

and selecting the minimum value of the allowable feedback torque of the drive axle, the maximum allowable braking feedback torque under the current motor rotating speed and the allowable maximum feedback torque of the current whole vehicle system, and calculating the product of the minimum value and the opening degree of a brake pedal to obtain the first required torque.

5. The control method according to claim 2, wherein obtaining the second required torque in the slip energy feedback mode includes:

obtaining allowable feedback torque of a drive axle;

calculating an allowable sliding feedback torque under a constant power feedback condition according to a preset sliding feedback power when the motor operates;

obtaining the maximum allowable braking feedback torque under the current motor rotating speed by a two-dimensional table lookup interpolation method according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a three-dimensional table lookup interpolation method according to the temperature information, the battery SOC value and the battery SOH value, and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current finished automobile system;

calculating to obtain a deceleration value of the vehicle at the current moment by a discrete system differentiation method according to the vehicle speed information, obtaining an adjusting torque by a Proportional Integral Derivative (PID) algorithm according to the deceleration value, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque; and

and selecting the minimum value of the allowable drive axle feedback torque, the allowable sliding feedback torque under the constant power feedback condition, the sliding feedback torque of the current whole vehicle system and the regulation limit feedback torque as the second required torque.

6. The control method according to claim 4 or 5,

the two-dimensional table is a corresponding relation table among the motor rotating speed, the motor generating torque and the maximum allowable braking feedback torque;

the three-dimensional table is a corresponding relation table among temperature information, a battery SOC value, a battery SOH value and the maximum allowable feedback torque of the whole vehicle system at present.

7. The control method according to claim 3, further comprising:

receiving ABS state information and/or EBS state information of an anti-lock braking system;

wherein, judging whether the electric automobile is in a fault state comprises:

judging whether the accelerator pedal is in a fault state or not according to the accelerator pedal state signal;

judging whether the gear shifting lever is in a fault state or not according to the gear state signal;

judging whether the brake pedal is in a fault state or not according to the brake pedal state signal;

judging whether the battery system is in a fault state or not according to the battery system fault state of the battery management system information; and

and judging whether the ABS system is in a fault state according to the ABS state information, and/or judging whether the EBS system is in a fault state according to the EBS state information.

8. The control method according to claim 1, further comprising:

and judging whether the electric automobile has the fault of the whole automobile system in real time, and if the fault of the whole automobile system occurs, exiting the energy feedback mode.

9. A vehicle control unit, comprising:

the receiving unit is used for receiving an accelerator pedal state signal, a gear state signal, a brake pedal state signal, the speed information of the electric automobile and the battery management system information;

a determining unit, configured to determine whether the electric vehicle satisfies a condition for turning on an energy feedback mode according to the accelerator pedal state signal, the gear state signal, vehicle speed information of the electric vehicle, and the battery management system information, and determine a type of the energy feedback mode according to the brake pedal state signal if the electric vehicle satisfies the condition for turning on the energy feedback mode, where the energy feedback mode includes: a braking energy feedback mode and a sliding energy feedback mode;

the first obtaining unit is used for determining that the electric automobile enters a braking energy feedback mode under the condition that the braking pedal state signal represents that the electric automobile is in a braking state, and obtaining a first required torque under the braking energy feedback mode;

a second obtaining unit, configured to determine that the electric vehicle enters a slip energy feedback mode and obtain a second required torque in the slip energy feedback mode, when the brake pedal state signal indicates that the electric vehicle is not in a braking state; and

and the output unit is used for outputting the first required torque to a motor controller or outputting the second required torque to the motor controller.

10. The hybrid vehicle controller according to claim 9,

the battery management system information includes: battery SOC value, battery SOH value, temperature information, and battery system fault status.

11. The hybrid vehicle controller according to claim 10,

the judging unit is used for judging whether the electric automobile is in a fault state or not, if the electric automobile is in the fault state, the electric automobile enters a fault mode, if the electric automobile is not in the fault state, the accelerator pedal state signal indicates that an accelerator pedal is not started, the gear state signal indicates that a current gear is in a forward gear, the speed information of the electric automobile is greater than a speed threshold value, and the battery SOC value is smaller than a charging allowable value, the electric automobile is determined to meet the condition of starting an energy feedback mode.

12. The hybrid vehicle controller according to claim 10,

the first obtaining unit is configured to: obtaining allowable feedback torque of a drive axle; according to the external characteristic curve data of the motor between the rotating speed of the motor and the generating torque of the motor, the maximum allowable braking feedback torque under the current rotating speed of the motor is obtained by a table look-up and interpolation method of a two-dimensional table; obtaining the allowable maximum feedback torque of the current finished automobile system by a method of table look-up and interpolation of a three-dimensional table according to the temperature information, the battery SOC value and the battery SOH value; and selecting the minimum value of the allowable feedback torque of the drive axle, the maximum allowable braking feedback torque under the current motor rotating speed and the allowable maximum feedback torque of the current whole vehicle system, and calculating the product of the minimum value and the opening degree of a brake pedal to obtain the first required torque.

13. The hybrid vehicle controller according to claim 10,

the second obtaining unit is configured to: obtaining allowable feedback torque of a drive axle; calculating an allowable sliding feedback torque under a constant power feedback condition according to a preset sliding feedback power when the motor operates; obtaining the maximum allowable braking feedback torque under the current motor rotating speed by a two-dimensional table lookup interpolation method according to the motor external characteristic curve data between the motor rotating speed and the motor generating torque, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain a first sliding feedback torque, obtaining the allowable maximum feedback torque of the current finished automobile system as a second sliding feedback torque by a three-dimensional table lookup interpolation method according to the temperature information, the battery SOC value and the battery SOH value, and selecting the smaller value of the first sliding feedback torque and the second sliding feedback torque as the sliding feedback torque of the current finished automobile system; calculating to obtain a deceleration value of the vehicle at the current moment by a discrete system differentiation method according to the vehicle speed information, obtaining an adjusting torque by a PID algorithm according to the deceleration value, and performing Kalman filtering processing on the adjusting torque to obtain a corresponding adjusting limit feedback torque; and selecting the minimum value of the allowable drive axle feedback torque, the allowable sliding feedback torque under the constant power feedback condition, the sliding feedback torque of the current whole vehicle system and the regulation limit feedback torque as the second required torque.

14. The hybrid vehicle controller according to claim 12 or 13, wherein,

15. The hybrid vehicle controller according to claim 11,

the receiving unit is further configured to receive ABS status information and/or EBS status information;

the judging unit is used for judging whether the accelerator pedal is in a fault state according to the accelerator pedal state signal, judging whether the gear lever is in a fault state according to the gear state signal, judging whether the brake pedal is in a fault state according to the brake pedal state signal, and judging whether the battery system is in a fault state according to the battery system fault state of the battery management system information; the judging unit is also used for judging whether the ABS system is in a fault state according to the ABS state information and/or judging whether the EBS system is in a fault state according to the EBS state information.

16. The hybrid vehicle controller according to claim 9,

the judging unit is also used for judging whether the electric automobile has a whole automobile system fault in real time, and if the whole automobile system fault occurs, the energy feedback mode is exited.

17. A vehicle control unit, comprising:

a memory; and

a processor coupled to the memory, the processor configured to perform the method of any of claims 1-8 based on instructions stored in the memory.

18. A control system for an electric vehicle, comprising: the vehicle control unit of any one of claims 9 to 17.

19. The control system of claim 18, further comprising:

the accelerator pedal is used for sending an accelerator pedal state signal to the vehicle control unit;

the gear shifting lever is used for sending a gear state signal to the vehicle control unit;

the brake pedal is used for sending a brake pedal state signal to the vehicle control unit;

the instrument control unit is used for sending the speed information of the electric automobile to the whole automobile controller;

the battery management system is used for sending battery management system information to the vehicle control unit; and

and the motor controller is used for receiving the first required torque or the second required torque from the vehicle control unit and controlling the magnitude of the motor recharging current according to the first required torque or the second required torque.

20. An electric vehicle comprising: a control system as claimed in claim 18 or 19.

21. A computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the method of any one of claims 1 to 8.