CN114475263B

CN114475263B - Control method, whole vehicle controller, control system, electric vehicle and storage medium

Info

Publication number: CN114475263B
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: 2023-11-10
Anticipated expiration: 2042-03-30
Also published as: CN114475263A

Abstract

The disclosure provides a control method, a whole vehicle controller, 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, gear state signal, speed information of the electric automobile and 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 braking state, determining that the electric automobile enters a braking energy feedback mode, obtaining a first required torque in 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 brake state, determining that the electric automobile enters a sliding energy feedback mode, obtaining a second required torque in the sliding energy feedback mode and outputting the second required torque to the motor controller.

Description

Control method, whole vehicle controller, control system, electric vehicle and storage medium

Technical Field

The disclosure relates to the technical field of control of electric automobiles, in particular to a control method, a whole vehicle controller, a control system, an electric automobile and a storage medium.

Background

With the increasing significant energy crisis, increasing fuel price, environmental pollution, carbon emission and other problems, the development of new energy electric vehicles is becoming more and more important. Currently, some vehicle enterprises are pushing new energy automobile development plans. In an electric vehicle, the braking energy feedback system can improve the driving range of the vehicle, and different operation vehicles have different requirements on the braking energy feedback function. For example, the washing and sweeping vehicle needs to keep a fixed vehicle speed operation and energy feedback is not needed; the weight change of the vehicle is larger when the slag car and the mine truck are fully loaded and unloaded, and the dynamic requirement is provided for braking energy feedback force.

At present, the existing electric commercial automobile does not have a braking energy feedback function or has single function, is poor in driving experience, and cannot fully cover all types of automobile types.

Disclosure of Invention

One technical problem solved by the present disclosure is: the control method for the electric automobile is convenient for providing different energy feedback functions for the electric automobile and improving driving experience.

According to one 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, speed information of an electric automobile and 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 braking state, determining that the electric automobile enters a braking energy feedback mode, obtaining a first required torque in 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 sliding energy feedback mode, obtaining a second required torque in the sliding energy feedback mode, and outputting the second required torque to the motor controller.

In some embodiments, the battery management system information includes: battery state of charge, SOC, battery state of health, SOH, temperature information, and battery system fault conditions.

In some embodiments, determining 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, 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; 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 larger than a speed threshold value and the battery SOC value is smaller than an allowable charge value.

In some embodiments, obtaining the first demand torque in the braking energy feedback mode includes: obtaining allowable feedback moment of the drive axle; obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up a table and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque; obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 moment of the drive axle, the maximum allowable braking feedback moment under the current motor rotating speed and the allowable maximum feedback moment 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 demand torque in the slip energy feedback mode includes: obtaining allowable feedback moment of the drive axle; calculating allowable sliding feedback moment under a constant power feedback condition according to preset sliding feedback power when the motor operates; obtaining maximum allowable braking feedback torque at the current motor rotation speed according to motor external characteristic curve data between the motor rotation speed and motor power generation torque by a method of table lookup interpolation of a two-dimensional table, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain first sliding feedback torque, obtaining allowable maximum feedback torque of the current whole vehicle system as second sliding feedback torque by a method of table lookup interpolation of the three-dimensional table 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 sliding feedback torque of the current whole vehicle system; calculating to obtain the deceleration value of the vehicle at the current moment through a discrete system differentiation method according to the vehicle speed information, obtaining the regulating torque through a proportional integral derivative PID algorithm according to the deceleration value, and carrying out Kalman filtering processing on the regulating torque to obtain a corresponding regulating limiting feedback moment; and selecting the minimum value of the allowable feedback moment of the driving axle, the allowable sliding feedback moment under the constant power feedback condition, the sliding feedback moment of the current whole vehicle system and the adjustment limiting feedback moment as the second required torque.

In some embodiments, the two-dimensional table is a table of correspondence between motor rotational speed, motor generated torque, and maximum allowable brake 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 moment of the current whole vehicle system.

In some embodiments, the control method further comprises: receiving ABS state information and/or EBS state information of an electronic braking system; wherein, judging whether the electric automobile is in a fault state comprises: judging whether the accelerator pedal is in a fault state according to the accelerator pedal state signal; judging whether the gear shifting 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; judging whether the battery system is in a fault state 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 the fault state according to the EBS state information.

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

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

In some embodiments, the battery management system information includes: 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, if the electric vehicle is not in the fault state, the accelerator pedal is not started by the accelerator pedal state signal, the current gear is in a forward gear by the gear state signal, the speed information of the electric vehicle is greater than a speed threshold, and if the battery SOC value is smaller than a charging permission value, it is determined that the electric vehicle satisfies a condition of starting an energy feedback mode.

In some embodiments, the first obtaining unit is configured to: obtaining allowable feedback moment of the drive axle; obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up a table and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque; obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 moment of the drive axle, the maximum allowable braking feedback moment under the current motor rotating speed and the allowable maximum feedback moment 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 moment of the drive axle; calculating allowable sliding feedback moment under a constant power feedback condition according to preset sliding feedback power when the motor operates; obtaining maximum allowable braking feedback torque at the current motor rotation speed according to motor external characteristic curve data between the motor rotation speed and motor power generation torque by a method of table lookup interpolation of a two-dimensional table, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain first sliding feedback torque, obtaining allowable maximum feedback torque of the current whole vehicle system as second sliding feedback torque by a method of table lookup interpolation of the three-dimensional table 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 sliding feedback torque of the current whole vehicle system; calculating to obtain the deceleration value of the vehicle at the current moment through a discrete system differentiation method according to the vehicle speed information, obtaining the regulating torque through a proportional integral derivative PID algorithm according to the deceleration value, and carrying out Kalman filtering processing on the regulating torque to obtain a corresponding regulating limiting feedback moment; and selecting the minimum value of the allowable feedback moment of the driving axle, the allowable sliding feedback moment under the constant power feedback condition, the sliding feedback moment of the current whole vehicle system and the adjustment limiting feedback moment 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 shifting 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 further 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 judging unit is further configured to judge in real time whether the electric vehicle has a complete vehicle system fault, and if the complete vehicle system fault occurs, exit the energy feedback mode.

According to another aspect of the present disclosure, there is provided a vehicle controller including: a memory; and a processor coupled to the memory, the processor configured to perform the method as described above 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 whole vehicle controller; the gear shifting lever is used for sending a gear state signal to the whole vehicle controller; the brake pedal is used for sending a brake pedal state signal to the whole vehicle controller; 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 whole vehicle controller; and the motor controller is used for receiving the first required torque or the second required torque from the whole vehicle controller and controlling the magnitude of 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 a method as described above.

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 improve driving experience. In addition, in the method, before the energy feedback mode is executed, the start judgment of the energy feedback mode is carried out, so that the driving safety can be improved.

Other features of the present disclosure and its advantages will become apparent from the following detailed description of exemplary embodiments of the disclosure, 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 disclosure may be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

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

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;

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

FIG. 4 is a block diagram illustrating a configuration of an overall vehicle controller according to some embodiments of the present disclosure;

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

FIG. 6 is a block diagram illustrating the construction of a vehicle controller 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, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless it is specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for 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 one 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 specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary 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 (Vehicle Control Unit, abbreviated VCU) according to some embodiments of the present disclosure. Control methods for an electric vehicle according to some embodiments of the present disclosure are described in detail below with reference to fig. 1 and 3. The control method can be executed by the vehicle controller.

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 an electric vehicle, and battery management system information are received.

For example, as shown in fig. 3, the vehicle controller 310 may receive an accelerator pedal status signal from an accelerator pedal (e.g., an accelerator pedal internal sensor, not shown in fig. 3), a gear status signal from a shift lever (not shown in fig. 3), a brake pedal status signal from a brake pedal (e.g., a brake pedal internal sensor, not shown in fig. 3), vehicle speed information of an electric vehicle from the meter control unit 340, and battery management system information from the battery management system (Battery Management System, abbreviated as 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 failure 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 vehicle controller 310 may transmit battery energy request information to the battery management system 330 in addition to receiving battery management system information from the battery management system 330.

In some embodiments, as shown in fig. 3, the method may further comprise: ABS (Antilock Brake System, brake antilock system) status information and/or EBS (Electronic Brake System ) status information is received. For example, the vehicle controller 310 may receive ABS status information from an ABS system and/or 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-up determination of the energy feedback mode is performed.

A specific embodiment of this step S104 is described below with reference to 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 of turning on the energy feedback mode includes steps S202 to S206, that is, step S104 includes steps S202 to S206.

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

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

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

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

In some embodiments, the step S202 further includes: and judging whether the battery system is in a fault state according to the fault state of the battery system of the battery management system information. Here, the battery system failure state reflects whether the battery system fails, and thus, whether the battery system is in a failure state can be determined based on the battery system failure state of the battery management system information.

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

Under the condition that at least one of the components or the systems fails, determining that the electric automobile is in a failure state; and under the condition that all the parts or the systems are not in failure, determining that the electric automobile is not in a failure state.

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

In step S206, if the electric vehicle is not in a fault state, when the accelerator pedal state signal indicates that the accelerator pedal is not started, 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 charge value, it is determined that the electric vehicle satisfies the condition of starting the energy feedback mode.

Here, the vehicle speed threshold value and the allowable charge value may each 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 inactive; 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, the battery SOC value given by the battery management system 330 is lower than the allowable charge value, no whole vehicle system fault exists after the whole vehicle controller 310 processes the information, and the high-voltage power-on of the vehicle is ready. The above condition is satisfied, and the vehicle is allowed to activate the energy feedback function.

Of course, if at least one of the conditions (the condition satisfied by the accelerator pedal state signal, the gear 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 far, a method of judging whether the electric vehicle satisfies the condition of turning on the energy feedback mode has been described in detail.

In other embodiments, as shown in fig. 3, the vehicle controller 310 may also receive motor controller failure information from the motor controller (Motor Control Unit, abbreviated as MCU) 320, so as to determine whether the motor controller is in a failure state. This can also be used to determine if the electric vehicle is in a fault condition. In addition, the vehicle 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 indicate that the electric vehicle is currently in a fault state.

Returning 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 status 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 status signal indicates that the electric vehicle is in a braking state, it is determined that the electric vehicle enters a 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 brake 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 demand torque in the braking energy feedback mode includes: obtaining allowable feedback moment of the drive axle; obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up a table and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque; obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 moment of the drive axle, the maximum allowable braking feedback moment under the current motor rotating speed and the allowable maximum feedback moment 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 is described in detail below with reference to fig. 3.

(1) Obtaining the allowable feedback moment of the drive axle. For example, the drive axle allowable feedback torque may be set to 30% of the motor generated torque, and the drive axle allowable feedback torque may be provided by a drive axle supplier or obtained through experiments. Of course, those skilled in the art will appreciate that the allowable feedback torque of the drive axle may be set according to actual situations.

(2) And obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque.

Here, the above-mentioned 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 indicates the motor rotation speed, the ordinate indicates the motor generation torque, and the element in the two-dimensional table indicates the maximum allowable braking feedback torque at a certain motor rotation speed and a certain motor generation torque. The two-dimensional table is a two-dimensional table provided in the prior art.

Here, a table look-up interpolation method may be used to obtain the maximum allowable braking feedback torque at the current motor speed. For example, for a certain motor speed, not shown in the two-dimensional table, but one motor speed (denoted as a first motor speed) that is closest to the motor speed and another motor speed (denoted as a second motor speed) that is greater than the certain motor speed are shown in the two-dimensional table, if the motor generated 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 at the motor generated torque and a second maximum allowable braking feedback torque corresponding to the second motor speed at the motor generated torque may be found, and then a suitable allowable braking feedback torque between the first maximum allowable braking feedback torque and the second maximum allowable braking feedback torque is selected as the maximum allowable braking feedback torque corresponding to the certain motor speed at the motor generated torque, that is, the maximum allowable braking feedback torque obtained by 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, it will be understood by those skilled in the art that, in the case where the motor generation torque corresponding to the 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 may be obtained by interpolation, so long as the first motor rotation speed and the second motor rotation speed are obtained, one motor generation torque (referred to as first motor generation torque) closest to the certain motor generation torque and the other motor generation torque (referred to as second motor generation torque) greater than the certain motor generation torque are obtained by table lookup, and then the maximum allowable braking feedback torque is obtained by comprehensive analysis by a difference method using the first motor rotation speed, the second motor rotation speed, the first motor generation torque and the second motor generation torque, which will not be described in detail herein.

(3) And obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 between temperature information, a battery SOC value and a battery SOH value in the battery management system information and the allowable maximum feedback moment of the current whole vehicle 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 the allowable maximum feedback torque of the current 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 of interpolating the three-dimensional table look-up is similar to the method of interpolating the two-dimensional table look-up described above and will not be described in detail here.

Then, the minimum value of the torque in the method (1) to the torque in the method (3) is selected, and the minimum value is multiplied by the opening degree of the brake pedal (which can be obtained through a system pedal state signal), so that the first required torque can be obtained. The vehicle controller 310 may output the first requested 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, when the brake pedal status signal indicates that the electric vehicle is not in a braking state, it is determined that the electric vehicle enters a 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 demand torque in the slip energy feedback mode includes: obtaining allowable feedback moment of the drive axle; calculating allowable sliding feedback moment under a constant power feedback condition according to preset sliding feedback power when the motor operates; obtaining maximum allowable braking feedback torque at the current motor rotation speed according to motor external characteristic curve data between the motor rotation speed and motor power generation torque by a method of table lookup interpolation of a two-dimensional table, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain first sliding feedback torque, obtaining allowable maximum feedback torque of the current whole vehicle system as second sliding feedback torque by a method of table lookup interpolation of the three-dimensional table 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 sliding feedback torque of the current whole vehicle system; calculating to obtain the deceleration value of the vehicle at the current moment according to the vehicle speed information by a discrete system differentiation method, obtaining the regulating torque according to the deceleration value by a proportional integral derivative PID algorithm, and carrying out Kalman filtering processing on the regulating torque to obtain a corresponding regulating limiting feedback moment; and selecting the minimum value of the allowable feedback moment of the driving axle, the allowable sliding feedback moment under the constant power feedback condition, the sliding feedback moment of the current whole vehicle system and the regulation limiting feedback moment as the second required torque.

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

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

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

For example, the slip feedback power of the motor during operation may be obtained by experiment or calibration (for example, the power may be a calibration value set by man), and the allowable slip feedback torque under the constant power feedback condition is calculated by the formula t=9549p/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 in a constant torque mode at low rotational speeds and in a constant power mode at high rotational speeds.

(c) Obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque, and calculating the product of the maximum allowable braking feedback moment and a preset protection coefficient to obtain a first sliding feedback torque; obtaining allowable maximum feedback torque of the current whole vehicle system as a second sliding feedback torque by a method of looking up a three-dimensional table and interpolating according to the temperature information, the battery SOC value and the battery SOH value; and selecting a 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.

Similar to the previous, the two-dimensional table is a corresponding relation table between the motor rotation speed, the motor power generation torque and the maximum allowable braking feedback torque, and the three-dimensional table is a corresponding relation table between temperature information, a battery SOC value, a battery SOH value and the current allowable maximum feedback torque of the whole vehicle system. Here, the method of table lookup interpolation for the two-dimensional table and the method of table lookup interpolation for the three-dimensional table have been described above, and will not be described here again.

In the method, when the first sliding feedback torque is calculated, the maximum allowable braking feedback torque obtained through a two-dimensional table lookup interpolation method is multiplied by a preset protection coefficient to obtain the first sliding feedback torque. For example, the protection factor ranges from 0.3 to 0.7. And then, according to the temperature information, the battery SOC value and the battery SOH value, obtaining the allowable maximum feedback moment of the current whole vehicle system as a second sliding feedback torque by a method of looking up a three-dimensional table and interpolating. 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) According to the vehicle speed information, the deceleration value of the vehicle at the current moment (for example, the vehicle is decelerated due to wind resistance, rolling resistance, friction and the like after losing power) is calculated through a discrete system differentiation method, then the adjusting torque is obtained through a variable proportion coefficient integral separation type PID (Proportion Integral Differential, proportional integral differentiation) algorithm according to the target deceleration value calibrated through the test and the deceleration value at the current moment, and then the adjusting torque is subjected to Kalman filtering processing to obtain the corresponding adjusting limiting feedback moment.

Here, the deceleration value of the vehicle at the present moment 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 point an adjusted torque is obtained by the PID algorithm. For example, the target deceleration value-the current deceleration value = the adjustment amount, and then the adjustment torque is obtained through a PID algorithm using the adjustment amount, the known proportional coefficient and the integral coefficient; the effect of the torque regulation is to control the deceleration of the vehicle towards a set target deceleration value, so that the vehicle can be decelerated at a constant deceleration and energy fed back regardless of the full load. The PID algorithm here is a prior art algorithm. And after the adjustment torque is obtained, carrying out Kalman filtering processing on the adjustment torque to obtain a corresponding adjustment limiting feedback torque.

Then, the minimum value of the moment in the method (a) to the moment in the method (d) is selected and used as the second required torque. The vehicle controller 310 may output the second requested 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 recharge 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 the empty and full load of the vehicle slides, the driving mileage is improved, the energy utilization rate is improved, and the driving comfort of a driver is enhanced.

To this end, control methods for an electric vehicle according to some embodiments of the present disclosure are provided. The control method comprises the following steps: receiving an accelerator pedal state signal, a gear state signal, a brake pedal state signal, speed information of an electric automobile and 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 a 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, obtaining a first required torque in 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 brake state, determining that the electric automobile enters a sliding energy feedback mode, obtaining a second required torque in the sliding 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 improve driving experience.

In addition, in the method, before the energy feedback mode is executed, the start judgment of the energy feedback mode is carried out, so that the driving safety can be improved.

In the related art, once a current electric car fails, for example: the transmission hard wire breaks down, the whole vehicle controller breaks down or communication between the whole vehicle controller and the motor controller breaks down, and the like, so that the vehicle can not normally exit from the braking energy feedback state, and traffic accidents can be caused.

In some embodiments of the present disclosure, the control method may further include: and judging whether the electric automobile has a complete vehicle system fault in real time, and if the electric automobile has the complete vehicle system fault, exiting the energy feedback mode. Here, whether the electric automobile has a whole automobile system fault or not is monitored in real time, and then after the whole automobile system fault occurs, the electric automobile exits from the energy feedback mode, so that the safety of the automobile can be improved.

For example, the vehicle controller processes the information including, but not limited to, a hard wire signal, a sensor signal, a CAN (Controller Area Network ) signal, and the like according to the collected vehicle information, and if the vehicle is determined to be in a fault state at present, the vehicle enters a fault mode and exits the brake energy feedback function.

Fig. 4 is a block diagram illustrating a configuration of an overall vehicle controller according to some embodiments of the present disclosure. As shown in fig. 4, the whole vehicle controller 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 an electric vehicle, and battery management system information.

The determining unit 404 is configured to determine whether the electric vehicle meets a condition for starting 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 starting 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 a braking energy feedback mode and obtain a first required torque in the braking energy feedback mode when the brake pedal status signal indicates that the electric vehicle is in a braking state.

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

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

Thus far, an overall vehicle controller according to some embodiments of the present disclosure is provided. The whole vehicle controller 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, if the electric vehicle is not in the fault state, the accelerator pedal is not started when the accelerator pedal state signal indicates that the current gear is in a forward gear, the speed information of the electric vehicle is greater than a speed threshold, and the battery SOC value is less than an allowable charge value, and determine that the electric vehicle satisfies a condition for starting the energy feedback mode.

In some embodiments, the first obtaining unit 406 is configured to: obtaining allowable feedback moment of the drive axle; obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up a table and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque; obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 moment of the drive axle, the maximum allowable braking feedback moment under the current motor rotating speed and the allowable maximum feedback moment 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 moment of the drive axle; calculating allowable sliding feedback moment under a constant power feedback condition according to preset sliding feedback power when the motor operates; obtaining maximum allowable braking feedback torque at the current motor rotation speed according to motor external characteristic curve data between the motor rotation speed and motor power generation torque by a method of table lookup interpolation of a two-dimensional table, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain first sliding feedback torque, obtaining allowable maximum feedback torque of the current whole vehicle system as second sliding feedback torque by a method of table lookup interpolation of the three-dimensional table 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 sliding feedback torque of the current whole vehicle system; calculating to obtain the deceleration value of the vehicle at the current moment according to the vehicle speed information by a discrete system differentiation method, obtaining the regulating torque according to the deceleration value by a proportional integral derivative PID algorithm, and carrying out Kalman filtering processing on the regulating torque to obtain a corresponding regulating limiting feedback moment; and selecting the minimum value of the allowable feedback moment of the driving axle, the allowable sliding feedback moment under the constant power feedback condition, the sliding feedback moment of the current whole vehicle system and the regulation limiting feedback moment as the second required torque.

In some embodiments, the two-dimensional table is a table of correspondence between motor speed, motor generated torque, and maximum allowable brake 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 moment of the current whole vehicle system.

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

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

Fig. 5 is a block diagram illustrating a configuration of an overall vehicle controller according to other embodiments of the present disclosure. The vehicle controller includes a memory 510 and a processor 520. Wherein:

memory 510 may be a magnetic disk, flash memory, or any other non-volatile storage medium. The memory is used to store instructions in the corresponding embodiments of 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 instructions stored in the memory, and may provide different energy feedback functions for the electric vehicle, thereby improving driving experience.

In some embodiments, as also shown in fig. 6, the vehicle controller 600 includes a memory 610 and a processor 620. Processor 620 is coupled to memory 610 through BUS 630. The vehicle controller 600 may also be connected to an external storage device 650 via a storage interface 640 for invoking external data, and may also be connected 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 instruction is stored by the memory, and then the instruction is 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 controller shown in fig. 4, 5 or 6 may be used as the vehicle controller 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 controller as described above (e.g., the vehicle controller shown in fig. 4, 5, or 6).

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

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

The accelerator pedal 720 is configured to send an accelerator pedal status signal to the vehicle controller 710.

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

The brake pedal 740 is configured to send a brake pedal status signal to the vehicle controller 710.

The meter control unit 750 is used for sending vehicle speed information of the electric vehicle to the whole vehicle controller 710.

The battery management system 760 is used to send battery management system information to the overall vehicle controller 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 used to send ABS status information to the vehicle controller 710. The EBS system is configured to send EBS status information to the vehicle controller 710.

In some embodiments, the vehicle controller is in communication with the controllers and components via a CAN network, and is in communication with the brake pedal, the accelerator pedal and data transmission via analog hard wires. The whole vehicle controller coordinates control signals, accelerator pedal signals, brake signals (brake pedal state signals), gear signals and ABS/EBS system signals; and analyzing the signals, and controlling the vehicle to decelerate and recover energy according to the whole vehicle state and the control requirement of a driver under the condition of meeting the braking energy feedback enabling condition. In other embodiments, the vehicle controller may also monitor the status of the vehicle system controllers in real time, analyze faults and perform recovery energy control or cancel energy recovery according to the level of the faults.

After the whole vehicle controller is electrified, the information from the motor controller and the battery management system is processed and diagnosed through self-checking, whether the whole vehicle gear state is a forward gear or not is diagnosed, whether a brake pedal is effective or not, whether the ABS/EBS system works normally or not is judged by the whole vehicle controller, whether the whole vehicle information meets the condition of starting a braking energy feedback function or not is judged by the whole vehicle controller, and the whole vehicle speed variable obtained by an internal function operation module through data chain operation is sent to the whole vehicle controller by the instrument control unit. When the VCU whole vehicle controller judges that the condition of starting the brake energy feedback function is met, the whole vehicle controller starts the energy feedback permission function and enters a vehicle energy feedback state. Judging whether a driver presses a brake pedal at the moment, and if the driver presses the brake pedal and a brake pedal state signal is valid, entering a brake energy feedback mode; 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.

According to some embodiments of the present disclosure, there is also provided an electric vehicle including: a control system as described hereinbefore (e.g. as shown in figure 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, perform the steps of the methods of the corresponding embodiments of fig. 1 and/or 2. It will be apparent to those skilled in the art that 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, etc.) 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. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above 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 above examples are for 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 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, speed information of an electric automobile and 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 braking state, determining that the electric automobile enters a braking energy feedback mode, obtaining a first required torque in 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 brake state, determining that the electric automobile enters a sliding energy feedback mode, obtaining a second required torque in the sliding energy feedback mode, and outputting the second required torque to the motor controller;

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

obtaining the first demand torque in the braking energy feedback mode includes:

obtaining allowable feedback moment of the drive axle;

obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up a table and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque;

obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 moment of the drive axle, the maximum allowable braking feedback moment under the current motor rotating speed and the allowable maximum feedback moment 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.

2. The control method according to claim 1, wherein determining whether the electric vehicle satisfies a condition for turning on an energy feedback mode based on the accelerator pedal state signal, the gear state signal, 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;

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 larger than a speed threshold value and the battery SOC value is smaller than an allowable charge value.

3. The control method according to claim 1, wherein obtaining the second required torque in the slip energy feedback mode includes:

obtaining allowable feedback moment of the drive axle;

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

obtaining maximum allowable braking feedback torque at the current motor rotation speed according to motor external characteristic curve data between the motor rotation speed and motor power generation torque by a method of table lookup interpolation of a two-dimensional table, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain first sliding feedback torque, obtaining allowable maximum feedback torque of the current whole vehicle system as second sliding feedback torque by a method of table lookup interpolation of the three-dimensional table 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 sliding feedback torque of the current whole vehicle system;

Calculating to obtain the deceleration value of the vehicle at the current moment through a discrete system differentiation method according to the vehicle speed information, obtaining the regulating torque through a proportional integral derivative PID algorithm according to the deceleration value, and carrying out Kalman filtering processing on the regulating torque to obtain a corresponding regulating limiting feedback moment; and

and selecting the minimum value of the allowable feedback moment of the driving axle, the allowable sliding feedback moment under the constant power feedback condition, the sliding feedback moment of the current whole vehicle system and the adjustment limiting feedback moment as the second required torque.

4. The control method according to claim 1 or 3, wherein,

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 allowable maximum feedback moment of the current whole vehicle system.

5. The control method according to claim 2, further comprising:

receiving ABS state information and/or EBS state information of an electronic braking system;

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

Judging whether the accelerator pedal is in a fault state according to the accelerator pedal state signal;

judging whether the gear shifting 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;

judging whether the battery system is in a fault state 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.

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

and judging whether the electric automobile has a complete vehicle system fault in real time, and if the electric automobile has the complete vehicle system fault, exiting the energy feedback mode.

7. 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, speed information of the electric automobile and battery management system information;

the judging unit is configured to judge whether the electric vehicle meets a condition for starting 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 if the electric vehicle meets the condition for starting the energy feedback mode, determine a type of the energy feedback mode according to the brake pedal state signal, 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 and obtaining a first required torque in the braking energy feedback mode under the condition that the braking pedal state signal indicates that the electric automobile is in a braking state;

the second obtaining unit is used for determining that the electric automobile enters a sliding energy feedback mode and obtaining a second required torque in the sliding energy feedback mode under the condition that the brake pedal state signal indicates that the electric automobile is not in a braking state; and

an output unit configured to output the first required torque to a motor controller or output the second required torque to the motor controller;

the first obtaining unit is configured to: obtaining allowable feedback moment of the drive axle; obtaining the maximum allowable braking feedback moment at the current motor speed by a method of looking up a table and interpolating a two-dimensional table according to the motor external characteristic curve data between the motor speed and the motor power generation torque; obtaining the allowable maximum feedback moment of the current whole vehicle system by a method of looking up and interpolating 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 moment of the drive axle, the maximum allowable braking feedback moment under the current motor rotating speed and the allowable maximum feedback moment 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.

8. The vehicle control unit according to claim 7, wherein,

the judging unit is used for judging whether the electric automobile is in a fault state, 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 is not started by the accelerator pedal state signal, the current gear is in a forward gear by the gear state signal, the speed information of the electric automobile is larger than a speed threshold value, and the condition that the electric automobile meets the condition of starting an energy feedback mode is determined under the condition that the battery SOC value is smaller than an allowable charging value.

9. The vehicle control unit according to claim 7, wherein,

the second obtaining unit is configured to: obtaining allowable feedback moment of the drive axle; calculating allowable sliding feedback moment under a constant power feedback condition according to preset sliding feedback power when the motor operates; obtaining maximum allowable braking feedback torque at the current motor rotation speed according to motor external characteristic curve data between the motor rotation speed and motor power generation torque by a method of table lookup interpolation of a two-dimensional table, calculating the product of the maximum allowable braking feedback torque and a preset protection coefficient to obtain first sliding feedback torque, obtaining allowable maximum feedback torque of the current whole vehicle system as second sliding feedback torque by a method of table lookup interpolation of the three-dimensional table 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 sliding feedback torque of the current whole vehicle system; calculating to obtain the deceleration value of the vehicle at the current moment through a discrete system differentiation method according to the vehicle speed information, obtaining the regulating torque through a PID algorithm according to the deceleration value, and carrying out Kalman filtering processing on the regulating torque to obtain a corresponding regulating limiting feedback moment; and selecting the minimum value of the allowable feedback moment of the driving axle, the allowable sliding feedback moment under the constant power feedback condition, the sliding feedback moment of the current whole vehicle system and the adjustment limiting feedback moment as the second required torque.

10. The vehicle control unit according to claim 7 or 9, wherein,

11. The vehicle control unit of claim 8, wherein,

the receiving unit is further used for receiving ABS state information and/or EBS state 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 shifting 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 further 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.

12. The vehicle control unit according to claim 7, wherein,

The judging unit is also used for judging whether the electric automobile has a complete vehicle system fault or not in real time, and if the electric automobile has the complete vehicle system fault, the energy feedback mode is exited.

13. 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 1-6 based on instructions stored in the memory.

14. A control system for an electric vehicle, comprising: the vehicle control unit according to any one of claims 7 to 13.

15. The control system of claim 14, further comprising:

the accelerator pedal is used for sending an accelerator pedal state signal to the whole vehicle controller;

the gear shifting lever is used for sending a gear state signal to the whole vehicle controller;

the brake pedal is used for sending a brake pedal state signal to the whole vehicle controller;

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 whole vehicle controller; and

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

16. An electric automobile, comprising: a control system according to claim 14 or 15.

17. A computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the method of any of claims 1 to 6.