A control method for electric vehicle launch

Abstract

The application discloses a control method for the electric vehicle to start by shooting, that is, the vehicle brake pedal and the vehicle accelerator pedal are pressed in turn, and the vehicle accelerator pedal is in a forced downshift position; the vehicle controller sends the motor control unit the motor output torque request information according to the position information of the vehicle brake pedal and the position information of the vehicle accelerator pedal; the motor control unit controls the motor output torque according to the motor output torque request information, and drives the vehicle to start by shooting after the vehicle brake pedal is released. The application can ensure the maximum acceleration when the vehicle starts by shooting and the stability of the vehicle, improve the starting speed of the electric vehicle, make the driver obtain the maximum pushback feeling, shorten the starting time and the acceleration time of the vehicle per 100 kilometers, improve the driving feeling and the driving pleasure of the driver, and fully ensure the safety of the starting by shooting.

Description

TECHNICAL FIELD

[0001] The present application relates to an electric vehicle control method, in particular to a control method for the electric vehicle to start by using the launch control. BACKGROUND

[0002] The so-called launch control is to obtain the maximum torque by operating the vehicle to start, so as to maximize the starting acceleration, shorten the starting time, and shorten the 100km acceleration time of the vehicle.

[0003] The launch control of the traditional fuel vehicle is to adjust the engine speed to the maximum torque output platform by using the gearbox, so that the engine starts to output the maximum torque at the moment of starting to realize the best acceleration. The specific operation is that the driver steps on the brake pedal and deeply steps on the accelerator pedal, and when the engine speed reaches about 3000 revolutions, the brake pedal is released, and the vehicle obtains the large torque to start instantly.

[0004] The control of the launch control torque of the traditional fuel vehicle is to avoid the vehicle from slipping and to obtain the maximum acceleration by artificially controlling the engine speed before starting, which is not accurate. Moreover, in order to avoid the vehicle from slipping and failing to start, the ESP system needs to be closed in advance, which has a great safety hazard. For the electric vehicle, there is no torque control scheme for the launch control because there is no engine. SUMMARY

[0005] The present application provides a control method for the electric vehicle to start by using the launch control.

[0006] In the control method for the electric vehicle to start by using the launch control, the vehicle brake pedal and the vehicle accelerator pedal are stepped on in sequence, and the vehicle accelerator pedal is placed in the forced downshift position.

[0007] The vehicle controller sends the motor output torque request information to the motor control unit according to the position information of the vehicle brake pedal and the position information of the vehicle accelerator pedal.

[0008] The motor control unit controls the motor output torque according to the motor output torque request information, and drives the vehicle to start by using the launch control after the vehicle brake pedal is released.

[0009] In the control method for the electric vehicle to start by using the launch control, before controlling the vehicle to start by using the launch control, it is determined that the maximum available power value of the battery is within a predetermined value range, and / or the working state of the vehicle power system is normal, and / or the tire pressure of the vehicle is normal, and / or the seat belt locking state is normal, and / or the steering wheel angle is within a predetermined angle range, and / or the motor temperature is within a predetermined temperature value range.

[0010] The control method for the electric vehicle to start by shooting according to the application determines that the vehicle is in a ready state, the current gear is D, and the current vehicle speed is zero before the vehicle brake pedal and the vehicle accelerator pedal are pressed in turn.

[0011] In the control method for the electric vehicle to start by shooting according to the application, after the motor control unit controls the motor output torque, the current motor torque state is fed back to the vehicle control unit, and the vehicle control unit outputs a shooting start activation prompt information through the vehicle instrument.

[0012] In the control method for the electric vehicle to start by shooting according to the application, if the vehicle brake pedal is released within a predetermined time, the motor drives the vehicle to start by shooting.

[0013] If the vehicle brake pedal is not released within a predetermined time, the vehicle control unit sends a request information of terminating the motor output torque to the motor control unit.

[0014] In the control method for the electric vehicle to start by shooting according to the application, before the vehicle is controlled to start by shooting, the electronic parking brake system is in an open state.

[0015] In the control method for the electric vehicle to start by shooting according to the application, the vehicle control unit determines the torque output value in the motor output torque request information according to the minimum value between the torque corresponding to the forced gear down position of the vehicle accelerator pedal and the maximum torque determined by the electronic stability control system.

[0016] In the control method for the electric vehicle to start by shooting according to the application, the electronic stability control system determines the maximum torque according to the optimal slip rate corresponding to the maximum acceleration of the vehicle.

[0017] In the control method for the electric vehicle to start by shooting according to the application, after the vehicle starts by shooting, if the vehicle accelerator pedal exits the forced gear down position or the vehicle brake pedal is pressed, the vehicle exits the shooting start.

[0018] In the control method for the electric vehicle to start by shooting according to the application, the control of the motor output torque can ensure that the vehicle obtains the maximum acceleration when starting by shooting and ensure the stability of the vehicle, not only improves the starting speed of the electric vehicle, makes the driver obtain the maximum back thrust feeling, shortens the starting time, shortens the acceleration time of the vehicle per 100 kilometers, improves the driving feeling and driving pleasure of the driver, but also fully ensures the safety of the shooting start. DETAILED DESCRIPTION

[0019] The application will be further described in detail below so that those skilled in the art can implement it according to the description.

[0020] The control method of the electric vehicle's kick start according to the present application is used to control the kick start process of the electric vehicle. That is, the vehicle brake pedal and the vehicle accelerator pedal are pressed in turn, and the vehicle accelerator pedal is in the kickdown position. At this time, the vehicle controller sends the motor control unit the motor output torque request information according to the position information of the vehicle brake pedal and the position information of the vehicle accelerator pedal. The motor control unit controls the motor output torque according to the motor output torque request information, and drives the vehicle to kick start after the vehicle brake pedal is released.

[0021] In the control method of the electric vehicle's kick start according to the present application, the control of the motor output torque can ensure the maximum acceleration when the vehicle kicks start, and ensure the stability of the vehicle. Not only the starting speed of the electric vehicle is improved, the driver obtains the maximum back thrust feeling, the starting time is shortened, the acceleration time of the vehicle per 100 kilometers is shortened, the driving feeling and the driving pleasure of the driver are improved, but also the safety of the kick start is fully ensured.

[0022] Specifically, in the control method of the electric vehicle's kick start according to the present application, before determining the kick start control of the vehicle, it is necessary to determine whether the vehicle condition allows the kick start. Only under the premise that the current vehicle condition allows the kick start, the subsequent kick start control can be performed. Therefore, before controlling the vehicle to kick start, it is necessary to determine that the maximum available power value of the battery is within a predetermined value range, and / or the working state of the vehicle power system is normal, and / or the tire pressure of the vehicle is normal, and / or the safety belt locking state is normal, and / or the steering wheel angle is within a predetermined angle range, and / or the motor temperature is within a predetermined temperature value range.

[0023] Because the acceleration of the kick start is very large, for safety, in the present application, before the vehicle brake pedal and the vehicle accelerator pedal are pressed in turn, it is necessary to determine that the vehicle is in the ready state, the current gear is D, and the current vehicle speed is zero.

[0024] In the control method of the electric vehicle's kick start according to the present application, the driver can be prompted after the vehicle meets the kick start condition, so that the driver can timely perform the subsequent kick start operation. For example, after the motor control unit controls the motor output torque, the current motor torque state is fed back to the vehicle controller, and the kick start activation prompt information is output by the vehicle instrument through the vehicle instrument.

[0025] If the vehicle brake pedal is released by the driver within a predetermined time, the motor drives the vehicle to start. If the vehicle brake pedal is not released within a predetermined time, to avoid over-temperature of the motor, the motor is prevented from being in a torque state for a long time when the vehicle is stationary, the vehicle controller sends a request information of terminating the motor output torque to the motor control unit, the motor control unit controls the motor to unload torque, and the current launch control is ended.

[0026] In the control method of the electric vehicle launch, to ensure the stability of the vehicle when starting, the EPB (electronic parking brake system) can be in an open state before the vehicle is launched.

[0027] For the torque output value of the motor during the vehicle launch, the torque output value in the torque output request information of the motor is determined by the vehicle controller according to the minimum value between the torque corresponding to the forced downshift position of the vehicle accelerator pedal and the maximum torque determined by the electronic stability control system (ESC). Further, the maximum torque is determined by the electronic stability control system according to the optimal slip rate corresponding to the maximum acceleration of the vehicle. In this way, the maximum acceleration of the vehicle when starting can be ensured, and the stability of the vehicle can also be ensured.

[0028] In the control method of the electric vehicle launch, after the vehicle is launched, if the vehicle accelerator pedal exits the forced downshift position or the vehicle brake pedal is depressed, the vehicle exits the launch.

[0029] Although the embodiments of the present application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, and it can be fully applied to various fields suitable for the present application, and other modifications can be easily realized by those skilled in the art, and therefore the present application is not limited to specific details and examples shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. A control method for launch control of an electric vehicle, characterized in that, Depress the vehicle's brake pedal and accelerator pedal in sequence, and position the accelerator pedal in a forced downshift position. The vehicle controller sends a motor output torque request to the motor control unit based on the position information of the vehicle brake pedal and the position information of the vehicle accelerator pedal. The vehicle controller determines the torque output value in the motor output torque request based on the minimum of the torque corresponding to the vehicle accelerator pedal when it is in a forced downshift position and the maximum torque determined by the electronic stability control system. The motor control unit controls the motor output torque according to the motor output torque request information, and drives the vehicle to launch and start after the vehicle brake pedal is released.

2. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, Before launching the vehicle, ensure that the maximum available power of the battery is within a predetermined range, and / or the vehicle's powertrain is operating normally, and / or the tire pressure is normal, and / or the seatbelt locking is normal, and / or the steering wheel angle is within a predetermined range, and / or the motor temperature is within a predetermined range.

3. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, Before pressing the brake pedal and accelerator pedal in sequence, ensure that the vehicle is in a ready state, the current gear is D, and the current speed is zero.

4. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, After the motor control unit controls the motor to output torque, it feeds back the current motor torque status to the vehicle controller, and the vehicle controller outputs a launch start activation prompt message through the vehicle instrument panel.

5. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, If the vehicle's brake pedal is released within a predetermined time, the motor drives the vehicle to launch. If the vehicle brake pedal is not released within a predetermined time, the vehicle controller sends a request to the motor control unit to terminate the motor output torque.

6. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, The electronic parking brake system is engaged before the vehicle can be launched from a standstill.

7. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, The electronic stability control system determines the maximum torque based on the optimal slip ratio corresponding to the vehicle's maximum acceleration.

8. The control method for launch control of an electric vehicle as described in claim 1, characterized in that, After the vehicle launches, if the accelerator pedal is disengaged from the forced downshift position or the brake pedal is depressed, the vehicle exits the launch start.