TWI861960B - Automatic shutdown method of electric vehicle - Google Patents

Abstract

The present invention relates to an automatic shutdown method of an electric vehicle. The electric vehicle includes a main battery, a motor controller, a motor, a car computer, a voltage reducing device, a permanent battery and a vehicle load. A motor angle sensor of the motor feeds back the motor speed signal to the motor controller, and the motor controller calculates the motor speed, and the motor can drive a rear wheel. The car computer can receive the key switch signal from the key switch, and can receive the front wheel speed signal from the front wheel speed sensor to obtain the front wheel speed. Wherein, the automatic shutdown method of the electric vehicle of the present invention can detect the automatic shutdown process of the electric vehicle when it is stationary for a period of time and is not moving, and an additional detection mode is designed for the conditions of automatic shutdown, which can be used in maintenance vehicles or other applications. In addition to the judgment of the front wheel speed, the motor speed is also added for judgment. Therefore, when entering the detection mode, if the rear wheel or the motor is rotating, it will not automatically shut down because the front wheel is stationary.

Description

Automatic shutdown method for electric vehicles

The present invention relates to an automatic shutdown method for an electric vehicle, and in particular to an automatic shutdown method suitable for an electric vehicle with a power saving function.

In common electric vehicles, once the vehicle is started and the power devices (such as the control system, instruments, headlights, etc.) are operating normally, the battery power will begin to be consumed. If the driver forgets to turn off the vehicle power and leaves the vehicle for a while, the battery power may be exhausted. At this time, a lot of battery power may be consumed additionally, resulting in a reduction in driving distance or an inability to continue driving, causing trouble in use.

In addition, when inspecting the vehicle by standing on the center pillar, if the rear wheel needs to be rotated to confirm whether the electric vehicle is functioning normally, or in other situations where there is no front wheel speed sensor, if the vehicle is judged to be stationary due to the front wheel not rotating, the system will automatically shut down, which will cause inconvenience during inspection.

Because of this, the inventor, based on the spirit of active invention, has been eager to think of an automatic shutdown method for electric vehicles that can solve the above-mentioned problems. After several years of research and experiments, the present invention was finally completed.

The main purpose of the present invention is to provide an automatic shutdown method for electric vehicles. This method can detect the automatic shutdown process of electric vehicles when they are stationary and not moving for a period of time, and an additional detection mode is designed for the automatic shutdown condition. In addition to using the front wheel speed for judgment during vehicle maintenance or other application scenarios (such as when the front wheel speed sensor is abnormal), the motor speed is also added for judgment. Therefore, when entering the detection mode, if the rear wheel or the motor is rotating, the vehicle will not be automatically shut down due to the stationary front wheel.

To achieve the above-mentioned purpose, the electric vehicle of the present invention includes a main battery, a motor controller, a motor, a driving computer, a voltage reducing device, a permanent battery and a vehicle load. The motor controller is electrically connected to the main battery. The motor is provided with a motor angle sensor, which is electrically connected to the motor controller. The motor angle sensor feeds back the motor speed signal to the motor controller, and the motor controller calculates the motor speed. The motor can drive a rear wheel to move. The on-board computer is connected to the main battery and the motor controller, and is electrically connected to a key switch and a front wheel speed sensor. It can receive the key switch signal from the key switch, and can receive the front wheel speed signal from the front wheel speed sensor to obtain the front wheel speed. In the normal mode, the vehicle speed is calculated from the front wheel speed, and then it is known whether the electric vehicle is stationary. The step-down device is electrically connected to the main battery. The permanent battery is electrically connected to the step-down device through a charging power switch, and is also electrically connected to the on-board computer. The vehicle load is electrically connected to the permanent battery through a load power switch, and is also electrically connected to the on-board computer.

Among them, the automatic shutdown method of the electric vehicle includes the following steps: (A) The electric vehicle is started by a key, enters a power-on state, and executes step (B); (B) Determine whether the electric vehicle unlocks the power output and enters a driving state, if so, execute step (C1), if not, execute step (C2); (C1) Determine whether the electric vehicle enters a detection mode from a general mode, if so, execute step (D1), if not, execute step (D2); (C2) Determine whether the electric vehicle enters a detection mode from a general mode, if so, execute step (D3), if not, execute step (D4); (D1) Determine whether the front wheel speed of the electric vehicle is lower than a specific front wheel speed and whether the motor speed is lower than a specific motor speed for a first specific time. If so, execute step (E), otherwise repeat step (D1); (D2) Determine whether the front wheel speed of the electric vehicle is lower than the specific front wheel speed for a first specific time. If so, execute step (E), otherwise repeat step (D2); (D3) Determine whether the front wheel speed of the electric vehicle is lower than the specific front wheel speed and whether the motor speed is lower than the specific motor speed for a second specific time. If so, execute step (F), otherwise repeat step (D3); (D4) Determine whether the front wheel speed of the electric vehicle is lower than the specific front wheel speed for a second specific time. If yes, execute step (F); if not, repeat step (D4); (E) The electric vehicle returns from the driving state to the starting state and returns to step (B); and (F) The electric vehicle automatically shuts down from the starting state.

The above step (F) may include the following sub-steps: (F1) the driving computer instructs the motor controller to prepare to stop operation, saves necessary parameters, and executes step (F2); (F2) the driving computer turns off the load power switch and the charging power switch, and executes step (F3); and (F3) the driving computer turns off the main battery power.

The above detection mode can be set by the on-board computer or by an external diagnostic tool of the electric vehicle. In the detection mode, in addition to using the front wheel speed for judgment, the motor speed is also added for judgment. Therefore, when the rear wheel or the motor is rotating, it does not automatically shut down because the front wheel is stationary.

The first specific time may be 3 minutes; the second specific time may be 5 minutes.

The above-mentioned specific front wheel speed may be 40RPM; the above-mentioned specific motor speed may be 300 RPM.

The main battery can be a 48V lead-acid battery or a lithium battery; the normal battery can be a 12V lead-acid battery or a lithium battery.

The above summary and the following detailed description are exemplary in nature and are intended to further illustrate the scope of the patent application of the present invention. Other purposes and advantages of the present invention will be described in the subsequent description and illustrations.

Please refer to FIG. 1 , which is a system configuration diagram of an electric vehicle of a preferred embodiment of the present invention. The figure shows an electric vehicle 1, which mainly includes a main battery 2, a motor controller 3, a motor 4, a driving computer 5, a voltage reduction device 6, a permanent battery 7 and a vehicle load 8.

In this embodiment, the main battery 2 is a 48-volt lead-acid battery or a lithium battery, which serves as the main power source of the electric vehicle 1 and can recharge the permanent battery 7. The motor controller 3 is electrically connected to the main battery 2 and can be supplied with power by the main battery 2 to drive the motor 4 to generate the forward power of the vehicle. The motor 4 is provided with a motor angle sensor 41 for detecting the angle change of the motor 4, which is electrically connected to the motor controller 3. The motor angle sensor 41 feeds back the motor angle signal S1 to the motor controller 3, and the motor controller 3 calculates the motor speed. The motor 4 can drive a rear wheel 11 to operate. The on-board computer 5 of this embodiment is connected to the main battery 2 and the motor controller 3 via the controller area network (CAN) communication, so that the main battery 2, the motor controller 3 and the on-board computer 5 can transmit data to each other via CAN communication. The on-board computer 5 has the function of calculating time, can wake up the main battery 2 via CAN communication, and can communicate with the motor controller 3 via CAN communication to obtain the motor speed calculated by the motor controller 3. In addition, the driving computer 5 is electrically connected to a key switch 13 and a front wheel speed sensor 120 located at a front wheel 12, and can receive a key switch signal S2 from the key switch 13, so that the driving computer 5 can perform startup and shutdown operations, and can receive a front wheel speed signal S3 from the front wheel speed sensor 120 to obtain the front wheel speed, which is used as a basis for determining the vehicle speed to know whether the electric vehicle 1 is stationary. The step-down device 6 of this embodiment is a DC-to-DC step-down device 6, one end of which is electrically connected to the main battery 2, and the other end of which is electrically connected to the permanent battery 7, so as to convert the high voltage of the main battery 2 into a low voltage, and to charge the permanent battery 7. The permanent battery 7 of this embodiment is a 12-volt lead-acid battery or a lithium battery, wherein a charging power switch 14 is used as a control switch between the permanent battery 7 and the step-down device 6, and the permanent battery 7 is electrically connected to the driving computer 5, so that the conduction of the charging power switch 14 is controlled by the driving computer 5. The vehicle load 8 of this embodiment is a lighting system or other 12-volt peripheral device, and the vehicle load 8 is electrically connected to the permanent battery 7 and the driving computer 5 through a load power switch 15, so that the conduction of the load power switch 15 is controlled by the driving computer 5, so that the vehicle load 8 can operate normally. The charging power switch 14 and the load power switch 15 can be in the form of a relay, a MOSFET switch, etc. to achieve their functions, and are not limited to a single switch form.

Please refer to FIG. 2, which is a flow chart of an automatic shutdown method for an electric vehicle according to a preferred embodiment of the present invention. As shown in the figure, before entering the flow description, the vehicle states or modes involved in the automatic shutdown method for the electric vehicle are briefly described here, mainly including: a power-on state, a driving state, a general mode, and a detection mode. The power-on state refers to a state in which the rider turns on the electric vehicle 1 by key, so that the electric vehicle 1 is normally powered on, but the power output has not been unlocked and it is not drivable. The driving state refers to the state in which the electric vehicle 1 has been unlocked and the power output is available for driving. The unlocking method is that the rider can press the brake handle and the start switch at the same time when the vehicle is turned on to unlock the vehicle and enter the driving state. However, the unlocking method is not limited to this and other methods may also be used. The general mode refers to obtaining the front wheel speed only by the front wheel speed signal S3 of the front wheel speed sensor 120, and using it as the basis for judging the vehicle speed, thereby knowing whether the electric vehicle 1 is stationary. In addition to judging by the front wheel speed, the detection mode also obtains the motor speed by feeding back the motor angle signal S1 from the motor angle sensor 41, and uses it as a basis for judging the vehicle speed. At the same time, the state of the rear wheel 11 is detected. Only when both the front wheel 12 and the rear wheel 11 are not moving can it be known whether the electric vehicle 1 is stationary. The detection mode is set by the driving computer 5 or by a diagnostic tool external to the electric vehicle 1.

The automatic shutdown method of the electric vehicle 1 of the present invention includes the following steps: (A) The electric vehicle 1 is started by a key, enters a power-on state, and executes step (B). (B) Determine whether the electric vehicle 1 unlocks the power output and enters a driving state. If so, execute step (C1), otherwise execute step (C2). Wherein, the driving state is a drivable state, and the power-on state and the driving state are both controlled and executed by the driving computer 5. (C1) Determine whether the electric vehicle 1 enters a detection mode from a general mode. If so, execute step (D1), otherwise execute step (D2). (C2) Determine whether the electric vehicle enters a detection mode from a normal mode. If yes, execute step (D3), if not, execute step (D4). In the normal mode, only the state of the front wheel 12 needs to be detected, while the state of the front wheel 12 and the state of the rear wheel 11 need to be detected simultaneously in the detection mode. (D1) Determine whether the front wheel speed of the electric vehicle 1 is lower than a specific front wheel speed and whether the motor speed is lower than a specific motor speed for a first specific time. If yes, execute step (E), if not, repeat step (D1). (D2) Determine whether the front wheel speed of the electric vehicle 1 is lower than the specific front wheel speed for the first specific time. If so, execute step (E), otherwise repeat step (D2). (D3) Determine whether the front wheel speed of the electric vehicle 1 is lower than the specific front wheel speed and whether the motor speed is lower than the specific motor speed for a second specific time. If so, execute step (F), otherwise repeat step (D3). (D4) Determine whether the front wheel speed of the electric vehicle 1 is lower than the specific front wheel speed for the second specific time. If so, execute step (F), otherwise repeat step (D4). In this embodiment, the first specific time is 3 minutes, the second specific time is 5 minutes, the specific front wheel speed is 40RPM, and the specific motor speed is 300RPM. The first specific time, the second specific time, the specific front wheel speed, and the specific motor speed can be adjusted to different times according to different models or different needs. (E) The electric vehicle returns to the start-up state from the driving state, and returns to step (B) to re-enter the judgment process. (F) The electric vehicle automatically shuts down from the start-up state to prevent the main battery 2 from being continuously depleted.

Please refer to FIG. 3, which is a flowchart of sub-steps of step (F) of the automatic shutdown method of an electric vehicle of a preferred embodiment of the present invention. As shown in the figure, the shutdown process of step (F) of the electric vehicle 1 automatically shutting down from the power-on state includes the following sub-steps: (F1) the driving computer 5 instructs the motor controller 3 to prepare to stop operation, and saves the necessary parameters, and executes step (F2); (F2) the driving computer 5 turns off the load power switch 15 and the charging power switch 14, and executes step (F3); and (F3) the driving computer 5 turns off the power of the main battery 2, thereby completing the automatic shutdown process. After the automatic shutdown is completed, all power is shut down. Even if the key switch 13 is still turned on, the on-board computer 5 will not issue commands to activate other components. It is necessary to wait for the key switch 13 to be turned off and then turned on again. The on-board computer 5 will restart and enter the boot state only when it receives the startup command of the key switch signal S2.

The above embodiments are merely examples for the convenience of explanation. The scope of rights claimed by the present invention should be based on the scope of the patent application, and is not limited to the above embodiments.

1: Electric vehicle 11: Rear wheel 12: Front wheel 120: Front wheel speed sensor 13: Key switch 14: Charging power switch 15: Load power switch 2: Main battery 3: Motor controller 4: Motor 41: Motor angle sensor 5: Onboard computer 6: Voltage reduction device 7: Constant battery 8: Vehicle load S1: Motor angle signal S2: Key switch signal S3: Front wheel speed signal A~F3: Steps

FIG. 1 is a system configuration diagram of an electric vehicle according to a preferred embodiment of the present invention. FIG. 2 is a flow chart of an automatic shutdown method for an electric vehicle according to a preferred embodiment of the present invention. FIG. 3 is a flow chart of sub-steps of step (F) of an automatic shutdown method for an electric vehicle according to a preferred embodiment of the present invention.

A~F: Steps

Claims (9)

An automatic shutdown method for an electric vehicle, the electric vehicle includes: a main battery; a motor controller, electrically connected to the main battery; a motor, provided with a motor angle sensor, electrically connected to the motor controller, the motor angle sensor feeds back a motor angle signal to the motor controller, and the motor controller calculates the motor speed, and the motor can drive a rear wheel to move; a driving computer, communicatively connected to the main battery and the motor controller, electrically connected to a key switch and a front wheel speed sensor, which can receive a key switch signal from the key switch, and can receive a front wheel speed signal from the front wheel speed sensor to obtain the front wheel speed; a voltage reducing device electrically connected to the main battery; a permanent battery electrically connected to the voltage reducing device via a charging power switch and electrically connected to the on-board computer; and a vehicle load electrically connected to the permanent battery via a load power switch and electrically connected to the on-board computer; wherein the automatic shutdown method of the electric vehicle includes The method comprises the following steps: (A) the electric vehicle is started by a key, enters a start-up state, and executes step (B); (B) determines whether the electric vehicle is unlocked for power output and enters a drive state, if so, executes step (C1), if not, executes step (C2); (C1) determines whether the electric vehicle is unlocked by a general mode to enter a detection mode, if yes, execute step (D1), if no, execute step (D2); (C2) Determine whether the electric vehicle enters the detection mode from the general mode, if yes, execute step (D3), if no, execute step (D4); (D1) Determine whether the front wheel speed of the electric vehicle is lower than a specific front wheel speed and whether the motor speed is lower than a specific motor speed for a first specific time, if yes, execute step (E), if no, repeat step (D1); (D2) Determine whether the front wheel speed of the electric vehicle is lower than the specific front wheel speed for the first specific time, if yes, execute step (E) ), if not, repeat step (D2); (D3) determine whether the front wheel speed of the electric vehicle is lower than the specific front wheel speed and whether the motor speed is lower than the specific motor speed for a second specific time, if yes, execute step (F), if not, repeat step (D3); (D4) determine whether the front wheel speed of the electric vehicle is lower than the specific front wheel speed for the second specific time, if yes, execute step (F), if not, repeat step (D4); (E) the electric vehicle returns from the driving state to the power-on state and returns to step (B); and (F) the electric vehicle automatically shuts down from the power-on state. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the step (F) includes the following sub-steps: (F1) the driving computer instructs the motor controller to prepare to stop operation, saves necessary parameters, and executes step (F2); (F2) the driving computer turns off the load power switch and the charging power switch, and executes step (F3); and (F3) the driving computer turns off the main battery power. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the detection mode is set by the on-board computer or by a diagnostic tool external to the electric vehicle. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the first specific time is 3 minutes. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the second specific time is 5 minutes. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the specific front wheel speed is 40RPM. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the specific motor speed is 300RPM. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the main battery is a 48-volt lead-acid battery or a lithium battery. The automatic shutdown method of an electric vehicle as described in claim 1, wherein the normal battery is a 12-volt lead-acid battery or a lithium battery.

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