TWI875032B - Optimizing method for tracking and anti-skid function of electric vehicle - Google Patents

Abstract

The invention relates to an optimizing method for a tracking and anti-skid function of an electric vehicle. The electric vehicle includes a power battery, an electric door handle, a motor, a motor controller, an instrument, a rear wheel and a front wheel. The motor has a motor angle sensor, and the motor angle sensor obtains the motor angle signal and calculates the rotation speed of the rear wheel. The front wheel has a front wheel speed signal generating device, and the driving control unit of the instrument receives the front wheel speed signal from the front wheel speed signal generating device and calculates the front wheel speed of the front wheel. The motor controller obtains the front wheel speed and the rear wheel speed and divides the rear wheel speed by the front wheel speed to obtain the slip ratio. Through the optimizing method of the tracking and anti-skid function of the electric vehicle of the present invention, the action of the tracking anti-skid function can be delayed by adding some threshold conditions, and the operation of the tracking and anti-skid function can be started after the front wheel speed catches up with the rear wheel speed, so as to avoid power being abnormally restricted, which affects the acceleration at the start.

Description

Method for optimizing the traction and anti-skid function of electric vehicles

The present invention relates to a method for optimizing the traction and anti-skid function of an electric vehicle, and in particular to a method for optimizing the traction and anti-skid function of an electric vehicle that is applicable to limiting the motor power output.

Generally, electric motorcycles use the rear wheels as driving wheels. When the electric motorcycle starts on a slippery road (such as a slippery tile road, or a wet and smooth iron plate road), the friction between the rear wheel tire and the ground is insufficient, which will cause the rear wheel to slip, deviate to the side, or even fail to track normally. Therefore, a tracking anti-skid function needs to be designed. When the speed of the front wheel is different from that of the rear wheel, the power output of the rear wheel needs to be limited or cut off to reduce the torque of the rear wheel and restore the grip.

However, electric vehicles generally require front and rear wheel speed information to implement traction control. The front wheel speed is provided by an instrument, and the rear wheel speed is usually provided by the controller used by the original drive motor to save costs. The motor speed is then divided by the transmission system reduction ratio to obtain the rear wheel speed. In this case, when the electric vehicle starts with full throttle, it is easy to obtain an incorrect slip rate because the rear wheel speed responds much faster than the front wheel speed, which in turn causes abnormal power limitation.

Because of this, the inventor, based on the spirit of active invention, has been thinking of a method to optimize the anti-skid function of electric vehicles that can solve the above problems. After several years of research and experiments, the present invention was finally completed.

The main purpose of the present invention is to provide a method for optimizing the traction and anti-skid function of electric vehicles. This method can delay the activation of the traction and anti-skid function by adding some threshold conditions. The traction and anti-skid function is activated after the front wheel speed catches up with the rear wheel speed, thus avoiding abnormal power restriction and affecting the acceleration at the start.

To achieve the above-mentioned purpose, the electric vehicle of the present invention includes a power battery, a throttle handle, a motor, a motor controller, an instrument, a rear wheel and a front wheel. The power battery is used to provide power for the entire vehicle and as a power source for supplying power to the motor. The throttle handle has a throttle opening sensor that can receive information from the driver on whether to increase or decrease the power of the vehicle. The motor has a motor angle sensor that can convert electrical energy into kinetic energy and connect to the power input end of the transmission system to provide power. The motor controller is electrically connected to the power battery, the throttle handle and the motor, respectively, receives the throttle opening signal from the throttle opening sensor, and receives the motor angle signal from the motor angle sensor, and outputs the corresponding power and phase to the motor. The instrument has a driving control unit, which is connected to the motor controller. The rear wheel is connected to the motor by a transmission system, and the motor angle signal of the motor angle sensor is used to calculate the rear wheel speed of the rear wheel. The front wheel has a front wheel speed signal generating device, which is electrically connected to the driving control unit. The driving control unit receives the front wheel speed signal from the front wheel speed signal generating device and calculates the front wheel speed of the front wheel, and transmits the front wheel speed to the motor controller.

The motor controller obtains the front wheel speed and the rear wheel speed and divides the rear wheel speed by the front wheel speed to get the slip ratio. The slip ratio is used to determine whether the electric vehicle is in a slipping state, and then limit the vehicle power to restore the friction between the rear wheel and the ground. The optimization method of the traction anti-skid function of an electric vehicle includes the following steps: (A) starting the electric vehicle and executing step (B); (B) determining whether the threshold condition for executing the traction anti-skid function has been reached and executing step (C); sub-steps of step (B) include: (B1) determining whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value, if so, executing the next step, if not, repeating step (B1); and (C) limiting the power output of the motor according to the slip rate to execute the traction anti-skid function.

The sub-steps of the above step (B) may further include: (B2) determining whether the switch opening signal has reached a switch actuation threshold value, if so, executing the next step, if not, returning to step (B1).

The sub-steps of the above step (B) may further include: (B3) continuing a specific action time, if yes, executing the next step, if not, returning to step (B1).

In addition, the present invention further provides a method for optimizing the traction and anti-skid function of an electric vehicle, the method comprising the following steps: (A) starting the electric vehicle and executing step (B2); (B') determining whether a threshold condition for executing the traction and anti-skid function has been reached and executing step (C); sub-steps of step (B') include: (B1') determining whether a switch opening signal has reached a switch actuation valve value, if so, executing the next step, if not, repeating step (B1'); and (C) limiting the power output of the motor according to the slip rate to execute the traction and anti-skid function.

The sub-steps of the above step (B’) may further include: (B2’) determining whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value, if so, executing the next step, if not, returning to step (B1’).

The sub-steps of the above step (B’) may further include: (B3’) continuing a specific action time, if yes, executing the next step, if not, returning to step (B1’).

The above speed actuation valve value can be 1000RPM.

The above switch actuation threshold value can be 1.2 volts.

The above specific action time can be 0.2 seconds.

The above overview 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 explained in the subsequent description and illustrations.

1: Electric vehicles

2: Power battery

3: Electric door handle

31: Electric door opening sensor

4: Motor

41: Motor angle sensor

5: Motor controller

6: Instruments

61: Driving control unit

7: Rear wheel

71: Transmission system

8:Front wheel

81:Front wheel speed signal generating device

S1: Electric switch opening signal

S2: Motor angle signal

A,B,B1~B3,B’,B1’~B3’,C: Steps

Figure 1 is a system architecture diagram of an electric vehicle in a preferred embodiment of the present invention.

Figure 2 is a flow chart of the method for optimizing the electric vehicle's traction and anti-skid function in the first embodiment of the present invention.

Figure 3 is a flow chart of the method for optimizing the electric vehicle's traction and anti-skid function in the second embodiment of the present invention.

Figure 4 is a flow chart of the method for optimizing the tracking and anti-skid function of an electric vehicle in the third embodiment of the present invention.

Figure 5 is a flow chart of the method for optimizing the electric vehicle's traction and anti-skid function in the fourth embodiment of the present invention.

Please refer to Figure 1, which is a system architecture diagram of an electric vehicle of a preferred embodiment of the present invention. The figure shows an electric vehicle 1, including a power battery 2, an electric throttle handle 3, a motor 4, a motor controller 5, an instrument 6, a rear wheel 7 and a front wheel 8.

The power battery 2 is used to provide power for the entire vehicle and as a power source for the motor. The throttle handle 3 has a throttle opening sensor 31, which can receive information from the driver about the increase or decrease of the power of the electric vehicle 1. The motor 4 has a motor angle sensor 41, which can convert electrical energy into kinetic energy and transmit the kinetic energy to the rear wheels 7 to provide power output. The motor angle sensor 41 can be a Hall angle sensor, an encoder, a resolver, etc., so that the motor controller 5 can calculate the motor angle increment/time difference to calculate the motor speed. The motor controller 5 is electrically connected to the power battery 2, the throttle handle 3 and the motor 4, receives the throttle opening signal S1 from the throttle opening sensor 31, and receives the motor angle signal S2 from the motor angle sensor 41, and outputs the corresponding power and phase to the motor 4. The instrument 6 has a driving control unit 61, and the driving control unit 61 is communicatively connected to the motor controller 5. The rear wheel 7 is connected to the motor 4 through a transmission system 71, and a rear wheel speed of the rear wheel 7 is calculated by the motor angle signal S2 of the motor angle sensor 41. The front wheel 8 has a front wheel speed signal generating device 81, and the front wheel speed signal generating device 81 is electrically connected to the driving control unit 61. The driving control unit 61 receives the front wheel speed signal from the front wheel speed signal generating device 81 and calculates a front wheel speed of the front wheel 8, and transmits the front wheel speed to the motor controller 5.

The motor controller 5 obtains the front wheel speed and the rear wheel speed and divides the rear wheel speed by the front wheel speed to obtain the slip ratio. The slip ratio is used to determine whether the electric vehicle 1 is in a slipping state, thereby limiting the vehicle power. Different power reduction ratios are given according to different slip ratios and front wheel speeds, so that the electric vehicle 1 can restore the friction between the rear wheel 7 and the ground.

Please refer to FIG. 2 , which is a flow chart of a method for optimizing the traction and anti-skid function of an electric vehicle according to the first embodiment of the present invention. As shown in the figure, the optimization method of the electric vehicle traction anti-skid function of the present embodiment includes the following steps: (A) starting the electric vehicle 1 and executing step (B); (B) determining whether the threshold condition for executing the traction anti-skid function has been reached, and executing step (C); the sub-steps of step (B) include: (B1) determining whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value. The speed actuation valve value of the present embodiment is 1000RPM, but it is not limited to this and can also be other values. If so, the next step is executed, and if not, step (B1) is repeated. (B3) Continue for a specific actuation time. The specific actuation time in this embodiment is 0.2 seconds, but it is not limited to this. It can also be 0 or other values. If yes, execute the next step, otherwise return to step (B1). (C) Limit the power output of the motor according to the slip rate and execute the traction anti-skid function. Therefore, the traction anti-skid function is delayed through the judgment process of sub-steps (B1) and (B3) of step (B). The traction anti-skid function is activated after the front wheel speed catches up with the rear wheel speed to avoid abnormal power limitation and affect the acceleration at the start.

Please refer to FIG. 3, which is a flow chart of the optimization method of the electric vehicle traction anti-skid function of the second embodiment of the present invention. As shown in the figure, the basic structure of the optimization method of the electric vehicle traction anti-skid function of the present embodiment is the same as that of the first embodiment, but the difference is that: step (B) further includes a step (B2) between (B1) and (B3), so the sub-steps of step (B) include: (B1) Determine whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value. The speed actuation valve value of the present embodiment is 1000RPM, but it is not limited to this and can also be other values. If yes, execute the next step, if not, repeat step (B1). (B2) Determine whether the switch opening signal S1 has reached a switch actuation threshold value. The switch actuation threshold value of this embodiment is 1.2 volts. If yes, execute the next step, otherwise return to step (B1). (B3) Continue for a specific actuation time. The specific actuation time of this embodiment is 0.2 seconds, but it is not limited to this. It can also be 0 or other values. If yes, execute the next step, otherwise return to step (B1). Therefore, through the judgment process of sub-steps (B1), (B2) and (B3) of step (B), the actuation of the traction anti-skid function is delayed. The traction anti-skid function is activated after the front wheel speed catches up with the rear wheel speed, so as to avoid abnormal power limitation and affect the acceleration at the start.

Please refer to FIG. 4, which is a flow chart of the optimization method of the electric vehicle tracking anti-skid function of the third embodiment of the present invention. As shown in the figure, the optimization method of the electric vehicle tracking anti-skid function of the present embodiment includes the following steps: (A) starting the electric vehicle 1 and executing step (B'); (B') judging whether the threshold condition for executing the tracking anti-skid function has been reached, and executing step (C); the sub-steps of step (B') include: (B1') judging whether the switch opening signal S1 has reached a switch actuation valve value, the switch actuation valve value of the present embodiment is 1.2 volts, if yes, executing the next step, if not, repeating step (B1'). (B3') continues for a specific actuation time. The specific actuation time of this embodiment is 0.2 seconds, but it is not limited to this. It can also be 0 or other values. If yes, execute the next step, otherwise return to step (B1'). (C) Limit the power output of the motor according to the slip rate and execute the traction anti-skid function. Therefore, the traction anti-skid function is delayed through the judgment process of sub-steps (B1') and (B3') of step (B'). The traction anti-skid function is activated after the front wheel speed catches up with the rear wheel speed to avoid abnormal power limitation and affect the acceleration at the start.

Please refer to FIG5, which is a flow chart of the optimization method of the electric vehicle traction anti-skid function of the fourth embodiment of the present invention. As shown in the figure, the basic structure of the optimization method of the electric vehicle traction anti-skid function of the present embodiment is the same as that of the third embodiment, but the difference is that: step (B') further includes a step (B2') between (B1') and (B3'), so the sub-steps of step (B') include: (B1') determines whether the switch opening signal S1 has reached a switch actuation threshold value, the switch actuation threshold value of the present embodiment is 1.2 volts, if yes, execute the next step, if not, repeat the step (B1'). (B2') Determine whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value. The speed actuation valve value of this embodiment is 1000RPM, but it is not limited to this and can also be other values. If yes, execute the next step, otherwise return to step (B1'). (B3') Continue for a specific actuation time. The specific actuation time of this embodiment is 0.2 seconds, but it is not limited to this and can also be 0 or other values. If yes, execute the next step, otherwise return to step (B1'). (C) Limit the power output of the motor according to the slip rate to perform the traction anti-skid function. Therefore, the activation of the traction control function is delayed through the judgment process of sub-steps (B1’), (B2’) and (B3’) of step (B’). The traction control function is activated after the front wheel speed catches up with the rear wheel speed, so as to avoid abnormal power restriction and affect the acceleration at the start.

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

A,B,B1~B3,C: Steps

Claims (10)

A method for optimizing the anti-skid function of an electric vehicle, the electric vehicle comprising: a power battery; a throttle handle having a throttle opening sensor; a motor having a motor angle sensor; a motor controller electrically connected to the power battery, the throttle handle and the motor, receiving a throttle opening signal from the throttle opening sensor and a motor angle signal from the motor angle sensor, and outputting a motor controller to the motor controller; outputting corresponding power and phase to the motor; an instrument having a driving control unit, the driving control unit being communicatively connected to the motor controller; a rear wheel connected to the motor by a transmission system, and calculating a rear wheel rotation speed of the rear wheel from a motor angle signal of the motor angle sensor; and a front wheel having a front wheel rotation speed signal generating device, the front wheel rotation speed signal generating device being electrically connected to the driving control unit, the driving The control unit receives the front wheel speed signal from the front wheel speed signal generating device and calculates the front wheel speed of the front wheel, and transmits the front wheel speed to the motor controller; wherein the motor controller obtains the front wheel speed and the rear wheel speed and divides the rear wheel speed by the front wheel speed to obtain the slip ratio. The method for optimizing the traction anti-skid function of the electric vehicle includes the following steps: (A) starting the electric vehicle and executing Step (B); (B) determining whether the threshold condition for executing the traction anti-skid function has been reached, and executing step (C); the sub-steps of step (B) include: (B1) determining whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value, if so, executing the next step, if not, repeating step (B1); and (C) limiting the power output of the motor according to the slip rate to execute the traction anti-skid function. As described in claim 1, the method for optimizing the anti-skid function of an electric vehicle, wherein the sub-step of step (B) further includes: (B2) determining whether the switch opening signal has reached a switch actuation valve value, if so, executing the next step, if not, returning to step (B1). As described in claim 1 or claim 2, the method for optimizing the anti-skid function of an electric vehicle, wherein the sub-step of step (B) further includes: (B3) continuing a specific actuation time, if yes, executing the next step, if no, returning to step (B1). The method for optimizing the anti-skid function of an electric vehicle as described in claim 3, wherein the specific actuation time is 0.2 seconds. A method for optimizing the anti-skid function of an electric vehicle, the electric vehicle comprising: a power battery; a throttle handle having a throttle opening sensor; a motor having a motor angle sensor; a motor controller electrically connected to the power battery, the throttle handle and the motor, receiving a throttle opening signal from the throttle opening sensor and a motor angle signal from the motor angle sensor, and outputting a motor controller to the motor controller; outputting corresponding power and phase to the motor; an instrument having a driving control unit, the driving control unit being communicatively connected to the motor controller; a rear wheel connected to the motor by a transmission system, and calculating a rear wheel rotation speed of the rear wheel from a motor angle signal of the motor angle sensor; and a front wheel having a front wheel rotation speed signal generating device, the front wheel rotation speed signal generating device being electrically connected to the driving control unit, the driving control The control unit receives the front wheel speed signal from the front wheel speed signal generating device and calculates the front wheel speed of the front wheel, and transmits the front wheel speed to the motor controller; wherein the motor controller obtains the front wheel speed and the rear wheel speed and divides the rear wheel speed by the front wheel speed to obtain the slip ratio. The method for optimizing the traction anti-skid function of the electric vehicle includes the following steps: (A) starting the electric vehicle and executing step (B’); (B’) determining whether the threshold condition for executing the tracking anti-skid function has been reached, and executing step (C); the sub-steps of step (B’) include: (B1’) determining whether the switch opening signal has reached a switch actuation valve value, if so, executing the next step, if not, repeating step (B1’); and (C) limiting the power output of the motor according to the slip rate to execute the tracking anti-skid function. As described in claim 5, the method for optimizing the anti-skid function of an electric vehicle, wherein the sub-step of step (B') further includes: (B2') determining whether the front wheel speed and the rear wheel speed have reached a speed actuation valve value, if so, executing the next step, if not, returning to step (B1'). As described in claim 5 or claim 6, the method for optimizing the anti-skid function of an electric vehicle, wherein the sub-step of step (B') further includes: (B3') continuing a specific actuation time, if yes, executing the next step, if no, returning to step (B1'). For example, in the method for optimizing the traction and anti-skid function of an electric vehicle as in claim 1 or claim 6, the speed actuation valve value is 1000RPM. For example, in the method for optimizing the anti-skid function of an electric vehicle in claim 2 or claim 5, the switch actuation valve value is 1.2 volts. The method for optimizing the anti-skid function of an electric vehicle as described in claim 7, wherein the specific actuation time is 0.2 seconds.

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