阅读说明：本技术 电动车控制方法及电动车控制器 (Electric vehicle control method and electric vehicle controller ) 是由 陈清付 梁英杰 谢欣 于 2019-11-01 设计创作，主要内容包括：本发明实施例公开了一种电动车控制方法及电动车控制器。该方法包括：接收到用户的启动信号时,根据启动信号输出包括正向驱动信号和反向驱动信号的第一启动驱动信号,第一启动驱动信号的占空比与启动信号的占空比相同,反向驱动信号施加给电机的电流方向与正向驱动信号施加给电机的电流方向相反；在向电机施加正向驱动信号时采样电机悬空相的第一反电动势,以及在施加反向驱动信号时采样电机悬空相的第二反电动势；根据第一反电动势与第二反电动势的差值输出第二启动驱动信号。根据这两个反电动势的差值的变化趋势得到准确的换相时刻并施加启动信号,让电机稳定启动。解决了现有技术中使用过零检测法产生驱动信号时出现电机控制失步的问题。(The embodiment of the invention discloses an electric vehicle control method and an electric vehicle controller. The method comprises the following steps: when a starting signal of a user is received, outputting a first starting driving signal comprising a forward driving signal and a reverse driving signal according to the starting signal, wherein the duty ratio of the first starting driving signal is the same as that of the starting signal, and the direction of current applied to the motor by the reverse driving signal is opposite to that of current applied to the motor by the forward driving signal; sampling a first back electromotive force of the motor suspension phase when the forward driving signal is applied to the motor, and sampling a second back electromotive force of the motor suspension phase when the reverse driving signal is applied; and outputting a second starting driving signal according to the difference value of the first counter electromotive force and the second counter electromotive force. And obtaining accurate phase change time according to the change trend of the difference value of the two back electromotive forces, and applying a starting signal to stably start the motor. The problem of motor control step out when using zero cross detection method to produce drive signal among the prior art is solved.)

1. An electric vehicle control method, characterized in that the electric vehicle is provided with a hall-less motor and an electric vehicle controller that controls the motor to drive the electric vehicle, the method being performed by the electric vehicle controller, the method comprising:

when a starting signal of a user is received, outputting a first starting driving signal comprising a forward driving signal and a reverse driving signal according to the starting signal, wherein the duty ratio of the first starting driving signal is the same as that of the starting signal, and the current direction applied to a motor by the reverse driving signal is opposite to that applied to the motor by the forward driving signal;

sampling a first back electromotive force of the motor suspension phase while applying the forward drive signal to the motor, and sampling a second back electromotive force of the motor suspension phase while applying the reverse drive signal;

and outputting a second starting driving signal according to the difference value of the first counter electromotive force and the second counter electromotive force.

2. The method of claim 1, wherein outputting a first start-up drive signal comprising a forward drive signal and a reverse drive signal based on the start-up signal comprises:

determining a duty cycle of the activation signal;

and outputting a forward driving signal with a duty ratio of a preset increment according to the duty ratio of the starting signal, and outputting a reverse driving signal with the duty ratio of the preset increment to obtain a first starting driving signal.

3. The method of claim 2, wherein a duty cycle of the forward driving signal is not less than a duty cycle of a lowest starting current of the motor when the electric vehicle is started.

4. The method of claim 1, wherein outputting a second start-up drive signal based on the difference between the first back-emf and the second back-emf comprises:

if the difference value is gradually increased, outputting a second starting driving signal for driving the motor to rotate forwards when the difference value is larger than a first set threshold value;

if the difference value is gradually reduced, outputting a second starting driving signal for driving the motor to reversely rotate when the difference value is smaller than a second set threshold value.

5. The method of claim 1, wherein outputting an activation drive signal based on the difference between the first back emf and the second back emf comprises:

and if the difference value is not changed, outputting a second starting driving signal for driving the motor to rotate forwards after waiting for a set time.

6. The method of claim 5, wherein the set time is a time required for the electric vehicle to switch from a reverse state to a forward state.

7. The method of claim 1, wherein after outputting the second start-up drive signal, the method further comprises:

after the electric vehicle is started, acquiring a third back electromotive force of the motor suspension phase;

and determining the phase commutation moment of the motor according to the third back electromotive force, and applying a target driving signal to the motor at the phase commutation moment.

8. An electric vehicle controller, characterized in that, the electric vehicle is configured with no hall motor, electric vehicle controller controls the motor to drive the electric vehicle, electric vehicle controller includes:

the first starting driving signal output module is used for outputting a first starting driving signal comprising a forward driving signal and a reverse driving signal according to the starting signal when receiving the starting signal of a user, wherein the duty ratio of the first starting driving signal is the same as that of the starting signal, and the current direction applied to the motor by the reverse driving signal is opposite to that applied to the motor by the forward driving signal;

a back electromotive force sampling module for sampling a first back electromotive force of the motor suspension phase when the forward driving signal is applied to the motor, and sampling a second back electromotive force of the motor suspension phase when the reverse driving signal is applied;

and the second starting driving signal output module is used for outputting a second starting driving signal according to the difference value of the first counter electromotive force and the second counter electromotive force.

9. The electric vehicle controller according to claim 8, wherein the start drive signal output module includes:

the first starting driving signal output unit is used for outputting a starting driving signal for driving the motor to rotate forwards when the difference value is larger than a first set threshold value if the difference value is gradually increased;

and the second starting driving signal output unit is used for outputting a starting driving signal for driving the motor to reversely rotate when the difference value is smaller than a second set threshold value if the difference value is gradually reduced.

10. The electric vehicle controller of claim 8, wherein the start drive signal output module further comprises:

and the third starting driving signal output unit is used for outputting a starting driving signal for driving the motor to rotate forwards after waiting for a set time if the difference value does not change.

Technical Field

The embodiment of the invention relates to the electric vehicle control technology, in particular to an electric vehicle control method and an electric vehicle controller.

Background

The existing Hall-free control method for the electric vehicle is a counter electromotive force zero crossing point detection method, driving is controlled by detecting the counter electromotive force trend generated by the rotation of a motor, the method cannot be applied to the situation of backward starting of the electric vehicle, the waveform of the counter electromotive force can be distorted during the backward starting, and the motor control is out of step due to the distortion, so that starting failure is caused.

Disclosure of Invention

The embodiment of the invention provides an electric vehicle control method and an electric vehicle controller, which are used for stably starting an electric vehicle, in particular stably starting the electric vehicle when the electric vehicle backs up.

In a first aspect, an embodiment of the present invention provides a method for controlling an electric vehicle, where the electric vehicle is configured with a hall-less motor and an electric vehicle controller, and the electric vehicle controller controls the motor to drive the electric vehicle, and the method is performed by the electric vehicle controller, and the method includes:

when a starting signal of a user is received, outputting a first starting driving signal comprising a forward driving signal and a reverse driving signal according to the starting signal, wherein the duty ratio of the first starting driving signal is the same as that of the starting signal, and the current direction applied to a motor by the reverse driving signal is opposite to that applied to the motor by the forward driving signal;

sampling a first back electromotive force of the motor suspension phase while applying the forward drive signal to the motor, and sampling a second back electromotive force of the motor suspension phase while applying the reverse drive signal;

and outputting a second starting driving signal according to the difference value of the first counter electromotive force and the second counter electromotive force.

In a second aspect, an embodiment of the present invention further provides that the electric vehicle is configured with a hall-less motor, the electric vehicle controller controls the motor to drive the electric vehicle, and the electric vehicle controller includes:

the first starting driving signal output module is used for outputting a first starting driving signal comprising a forward driving signal and a reverse driving signal according to the starting signal when receiving the starting signal of a user, wherein the duty ratio of the first starting driving signal is the same as that of the starting signal, and the current direction applied to the motor by the reverse driving signal is opposite to that applied to the motor by the forward driving signal;

a back electromotive force sampling module for sampling a first back electromotive force of the motor suspension phase when the forward driving signal is applied to the motor, and sampling a second back electromotive force of the motor suspension phase when the reverse driving signal is applied;

and the second starting driving signal output module is used for outputting a second starting driving signal according to the difference value of the first counter electromotive force and the second counter electromotive force.

According to the embodiment of the invention, when the starting signal sent by a user is acquired, the first starting driving signal with the forward driving signal and the reverse driving signal is output, the counter electromotive force of the suspended phase of the motor is respectively sampled during the period of applying the forward driving signal and the reverse driving signal to the motor, so that two stable counter electromotive force signals are obtained, the accurate phase change moment is obtained according to the variation trend of the difference value of the two counter electromotive forces, the starting signal is accurately applied to the motor, and the motor is stably started. The motor noise when the electric vehicle is backed up and started is reduced, and the problem that the motor control is out of step when a driving signal is generated by using a zero-crossing detection method in the prior art is solved, so that the Hall-free electric vehicle is stably started when the electric vehicle is backed up.

Drawings

Fig. 1 is a flowchart of a control method for an electric vehicle according to an embodiment of the present invention;

fig. 2 is a flowchart of a control method for an electric vehicle according to a second embodiment of the present invention;

fig. 3 is a flowchart of a control method for an electric vehicle according to a third embodiment of the present invention;

fig. 4 is a block diagram of a structure of an electric vehicle controller according to a fourth embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.