JPH08156607A - Irregular vibration preventive device for electric vehicle - Google Patents

Abstract

PURPOSE: To effectively prevent irregular vibration by providing an electric motor control means for conducting output control of a driving motor through output of a torque correcting means. CONSTITUTION: An irregular vibration signal is converted into an opposite phase to be outputted to a torque command part 19 by a torque limiting part 17, and the opposite phase signal of the irregular vibration frequency is synthesized with a torque command from an acceleration sensor 18 in the torque command part 19 to be imparted as a torque command signal to an inverter 20. The inverter 20 based on the inputted torque command signal controls driving power of an electric motor 13. As a result, the torque outputted by the motor 13 becomes the torque wherein a torque fluctuation component of an opposite phase component of the irregular vibration frequency is superposed on a nearly constant torque command instructed by stepping degree of an accelerator so that torque for cancelling the irregular vibration can be generated so as to prevent the irregular vibration of the motor 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an irregular vibration preventing device for an electric vehicle.

[0002]

2. Description of the Related Art Generally, in an electric vehicle, when an electric drive motor is accelerated in response to an acceleration command by depressing an accelerator pedal, the acceleration response speed of the electric motor and the follow-up response speed resulting from the gravity inertia of a mechanical system are There is a gap in
The electric motor starts rotating at high speed, but the actual vehicle body side starts accelerating with a slight delay, which acts as a reaction of the electric motor that is relatively light with respect to the vehicle body weight, causing large torque fluctuations in the electric motor and causing a large amount of rattling. Vibrations, that is, irregular vibrations may occur to deteriorate the riding comfort.

However, conventionally, an irregular vibration preventing device for directly canceling the irregular vibration of such an electric vehicle has not been proposed, and unlike the torque control device shown in FIG. 6, the output shaft of the driving electric motor 1 is prevented. 2 is provided with a torque sensor 3 and a slip ring 4 extracts a torque signal,
This is fed back to the torque command unit 5, and feedback control is performed between the torque command from the accelerator sensor 6 that outputs a torque command proportional to the degree of depression of the accelerator, and the necessary torque control amount is given to the inverter 7.
By controlling the output of the driving motor 1, as a result, the irregular vibration was only suppressed.

[0004]

In such a conventional torque control device for an electric vehicle, the torque of the output shaft of the drive motor is detected and the constant speed torque fluctuation is compensated by the torque feedback control. Since the irregular vibration generated between the mechanical system and the electric motor as a result of the reaction received from the mechanical system during acceleration of the electric motor is not detected, the irregular vibration cannot be effectively suppressed.

The present invention has been made in view of the above conventional problems, and detects irregular vibration itself generated between a mechanical system and an electric motor as a result of a reaction received from the mechanical system at the time of acceleration of the electric motor. It is an object of the present invention to provide an irregular vibration preventing device for an electric vehicle, which can perform torque control of an electric motor so as to cancel the noise, can effectively prevent irregular vibration, and can improve riding comfort.

[0006]

According to a first aspect of the present invention, there is provided an irregular vibration preventing device for an electric vehicle, which is located on a holding member which receives a driving electric motor, and which positions are opposed to each other with the axis of the driving electric motor interposed therebetween. Load detecting means for detecting the load of the driving electric motor, and anti-phase superimposing means for adding the load signals detected by the load detecting means at the opposite positions to each other in the opposite phase with respect to the other. A band-pass filter that passes only a specific low-frequency signal from the output of the anti-phase superimposing means, a torque correcting means that superimposes the output of the band-pass filter in anti-phase with respect to an accelerator torque command, and the torque correcting means And an electric motor control means for controlling the output of the driving electric motor according to the output of.

According to a second aspect of the present invention, there is provided an irregular vibration preventing device for an electric vehicle, comprising acceleration pickup means in place of the load detecting means.

[0008]

In the irregular vibration preventing apparatus for an electric vehicle according to the present invention, the electric motor which may be generated due to a delay in following the mechanical system during acceleration of the electric motor due to a difference in load fluctuation detected by the load detecting means on both sides of the electric motor. The irregular vibration component is extracted in advance and superimposed on the accelerator torque command in the reverse phase, whereby the irregular vibration and the reverse phase torque fluctuation are generated in the electric motor in advance. As a result, irregular vibration that may occur in the drive motor is prevented, and riding comfort is improved.

In the irregular vibration prevention apparatus for an electric vehicle according to the second aspect of the present invention, instead of detecting the load of the electric motor, an acceleration pickup detects the acceleration generated on both sides of the electric motor due to the irregular vibration, and the acceleration of the electric motor is detected from the difference in the accelerations. In some cases, the irregular vibration component of the electric motor, which may occur due to the delay in following the mechanical system, is extracted in advance, and by superimposing this on the accelerator torque command in reverse phase, the irregular vibration and torque fluctuation in reverse phase are generated in the electric motor in advance. . This prevents irregular vibration that may occur in the drive motor,
Improves ride comfort.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. The motor mount 12 is mounted on the vehicle body 11 as a fixing member.
The driving electric motor 13 is attached by a and 12b. Then, load sensors 14a and 14b for detecting the load of the electric motor are provided at portions where the load of the electric motor 13 is applied to the vehicle body 11 via the electric motor mounts 12a and 12b.

The positional relationship between these load sensors 14a and 14b is a symmetrical position on both sides of a vertical plane passing through the central axis of the electric motor 13. In addition, the load sensors 14a, 1
As 4b, a piezoelectric element or an element such as a strain gauge that outputs an electric signal having a magnitude proportional to the pressure is used.

As a torque control circuit, an anti-phase component detector 15 for adding the signals of the load sensors 14a and 14b in anti-phase with each other and an output signal of the anti-phase component detector 15 corresponds to the frequency of the irregular vibration. A band pulse filter (BPF) 16 that allows only a vibration component of a frequency of about 2 to 10 Hertz to pass, a torque limiting unit 17 that controls the phase of an output signal of the band pass filter 16, and a degree of depression of an accelerator pedal. An accelerator sensor 18 that outputs a torque command signal is provided.

A torque command unit 19 for superposing the output of the torque limiting unit 17 on the torque command of the accelerator sensor 18 to output an actual torque command signal, and the torque command unit 1
An inverter 20 for controlling the electric power of the electric motor is provided according to the torque command output by the inverter 9.

Next, the operation of the irregular vibration preventing device for an electric vehicle having the above-described structure will be described. By rotationally driving the electric motor 13, an additional load due to the reaction force applied to the output shaft is applied to the vehicle body 11 together with the load of the electric motor 13, and the load sensors 14a and 14b detect the load and detect the load. ) And (b) output the load signal to the anti-phase component detection unit 15.

In the anti-phase component detecting section 15, the load sensor 14
The load of the electric motor 13 is canceled by making one of the load detection signals a and 14b in the opposite phase and adding the other to the other, and the torque component as shown in FIG. 3 is extracted.

The torque component extracted by the anti-phase component detecting section 15 is passed through a bandpass filter 16, where FIG.
As shown in (3), only the signal of the irregular vibration frequency of about 2 to 10 Hertz is extracted and output to the torque limiting unit 17.

The torque limiting section 17 outputs the irregular vibration signal in the opposite phase to the torque command section 19, and the torque command section 1
At 9, the reverse phase signal of the irregular vibration frequency is combined with the torque command coming from the accelerator sensor 18, and this is given to the inverter 20 as a torque command signal. The inverter 20 controls the drive power of the electric motor 13 based on the input torque command signal.

As a result, the torque output from the electric motor 13 becomes a torque in which a torque fluctuation component, which is the inverse component of the irregular vibration frequency, is superimposed on a substantially constant torque command instructed by the degree of depression of the accelerator, and the irregular vibration is generated. Torque to be canceled can be generated, and irregular vibration of the electric motor 13 can be prevented.

Although the feedback of the torque fluctuation component seems to be slow, the actual irregular vibration frequency is 2 to.
Since the frequency is as slow as about 10 hertz, it is not difficult to control the current high-speed electronic circuit technology.

Next, an embodiment of the invention of claim 2 will be described with reference to FIG. The irregular vibration preventing apparatus for an electric vehicle according to this embodiment is the load sensor 14 used in the first embodiment.
Accelerometers 21a and 21b are installed on the motor mounts 12a and 12b, respectively, in place of a and 14b, and the acceleration detection signals of these are picked up by the anti-phase component detector 1.
It is characterized in that the input is made to 5. Therefore, the other components are the same as those in the first embodiment shown in FIG. 1, and the same reference numerals are given and the description thereof is omitted.

In this embodiment, when the electric motor 13 is started and irregular vibration occurs, the acceleration pickup 21
Vibration accelerations are detected by a and 21b, and these acceleration signals are input to the anti-phase component detection unit 15 so as to be in anti-phase with each other. The anti-phase component detection unit 15 extracts a signal including an asymmetric vibration component as in the first embodiment, and further passes only the asymmetric vibration frequency component by the bandpass filter 16 to give it to the torque limiting unit 17.

The torque limiting section 17 outputs the irregular vibration signal in reverse phase to the torque command section 19, and the torque command section 1
At 9, the reverse phase signal of the irregular vibration frequency is combined with the torque command coming from the accelerator sensor 18, and this is given to the inverter 20 as a torque command signal. The inverter 20 controls the drive power of the electric motor 13 based on the input torque command signal.

As a result, the torque output from the electric motor 13 becomes a torque in which a torque fluctuation component, which is the inverse component of the irregular vibration frequency, is superimposed on a substantially constant torque command instructed by the degree of depression of the accelerator, and the irregular vibration is generated. Torque to be canceled can be generated, and the irregular vibration preventing apparatus for an electric vehicle according to the second embodiment can also prevent irregular vibration of the electric motor 13.

[0024]

As described above, according to the invention of claim 1,
From the difference in the load fluctuations detected by the load detection means on both sides of the motor, the irregular vibration component of the motor that may occur due to the delay in following the mechanical system during acceleration of the motor is extracted in advance and superimposed on the accelerator torque command in reverse phase. By doing so, the irregular vibration and the torque fluctuation having the opposite phase to the irregular vibration are generated in advance in the electric motor, so that the irregular vibration that can occur in the driving electric motor can be effectively prevented and the riding comfort can be improved.

According to the second aspect of the present invention, instead of detecting the load of the electric motor, the acceleration pick-up detects the acceleration generated on both sides of the electric motor due to the irregular vibration. Since the irregular vibration component of the electric motor that may be generated by is extracted in advance and superimposed on the accelerator torque command in the opposite phase, the irregular vibration and the torque fluctuation of the opposite phase are generated in the electric motor in advance. It is possible to effectively prevent irregular vibrations that may occur in the drive motor and improve the riding comfort.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of an embodiment of the invention of claim 1;

FIG. 2 is a waveform diagram of an output signal of the load sensor in the above embodiment.

FIG. 3 is a waveform diagram of an output signal of the anti-phase component detection unit in the above embodiment.

FIG. 4 is a waveform diagram of an output signal of the bandpass filter in the above embodiment.

FIG. 5 is a circuit block diagram of an embodiment of the invention of claim 2;

FIG. 6 is a circuit block diagram of a conventional example.

[Explanation of symbols]

 Reference Signs List 11 vehicle body 12a, 12b electric motor mount 13 electric motor 14a, 14b load sensor 15 anti-phase component detection unit 16 bandpass filter 17 torque limiting unit 18 accelerator sensor 19 torque command unit 20 inverter 21a, 21b acceleration pickup

Claims (2)

[Claims] 1. A holding member for holding a driving electric motor,
Installed at positions facing each other with the axis of the driving electric motor sandwiched therebetween, load detecting means for detecting the load of the driving electric motor, and one of the load signals detected by the load detecting means at the facing position to the other. On the other hand, an anti-phase superimposing unit that adds the signals in anti-phase, a band-pass filter that passes only a specific low frequency signal from the output of the anti-phase superimposing unit, and an output of the band-pass filter that is inverse to the accelerator torque command An irregular vibration prevention device for an electric vehicle, comprising: torque correction means that are superposed in phases; and electric motor control means that controls the output of the drive electric motor by the output of the torque correction means. 2. The irregular vibration preventing apparatus for an electric vehicle according to claim 1, further comprising acceleration pickup means in place of the load detection means.