KR20100081515A

KR20100081515A - Control method for piezoelectric motor and piezoelectric motor using thereof

Info

Publication number: KR20100081515A
Application number: KR1020090000801A
Authority: KR
Inventors: 성운탁
Original assignee: 삼성전자주식회사
Priority date: 2009-01-06
Filing date: 2009-01-06
Publication date: 2010-07-15

Abstract

PURPOSE: A control method of a piezoelectric motor and a piezoelectric motor thereof are provided to control noises which are generated when driving a piezoelectric motor by controlling an interval between the pulse sequences of a driving part. CONSTITUTION: A controller(110) generates a first pulse signal for driving a piezoelectric motor. The controller generates the first pulse signal which has an interval which becomes narrower from a period where the operation of a driving part starts. The controller generates a first pulse signal which has an interval between pulse sequences from a period where the operation of a driving part is completed. A signal converter(120) generates at least two second pulse signals which have dissimilar phases. The driving part(130) generates driving force with the second pulse signal.

Description

CONTROL METHOD FOR PIEZOELECTRIC MOTOR AND PIEZOELECTRIC MOTOR USING THEREOF}

The present invention relates to a piezoelectric motor, and more particularly to a piezoelectric motor capable of suppressing noise during driving.

The piezoelectric motor-type linear motor has a problem in that a sudden speed change and noise are generated due to the application and removal of a pulse signal during driving. As an electrical solution for preventing a sudden change in speed of an object as described above, a method of minimizing vibration and noise by changing a gradual speed by adjusting a voltage or a duty of a pulse signal has been proposed.

That is, as a method for reducing the noise of a conventional piezoelectric motor, it can be divided into a method of controlling a voltage of a pulse and a method of adjusting a duty.

The above-described voltage regulation method is relatively efficient in terms of performance, but the circuit configuration is complicated and not easy to implement.How to adjust the duty is possible only if the driving characteristics of the motor are changed continuously according to the duty change. There is a disadvantage in that such a method is difficult to apply.

An object of the present invention is to suppress noise generated when driving a piezoelectric motor without changing the voltage or duty of a pulse signal.

The driving method of the piezoelectric motor according to the first aspect of the present invention,

In the section in which the pulse signal is applied to the piezoelectric motor gradually increases the number of pulses, the number of pulses is kept constant in the section in which the piezoelectric motor operates at the same speed, the section in which the operation of the piezoelectric motor is terminated Gradually decrease the number of pulses.

The piezoelectric motor according to the second aspect of the present invention,

A controller which calculates the number of pulse signals generated by the controller to drive a piezoelectric motor and generates a first pulse signal whose time interval is controlled;

A signal converter which generates two or more second pulse signals having different phases;

It includes a drive unit for generating a driving force by the second pulse signal,

The controller generates a first pulse signal in which the interval between pulse strings is gradually narrowed in a section in which the operation of the driver starts, and generates a first pulse signal in which the interval between pulse strings gradually widens in a section in which the operation of the driver is terminated. Create

The present invention can provide a motor capable of suppressing noise without including an additional configuration.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The present invention provides a method of driving a piezoelectric motor operated by application of a pulse signal, the pulse signal of which the number of pulses gradually increases in a starting section in order to drive the piezoelectric motor, and the piezoelectric motor operates at a constant speed (equivalent velocity). The piezoelectric motor is driven by a pulse signal in which the interval (or the number of pulses) between the pulse trains is constant in the section (operation section) to be driven by (). On the other hand, in the end section for stopping the operation of the piezoelectric motor is gradually reduced the number of pulses included in the pulse signal.

The start section and the end section may be defined from a threshold point at which the intensity of the pulse signal applied for driving the piezoelectric motor exceeds the friction force of the piezoelectric motor, to the point where the piezoelectric motor continues at a constant speed constant velocity motion. In addition, the degree of decrease and increase in the number of pulses may be determined according to a start section and an end section.

1 is a block diagram schematically showing a piezoelectric motor according to the present invention. Referring to FIG. 1, the piezoelectric motor 100 according to the present invention includes a control unit 110 for generating a first pulse signal, a signal converter 120 for generating two or more second pulse signals having different phases, and The driving unit 130 generates a driving force by the second pulse signal.

The controller 110 generates a first pulse signal in which the interval between pulse strings gradually decreases in a section in which the operation of the driver 130 starts, and in a section in which the operation of the driver 130 ends, the interval between pulse strings is increased. Generate a first pulse signal that gradually widens. In addition, the interval between pulse strings of the first pulse signal in a section in which the piezoelectric motor 100 moves at a constant speed is maintained.

The start section may be started from a threshold point (the point at which the intensity of the first pulse signal is greater than the friction force), and the end point may be included in the operation section (the point at which the driver starts the constant velocity motion) or the predetermined point in the operation section. have.

The end section may be defined as a point from which the speed of the operation section or the driving unit is reduced to a threshold point (a point where the intensity of the first pulse signal is smaller than the friction force).

The controller 110 may control the initial speed of the drive to be smaller by making the on time interval of the first pulse signal in the section where the drive unit 130 starts to be driven smaller than the off time interval. The ratio of the first pulse signal is increased in contrast to the starting section at a time when the piezoelectric motor 100 is stopped (ending section) while maintaining a constant on state in the middle of driving (operation time) while gradually increasing this ratio. Gradually decrease the rate of on.

The controller 110 controls the timer 113 by calculating a pulse pattern from a memory 112 in which pulse information is stored, a timer 113 generating a pulse pattern, and pulse information stored in the memory 113. And a pulse generator 114 for generating a first pulse signal modulated to a pulse waveform to which the pulse pattern generated by the timer 113 is applied at a predetermined period.

4 is a graph illustrating a control method of a piezoelectric motor according to the present invention, and is a graph illustrating an example of a start section control of the piezoelectric motor according to the present invention. FIG. 4A is a graph obtained by arbitrarily dividing a starting section into a plurality of regions A to J, and FIG. 4B is the regions A to J divided in FIG. 4A. It is a graph showing an example of each pulse control. That is, it can be seen that the time off in which the pulse is not provided in the A region is longer than the D region, and the off time of the G region is set longer than the off time of the D region.

The first pulse signal is transmitted to the driver in the form of second pulse signals amplified and phase modulated by the signal converter. In addition, the first pulse signal may control the speed of the driving unit by adjusting the number of pulses for each section (start section, operation section, end section). That is, the controller according to the present invention sets the on-off time of the pulse so that one cycle to be driven has a period of low speed, medium speed, high speed, medium speed, and low speed, thereby starting the driving of the piezoelectric motor. Vibration and noise generated at the end can be minimized.

The driving unit converts the second pulse signals provided from the signal converter into physical motion, and the vibration frequency at this time is the same frequency as the second pulse signals, and generates non-uniform vibration according to the duty ratio. Conduct.

Figure 3 is a graph for comparing the noise according to the driving of the piezoelectric motor and the conventional piezoelectric motor according to the present invention. Figure 3 (a) is a graph for explaining the speed control and method for a conventional piezoelectric motor, Figure 3 (b) is a graph for explaining the speed control and method of a piezoelectric motor according to the present invention.

Figure 3 (a) is a sudden start and end of the pulse applied to the piezoelectric motor, while Figure 3 (b) according to the present invention is a progressively made at the start and end of the pulse applied to the piezoelectric motor It can be seen.

As a result, it can be seen that (b) of FIG. 3 is smaller than that of FIG. 3 (a) at the initial stage when the piezoelectric motor starts to drive and when the driving ends.

1 is a block diagram schematically showing a piezoelectric motor according to the present invention;

2 is a block diagram showing the configuration of a control unit shown in FIG. 1;

Figure 3 is a graph for comparing the noise according to the driving of the piezoelectric motor and the conventional piezoelectric motor according to the present invention,

4 is a graph illustrating a control method of a piezoelectric motor according to the present invention;

Claims

In the method of driving a piezoelectric motor,

In the section in which the pulse signal is applied to the piezoelectric motor gradually increases the number of pulses, the number of pulses is kept constant in the section in which the piezoelectric motor operates at the same speed, the section in which the operation of the piezoelectric motor is terminated A method of driving a piezoelectric motor, characterized in that it gradually reduces the number of pulses.

In piezoelectric motors,

A control unit for generating a first pulse signal for driving the piezoelectric motor;

The controller generates a first pulse signal in which the interval between pulse strings is gradually narrowed in a section in which the operation of the driver starts, and generates a first pulse signal in which the interval between pulse strings gradually widens in a section in which the operation of the driver is terminated. Piezoelectric motor, characterized in that it produces.

The method of claim 2, wherein the control unit,

A memory into which pulse information is input;

A timer for generating a pulse pattern;

Computing means for controlling the timer by calculating a pulse pattern from the pulse information stored in the memory;

And a pulse generator for generating a first pulse signal modulated to a pulse waveform applied to the pulse pattern generated by the timer at regular intervals.