Drive control device and ultrasonic motor system

Patent metadata

Field	Value
Publication number	US-12246346-B2
Application number	US-202218086816-A
Country	US
Kind code	B2
Filing date	Dec 22, 2022
Priority date	Aug 21, 2020
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

A drive control device is provided that drives an ultrasonic motor element including a piezoelectric element. The drive control device includes a voltage divider circuit unit resistor forming a voltage divider circuit unit together with an identification resistor that identifies the ultrasonic motor element; a control circuit unit connected to the voltage divider circuit unit and that sets a drive condition of the ultrasonic motor element according to a voltage of an identification signal for identifying the ultrasonic motor element; and a drive circuit unit that applies a drive voltage to the piezoelectric element based on the drive condition set by the control circuit unit.

First claim

The invention claimed is:

1. A drive control device for driving an ultrasonic motor element including a piezoelectric element, the drive control device comprising:
a voltage divider circuit formed by a voltage divider circuit unit resistor and an identification resistor that identifies the ultrasonic motor element;
a control circuit unit connected to the voltage divider circuit unit and configured to set a drive condition of the ultrasonic motor element based on a voltage of an identification signal that identifies the ultrasonic motor element; and
a drive circuit unit configured to apply a drive voltage to the piezoelectric element based on the drive condition set by the control circuit unit
wherein:
the control circuit unit is configured to set a sweep range of a drive frequency of the piezoelectric element,
the drive circuit unit is configured to sweep the drive frequency of the piezoelectric element within the sweep range of the drive frequency set by the control circuit unit, and
the control circuit unit is configured to set the drive condition based on a result of the sweep of the drive frequency.

2. The drive control device according to claim 1 , wherein the control circuit unit includes a storage unit configured to store a plurality of patterns of the sweep range of the drive frequency.

3. The drive control device according to claim 2 , wherein the control circuit unit includes a control unit configured to select the sweep range of the drive frequency from the plurality of patterns and to set the drive condition.

4. The drive control device according to claim 1 , wherein the voltage divider circuit unit resistor branches on one end side so as to be connected to the identification resistor and the control circuit unit.

5. The drive control device according to claim 4 , wherein the voltage divider circuit unit resistor branches on another side so as to be connected to a power supply.

6. The drive control device according to claim 1 , further comprising a plurality of the voltage divider circuit unit resistors each forming the voltage divider circuit unit with a plurality of the identification resistors, respectively.

7. The drive control device according to claim 6 , further comprising a selection switch disposed between the plurality of voltage divider circuit units and the control circuit unit and configured to switch connections between each of the plurality of voltage divider circuit units and the control circuit unit.

8. The drive control device according to claim 7 , further comprising an analog-to-digital conversion unit connected between the selection switch and the control circuit unit and configured to digitally convert the identification signal.

9. An ultrasonic motor system comprising:
the drive control device according to claim 1 ; and
the ultrasonic motor element including the piezoelectric element and the identification resistor.

10. An ultrasonic motor system comprising:
the drive control device according to claim 6 ; and
the ultrasonic motor element that includes a plurality of the piezoelectric elements and a plurality of the identification resistors.

11. An ultrasonic motor system comprising:
the drive control device according to claim 6 ; and
a plurality of the ultrasonic motor elements that each include the piezoelectric element and the identification resistor.

12. The drive control device according to claim 1 , further comprising a single microcomputer that includes the voltage divider circuit, the control circuit and the drive circuit.

13. A drive control device for driving an ultrasonic motor element including a piezoelectric element, the drive control device comprising:
a voltage divider circuit formed by a voltage divider circuit unit resistor and an identification resistor that identifies the ultrasonic motor element;
a control circuit unit connected to the voltage divider circuit unit and configured to set a drive condition of the ultrasonic motor element based on a voltage of an identification signal that identifies the ultrasonic motor element;
a drive circuit unit configured to apply a drive voltage to the piezoelectric element based on the drive condition set by the control circuit unit; and
an analog-to-digital conversion unit connected between the voltage divider circuit unit and the control circuit unit and configured to digitally convert the identification signal.

14. The drive control device according to claim 13 , wherein the voltage divider circuit unit resistor branches on one end side so as to be connected to the identification resistor and the control circuit unit.

15. The drive control device according to claim 14 , wherein the voltage divider circuit unit resistor branches on another side so as to be connected to ground potential.

16. The drive control device according to claim 15 , wherein:
the voltage divider circuit unit resistor is a pull-up resistor, and
the drive control device further comprises a switch configured to switch a connection between the voltage divider circuit unit resistor and the identification resistor between an ON state and an OFF state.

17. A method for driving an ultrasonic motor element including a piezoelectric element, the method comprising:
measuring an identification signal from an identification resistor that forms a voltage divider circuit with a voltage divider circuit unit resistor;
setting, by a control circuit unit coupled to the voltage divider circuit, a drive condition of the ultrasonic motor element based on a voltage of an identification signal that identifies the ultrasonic motor element;
applying a drive voltage to the piezoelectric element based on the drive condition set by the control circuit unit;
wherein the setting of the drive condition further comprises:
setting, by the control circuit unit, a sweep range of a drive frequency of the piezoelectric element;
sweeping the drive frequency of the piezoelectric element within the sweep range of the drive frequency set by the control circuit unit; and
setting, by the control circuit unit, the drive condition based on a result of the sweep of the drive frequency.

18. The method according to claim 17 , further comprising:
storing a plurality of patterns of the sweep range of the drive frequency; and
selecting, by the control circuit unit, the sweep range of the drive frequency from the plurality of patterns and setting the drive condition.

Assignees

• Murata Manufacturing Co

Inventors

• Terasawa Mitsushiro

Classifications

• B06B1/0644

  using a single piezoelectric element (B06B1/0688 takes precedence) · CPC title

• B06B1/0215 Primary

  for generating pulses, e.g. bursts of oscillations, envelopes · CPC title

• B06B2201/55

  Piezoelectric transducer · CPC title

• H02N2/16

  using travelling waves {, i.e. Rayleigh surface waves} · CPC title

• H02N2/14 Primary

  Drive circuits; Control arrangements {or methods} · CPC title