Piezoelectric apparatus for motorization

Patent metadata

Field	Value
Publication number	US-11258378-B2
Application number	US-201916424835-A
Country	US
Kind code	B2
Filing date	May 29, 2019
Priority date	May 29, 2018
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

A piezoelectric motorization system has a mechanically flexible body that has one or more surfaces for placing piezoelectric actuators. The system has groups of piezoelectric actuators each positioned on one of the surfaces of the mechanically flexible body that is connected to the electronic circuitry. The electronic circuitry controls the driving of the mechanical loads by the mechanically flexible body by injecting sets of control signals into different groups of actuators positioned on the mechanically flexible body. Each control signal operates groups of driving frequencies with an adjustable amplitude ratio and an adjustable phase difference among driving frequencies. And, under a set of boundary conditions exhibited by a set of structural dimensions of the mechanically flexible body, each control signal induces multi-mode resonance of the mechanically flexible body for driving the mechanical loads multi-dimensionally.

First claim

What is claimed is:

1. A piezoelectric motorization system for driving mechanical loads multi-dimensionally by an electronic circuitry comprising:
a mechanically flexible body having one or more surfaces; and
at least two groups of a plurality of piezoelectric actuators, each actuator being positioned on one of the one or more surfaces of the mechanically flexible body at a corresponding actuating area and being electrically connected to a corresponding output of the electronic circuitry;
wherein
the electronic circuitry controls the driving of the mechanical loads by the mechanically flexible body by injecting at least two sets of control signals respectively into different groups of actuators positioned on the mechanically flexible body; and
each control signal operates at least two groups of driving frequencies with an adjustable amplitude ratio and an adjustable phase difference among driving frequencies, and, under a set of boundary conditions exhibited by a set of structural dimensions of the mechanically flexible body, induces multi-mode resonance of the mechanically flexible body for driving the mechanical loads multi-dimensionally.

2. The piezoelectric motorization system of claim 1 wherein each driving frequency is at or near one resonant frequency of the mechanically flexible body and all driving frequencies are different and adjacent to each other.

3. The piezoelectric motorization system of claim 1 wherein each driving frequency is at or near one resonant frequency of the mechanically flexible body and all driving frequencies are different and not adjacent to each other.

4. The piezoelectric motorization system of claim 1 wherein each driving frequency is at or near one resonant frequency of the mechanically flexible body and each driving frequency has an integer relationship with respect to each other.

5. The piezoelectric motorization system of claim 1 wherein the driving frequencies are at or near the driving frequencies of out-of-plane resonant modes of the mechanically flexible body, including bending and/or twisting modes.

6. The piezoelectric motorization system of claim 1 wherein the driving frequencies for each piezoelectric actuator are a superposition of at least one frequency at or near different resonant modes of the mechanically flexible body.

7. The piezoelectric motorization system of claim 6 wherein the driving frequencies for each group of piezoelectric actuators are different.

8. The piezoelectric motorization system of claim 1 wherein the size, shape and location of all piezoelectric actuators determine a motorization direction and a velocity of the mechanical load.

9. A piezoelectric motorization system for driving mechanical loads multi-dimensionally by an electronic circuitry comprising:
a mechanically flexible body comprising at least one layer of piezoelectric plate having a top surface and a bottom surface; and
at least two groups of paired electrodes placed respectively on the top and the bottom surface of each piezoelectric plate and electrically connected to a corresponding output of the electronic circuitry;
wherein
the electronic circuitry controls the driving of the mechanical loads by the mechanically flexible body by injecting at least two sets of control signals respectively into different groups of paired electrodes positioned on the piezoelectric plate; and
each control signal operates at least two groups of driving frequencies with an adjustable amplitude ratio and an adjustable phase difference among driving frequencies, and, under a set of boundary conditions exhibited by a set of structural dimensions of the mechanically flexible body, induces multi-mode resonance of the mechanically flexible body for driving the mechanical loads multi-dimensionally.

10. A piezoelectric motorization system for driving mechanical loads of a three-dimensional mass multi-dimensionally by electronic circuitry, the three-dimensional mass having three mutually orthogonal surfaces, the system comprising:
a) at least three mechanically flexible bodies each having one or more surfaces and placed adjacent to a corresponding one of the three mutually orthogonal surfaces of the three-dimensional mass; and
b) at least two groups of a plurality of piezoelectric actuators, each group of piezoelectric actuators being positioned on one of the one or more surfaces of each mechanically flexible body at a corresponding actuating area and being electrically connected to a corresponding output of the electronic circuitry;
wherein
the electronic circuitry controls the driving of the mechanical loads by the mechanically flexible bodies by injecting at least two sets of control signals respectively into different groups of actuators positioned on each mechanically flexible body; and
each control signal operates at least two groups of driving frequencies with an adjustable amplitude ratio and an adjustable phase difference among driving frequencies, and, under a combination of a set of boundary conditions exhibited by a set of structural dimensions of each mechanically flexible body, induces multi-mode resonance of the mechanically flexible bodies for driving the mechanical loads of the three-dimensional mass multi-dimensionally and moving the three-dimensional mass on a corresponding plane of one of the three mutually orthogonal surfaces.

11. A method for a piezoelectric motorization system to drive mechanical loads multi-dimensionally by an electronic circuitry, the piezoelectric motorization system having a mechanically flexible body that has one or more surfaces and at least two groups of a plurality of piezoelectric actuators, each actuator being positioned on one of the one or more surfaces of the mechanically flexible body at a corresponding actuating area and being electrically connected to a corresponding output of the electronic circuitry, the method comprising:
the electronic circuitry injecting at least two sets of control signals respectively into different groups of actuators positioned on the mechanically flexible body for controlling the driving of the mechanical loads by the mechanically flexible body;
wherein
each control signal operates at least two groups of driving frequencies of the mechanically flexible body with an adjustable amplitude ratio and an adjustable phase difference among the driving frequencies, and, under a set of boundary conditions exhibited by a set of structural dimensions of the mechanically flexible body, induces multi-mode resonance of the body for driving the mechanical loads multi-dimensionally.

12. The method of claim 11 wherein each driving frequency is at or near one resonant frequency of the mechanically flexible body and all driving frequencies are different and adjacent to each other.

13. The method of claim 11 wherein each driving frequency is at or near one resonant frequency of the mechanically flexible body and all driving frequencies are different and not adjacent to each other.

14. The method of claim 11 wherein each driving frequency is at or near one resonant frequency of the mechanically flexible body and each driving frequency has an integer relationship with respect to each other.

15. The method of claim 11 wherein the driving frequencies are at or near the driving frequencies of out-of-plane resonant modes of the mechanically flexible body, including bending and/or twisting modes.

16. The method of claim 11 wherein the driving frequencies for each piezoelectric actuator are a superposition of at least one frequency at or near different resonant modes of the mechanically flexible body.

Assignees

• Univ Nat Taiwan

Inventors

• Lee Chih-Kung
• Hsu Yu-Hsiang
• Wu Wen-Jong
• Chu Tsung-Yu
• Lin Yu-Min

Classifications

• H02N2/028 Primary

  along multiple or arbitrary translation directions, e.g. XYZ stages · CPC title

• H02N2/065

  Large signal circuits, e.g. final stages · CPC title

• H02N2/021 Primary

  using intermittent driving, e.g. step motors, piezoleg motors · CPC title

• H02N2/08

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

• H02N2/062

  Small signal circuits; Means for controlling position or derived quantities, e.g. for removing hysteresis · CPC title