Piezoelectric Drive Voltage Sensing for Vibration Abnormality Detection

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Solution Overview

Problem

Existing piezoelectric drive devices require costly monitor electrodes and protection circuits for abnormality sensing, making cost reduction difficult.

Innovation Solution

A method and device for sensing vibration abnormalities in piezoelectric drive devices using a substrate with thin-film piezoelectric elements, where a drive control signal generates a drive voltage to detect abnormalities through a software-based sensing portion within the controller, eliminating the need for a dedicated abnormality sensing circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a monitor electrode and protection circuit are added to sense abnormality, then reliability is improved, but device complexity and cost increase

Engineering Contradiction:

Improveabnormality sensing capabilityVSAvoidcircuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The drive control signal is used for multiple purposes: both driving the piezoelectric element and sensing vibration abnormalities. The existing drive circuit performs dual functions, eliminating the need for separate monitor electrodes and protection circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The piezoelectric element itself generates the vibration signal that is used for abnormality detection. By analyzing the drive voltage characteristics during normal operation, the system self-diagnoses abnormalities without external sensing components.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If dedicated abnormality sensing circuit is implemented, then measurement precision is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improvevibration abnormality detection accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces physical sensing hardware (monitor electrodes and protection circuits) with a software-based analysis method. By processing the drive voltage signal through control algorithms, abnormality detection is achieved without additional manufacturing complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for cost-effective abnormality sensing in piezoelectric drive devices, preventing damage by detecting vibration anomalies without additional hardware, thus enhancing reliability and performance.

Implementation Method 1

piezoelectric motors using vibration of piezoelectric materials

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

monitoring a voltage generated by vibration of the piezoelectric material

Methodology Applied

Scientific EffectConverse piezoelectric effect: Converse Piezoelectric Effect

Data Source

PatentUS11824469B2Method for sensing abnormality of piezoelectric drive device, piezoelectric drive device, and robot

Publication Date: 2023.11.21 SEIKO EPSON CORP

AI summary

A method for sensing an abnormality of a piezoelectric drive device is a method for sensing a vibration abnormality of the piezoelectric drive device having a substrate and thin-film piezoelectric elements placed on the substrate and controlling amplitude of the piezoelectric elements using a drive control signal, and the method includes sensing the vibration abnormality by a drive voltage corresponding to the drive control signal.