Electret Vibration Detection System Using Transfer Function Analysis

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Solution Overview

Problem

Existing technologies face challenges in accurately detecting external vibration information in constructional structures, particularly due to the large size and power requirements of optical devices, and the inability of vibration-powered generators to effectively convert output power into usable vibration information.

Innovation Solution

An electret-type vibration detection system that utilizes a vibration-powered generator to generate output power voltage correlated with external vibration velocity, allowing for the creation of transfer function information to accurately compute vibration velocity and displacement through Fourier transforms and proportionality constants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a laser displacement sensor or electromagnetic energy detection method is used to detect external vibration information, then measurement precision is improved, but device complexity and power consumption increase due to large size and separate power supply requirements

Engineering Contradiction:
Improvevibration detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the power generation function and vibration detection function into a single integrated system. The vibration-powered generator simultaneously generates electrical power from external vibration and produces output signals that correlate with vibration velocity, eliminating the need for separate power supplies and reducing overall system complexity while maintaining detection accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The vibration-powered generator serves multiple functions: it generates electrical power for the detection system and simultaneously provides vibration velocity information through its output signal. This multi-functionality reduces the number of components needed and simplifies the overall system architecture while maintaining precise vibration measurement capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Use of energy by moving object

If a vibration-powered generator is used to generate electricity from external vibration, then power consumption is reduced by using self-generated power, but the ability to accurately detect vibration velocity and displacement information is insufficient

Engineering Contradiction:
Improvepower consumptionVSAvoidvibration velocity detection accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent establishes a feedback relationship where the output signal from the vibration-powered generator, which is naturally correlated with vibration velocity, is used to accurately determine vibration characteristics. By analyzing the relationship between output power voltage and vibration velocity through transfer function information, the system achieves precise vibration measurement while maintaining low power consumption through self-generated power.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent utilizes the inherent parameter relationship between the generator's output power voltage and vibration velocity. By creating transfer function information that defines the correlation between these parameters at different frequencies, the system can accurately extract vibration velocity and displacement information from the power generation output itself, transforming the generator into both a power source and a precise sensor.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If output power from vibration-powered generator is used as power supply, then ease of operation is improved by eliminating separate power supply, but difficulty in connecting output power to vibration information remains

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidvibration information extraction
Core Design Contradiction:
Ease of operationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces complex mechanical or optical vibration measurement systems with an electrical measurement approach based on the generator's output characteristics. By substituting traditional vibration sensors with analysis of the generator's electrical output, the system simplifies operation while effectively extracting vibration velocity and displacement information through established electrical measurement techniques.

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

Enables easy and accurate detection of external vibration information, reducing noise and power consumption by leveraging the correlation between output power voltage and vibration velocity, effectively addressing the limitations of previous methods.

Implementation Method 1

an electret group that can move relatively using a property of an electret capable of semipermanently holding charges

Methodology Applied
Scientific EffectElectret: Electret

Implementation Method 2

a vibration-powered generator that generates electricity from external vibration using an electret

Methodology Applied
Scientific EffectVibration-induced power generation: Electromagnetic Induction

Data Source

PatentEP2857808B1Electret type vibration detection system, method of creating external vibration information, method of creating transfer function information regarding external vibration, program for creating external vibration information, and program for creating transfer function information regarding external vibration
Publication Date: 2019.05.01 OMRON CORP
  • EP2857808B1 patent drawingFigure 1~2
  • EP2857808B1 patent drawingFigure 3
  • EP2857808B1 patent drawingFigure 4

AI summary

Transition information relating to an output power voltage in a predetermined time period is obtained from a vibration-powered generator that performs vibration-induced power generation by relatively displacing on the basis of external vibration an electret group and an electrode group. A Fourier transform for the transition information relating to the output power voltage is performed to compute output spectrum information relating to the output power voltage. Moreover, vibration velocity information relating to the external vibration within the predetermined period is created for the computed output spectrum information, by taking into account transfer function information that defines a correlation between the vibration velocity of the external vibration of the predetermined frequency range included in the external vibration and the output power voltage of the vibration-powered generator, with this transfer function information containing a transfer coefficient set corresponding to on each of a plurality of frequencies belonging to the predetermined frequency range to place the vibration velocity of the external vibration and the output power voltage of the vibration-powered generator in a predetermined proportional relationship. As a result, it is possible to easily and accurately detect external vibration information using electrets.