Crack Detection Device Using Impedance Frequency Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing crack detection methods face challenges in distinguishing impedance changes due to cracking from those caused by dielectric adhesion or environmental factors, and are limited by the fixed shape of sensors.
Innovation Solution
A crack detection device with a three-layer conductor-insulator-conductor sensor unit that acquires frequency characteristics across a range, determines crack presence based on nonuniformity, and uses a crack position table to identify crack positions by analyzing frequency shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a sensor with fixed shape is used for crack detection, then the sensor can be manufactured with standard processes, but it becomes difficult to apply the sensor to various shapes of various structures
Solution Approach 1:
The patent applies parameter changes by transforming the sensor design from a fixed geometric shape to a flexible configuration that can adapt to different structural forms. The sensor's electrical characteristics (impedance frequency characteristics) are used as the identification parameter rather than relying on fixed geometric matching, enabling the same sensor to be applied to various structure shapes while maintaining manufacturability through standardized sensor production processes.
2Extent of automation
If impedance monitoring is used to detect cracks, then continuous monitoring is possible, but it becomes difficult to distinguish impedance changes due to cracking from changes due to dielectric adhesion or time passage
Solution Approach 1:
The patent employs periodic action by sweeping through a predetermined frequency range to acquire multiple frequency points (e.g., 100 points from 10 kHz to 1 MHz) and analyzing the impedance characteristics at each frequency. This periodic frequency sweeping creates a detailed frequency response signature that can be compared against reference data, enabling accurate distinction between crack-induced impedance changes and other factors like dielectric adhesion or temporal drift, while maintaining continuous monitoring capability.
3Measurement precision
If visual inspection with workers is performed, then crack detection can be conducted, but the cost for dispatching workers is necessary and continuous monitoring is impossible
Solution Approach 1:
The patent implements self-service by deploying an automated sensor-based monitoring system that continuously monitors structures without requiring human presence. The sensor unit, equipped with impedance measurement capabilities and frequency sweeping functionality, autonomously detects crack conditions and transmits data remotely. This eliminates the need for continuous worker deployment while maintaining reliable crack detection, significantly improving monitoring efficiency and reducing costs associated with manual inspection.
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 effective identification of impedance changes due to cracking without shape limitations, distinguishing them from other factors, and accurately detects crack positions.
Implementation Method 1
a frequency characteristics acquisition unit that sweeps a predetermined frequency range to acquire a plurality of frequencies at which the impedance of the sensor unit is maximum or minimum
Data Source
AI summary
A crack detection device includes: a sensor unit that has a three-layer structure of conductor-insulator-conductor and is attached to a structure; a frequency characteristics acquisition unit that sweeps a predetermined frequency range to acquire a plurality of frequencies at which the impedance of the sensor unit is maximum or minimum; a crack presence/absence determination unit that determines the presence or absence of a crack based on a nonuniformity of the plurality of frequencies; a crack position table in which a relationship between crack positions and frequency shift directions is recorded; and a crack position detection unit that, when the crack presence/absence determination unit determines that there is a crack, takes a difference between two frequencies acquired by the frequency characteristics acquisition unit to determine a sign, and then refers to the crack position table in accordance with the sign to detect a crack position.