Eddy Current Testing Digital Signal Processing Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing eddy current testing methods for non-destructive flaw detection in devices lack accuracy due to limitations in signal processing and demodulation techniques, leading to suboptimal detection capabilities.
Innovation Solution
A test set-up and method incorporating an excitation coil, receiving coil, analog-digital converter, filter arrangement, and demodulator for digital filtering and demodulation, allowing for high-frequency scanning and band-pass filtering to enhance accuracy by reducing analog components and achieving precise demodulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analog components are used for filtering and demodulation, then the system can process eddy current signals, but the cost increases and accuracy is limited
Solution Approach 1:
The patent replaces the mechanical/analog filtering and demodulation system with a digital signal processing system. The eddy current signal is converted to digital form and processed using digital filters and demodulation algorithms, eliminating the need for complex analog components while improving measurement precision and detection accuracy.
Solution Approach 2:
The patent changes the state of the signal from analog to digital domain. By converting the eddy current signal to digital form through an analog-to-digital converter, the system can apply digital signal processing techniques that offer higher precision and flexibility in filtering and demodulation, thereby improving detection accuracy without relying on expensive analog components.
2Measurement precision
If the analog-digital converter scan frequency is set high for accurate coil signal detection, then detection accuracy improves, but the demodulator must process high-frequency signals which increases complexity
Solution Approach 1:
The patent applies digital filtering and scan frequency reduction to the high-frequency digital signal before it reaches the demodulator. This preliminary processing step reduces the signal frequency and filters out unwanted components, allowing the demodulator to operate at lower frequencies with reduced complexity while maintaining the high detection accuracy achieved by the high-frequency analog-to-digital conversion.
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
The solution significantly increases the accuracy of flaw detection by enabling high-frequency scanning and precise demodulation, reducing the need for expensive analog components and allowing for flexible analysis of eddy current signals at various phase angles.
Implementation Method 1
An excitation signal can be sent to the excitation coil to act on the device being tested with an electromagnetic alternating field
Implementation Method 2
Eddy currents form in the device being tested and are picked up
Data Source
AI summary
A test set-up (10) for non-destructive detection of a flaw in a device being tested by means of an eddy current has an excitation coil (14), to which an excitation signal (SE) can be sent to act on the device being tested (16) with an electromagnetic alternating field, a receiving coil (17) to generate a coil signal (SP), which is a function of the flaw in the device being tested (16), an analog-digital converter (21), which is coupled to the receiving coil (17) on the input side, a filter arrangement (22), which is coupled to the analog-digital converter (21) on the input side and is designed for band-pass filtering and scan rate reduction, and a demodulator (27), which is coupled to an output of the filter arrangement (22) on the input side.