Acoustic Emission Detection System with Strain Triggered Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing detection systems for structural deterioration, such as in bridges, face challenges in accurately distinguishing acoustic emission waves from cracks amidst environmental noise, leading to false positives and reduced diagnostic accuracy.
Innovation Solution
A detection system comprising strain sensors and acoustic emission sensors connected to a signal processing device that performs first signal processing, which includes noise removal and characteristic parameter extraction, to minimize the effect of environmental noise by processing signals only after a strain threshold is exceeded and within a defined time period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a highly sensitive acoustic emission sensor is employed to detect feeble AE waves, then the sensitivity of detection is improved, but the sensor also picks up environmental noise leading to false positives
Solution Approach 1:
The patent introduces an intermediary strain sensor that detects strain changes in the structure. This strain detection serves as a trigger mechanism - only when strain exceeds a threshold does the system process acoustic emission signals. This intermediary detection method filters out environmental noise that does not correspond to actual structural loading events, while preserving genuine AE signals from cracks.
Solution Approach 2:
The system performs preliminary detection using strain sensors before processing acoustic emission signals. By monitoring strain changes first and using them to trigger subsequent AE signal processing, the system prepares in advance to distinguish relevant signals from noise. This preliminary action prevents false positives by ensuring AE signals are only analyzed when structural loading conditions warrant such analysis.
2Reliability
If continuous monitoring of acoustic emission signals is performed, then crack detection coverage is improved, but the system processes unnecessary signals during non-loading periods increasing false positives
Solution Approach 1:
The patent implements periodic action by triggering acoustic emission signal processing only during specific periods when strain exceeds the threshold. Rather than continuous monitoring, the system activates signal processing intermittently - specifically when loading conditions indicate potential crack activity. This periodic approach maintains detection coverage during critical periods while eliminating unnecessary processing during non-loading periods.
Solution Approach 2:
The system applies partial action by processing acoustic emission signals only partially - specifically only when strain threshold conditions are met. Instead of processing all AE signals continuously, the system selectively processes signals during periods when structural loading suggests crack risk. This partial processing maintains reliability for actual cracks while reducing false positives from processing during idle periods.
3Loss of information
If acoustic emission signals are processed continuously, then detection completeness is improved, but environmental noise reduces measurement accuracy
Solution Approach 1:
The strain sensor acts as an intermediary filter between the acoustic emission sensor and the signal processing system. It provides additional information about structural loading conditions, allowing the system to distinguish between AE signals caused by cracks under load versus those caused by environmental noise. This intermediary data layer improves measurement precision without sacrificing detection completeness.
Solution Approach 2:
The system uses strain detection as feedback to control acoustic emission signal processing. When strain exceeds the threshold, the system activates AE signal processing; when strain is below threshold, processing is suspended. This feedback mechanism ensures that signal processing occurs only when structurally relevant, improving accuracy while maintaining completeness of crack detection.
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 significantly reduces the impact of environmental noise, enhancing the accuracy of detecting actual crack-related acoustic emission waves and improving the reliability of structural health monitoring.
Implementation Method 1
acoustic emission (AE) waves are produced from the deteriorated portion as a crack occurs and propagates. These AE waves can be detected using an AE sensor, such as a piezoelectric sensor
Implementation Method 2
AE sensor, such as a piezoelectric sensor
Data Source
AI summary
According to an embodiment, a detection system includes a detection device, an acoustic emission sensor, and a processing unit. The detection device detects a change that occurs in a structure or a change in an environment related to the structure. The acoustic emission sensor detects an acoustic emission wave produced from the structure. The processing unit performs first signal processing to process an acoustic emission signal indicating the acoustic emission wave, which is input from the acoustic emission sensor until a first period of time elapses after a detection signal is input from the detection device. The detection signal indicates that a change has occurred in the structure or the environment related to the structure.