Hydraulic Damper Defect Detection Using Vibration Signal Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for testing hydraulic shock absorbers are inefficient for production lines, as they primarily assess overall capacity rather than manufacturing defects and provide qualitative information, are complex, costly, and require skilled operators, making them unsuitable for quick and accurate defect classification.
Innovation Solution
A method and device that process vibration acceleration signals using FFT algorithms to determine statistical characteristics and boundary values, enabling automatic classification of hydraulic damper conditions, allowing for fast and repeatable testing on production lines without needing complex systems or expert operators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional bench methods are used to test shock absorbers, then overall capacity assessment is achieved, but manufacturing defect detection capability is insufficient
Solution Approach 1:
The patent applies mechanical vibration by subjecting the shock absorber to controlled vibrational movements during testing. The vibration generator creates specific vibration patterns that excite the shock absorber, and the resulting vibrations are captured by sensors to detect manufacturing defects. This approach enables precise defect detection through spectral analysis of vibration signals without requiring overly complex test equipment.
2Loss of information
If traditional testing methods are used, then qualitative information is obtained, but quantitative defect classification is not achieved
Solution Approach 1:
The patent implements feedback through automated signal processing where vibration signals are captured, processed through FFT (Fast Fourier Transform) algorithms, and compared against reference spectral data. The system automatically generates defect classification results based on the analysis of spectral characteristics, eliminating the need for manual qualitative assessment and providing quantitative defect identification.
Solution Approach 2:
The patent replaces manual mechanical assessment methods with automated electronic signal processing. Instead of relying on operators to manually evaluate shock absorber performance, the system uses sensors to capture vibration signals and automated algorithms to analyze spectral characteristics, transforming subjective qualitative information into objective quantitative defect classification.
3Measurement precision
If complex test stands are used, then measurement capability is improved, but testing time and cost increase
Solution Approach 1:
The patent extracts only the essential measurement functions needed for defect detection, eliminating unnecessary complexity from the test stand. By focusing on capturing and analyzing vibration signals rather than implementing comprehensive mechanical testing systems, the patent achieves accurate defect detection with simpler, faster, and more cost-effective equipment suitable for production line integration.
4Reliability
If manual operation is used, then flexibility is maintained, but measurement repeatability decreases
Solution Approach 1:
The patent implements self-service through automated testing and analysis systems that perform defect detection without requiring skilled operators. The system automatically generates test protocols, captures vibration signals, processes data through spectral analysis, and produces defect classification results, ensuring consistent and repeatable measurements while reducing dependency on operator expertise and minimizing human variability in test execution.
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 rapid and accurate classification of hydraulic damper conditions, reducing testing time and costs, and improving measurement repeatability, allowing for efficient defect detection on production lines without relying on operator expertise.
Implementation Method 1
recording a vibration acceleration signal generated by movement of the piston rod
Implementation Method 2
the signal is processed using an FFT algorithm; then statistical characteristics of the spectrum, such as the mean, variance and standard deviation, are determined
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The method for detecting manufacturing defects of hydraulic dampers, especially hydraulic shock absorbers, consists in recording a vibration acceleration signal by means of an accelerometer secured to the end of the piston rod of a forcing actuator, and in that sample hydraulic dampers used in the phase of determining boundary characteristics are standard dampers, wherein automatic clipping of the signal in the time domain by the range of t0-ts is applied, wherein the t0 point is determined by the instant the accelerometer comes into contact with the end of the hydraulic damper piston rod, and in order to determine the boundary characteristics an iteratively determined maximum correction factor of the standard deviation amax and adjusted standard deviation σcj are used. The device for detecting manufacturing defects of hydraulic dampers, especially shock absorbers, has a shock absorber seat in which the shock absorber's end is placed, and the seat is made of plastic of Shore A hardness 93-98. The front side of the plate (12) located in the front part of the machine (7) has its upper edge inclined from the vertical of the machine towards the inside of the machine so as to enable placing a shock absorber in the axis of forcing actuator (9d) operation.