Acoustic Tool Wear Detection Using Multi-Band Frequency Analysis
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Solution Overview
Problem
Existing tool abnormality detection systems are prone to erroneous determinations due to the inclusion of noise sound waves caused by ambient noise, which can interfere with the detection of tool wear.
Innovation Solution
A tool abnormality detection system that generates determination signals for both a fundamental frequency band and higher frequency bands of wear-indicative sound waves, using a controller to compare these signals with respective wear thresholds to suppress erroneous determinations, and optionally includes a resonant unit to enhance the detection of wear-indicative sound waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single frequency band is used for tool abnormality detection, then the detection process is simple, but erroneous determination occurs due to noise sound waves
Solution Approach 1:
The patent divides the sound wave spectrum into multiple frequency bands (first frequency band containing fundamental frequency, second frequency band containing higher frequency components) and analyzes each band separately. This segmentation allows the system to distinguish between wear-indicative sound waves and noise sound waves by comparing characteristics across different frequency ranges, thereby improving detection accuracy without excessive complexity.
Solution Approach 2:
The patent applies different analysis methods and thresholds to different frequency bands. The first frequency band analysis focuses on fundamental wear characteristics while the second frequency band analysis targets higher frequency wear indicators. This localized quality approach allows each frequency band to be optimized for its specific detection purpose, improving overall measurement precision.
2Ease of operation
If noise sound waves are included in the detection frequency band, then the detection system is simple to operate, but erroneous tool wear determination occurs
Solution Approach 1:
By segmenting the frequency spectrum into multiple bands and analyzing each separately, the system automatically filters out noise sound waves that typically occupy different frequency ranges than wear-indicative waves. This maintains ease of operation as the process remains automated while significantly improving reliability through multi-band comparison.
Solution Approach 2:
The patent introduces an intermediary analysis process that compares sound wave characteristics across multiple frequency bands before determining tool wear. This intermediary step acts as a filter between the raw sound wave detection and the final wear determination, preventing erroneous conclusions while keeping the overall system easy to operate.
3Device complexity
If only the fundamental frequency band is analyzed, then the analysis is straightforward, but wear indication may be missed due to noise interference
Solution Approach 1:
The patent segments the frequency analysis into multiple bands, adding the second frequency band analysis to the straightforward fundamental frequency analysis. This segmentation improves wear detection precision by providing additional wear indicators in the higher frequency range while maintaining relatively simple analysis procedures for each individual band.
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 system effectively reduces erroneous determinations of tool wear by utilizing multiple frequency bands and, in some embodiments, a resonant unit to increase the intensity of wear-indicative sound waves, thereby improving the accuracy of tool condition assessment.
Implementation Method 1
The resonant unit is configured to generate a resonant sound wave by resonating with a wear-indicative sound wave which is generated when the tool is worn
Data Source
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AI summary
A tool abnormality detection system includes a detector (10) configured to detect a sound wave generated in processing a workpiece (200) with a tool (140, 410) and output a detection signal based on the sound wave, and a controller (30) configured to generate, based on the detection signal, determination signals indicating intensities in respective frequency bands: a fundamental frequency band of a wear-indicative sound wave; and a higher frequency band that is higher than the fundamental frequency band, and determine whether the tool is worn by comparing each of the determination signals to its respective wear threshold which is set for the respective frequency bands.