Acoustic tool break detection system and method
US4642617A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1984 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | Dec 21, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01H1/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Substantial cutting condition changes that occur gradually, as opposed to the more usual sudden large change, are detected by setting upper and lower cutting noise mean level thresholds. When the mean cutting noise exceeds the upper threshold or stays below the lower threshold for a preset number of signal samples, a tool break alarm is generated. Techniques are given to reduce false alarms at the start and end of the cut and on runout on initial rough surface cuts. The system comprises an accelerometer or other sensor whose signal is preprocessed to attenuate lower frequency machinery noise and detect the signal energy in a band below 100 KHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.