Glass break detection using temporal sequence of selected frequency characteristics
US5450061A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 8, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Apr 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/1672
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Apparatus and a method for detecting glass breaking from an impact. Low frequencies are detected that are characteristics of the glass flexing from the impact, and high frequencies are detected that are characteristic of a) the sound of the impact and b) the glass breaking. An alarm signal is issued when the low and high frequencies occur in a predetermined sequence, and have appropriate durations, that are characteristic of glass breaking events. More specifically, the alarm signal is issued only when the detected low frequencies last for a minimum duration on a sliding scale related to their magnitude. Weaker signals must last longer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.