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1. GB2451241 - Infrasonic intruder alarm using digital signature matching

Office
United Kingdom
Application Number 0714332
Application Date 24.07.2007
Publication Number 2451241
Publication Date 29.08.2007
Publication Kind A
IPC
G08B 13/16
GPHYSICS
08SIGNALLING
BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
13Burglar, theft or intruder alarms
16Actuation by interference with mechanical vibrations in air or other fluid
G08B 25/00
GPHYSICS
08SIGNALLING
BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
25Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
CPC
G08B 13/1681
GPHYSICS
08SIGNALLING
BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
13Burglar, theft or intruder alarms
16Actuation by interference with mechanical vibrations in air or other fluid
1654using passive vibration detection systems
1681using infrasonic detecting means, e.g. a microphone operating below the audible frequency range
G08B 29/24
GPHYSICS
08SIGNALLING
BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
29Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
18Prevention or correction of operating errors
20Calibration, including self-calibrating arrangements
24Self-calibration, e.g. compensating for environmental drift or ageing of components
G08B 25/00
GPHYSICS
08SIGNALLING
BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
25Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
Applicants INFRASONIC PULSE SENSING LTD
Inventors RUDDOCK DEREK JAMES
Priority Data 0714332 24.07.2007 GB
Title
(EN) Infrasonic intruder alarm using digital signature matching
Abstract
(EN) An infrasonic intruder alarm system 100 comprises a transducer 13 for sensing infrasonic frequency variations, a signal amplifier, an analogue to digital converter which converts a portion of the analogue signal which crosses at least one predetermined threshold into a digital signature, and a processor 15 which compares the digital signature against known digital signatures. An alarm event is triggered if the digital signal produced matches a known signature. Preferably the alarm system detects crossings of multiple positive and negative thresholds. The sequence of threshold crossings and the direction of each crossing is used to determine whether and alarm event will occur. The analogue signal from the transducer (e.g. microphone) may be filtered to remove unwanted frequencies. The alarm system may include a device which monitors a person's health (e.g. heart rate). The processor may include an adaptive self learning protocol. The alarm may be audible, or the system may be coupled to a telephone or ASDL line. False alarms, due to wind for example, are reduced.
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