Patent Document ID: 7541923
Application ID: 11034146
Patent Flag: 1

Claim One:
1. An intrusion detection method by using ultrasonic signals, said intrusion detection method including a training phase and a detection phase, said training phase being performed when an intrusion does not occur, said training phase comprising the steps of: (a) sequentially capturing plural ultrasonic echoes from an ultrasonic sensor to form one or more ultrasonic signals; (b) performing signal processing and feature extraction for said ultrasonic signals; and (c) conducting a feature training to establish at least one background module which is used for comparison in said detection phase; said detection phase comprising the steps (a), (b), and the following steps of: (d) forming testing features by sampling a plurality of the extracted features in step (b); (e) comparing said testing features with said background module established in said training phase; and (f) determining if an intruder is detected according to the results of comparison from step (e); wherein said feature extraction for said ultrasonic signals in step (b) is done by the following steps: (b1) applying a size of window to a length of said ultrasonic signals; (b2) moving said window forwards a distance each time so that a new window and a previous window have an overlap; and (b3) extracting coefficients of a transformation on said ultrasonic signals in the overlapped windows as features.