Active localization of a silent intruder with audible frequency in 2D security space

摘要

This paper mainly addresses an active localization technique to detect thelocationof a silent intruder with audible frequency.A number of sensors are used in building security system. Acoustic sensors such as microphones and ultrasound sensors detect noise of an intruder or distinguish variation of acoustic field, so microphones can beemployed to sense the intrusion or transmit location of the event to a security camera.However,becausean intrudertries to enter the security zonequietly,localization techniques of a silent intruder are also necessary to get spatial information in a closed space.We set a strategy to estimate the angle and distance of a silent intruderusing audible frequency and acoustic imagingin targeted security space. First, a microphone array and a loudspeaker are fixed at the same position. Second, burst sine is generated in non-intrusion and the measured signals from a microphone array are considered as reference signals, then also measured signals in intrusion are thought of as intrusion signals. Third, the deconvolution technique is used to extract reflected signals resulted in intrusion using reference signals and intrusion signals. Fourth, beamforming and beam steering with the reflected signals are applied to make acoustic imaging. We considered a silent intruder as an object, a PVC pipe, and testedthe proposed technique to find locations of a PVC pipe in an anechoic chamber.