Research of the information signal of the security acoustic detector

Abstract

In the present paper, modeling of security acoustic detector is carried out at the level of a functional circuit using MATLAB. The security acoustic remote detector is designed to protect the premises from the penetration of unauthorized persons through the window by breaking glass. An acoustic detector must remotely perceive sounds in a guarded room, analyze them and automatically make a decision about the presence or absence of glass breaking. There are cases of a missed target (if the sound is too quiet) or a false alarm (when triggered, for example, by the sound of broken dishes). The purpose of the development of the model is to obtain the possibility of a theoretical study of the influence of signal processing parameters in the detector on the effectiveness of its detection of the intruder in acoustic noise.

The development of a computer model of a security acoustic detector is carried out using a recognition algorithm based on two-channel processing. In one channel, low-frequency sound vibrations in the range from 1 to 200 Hz are analyzed. In another channel, the high-frequency components of the sound of breaking glass are analyzed. The simulation results coincide with the technical characteristics of the prototype detector, which confirms the adequacy of the constructed model. The developed model makes it possible to evaluate the reliability of separation by the security detector of signals from the intruder and signals from interference, to determine the parameters of the signals that create cases of false alarms. The developed model allows evaluating the quality of signal processing using the algorithm of this detector. It is a tool for choosing the optimal detector design parameters.