Acoustic-Based Position Estimation of an Object and a Person Using Active Localization and Sound Field Analysis

This paper proposes a new method to estimate the position of an object and a silent person with a home security system using a loudspeaker and an array of microphones. The conventional acoustic-based security systems have been developed to detect intruders and estimate the direction of intruders who generate noise. However, there is a need for a method to estimate the distance and angular position of a silent intruder for interoperation with the conventional security sensors, thus overcoming the disadvantage of acoustic-based home security systems, which operate only when sound is generated. Therefore, an active localization method is proposed to estimate the direction and distance of a silent person by actively detecting the sound field variation measured by the microphone array after playing the sound source in the control zone. To implement the idea of the proposed method, two main aspects were studied. Firstly, a signal processing method that estimates the position of a person by the reflected sound, and secondly, the environment in which the proposed method can be operated through a finite-difference time-domain (FDTD) simulation and the acoustic parameters of early decay time (EDT) and reverberation time (RT20). Consequently, we verified that with the proposed method it is possible to estimate the position of a polyvinyl chloride (PVC) pipe and a person by using their reflection in a classroom.