JPS6450980A - Apparatus for detecting position of whistle sound generating source - Google Patents

Abstract

PURPOSE:To automatically measure the position of a whistle sound generating source with good accuracy, by arranging non-directional microphones at the apex positions of a right- angled equilateral triangle having short sides each having a length equal to or less than the half-wavelength of the whistle sound from the whistle sound generating source. CONSTITUTION:A plurality of sound collecting means 1 each constituted by arranging non- directional microphones M to the apex positions of a right-angled equilateral triangle having short sides each having a length equal to or less than the half-wavelength of the whistle sound from a whistle sound generating source are provided. The whistle sound received by each microphone M is inputted to a processing means 7 consisting of an amplifier 4, a BPF 5 or the like to remove noise. A microcomputer (MC) 8 leads out the time shift of the waveforms of the whistle sound due to the microphones M, that is, the phase difference from the output signal of the processing means 7 to lead out the direction of the whistle sound generating source from each sound collecting means 1. At this time, from the arrangement of the microphones M, the lead-out phase difference becomes a half-wavelength (180 deg.) at the max. and the lead-out accuracy of the time shift of the waveforms of the whistle sound is enhanced. Therefore, by the enhancement of the direction accuracy of the whistle sound generating source, the accuracy of the position of the whistle sound generating source calculated by triangulation is enhanced.