PERSONAL OBJECT DETECTOR

摘要

PURPOSE: A personal object detector, in particular a sonar-based object detector is disclosed. CONSTITUTION: The personal object or obstacle detector apparatus comprises a continuous transmission frequency modulation (CTFM) ranging system (12) and an audio output device (14). The CTFM ranging system transmits a frequency swept pressure wave, receives a reflected frequency swept pressure wave from at least one object (34), and forms an audio signal based upon a frequency difference between the frequency swept pressure wave and the reflected frequency swept pressure wave. The audio output device (14) produces an acoustic pressure wave in dependence upon the audio signal. In a preferred embodiment, the acoustic pressure wave contains separate tones (30, 32) for each of the objects detected, wherein each tone has a pitch dependent upon the distance from the CTFM ranging system (12) to the corresponding object. Another embodiment utilizes a pair of CTFM ranging systems to produce a stereo auditory map of objects and obstacles.