| 摘要 |
PURPOSE:To attain the position detection with low cost and high accuracy by providing an ultrasonic transmission means to a traveling object and a receiving means at the outer side to detect the position of the traveling object from the transmission time of an ultrasonic wave. CONSTITUTION:An ultrasonic microphone 2 for transmission and an antenna 3 for FM radio communication are set on a traveling object 1. While utlrasonic microphones 5a and 5b for reception of an ultrasonic wave (b) transmitted from the microphone 2 are provided to a station 4 which monitors the movement of the object 1 together with an antenna 6 for FM radio communication. The wave (b) transmitted from the object 1 is received (d) and (f) by microphones 5a and 5b of the station 4. Thus the position of the object 1 is detected from time t1 and t2 of receptions 5a and 5b as well as the difference between t1 and t2. |
