ULTRASONIC DISTANCE MEASURING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an ultrasonic distance measuring device which can perform the measurement at high accuracy. SOLUTION: The ultrasonic distance measuring device is provided with: a transmission ultrasonic oscillator 1; a receiving ultrasonic oscillator 2; a driving part 32 for driving the transmission ultrasonic oscillator with a driving signal, by generating the driving signal in which a carrier signal is frequency modulated by a modulation signal so that an ultrasonic wave is transmitted from the transmission ultrasonic oscillator to an object; an oscillation generation part 31 for oscillating the transmission ultrasonic oscillator so that a Doppler shift is generated in the ultrasonic wave transmitted from the transmission ultrasonic oscillator; a receiving part 34 for amplifying the receiving signal by the reflection wave from the object detected by the receiving ultrasonic oscillator and for demodulating the receiving signal; a mutual correlation part 33 for obtaining a mutual correlation function between a signal in which the modulation signal is modulated by a Doppler shift frequency by the Doppler shift and the demodulated signal; and a distance calculation part 20 for determining the propagation time of the ultrasonic wave on the basis of the time in which the mutual correlation function is at the maximum and for obtaining the distance to the object, from the propagation time. COPYRIGHT: (C)2006,JPO&NCIPI