ULTRASONIC POSITION DETECTOR

摘要

PROBLEM TO BE SOLVED: To provide a compact ultrasonic position detector capable of ensuring position detection accuracy equal to distance detection accuracy without narrowing a position detecting range. SOLUTION: A transmitting ultrasonic element attached to a detection object transmits ultrasonic signal. Two receiving ultrasonic elements arranged adjacently in a reference position receive ultrasonic wave. A receiving detector detects that either of the receiving ultrasonic elements received the ultrasonic wave. A time difference detection means detects the time difference from the transmission of the ultrasonic wave to the receipt thereof. A distance arithmetic means computes the distance between the transmitting ultrasonic element and the receiving ultrasonic element from the time difference detected by the time difference detection means. A phase difference detector detects a phase difference between ultrasonic waves received by two or more receiving ultrasonic elements. A position arithmetic means computes the position of the transmitting ultrasonic element based on the reference position from the distance detected by the distance arithmetic means and the phase difference detected by the phase difference detector. COPYRIGHT: (C)2006,JPO&NCIPI