METHOD AND APPARATUS FOR MEASURING OF MINIMUM DISTANCE USING A ULTRASONIC

摘要

A distance measuring method and a device using an ultrasonic wave are provided to smoothly detect an ultrasonic receiving signal turned back within a short time after transmitting the signal, by effectively removing an undesirable excitation signal generated after transmitting the ultrasonic signal, thereby improving short distance measuring performance. A distance measuring method using an ultrasonic sensor measures the distance by measuring the time interval between a period of transmitting an ultrasonic signal to the object and a period of receiving the ultrasonic signal of predetermined frequency turned back by colliding with an object. A pulse-type driving signal for transmitting an ultrasonic wave for measurement of the distance is applied to the ultrasonic sensor and then an excitation removing signal with an inverse phase different from that of the driving signal about 180 degrees is continuously applied to remove excitation.