Using ultrasonics to control robot arm positioning

A microprocessor-based ultrasonic system, developed to implement a robot-arm positioning control, is described. Time-of-flight-based gaging techniques are used to obtain the desired arm positioning, both in distance and alignment, with respect to the target surface. The experimental system consists of three aligned ultrasonic transducers mounted on a rod. Two transducers work as receivers, while the third work both as a transmitter and as a receiver. An electronic circuit was developed so that the echo detection is independent of the amplitude of the echo itself