Ultrasonic echoes from different orientations finding the normal inclination

Abstract One usual problem for robots interacting with their environment is to identify the normal orientation of the surface of a workpiece; this information cannot be provided by a nonstereo vision system. We have developed a sensory system based on a single 220 kHz ultrasonic transducer (emitter/receiver), working in the pulse-echo mode that is able to find the normal orientation with a precision of 0.3° and to measure distance (depth) with a precision of 0.1 mm in a range from 50 up to 800 mm.