Possibility of an embedded system for ultrasound-based measurement of the distances to two target objects

We developed an embedded system by which to simultaneously measure the distances to two target objects, such as an obstacle and a wall. The embedded system incorporates a set of ultrasound sensors, analog circuits, and a microcomputer to automatically measure the distances to the two targets, and displays the information on a liquid crystal display. For a single target, a large iron-plate wall, at a distance of from 0.5 to 2.75m, the percentage error in the detected distance was less than 5%. For two targets, such as an acrylic resin cylinder (object 1) in front of a wall (object 2), the percentage error in the detected distances was less than 5% in most cases. In some cases, however, there were significant measurement errors. Nevertheless, since the proposed measurement system revealed the exact distance in the majority of cases, this system could be applied to industrial and autonomous moving robots.