Local measurement validation for an intelligent telemeter

An important intelligent functionality for the improvement of measurement systems is the validity of the returned information. To obtain this validity at the sensor level itself, if is essential that the sensor produces additional information at this aim. This aspect follows directly from the measurement principle. In this article, we apply these ideas to an ultrasonic range finding sensor dedicated to the navigation of a mobile robot. The original measurement method proposed, based on a modulated emission, provides many configuration parameters acting on the performances in precision and in detection, and two measurement parameters linked to the distance to the obstacle. The redundancy between these two parameters allows to build a local index of validity of the measured distance. The analog-numeric implementation of this measurement method around a microprocessor board 80C196 provides an easy adjustment and observation of all the considered parameters. In particular the theoretical and experimental study of the influence of these configuration parameters on the validity leads to the determination of their values according to the considered detection range.