Navigation sensor for collaborative mobile robots

Abstract

This thesis presents a possible inexpensive and simple solution for humanitarian demining in developing countries. It consists of a group of mobile robots that can advance and interact collaboratively with each other in a mine field. A base station controls the group and can map their position with the aid of a long range positioning system, thus, identify the landmine position when one is detected by a robot. A short range positioning system is used within the group to measure the distance separating them from one another and the geometry of the formation. A prototype battery powered mobile robot platform has been developed and tested. Electronic hardware and software was designed and built to allow for low level control of the movements of the vehicle and for wireless communications with a base station. The base station exercises high level control over the mobile robot. A positioning system consisting of a long and a short range positioning system has been designed. The short range positioning system, which uses sonic waves within the audible frequency range, has been implemented and tested. Operating within the audible frequency range reduces the sensory system cost and results in an omni-directional range measuring system. The system provides sub-wavelength precision with an absolute error less than 2 cm for distances from 1 m to 4 m at a 5 KHz frequency.