Using sonar ears for robotic navigation

Abstract

This thesis presents work on previously developed hardware module for in-air ultrasound measurements and analysis. Redesigned hardware and firmware enable real-time ultrasound echo measurements which are then transmitted to a computer for signal analysis and distance computation. The ultrasound modules and the computer are connected with a bus structure using a special communication protocol. Two alternative con gurations are considered. In the first, a single transmitter and a single receiver placed on a pan-and-tilt head enable time-of- flight measurements. The maximum of the received signal amplitudes at two different frequencies are measured and are analyzed. In the second setup, where a single transmitter transducer is flanked by two ultrasound receiver modules on each side, again placed on a pan-and-tilt head, constitute the two ears of the robot. The system dynamics is setup as to move the system's line of sight so that it falls on a detected target.