Development of Position Measurement System in Wide-area Using Ultrasonic Receiver Net

Abstract

This paper proposes an ultrasonic position measurement system for mobile robot moving in wide-area. The system uses ultrasonic receiver net which consists of many ultrasonic receivers with wide beam (100°) allocated at a constant interval on a ceiling. The ultrasonic receiver net covers all area where mobile robot moves. And two ultrasonic transmitters with wide beam (100°) are placed at rear and front of mobile robot to transmit ultrasonic wave toward ceiling alternately. Some receivers of receiver net can receive the ultrasonic wave, so the distances between transmitters and receivers can be obtained. Three optimal distances are selected to estimate the positions of the transmitters, and the posture of the mobile robot is estimated by the positions of the two transmitters. Theoretical analysis and experimental results show that the estimated position measurement error is φ 62mm and estimated posture error is ±4°. The ultrasonic receiver net can be expanded easily, making possible to measure position of a mobile robot moving in wide-area, especially in bad visible environment. © 2001, The Japan Society for Precision Engineering. All rights reserved.