``Indoor Environment Recognition for a Mobile Robot Using Ultrasonic Sensors
- Measuring the Direction and Distance of Multiple Objects -'',
by Teruko YATA, Akihisa OHYA, Shin'ichi YUTA.

The World Automation Congress 1996


Abstract

A wall is one of the most important objects in an indoor environment for mobile robot localization and environment sensing. In a conventional ultrasonic sensor for a mobile robot, the range to a wall is obtained by the pulse-echo method, but the orientation angle of the walls can not be measured. We developed an ultrasonic sensor system containing one transmitter and multiple receivers to measure the inclination angle of the walls and named it the RADIAN sensor. In this paper we firstly present a way to measure the angles of walls with the RADIAN sensor system. Second, we describe an extension of the RADIAN sensor system to measure multiple walls and objects. And finally, we present an experiment which uses an extended RADIAN sensor. The experiment was successful, and demonstrated the feasibility of this extended method.