Rapid obstacle sensing using mobile robot sonar

This paper introduces rapid obstacle sensing using mobile robot sonar (ROSUM) a new method of applying simultaneous ultrasonic firing in environmental scanning. ROSUM focuses on treating undesirable crosstalk data with a heuristic pattern classification technique. In addition, least square curve fitting is applied to estimate bearing angles to the echoes' reflecting points which partially eliminates the problem of sonar's poor directionality. ROSUM enables full panorama scanning to be performed more rapidly then error eliminating rapid ultrasonic firing (EERUF), currently the most;rapid method available. This makes ROSUM suitable for fast mobile robots navigating in dynamic environments since the system can detect obstacles which suddenly appear in the robot's path, and which may not be detected by the low-frequency scans in time for the robot to safely avoid them. Criteria for sonar ring design enabling multi-wave;superposition to attain a quasi-homogenous sonar beam intensity pattern are also outlined. ROSUM has been implemented and tested in a specular office-like environment using a mobile robot. As a result, obstacle detection was performed not only faster, but also more accurately in comparison to conventional methods. (C) 1999 Elsevier Science Ltd. All rights reserved.