Generating Sonar Maps in Highly Specular Environments

We address the problem of building environment maps from ultrasonic range data obtained from multiple viewpoints. We present a novel environment modelling technique called the `response grid' that allows us to build occupancy maps in highly specular environments. We present two di erent approaches that utilise this technique: a Bayesian probabilisitic approach and a Dempster-Shafer evidential reasoning approach. Both approaches can be implemented in realtime with modest computational resources, and as such are suitable for use in mobile robot navigation tasks. We present and compare the experimental results obtained by these methods in a highly specular indoor environment.