A histogram sensor fusion method for mobile robots

We describe a new method for a mobile robot equipped with ultrasonic sensors to construct and maintain a map of the environment for the purpose of obstacle avoidance and navigation. A new sonar model is given, which is a simplified Gaussian model for the sake of computing time. Furthermore, incidence angle information of sonar is combined with the range measurement to construct a two-dimensional histogram grid. The histogram grid shows a quick and accurate mapping. At the same time, with the incidence angle information, the method exhibits a good performance in solving the problem of door-finding and reducing phantom targets. Finally, the map-building system is experimentally evaluated in the real environment.