Building local floor map by use of ultrasonic and omni-directional vision sensor

In this paper, we propose a new fusion approach which uses the ultrasonic sensor aided by an omnidirectional vision sensor to give a grid based free space around the robot. By use of the ultrasonic sensor, the robot can obtain a conservative range information based on our nearby range filtering method. This filtering can give a more reliable result considering the sensor´s problem of specular reflection. Also, by use of the special omni-directional vision sensor we developed, the color and edge information can be obtained in a single picture and mapped to the ground plane by the inverse perspective transformation. Thus the range, color and edge information can all be expressed on a metric grid-based representation which forms the basis of our radial fusion processing. Results in an indoor cluttered environment are given which show the usefulness of our proposed sensor fusion approach