A visual navigation system using a multi-information local map

A visual navigation system for a robot working in a nuclear power plant is presented. Such a system should have two functions. One is to provide a rough environment map or directions towards a goal, such as turning left at the second corner. The other is to avoid obstacles and to find a passage for continuous movement of the robot. The operation of the system is divided into two stages. In the first stage, a multi-information local map (MIL map) describing information necessary for self-location measurement is created interactively from stereo images collected during remote-controlled navigation. The second stage is autonomous navigation. The robot moves autonomously by using the map with the aid of the second function of the system. The system consists of five subsystems: an environment teaching subsystem, to create the MIL map; a self-location measurement subsystem, to find the robot´s own location; an obstacle detection subsystem; a path planning subsystem; and a path following subsystem. Experimental results from a mobile robot show the usefulness of the system