A robust self-localization system for a small mobile robot

This paper presents a low-cost self-localization system suitable for small mobile autonomous robots. This system is particularly adapted to situations in which the robots might suffer undesirable movements, during which the wheels slip over the ground, caused either by collisions with non-detected obstacles or collisions with other robots. These situations are normally fatal for encoder-based odometry. The system was integrated in the Bulldozer IV robot, developed to participate in a robotics contest, the Micro-Rato 2001, where situations as those referred to above are frequent. The system combines azimuth from an analog compass with odometry from an optical PC mouse and allows the robot, within an unknown maze, to return to the start point after having reached a given goal. This paper presents a brief discussion on the techniques commonly used to provide the notion of self-localization in mobile autonomous robots. Then, the developed self-localization system is described, as well as its integration in the navigational system of the Bulldozer IV robot. Finally, a set of experimental results is presented that allow characterizing the performance of the navigational/self-localization system, illustrating its robustness in terms of resilience to externally forced movement