Siemens has developed a prototype of an autonomous navigation system for mobile service robots. Its suitability for tough everyday operation has been successfully demonstrated since August 1996 with cleaning machines in chain store supermarkets of Albert Heijn BV in the Netherlands. Here, HEFTER CLEANTECH (HCT) cleaning robots are being used in cooperation with the cleaning specialist RTB.

This paper presents a novel local obstacle avoidance module. The main idea of the steer angle field approach is to discard all steer angles that, given the nonholonomic kinematics of the robot, would lead to collisions within a certain hit distance. The approach has been implemented and tested over a period of one year on our mobile robot. Results have shown that the robot is able to operate robustly in unknown, unprepared and cramped in-door environments for hours.>

Autonomous low-cost mobility of robots has been a challenging problem for quite a long time. In this paper the typical problems of sonar based autonomous navigation and the authors' solutions to overcome them are discussed. The authors have created, robust modules for sonar data fusion and safe steering which significantly improve known methods. There are furthermore robot control behaviors which offer specific competence to solve high-level tasks. These behaviors build a hierarchical architecture but have the ability to assess their respective task and autonomously suggest a different, more competent behavior to continue. Thus, the behaviors work together as distributed competencies. The concept described here is being evaluated in a system on the authors' experimental robot ROAMER. The available modules already operate robustly in cluttered office environments.>