A Robotic Wheelchair Roaming in a Railway Station

In this paper we describe the hardware design and the control, and navigation system of our robotic wheelchair MAid (Mobility Aid for Elderly and Disabled People). Following the advice of disabled people and physicians we did not set out to re-invent and redevelop the set of standard skills of so-called intelligent wheelchairs , such as FollowWall, FollowCorridor, PassDoorway, which are commonly described in the literature. In spite of their disability handicapped people are often well capable of navigating their wheelchair along a corridor and actually eager to do it. Instead, we focused on maneuvers which are very burdensome because they take a long time and require extreme attention. One of these functions is deliberative locomotion in rapidly changing, large-scale environments, such as shopping malls or concourses of airports or railway stations, where tens or hundreds of people and objects are moving around. MAid's performance was tested in the central station of Ulm during rush-hour, and in the exhibition halls of the Hannover Messe '98, the biggest industrial fair worldwide. Meanwhile , MAid has survived more than 36 hours of testing in those environments. To our knowledge this is the rst system among robotic wheelchairs and mobile robots to have achieved a similar performance.