Backwards maneuvering powered wheelchairs with haptic guidance

Abstract

This paper describes a novel haptic guidance scheme that helps powered wheelchair users steer their wheelchair through narrow and complex environments. The proposed scheme encodes the local environment of the wheelchair as a set of collision-free circular paths. An adaptive impedance controller is constructed upon these circular paths. The controller increases resistance when nearing obstacles and simultaneously helps the user to change motion towards a safer circular path. To test the algorithm, a commercial powered wheelchair was interfaced and equipped with necessary sensors and an in-house built haptic joystick. The user was asked to drive backwards into a narrow elevator with and without navigation assistance. Although there is still room for improvements, the first results are promising. Thanks to the assistance the user can perform this maneuver successfully in most of the cases without even looking backwards. © 2012 Springer-Verlag.