3-DOF haptic feedback of assisted driving of an omnidirectional wheelchair

Increased demand for powered wheelchairs and their inherent mobility limitations have prompted the development of omnidirectional wheelchairs. These wheelchairs provide improved mobility in confined spaces, but can be more difficult to control and impact the ability of their users to embody the wheelchair. We hypothesize that control and embodiment of omnidirectional wheelchairs can be significantly improved by providing intuitive control with 3-DOF haptic feedback that directly corresponds to the degrees of freedom of an omnidirectional wheelchair. This paper introduces a novel 3-DOF Haptic Joystick designed for the purpose of controlling omnidirectional wheelchairs. When coupled with range finders, it is able to provide the user with feedback that improves the operator´s awareness of the area surrounding the vehicle and assists the driver in obstacle avoidance. The haptic controller design and a stability analysis of the coupled wheelchair joystick systems are presented. Experimental results of the coupled systems validate the ability of the controller to influence the trajectory of the wheelchair and assist in obstacle avoidance.