Open platform and open software for an Intelligent Wheelchair with autonomous navigation using sensor fusion

This paper is focused in the inclusion of open software tools and standard hardware devices into advanced mobility aids. Its urgency is due to the incorporation need of the numerous advances in mobile robotics to the area of the Assistive Technologies, and more specifically in the field of the so called Intelligent Wheelchairs (IW). In this paper we propose a common core for IWs based both on an open robotic platform and an open and a well extended software for robotics (ROS “Robotic Operating System”). Such an IW core has got a distributed architecture whose processing nodes are linked through a CAN standard bus, which connects the low level control functions based on low cost and highly portable Cortex platforms. This paper describes also the autonomous navigation algorithm developed for the Intelligent Wheelchair by using an Extended Kalman Filter. In the chosen approach the absolute position of the IW (a mobile robot) is estimated using sensor fusion which combines data from two of the sensory systems included in the described open platform: the dead-reckoning system and a visual system based on QR landmarks located on the ceiling. Within this context, the paper demonstrates the potential of the platform proposal in relation to the quick and easy incorporation of recent advances in mobile robotics.