Opening-door assistance by vision-based control for power-assisted wheelchair

This paper describes an application to opening-door assistance by using visual feedback for power-assisted wheelchair. Generally, the power-assisted wheelchair enables the human-friendly support while manually driving. The opening-door action for rider is one of difficult operations in generic wheelchair driving. However, additional operational assistance is difficult in conventional power assist control, because of considering only the relationship between the human pushing force and the wheelchair dynamics. In our approach, by using the vision-based assist controller, the relative velocity between wheelchair and door can be controlled so as to be easy handling of opening door. For relative velocity estimation, three-dimensional information is obtained from stereo images, and simultaneously optical flow vectors are also used at real-time. Additionally, we try for assisting human force to open the door by switching virtual impedance according to the environment information obtained from vision. The validity of the proposed approach is confirmed by several experimental results.