Mechanical design and control system of robotic wheelchair with inverse pendulum control

Abstract

A robotic wheelchair with inverse pendulum control has been proposed in this paper. By using the robotic wheelchair, a wheelchair-bound person can climb over a step up to about 7 cm without a helper’s assistance. The robotic wheelchair moves on ‘at ground using four wheels. It raises its front wheels in front of a step, and maintains inverse pendulum control. A user riding can go forward and backward using his/her body inclination maintaining the inverse pendulum control. The inverse pendulum control is stopped when the front wheels proceed over a step. After the front wheels have landed on the step, the robotic wheelchair can climb over the step, assisted by d.c. motor force. In order to raise the front wheels using small d.c. motors, the robotic wheelchair can move its rear-wheel drive shafts. In this paper, the dynamics of the front-wheel raising, the mechanical designs of the robotic wheelchair, the control system of the inverse pendulum control and some of the experimental results are presented. The validity of the proposed robotic wheelchair has been confirmed by experimental results.