A pair of step-climbing units for a manual wheelchair user: Passing over several steps using a pair of portable slopes

Abstract

We have developed a pair of step-climbing units that can be installed on a standard manual wheelchair. Many wheelchair users hope to lead an independent life without assistance. The target users of these units are those who can independently lift the front casters of their wheelchairs. The units are installed on the back frames of a wheelchair. Each unit comprises two actuators and has 2 degrees of freedom: telescopic motion and rotational motion. They are lightweight and do not prevent the wheelchair from being folded. Therefore, it is still relatively easy to load a wheelchair fixed with these units into a car. In our earlier project, these units addressed the problem of climbing a single step. In this article, we primarily discuss a strategy that enables wheelchair users to climb stairs comprising multiple steps. We additionally use a pair of portable slopes to achieve this task. Results of experiments where users traveled on a pair of slopes that covered a height of 30 cm over two steps confirm the effectiveness of the design.