Development of a pair of step-climbing units for a manual wheelchair user

Abstract

Many people with lower limb disabilities use wheelchairs, but their degrees of physical impairment vary greatly. We direct our investigation to manual wheelchair users who are able to lift the front wheelchair casters independently. They hope to establish an independent life without assistance to the greatest extent possible. We developed a pair of step-climbing units that can be installed in a standard manual wheelchair. This mechanism is simpler than any other because it uses the remaining capabilities of the wheelchair user. Each unit comprises two actuators and has two degrees of freedom: a telescopic motion and a rotational motion. We mainly discuss the step-climbing motion using this system. Experimental results obtained when ascending and descending a step of 15 cm height confirm the design's effectiveness.