Power assist effects of a new type assist unit in a one hand drive wheelchair with a triple ring

We have proposed a one hand drive wheelchair with the original manipulation mechanism and the power assist mechanism. Recently, we have developed a new type assist unit, which had a new ON/OFF mechanism constructed by link and sliding mechanism, in order to realize the sure assist torque transformation. During assist, this new assist unit surely keeps the distance of two rollers, which transfer assist torque to tires. In this paper, first, the assist system, including the proposed assist unit, is explained. Furthermore, by using the prototype of the one hand drive wheelchair, implemented new assist units, the effectiveness of power assist function is confirmed, based on running experiments on the flat ground. In this experiment, we have found the following facts: For the user with enough manipulation ability, the power assist effect is week. On the other hand, for the user with inadequate power, the evident power assist effect is observed.