Analysis of the Static Stability for an Electric Stair-Climbing Wheelchair

In this paper, an electric stair-climbing wheelchair is presented. The proposed solution is based on a smart hybrid leg-wheel locomotion system. This idea has been developed through several wheelchair concepts presented in the first part of the paper, pointing out the main advantages and disadvantages for each solution. In the second part, an optimization procedure regarding the geometry of the latest wheelchair architecture is presented. The aim is to maximize the wheelchair performances in terms of safety and comfort for the user. In particular, the geometric parameters of the wheelchair structure have been analysed in order to assess which configuration guarantees an acceptable static stability of the wheelchair during stair climbing motion. Moreover, considering the goal of maximizing the comfort for the user, the oscillation introduced on the wheelchair seat by the locomotion system has been studied and solutions able to reduce them are proposed.