Motion control algorithm of walking assist machine using crutches to achieve variable gait style and step length

Abstract

A new scheme to determine actuator input trajectory for a walking assist machine using crutches to achieve various desired step length will be discussed. First of all, two different gaits, swing-to and dragging gait and typical patterns of actuator input trajectory regarding those two gaits were defined. Secondly, some dominant parameters, maximum stroke and amplitude of acceleration of linear actuator in the phase to get off the ground, were investigated to find reasonable parameter region called gait feasible region to achieve the above-proposed gaits safely. In addition, initial condition of the apparatus to start walking were also determined. By using a prototype walking device, effectiveness of the proposed scheme has been demonstrated by achieving several different desired step lengths in the swing-to and dragging gaits.