A Control Strategy for Maintaining Gait Stability and Reducing Body-Exoskeleton Interference Force in Load-Carrying Exoskeleton

A key issue of load-carrying exoskeleton is to maintain the stability of gait during walking and prevent the wearer from falling over. Some of current strategies were to maintain ZMP (zero-moment point) in the support area, which had been widely used in humanoid robot. However, this method would cause serious interference between body and exoskeleton. because the body often gets energy-saving and rapid walking through unstable conditions during human walking. A control strategy for load-carrying exoskeleton was presented in this paper, which maintained the consistency of body ZMP and exoskeleton ZMP. This control strategy could reduce body-exoskeleton interference while maintaining the stability of walking. In this paper, we firstly introduced the experimental environment and the ZMP detection method, and then designed a computational model of the body-exoskeleton interaction force and evaluation criterion for gait stability. Then, a control strategy based on ZMP was designed. Finally, experiments showed that the control strategy could effectively reduce the body-exoskeleton interference, and maintained the stability of wearer’s walking.