Estimating the Center of Mass of Human-Exoskeleton Systems with Physically Coupled Serial Chain

Estimating the center of mass (CoM) is essential for both gait planning and controlling of lower limb exoskeletons. Different from CoM estimation in human and humanoid robots, a critical issue in human-exoskeleton systems pis how to describe the effect of physical human-exoskeleton interactions in estimating the CoM of lower limb exoskeletons. This paper presents a novel center of mass estimation method Physically Coupled Serial Chain (PCSC) for human-coupled lower limb exoskeleton systems. Different from traditional serial chain methods, the proposed PCSC involves physical human-exoskeleton models to describe physical interactions between the pilot and the lower limb exoskeleton. We demonstrated the effectiveness of proposed PCSC model in the AIDER lower limb exoskeleton system. Experimental results indicate that the proposed PCSC model is more accuracy than traditional serial chain methods.