An Optimized Capture Point Concept Considering the Ankle Stiffness

For the load-carrying exoskeletons, balance is a problem that must be solved, which is an important prerequisite for ensuring the safety of wearers. Under external intervention, to enhance the lower extremity exoskeleton's ability to restore balance, the capture point (CP) concept is usually used to perform the push recovery of the lower extremity exoskeleton. However, the traditional CP concept does not consider the impact of ankle stiffness of the lower extremity exoskeleton. This paper proposes the linear inverted torsion spring pendulum model (LITPM) and enhances the CP concept. Push recovery control for the lower extremity exoskeleton is realized based on the LITPM. The experiment results show that the improved CP concept has a smaller step length, under large external interference, which enhances the stability of the lower extremity exoskeleton.