Human-machine force interaction design and control for the HIT load-carrying exoskeleton

The HIT load-carrying exoskeleton is designed for enhancing the operator's load-carrying capability. Human walking has the characteristics of diversity and randomness. It requires that the sensing system of exoskeleton could detect and identify the random motion of human body. In this article, a human-machine force interaction designing architecture is proposed for HIT load-carrying exoskeleton. The human-machine interactive forces at the kinematic terminals (the back and feet) are detected for the human movement identification. Four basic body modalities during the movement process are proposed, which could be automatically identified by the sensing system. The kinematic models for the swing leg and supporting leg are established, respectively. A positional deviation feedback control method based on the interaction force detection is designed. The experiments show that the human-machine interaction force detection at the back and feet and the identification of different body modalities and movement intention are feasible. The interactive forces on the back are far less than the payload, indicating that the exoskeleton has good power-assisted effect.