Design and optimization of a novel sagittal-plane knee exoskeleton with remote-center-of-motion mechanism

Powered exoskeleton is a wearable robot that can provide power-assisted motion for the human body. One of the challenges in the exoskeleton research is how to improve its kinematic synergy. In this paper, a novel knee exoskeleton robot is designed to improve the kinematic synergy between the exoskeleton and the human body. The novel exoskeleton adopts the sagittal-plane layout to reduce the bias moment, and uses a remote-center-of-rotation mechanism to ensure the coincidence of the rotation centers of the exoskeleton and the human body. To analyze the influence of the interaction error on the performance of the exoskeleton, this paper proposes a human-exoskeleton fusion model based on the virtual equivalent parallel mechanism method, and parameterize the interaction error through virtual kinematic chains. Finally, the assisting performance of the novel exoskeleton is analyzed and verified through simulation experiments, motion experiments, body motion experiments and human simulation experiments. The human-exoskeleton fusion model proposed in this paper has positive significance for the configuration design, biomechanical analysis and application of exoskeleton robots.