Design and Performance Analysis of a Novel Ankle Rehabilitation Robot Considering the Human Body Soft Tissue Deformation

This paper designs a novel ankle rehabilitation based on the remote center of motion (RCM) mechanism, which can be adapt to various training scenarios such as sitting and lying-down training. In order to explore the impact of human soft tissue viscoelasticity on the comprehensive performance of the rehabilitation, the relationship between the human-rehabilitation interaction torque and the posture deviation of the rehabilitation are quantitatively analyzed and expressed by kinematic branch chains. Then, a coupling mathematical model of the human-rehabilitation is further constructed according to the virtual equivalent parallel mechanism (VEPM) modeling method, and performance indicators (workspace, angle deviation, motion center deviation, condition number ratio and motion/force transmission) of the VEPM model are derived. The performance of the VEPM under different interaction forces are analyzed and verified by simulation and motion experiments. The results of this paper have positive significance for further exploring the human-robot physical interaction principle and improving the human-robot collaboration of wearable exoskeletons.