Kinematic and Rehabilitation Performance Analysis of a Reconfigurable Parallel Mechanism for Staged Ankle Rehabilitation

Abstract

A reconfigurable parallel mechanism for staged ankle rehabilitation is proposed. The mechanism consists of three UPS driving limbs and a central reconfigurable constraint chain, which can switch among 1R, 2R, and 3R modes to match early, middle, and late rehabilitation training requirements. Normal-gait ankle motion is analyzed in AnyBody, and the configuration, mobility, inverse kinematics, velocity Jacobian, workspace, and dexterity of the mechanism are investigated. ADAMS virtual prototype simulation verifies that the DOFs and limb motion laws of the three configurations are consistent with the theoretical analysis. human–machine coupling simulation in AnyBody further shows that the maximum muscle activity values of six typical training motions are all below 1.0, and different training directions induce direction-selective responses of the target muscle groups. The results indicate that the proposed mechanism has certain training safety and adaptability for staged ankle rehabilitation.