Active Joint Configuration Analysis of Multi-DOF Hip Exoskeleton for Dynamic Gaits and Balancing

Abstract

This paper presents kinematics-based methodologies for performance comparison and optimization of humanmotion compatible multi-DOF hip assistant robot. In our simulation, we compared the workspace and the manipulability between two different joint configurations capable of driving flexion-extension and abduction-adduction of hip motion. In contrast to the conventional multi-DOF active hip joint configuration, where the abduction-adduction motion is driven rear to the hip, followed by the driver in flexion-extension motion to side of the thigh (AA(fixed)-FE joint), the FE-AA(offset) joint configuration we propose, has the active component to drive flexion-extension followed by the active component driving abduction-adduction. The projected surface areas for workspace of the contact point is 25% and 245% higher than that of conventional one in transverse and frontal plane, respectively. In addition, the manipulability index of the hip flexion angle near 90° of the proposed configuration has results 10 times better than the conventional one without imposing a singularity problem.