Mechanical design of a passive lower-limb exoskeleton for load-carrying assistance

Abstract This paper presents a passive exoskeleton with 17 degrees-of-freedom (DOF) for load-carrying, which includes two 3DOFs ankle joint, 2DOFs hip 1DOF knee one backpack, and redundant DOFs at the thigh shank, respectively, to improve compatibility of human-machine locomotion. The modular backpack was designed facilitate carrying different loads. A horn-shaped spatial mechanism connect joint transfer payload ground. tension spring adopted absorb gravitational potential energy load when walking, fix both sides. segmented brace shank were adjust legs. In order force transmission performance, we cancelled extension DOF moved rotation axis backward. assistance allow move freely flexion angle did not exceed 60°. However, bends over 60°, presses torsion store energy. After then, it releases assist extending. Cooper-Harper scale tests demonstrated that had excellent static support effect movement flexibility, verified rationality design.