Mechanical Design and Human-Machine Coupling Dynamic Analysis of a Lower Extremity Exoskeleton

Abstract

Wearable exoskeleton enhances human abilities by integrating human body with machines. In order to design an anthropomorphic exoskeleton, the anatomical structure and biomechanical characteristics of lower limb are studied, the degrees of freedom of movement on each lower limb is 7, and the movement range is given out. The kinematic and dynamic characteristic of walking gait analyzed by OpenSim indicates that the ankle joint demands asymmetric unidirectional actuators, the knee and hip joint demands bidirectional actuators. The mechanical structure was designed according to the anatomy structure and gait analysis of the lower limb. The human-machine interaction forces at different interface position were analyzed. It demonstrates that, in order to improve wearability, the passive exoskeleton’s choices of human-machine interaction positions on the shank and thigh limb are the down and middle position on each part respectively, and the active exoskeleton’s choices of human-machine interaction positions on the shank and thigh limb are the middle and down position on each part respectively.