Dynamic analysis and design of lower extremity power-assisted exoskeleton

Abstract

A new design of lower extremity power-assisted exoskeleton (LEPEX), is presented in this paper, which is used for transmitting the backpack weight of the wearer to the ground and enhancing human motion, with each joint driven by corresponding actuator. Primarily, a 7-bar human machine mathematical model is introduced and analyzed with different walking phases using Lagrange’s Equations. Second, dynamic parameters, such as torque and power consumptions of each joint in the sagittal plane are obtained for human with 75 kg payload in his (her) back with different conditions, i.e., flat walking and climbing stairs. Afterwards, the actuator for each joint is chosen based on the torque and power consumptions, i.e., a passive actuator for each knee joint and an active actuator for each ankle and hip joint; as well as the structure of LEPEX. Last but not least, the designed LEPEX is simulated under ADAMS environment by using wearer’s joint movement data, which is obtained from flat walking and climbing stairs experiments. Eventually, the simulation results are reported to witness the potentialities of the structure.