Optimization design of a bionic lower limb rehabilitation robot with dynamic analysis

Libo Zhou, Weihai Chen, Jianhua Wang, Jingmeng Liu, Wenjie Chen, Shaoping Bai

Abstract: Considering that the knee joint of the human body involves both rotation and translation, a 3-RPR (Revolute pair - Prismatic pair - Revolute pair) parallel mechanism was developed to fully accommodate this. Further study indicated that several different mechanism configurations can meet the requirements of a bionic lower limb exoskeleton. Furthermore, the bionic exoskeleton is a redundant mechanism which shows different dynamics and stability characteristics in different configurations. In this paper, the dynamics and stability of the bionic rehabilitation robot in respect of patient lower limb gravity is analyzed in order to select the best configuration. The interaction force between the patient's lower limb and the exoskeleton is first estimated. Simulations by Matlab/SimMechanics software are then conducted to analyze the dynamics of the exoskeleton and to verify the exoskeleton's feasibility.