Admittance Control of Lower Limb Exoskeleton Robot

Abstract

As an interactive robot, exoskeleton robot plays an increasingly important role in the field of individual combat and daily walking assistance. Aiming at the problem of accurate identification of human motion intention and high efficiency and safety of human-machine interaction during lower limb exoskeleton robot works, an admittance control algorithm based on velocity compensation is proposed in this paper. Firstly, the exoskeleton robot system and the installation methods of force sensor are introduced, and the human-machine interaction force is calculated through the analysis of mechanism dynamics model. Based on the above information, a reasonable admittance control algorithm is designed to control the human- machine interaction force by adjusting the dynamic relationship between the position and interactive force of exoskeleton robots and wearer, so as to realize the assistance of exoskeleton to human movement. The simulation results show that compared with the traditional position control algorithm, the efficiency of human-machine interaction is improved effectively, and the joint angle error between the exoskeleton and the wearer is controlled within 0.5°.