Fuzzy Variable Impedance Adaptive Robust Control Algorithm of Exoskeleton Robots

Abstract

As a frontier research field, the flexible control of exoskeleton robots still exists many problems to be solved. In this paper, a fuzzy variable impedance adaptive robust control algorithm (FARC) based on the exoskeleton robot dynamics model is proposed. This algorithm aims to solve problems that are the uncertain parameters of the dynamics model and the influence of the external disturbance. In particular, the impedance parameters are updated in real time by using fuzzy inference. In detail, dynamics model of the exoskeleton robot by using Lagrange equation is established, firstly. Then an adaptive robust control algorithm with fuzzy variable impedance based on dynamics model is proposed to solve the problems mentioned above. And it can be proven to yield asymptotic stability for the control algorithm in the presence of bounded nonlinear disturbances. Finally, the experimental results by co-simulation of Simulink and OpenSim demonstrate the effectiveness of our control algorithm.