Dynamics Based Fuzzy Adaptive Impedance Control for Lower Limb Rehabilitation Robot

Human-robot interaction control plays a significant role in the research and clinical application of rehabilitation robots. A fuzzy adaptive variable impedance control strategy is proposed in this paper. Firstly, a dynamic model is established by using the Lagrangian method and the traditional friction model, which can be used to predict human-robot interaction forces. Then, a fuzzy adaptive variable impedance control strategy based on the human-robot system dynamic model is designed. In the designed control strategy, the interaction forces, position and velocity errors are taken as the system inputs, and a fuzzy adaptive law is used to adjust the damping and stiffness coefficients. Finally, the dynamics identification experiments and simulation of the fuzzy adaptive variable impedance control strategy are carried out, by which performance of the proposed method is validated.