Adaptive Robust Fuzzy Impedance Control of an Electro-Hydraulic Actuator
Mingjie Li, Qiang Zhang
Abstract
This paper concentrates on both velocity and force control of a single-rod electro-hydraulic actuator in the presence of parameter uncertainties and uncertain nonlinearities. Both velocity control and force control are required in some cases. Impedance control and adaptive robust control are synthesized to deal with this problem. In this paper, the primary goal is velocity control while the contact force is kept in an acceptable range. To keep proper contact force with environment or workpieces, impedance control is adopted to regulate the dynamic relationship between velocity and force. Fuzzy logic is used to adjust the parameters of impedance rules to improve control performance. The velocity command of adaptive robust velocity control is determined by impedance control based on fuzzy logic. Parameter uncertainties and uncertain nonlinearities can be compensated through adaptive robust velocity control, which leads to accurate velocity tracking. The stability of the overall system was analyzed. Comparative experiments verified that the proposed control strategy has both high-accuracy velocity tracking and force regulation performance.