Fuzzy impedance control of an electro-hydraulic actuator with an extended disturbance observer

Abstract

In this paper, we deal with both velocity control and force control of a single-rod electro-hydraulic actuator subject to external disturbances and parameter uncertainties. In some implementations, both velocity control and force control are required. Impedance control and an extended disturbance observer are combined to solve this issue. Impedance control is applied to regulate the dynamic relationship between the velocity and output force of the actuator, which can help avoid impact and keep a proper contact force on the environment or workpieces. Parameters of impedance rules are regulated by a fuzzy algorithm. An extended disturbance observer is employed to account for external disturbances and parameter uncertainties to achieve an accurate velocity tracking. A detailed model of load force dynamics is presented for the development of the extended disturbance observer. The stability of the whole system is analyzed. Experimental results demonstrate that the proposed control strategy has not only a high velocity tracking performance, but also a good force adjustment performance, and that it should be widely applied in construction and assembly.

Keywords

Fuzzy control / Impedance control / Disturbance observer / Parameter uncertainties / Electro-hydraulic actuator

RIGHTS & PERMISSIONS

2019 Zhejiang University and Springer-Verlag GmbH Germany, part of Springer Nature