Self-tuning position tracking control of an electro-hydraulic servo system in the presence of internal leakage and friction

Abstract

Friction and the internal leakage significantly deteriorates the performance of an electro-hydraulic servo system. Hence, an adaptive scheme could be better choice to handle these effects. Therefore, in this paper a Self-tuning fuzzy PID (SFPID) control scheme is employed for the position tracking performance of an electro-hydraulic servo system. A mathematical model of the system was designed with the consideration of internal leakage and friction inside the system. The internal leakage flow was implemented by introducing several levels and the friction was modeled using LuGre model. The self tuning capability of PID controller was achieved through fuzzy logic theory and the PID controller parameters namely, Kp, Ki and Kd were tuned by selecting appropriate fuzzy rules. The capability of the proposed controller was examined through simulation works in Matlab Simulink and validation was carried out in the real system. The results indicate that the proposed controller successfully improves the positioning performance of the system. The proposed controller can be applied potentially to control the modern equipments positioning applications.