Fuzzy Control Systems Dedicated to Electro-Hydraulic Servo-Systems. IFT Techniques and Sensitivity Analysis

The paper proposes fuzzy control systems meant for controlling the electro-hydraulic servo-systems considered as actuators as part of speed control systems in hydro-turbine generators. In this situation the controlled plants are characterized by simplified mathematical models of second-order and third-order integral type. The development is done by using the linear case results on the basis of the Extended Symmetrical Optimum (ESO) method and of Iterative Feedback Tuning (IFT) techniques, and by the transfer of these results to the fuzzy case. There are proposed six fuzzy control system structures employing a basic Pi-fuzzy controller. There is performed the sensitivity analysis of the fuzzy control systems with respect to the parametric variations of the controlled plant, that enables the development of the fuzzy controllers. Digital simulation results and real-time experimental results corresponding to a case study validate the proposed fuzzy control systems.