Nonlinear fuzzy control on a hydraulic servo system

Hydraulic position servo systems are commonly used in industry. This kind of systems is nonlinear in nature and generally difficult to control. The ordinary linear constant gain controller will cause overshoot or even loss of system stability. Application of fuzzy logic controller to a nonlinear hydraulic servo system is investigated in this paper. The dynamic model of the system is given and the stability is also analyzed using Kriging approximation method and Popov's criterion. The steady state error can be eliminated with dead band nonlinearity using this fuzzy controller combined with an integration term. Simulation results show the performance of the fuzzy controller with fast response and less overshoot.