A Linear Interpolation Fuzzy Controller with NN Compensator for an Electro-hydraulic Servo System

A linear interpolation fuzzy controller with NN compensator is proposed for an electro-hydraulic position servo system. First, to overcome the conventional fuzzy controller´s disadvantage of lower precision caused by discretization, bilinear interpolation 2-D table lookup method is used to replace the exact lookup method. Then, to minimize the steady state error caused by force load, a neural network feed forward compensator is proposed. Finally, to imitate the practical system, co-simulation technique between AMESim and MATLAB/Simulink is adopted. The model of the valve controlled hydraulic cylinder system is constructed in AMESim, which can reflect the nonlinear characteristics of the system. And the controller model is established in Simulink. Lots of simulation experiments are carried out. And the simulating results indicate that with the proposed control scheme good dynamic and static control performance can be achieved. The steady state error caused by discretization can be avoided and that caused by force load can be minimized.