IMPLEMENTATION OF PID AND FPD+I CONTROLLER ON NON-LINEAR SYSTEMS

Abstract

Since Fuzzy controllers are nonlinear, it is more difficult to set the controller gains compared to Proportional-Integral-Derivative (PID) controller. The idea is to start with a tuned conventional PID controller, replace it with an equivalent fuzzy controller. In contrast, a PID controller is a simple, linear combination of three signals: P action proportional to error, the I-action proportional to the integral of the error and the D-action proportional to the time derivative of error. This introduces a systematic tuning procedure for fuzzy PID type controllers and study of higher order systems based on Fuzzy controller This comprises of level control of a surge tank level system and inverted pendulum’s angular position as well as cart position using fuzzy PD+I controller with effect of different membership function on the system control as well as comparison with conventional PID Controller has been carved out. Different type of membership functions like Bell, Pi, Gaussian and Psigmoid are used in the fuzzy PD+I control of the system. The stability of the system has also been discussed upon using phase plot. The simulation results have been obtained using MATLAB.