Implementation of Pi, Pd, And Pi+D Type Fuzzy Logic Controller of SISO and MIMO Level Process and Their Performance Analysis

Abstract

This thesis presents the implementation of fuzzy logic controllers (FLCs) and scrutinizes the performance of FLC controllers with IMC and conventional PID controller. The core of the FLC design is based on Mamdani model. Various controllers such as Proportional Integral (PI) FLC, Proportional-Derivative (PD) FLC, and PI+D FLC (PI fuzzy plus conventional derivative controller) are designed. Different Level Process such As SISO Three Tank Systems (one manipulated variable and one controlled variable), MIMO Two Tank Systems (two manipulated variables and two controlled variables) and MIMO Three Tank System (two manipulated variables and two controlled variables) are taken. With certain disturbance added, while chasing the set point, the performance of FLCs ,IMC and PID conventional controller are analyzed by calculating Settling Time(sec), Peak Overshoot(%), Integral Absolute Error (IAE) and Integral Time Weighted Absolute Error (ITAE). The behavior of the different level process in terms of the output response while achieving set point between fuzzy logic controllers, IMC and PID conventional controller are studied. The level processes, which are based on interacting and non -interacting mode are monitored with providing step input. Output responses of these systems are studied by designing various types of controllers. Effect of interaction is also observed by calculating the Relative Gain and the effect of this interaction is minimized by using decoupler. The analysis of the output responses is studied through computer simulation using Matlab/Simulink toolbox.