Abstract: One of the major problems in process industries is to control the liquid level in a tank. Proportional Integral Derivative (PID) controllers are commonly used controller in the process industries. Interacting Spherical Tank Liquid Level System (ISTLLS) has the characteristics of nonlinearity due to the dynamic behavior and area of cross section of tank. The time delay reduces the performance of the system that occurs when conventional controller is used. Our project aim is to analyze the performance of the Internal Model Control (IMC) based PID Controller and Metaheurstic algorithm for an Interacting spherical tank system. Using the mathematical model of the process simulation is done and their performance is analyzed under MATLAB environment. Metaheurstic algorithm like Genetic Algorithm (GA) and Firefly Algorithm (FA) are used for obtaining the best PID tuning values. The motive of Metaheurstic algorithm is to provide the auto tuning and obtaining the best solution to reduce error. Finally the performance of conventional controller (PID), Internal Model Control (IMC)-PID controller, FA-PID algorithm and GA-PID algorithm performances are compared and analyzed.

Keywords: Nonlinear system, Genetic Algorithm Optimization, and Firefly Algorithm Optimization, IMC PID Controller.