Design of IMC Based PI Controllers for Three Tank Interacting Level Control Process

India is a country that consists of most process industries, where most of the end products are related to water or other liquid state materials. In recent days pharmaceutical industries have grown on a larger scale due to the COVID’19 situation. One of the major processes is to maintain the level of the liquid for having a continuous process. In this proposed process, Proportional Integral (PI), Internal Model Controller (IMC) based PI is implemented on a three-tank integrating system with two input and two output (TITO). IMC-PI gain values are acquired and decoupled using the decoupler matrix by determining RHP poles and zeros for the TITO system. Since two input tanks are involved, therefore two different gain values are calculated keep the liquid at the given level. The proposed system has given has resulted with 180 seconds and 190 seconds for Settling time and 5% and 0% of Overshoot for two tanks.