Investigation of Intelligent Controller for Non-Linear Spherical Tank System

Abstract

Spherical tanks are used to store fluids in many industries such as petrochemical, effluent treatment, and aerospace. Spherical tanks are used as they are highly resistant to internal pressure making them suitable for storing high-pressure materials due to their large volume, small weight, and strong load-bearing capacity. The spherical tanks have the lowest possible surface area to volume ratio. These tanks are preferred due to their capability of balancing pressure in and out of the tank and their ability to minimize the amount of heat that gets inside the tank wall. It is cost-effective when compared to other tanks. But, controlling the water level in the spherical tank is difficult and a highly challenging one. In this article, the aim is to stabilize the level of the spherical tank by using the PID and FUZZY logic controllers. By controlling nonlinear dynamic behavior, uncertainty, time-varying parameters, frequency disturbances and dead time, the stability of the tank is achieved. The mathematical modelling of the spherical system is obtained using first principles design and the stability of the model is analyzed using various techniques. Then, the simulation is done using MATLAB and the responses are obtained and compared for PID and FUZZY logic. Based on these comparisons made on the performance of the PID and FUZZY logic controllers, the results are concluded