Control of process parameters is one of the important problems in process industry. The
process considered for modeling is spherical tank liquid level system. Control of liquid level
in a spherical tank is nonlinear due to the variation in the area of cross section of the level
system with change in shape. System identification of this nonlinear process is done using
black box model, which is identified to be nonlinear and approximated to be a First Order
Plus Dead Time (FOPDT) model. Here the controller design is compared based on …

The aim of this paper is to implement optimum controller for a spherical tank. The objective
of the controller is to maintain the level inside the process tank in a desired value. The real
time implementation of the process is designed and implemented in MATLAB using data
acquisition module. The process model is obtained step test method. The identified model is
in the form of first order plus delay time (FOPDT) process. Controller design is compared
based on conventional Proportional Integral (PI) with Internal Model Control (IMC) based on …