Control of Levels of Water of Coupled Tank System with Input Constraints Present

Nonlinear Model Predictive Control (NMPC) has applications in many fields of engineering. Several variants of MPC exist such as linear MPC, successive linearization MPC, nonlinear MPC, quasi infinite horizon NMPC. Current work presents application of the quasi infinite horizon NMPC to chemical engineering domain. Results are presented for a four tank case study. System aims to control levels of the 4 tanks using 2 flow rates as the control inputs. System is complex because of the coupling of the levels and constraints on the input, i.e., the flow rates. First principles model is used for getting the results. Average deviation of 5 cm is given in the initial condition and all the levels converge to the steady state within 80 seconds.