Comparison of ARX and OBF-ARX models for Closed-loop Identification of Multiple Input Multiple Output (MIMO) System

ARX is simple and effective model structure for closed-loop system identification. OBF-ARX is also shown to be very effective and more advantageous for closed-loop identification of system involving time delays. However, these arguments are done in most literature in the context of SISO systems. This project will focus on the two systems which will be discussed and compared for identification of MIMO systems. The MIMO system used is the Wood & Berry Distillation Column. In this project, a mathematical model will be developed based on the distillation column with a closed loop system using the experimental data obtained from SIMULINK MATLAB. The Wood & Berry models will be used to compare the ARX and OBF-ARX model and to obtain the suitable and better model choice for a close loop system of MIMO system. The model structure with the highest average fitness value will be selected as the best model structure and the comparison plot of XD and XB of both condition of certain and uncertain time delays was plotted.