Searching the optimal order for high order models - MIMO case

In some system identification methods, high order ARX models are adopted as true descriptions of the process to be identified. Afterwards, such high order model is used as a basis for a model order reduction procedure. The optimization strategy for the search of the best high order (in the fit index sense) for SISO ARX models, presented in a related paper [1], is extended to the MIMO case. The analyzed system is the Wood & Berry binary distillation column [2]. In this study, the search for the best dead times associated with the high order ARX model is also addressed. The results obtained by the optimization strategy are compared with those derived by exhaustive search.