In matlab documentation http://www.mathworks.com/help/toolbox/ident/ug/bq5o_xw-1.html, the block diagram that "represents" the structure of a nonlinear ARX model may have an error.
According [R. Isermann, and M. Münchhof, Identification of Dynamic Systems – An Introduction with Applications,Springer, 2011], the NARX model depends on measured inputs and measured outputs, and the NOE model depends on measured inputs and modeled outputs. In other words, the block diagram that "represents" the structure of a nonlinear ARX model in matlab documentation shows a NOE model and not a NARX model, because the figure uses modeled outputs(modeled output feedback) as input to the model, instead of using the measured output of the process.
Is not it?
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