On primary output estimation by use of secondary measurements as input signals in system identification

In many cases, vital output variables in, e.g,, industrial processes cannot be measured online. It is then of interest to estimate these primary varia bles from manipulated and measured inputs and the secondary output measurem ents that are available, In order to identify an optimal estimator from inp ut-output data, a suitable model structure must be chosen. The paper compar es use of ARMAX and output error (OE) structures in prediction error identi fication methods, theoretically and through simulations.