IDENTIFICATION OF WIENER MODEL USING RELAY FEEDBACK TEST

A method for identifying a wiener-type model for nonlinear processes i s proposed. The linear subsystem of the model is represented by simple transfer functions of the form such as: FOPDT (i,e, First-Order-Plus- Dead-Time) or an SOPDT (i,e, Second-Order-Plus-Dead-Time). The static nonlinearity is represented by an invertible function defined on an op eration domain. Data from a two-stage relay feedback experiment in one single run is required. Simple algorithms are formulated to identifyi ng both structure and parameters of the model. Estimation of parameter s in both linear and nonlinear parts is performed separately and in an one-by-one sequence.