ON THE DISCRETIZATION OF SINGLE-INPUT SINGLE-OUTPUT BILINEAR-SYSTEMS

Prompted by the observation that the parameters of a discrete bilinear model structure corresponding to a time invariant continuous bilinear model structure are input dependent quantities, this paper deduces a correction factor that relates the continuous and discrete time models . The correction factor that is obtained analytically is shown to prov ide an exact discretization. An approximation to the correction factor is also included, which produces a satisfactory discretization provid ed realistic bounds are placed on the choice of the sampling interval. Building on the developed approach for discretizing a first-order bil inear system, the procedure is extended to the case of higher order sy stems. The new approach differs from existing schemes in that a discre te time bilinear model structure is retained. With consideration given to a first-order model of a high temperature furnace application, it is shown that the resulting parameter variation is significantly reduc ed when a bilinear model structure is retained and use is made of the proposed bilinear discretization.