Bilinear system identification by Walsh functions

A new technique, which uses a finite orthonormal expansion to approximate input and output functions, is proposed for file identification of a class of nonlinear systems. Walsh functions form the basis of the expansions as a consequence of their useful properties here. That is, the parameter estimation problem is reduced to algebraic form by Fine's relationship for the integral of Walsh functions [1], by the operational matrix concept of Chen and Hsiao [2], and by the very desirable group properties of Walsh functions [3]. Computational examples are presented to illustrate the utility of this method. The availability of Walsh-function programs makes the method particularly amenable to practice.