Computation of the MIMO Volterra frequency response functions of nonlinear systems

Abstract A new and efficient algorithm for computing the higher order Multiple-Input, Multiple-Output (MIMO) Volterra frequency response functions (FRFs) from nonlinear time domain parametric models is presented. Recently developed MIMO harmonic probing techniques are applied to a general class of nonlinear MIMO differential, or difference equation models in order to obtain algebraic expressions relating the parameters of the time-domain system to the desired MIMO Volterra FRFs. The FRFs for any specific system of interest can then be written directly by substitution of model parameters. The expressions also reveal the structure of the resultant MIMO Volterra FRFs providing insight into system behaviour. The method is readily automated in software, and results are illustrated by means of an example.