Analog-digital systems descriptions for signal processing and control application

The paper deals with two comparatively simple but common approaches to deal with real analog-digital systems (ADS). The first description involves decomposition of the static input-output characteristic, which is used to obtain properties for a wide class of nonlinearities and it allows to calculate the output signal for any input signal; to deal with dynamics, coefficients of a differential equation are used. As a result, the behaviour of the nonlinear object, which has a nonlinear static part and a linear dynamic part, can be described by a small set of parameters only and each of them can be estimated experimentally. The second description is based on a linear inertial stochastic for the model, which takes account of nonlinear and inertial conversion effects by introducing equivalent noise. This makes it possible to remain within the class of linear operators in normalizing the total dynamic responses to allow for nonlinear properties of ADS. The simulation and experimental results confirm the usefulness of both kinds of descriptions utilizing the same coefficients of the differential equation estimated experimentally.