TRANSFER EQUIVALENCE AND REALIZATION OF NONLINEAR HIGHER ORDER I/O DIFFERENCE EQUATIONS USING MAPLE

摘要

The paper presents a contribution to the development of symbolic computation tools for discrete-time nonlinear control systems. It presents certain modelling problems to show what can be achieved in nonlinear control with symbolic computation. A set of procedures is developed in Maple V that test if a given input-output (i/o) difference equation is realizable in the classical state space form, and for simple control systems also find the transformation. Other procedures test whether two (or more) input-output difference equations are equivalent, and find the minimal (irreducible) representation of the i/o model. The irreducible form is the basis for constructing the minimal, i.e. accessible and observable, realization. The application of the developed procedures is demonstrated on the example of the model of the grain-drying process, obtained via identification.