Approximation of Linear Time Invariant Systems by Lower Order Systems - 2.

The concluding part of the article considers the choice of a special description of state for the sought-for mathematical model. The parameters of the sought-for model, stated in a modified Schwarz canonical form with a minimum number of parameters, are obtained by means of minimization of a weighted quadratic error integral. The problem is formulated as a nonlinear programming task and is solved by applying effective methods from this field.