Model Reduction of Descriptor Systems with the MORLAB Toolbox

Abstract

The MORLAB (Model Order Reduction Laboratory) toolbox is a software solution in MATLAB for the model reduction of linear time-invariant continuous-time systems. It contains several methods to deal with unstructured medium-scale descriptor systems. In order to illustrate the use of MORLAB in this context, in this paper, a damped mass-spring system with a holonomic constraint is reduced by the generalized balanced truncation subroutine from the MORLAB toolbox. The basic ideas of the MORLAB implementation are shown by introducing the used spectral projection methods based on the matrix sign and matrix disk function. To show the numerical behavior, the MORLAB routine and all the corresponding subroutines are used for computations applied to the introduced example. An overview about further model reduction methods for descriptor systems in MORLAB is given, on which similar implementational ideas as for the generalized balanced truncation method are used.