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Systematic discretization of input-output maps of linear infinite dimensional systems (revised)

Schmidt, Michael

Preprint-Reihe des Instituts für Mathematik, Technische Universität Berlin

Many model reduction techniques take a semi-discretization of a PDE model as starting point and aim then at an accurate approximation of its input/output map. In this contribution, we discuss the direct discretization of the i/o map of the infinite-dimensional system for a general class of linear time-invariant systems with distributed inputs and outputs. First, the input and output signals are discretized in space and time, resulting in the matrix representation of an approximated i/o-map. In a generalized sense, the matrix contains the Markov parameters of a corresponding time-discrete multi-input-multi-output system. Second, the system dynamics is approximated in form of the underlying evolution operator, in order to calculate the matrix representation numerically. The discretization framework, corresponding error estimates, a SVD-based system reduction method and a numerical application in an optimization problem are presented, and illustrated for a heat control system.
  • This preprint is a completely revised version of Preprint 2006-06. For more details see the dissertation thesis of the author published in 2007.