Model order reduction by parameter-varying oblique projection

A method to reduce the dynamic order of linear parameter-varying (LPV) systems in grid representation is developed in this paper. It approximates balancing and truncation by an oblique projection onto a dominant subspace. The approach is novel in its use of a parameter-varying kernel to define the direction of this projection. Parameter-varying state transformations in general lead to parameter rate dependence in the model. The proposed projection avoids this dependence and maintains a consistent state space basis for the reduced-order system. The method is compared with LPV balancing and truncation for a nonlinear mass-spring-damper system. It is shown to yield similar accuracy, while the required computation time is reduced by a factor of almost 100,000.

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