A Parametrized Controller Reduction Technique via a New Frequency Weighted Model Reduction Formulation

In this technical note, the solution to the controller reduction problem via a double-sided frequency weighted model reduction technique is considered. A new method for finding low-order controllers based on new frequency weights derived using closed-loop system approximation criterion is proposed. The formulas of frequency weights are obtained in terms of the plant, the original controller and a matrix of free parameters. By varying the free parameters in the resulting two-sided frequency weighted model reduction problem, frequency weighted error can be significantly reduced to yield more accurate low-order controllers.