Abstract
We propose a method of controller reduction, which aims to replace an ideal high-order controller with a reduced-order one so that finite numbers of 1st-and 2nd-order information of the closed-loop system can be preserved. The preserved 1st-and 2nd-order information are those associated with the transfer characteristics of the closed-loop system and its power spectrum characteristics at appropriate complex frequency points, respectively. The proposed method provides the reduced-order controller which yields a frequency-weighted approximation of the closed-loop system considering its stability.
