Robust, fragile, or optimal?
暂无分享,去创建一个
We show by examples that optimum and robust controllers, designed by using the H/sub 2/, H/sub /spl infin//, l/sup 1/, and /spl mu/ formulations, can produce extremely fragile controllers, in the sense that vanishingly small perturbations of the coefficients of the designed controller destabilize the closed-loop control system. The examples show that this fragility usually manifests itself as extremely poor gain and phase margins of the closed-loop system. The calculations given here should raise a cautionary note and draw attention to the larger issue of controller sensitivity which may be important in other nonoptimal design techniques as well.
[1] H. Kimura,et al. On the structure of H/sup infinity / control systems and related extensions , 1991 .
[2] Diederich Hinrichsen,et al. Control of Uncertain Systems , 1990 .
[3] P. Khargonekar,et al. State-space solutions to standard H/sub 2/ and H/sub infinity / control problems , 1989 .
[4] Masayuki Fujita,et al. Μ -synthesis of an Electromagnetic Suspension System , 1995, IEEE Trans. Autom. Control..