FIXED ORDER H 2 / H ∞ CONTROL OF UNCERTAIN SYSTEMS

Abstract This paper considers the design of fixed order dynamic controllers for uncertain systems. Necessary conditions are derived for the minimum of a mixed H2/H∞ performance objective. Additionally. the paper considers the problem of deriving relevant uncertainty descriptions in this H2/H∞ framework. The design method is applied to a high bandwidth control design problem for a flexible servo system with an uncertainty of the frequency of the resonance. The H2/H∞ controller has been implemented in a Digital Signal Processor. The servo behaviour shows robust performance for the considered envelope of frequencies of the resonance.

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