STRUCTURED SINGULAR-VALUE CONTROLLER SYNTHESIS USING CONSTANT D-SCALES WITHOUT D-K ITERATION

Structured singular value synthesis allows the design of controllers t hat are robust with respect to multiple block-structured uncertainty. This type of design process commonly relies on 'D-K iteration' and cur ve fitting. In particular, the optimal D-scales and the controller are iteratively optimized. Since the D-scales are optimized over frequenc y, they must be curve fitted with rational transfer functions before t he controller is optimized. This curve fitting can be difficult and of ten leads to suboptimal designs. This paper presents a structured sing ular value process that allows the D-scales to be constrained to be co nstant and simultaneously optimizes the D-scales and the controller K. The approach relies on recent results on mixed-norm H-2/H-infinity co ntroller synthesis and also enables the direct design of reduced-order controllers.