Structured Robust Synthesis with Parameter-Dependent D-Scales

Structured robust control synthesis has been actively researched in recent years. The advantage of any structured design technique is that it is capable of bringing advanced optimization-based methods to real-life applications. Drawing on a recently published paper, a novel algorithm is presented for structured control synthesis against mixed uncertainty. The method is iterative, alternating between collecting worst-case perturbation samples of the parametric uncertainty, and designing a controller for all the samples. During the synthesis procedure, the controller is designed for a set of plants with structured dynamic uncertainty employing a process similar to the classical D-K iteration. The key feature of this algorithm is that separate D-scales are assigned to the individual samples. Two numerical examples are provided, one specifically chosen to highlight the advantage of this approach.