A Youla-based, state space approach to the parameterization of H2 suboptimal, regulating controllers

A Youla-like parameterization method is developed for multi-objective output regulating controllers meeting a suboptimal H₂ performance level. Many engineering applications, from management of nuclear power to hard disk data, all incorporate a form of regulation in terms of asymptotic tracking and disturbance rejection of a fully or partially known disturbance. The ability to directly define a convex set of controllers which regulate the output and satisfy certain H₂ performance criterion is crucial. Thus, the proposed method attempts to address this issue through an affine parameterization of controllers to a set of convex control parameters. Lastly, an example exploring flying height regulation of a disk drive head is considered where a switched controller is constructed based on the proposed parameterization.