H_∞ optimal control with an output regulation constraint — continuous-time systems

Abstract

For continuous-time systems, we consider here an output regulation problem which seeks to achieve simultaneously a desired H_∞ norm of a closed-loop transfer function. That is, we seek here a controller that achieves output regulation while resulting in at most a specified value for the H_∞ norm of a transfer function from a certain input signal to a desired output signal of the system. Such a multi-objective problem clearly takes into account certain performance requirements. This is obvious when we recognize that the H∞ norm can identify robustness to unstructured plant uncertainties.