Weakened partial pole placement with H∞ criterion

This paper considers a method for designing a state feedback law that simultaneously places some (dominant) closed-loop poles at specified points, and satisfies another feedback performance such as an H_∞ criterion. This method first parametrizes all feedback laws that achieve the given partial pole specification, and then adjusts the parameter. In particular, this paper generalizes a method proposed earlier by the author in two points: i) the number of placeable poles is generalized, so that a higher degree of freedom is left for an additional performance, and ii) the parameter may possess dynamics, thereby allowing to apply the conventional observer-based design for optimal control.