Synthesis of anisotropic suboptimal fixed-order controllers via semidefinite programming and algorithm for searching reciprocal matrices

This paper considers a disturbance attenuation problem for a linear discrete time invariant system under random disturbances with imprecisely known distributions. The designed anisotropic suboptimal controller is a dynamic fixed-order output-feedback compensator which is required to stabilize the closed-loop system and keep its anisotropic norm below a prescribed threshold value. The proposed optimization-based approach to synthesis of the anisotropic controllers is novel.