Automatic Loop Shaping of MIMO Controllers Satisfying Sensitivity Specifications

Abstract

An existing automatic loop shaping algorithm for designing SISO controllers is extended to automatic loop shaping of MIMO controllers that is based on the sequential QFT method. The algorithm is efficient and fast and can search for controllers satisfying many types of restrictions, including constraints on each one of the controller’s elements such as hard restrictions on the high-frequency amplitude or damping factor of notch filters. Moreover, the algorithm can be applied to unstructured uncertain plants, be they stable, unstable, or nonminimum phase, including pure delay.