H_∞ Control and Filtering

Abstract

Almost all practical systems are subject to external disturbances that can in some situations degrade system performance if their effects are not considered during the design phase. In the current literature there are many ways to eliminate the effects of the external disturbances. One of them is the -1_oocontrol technique. It consists of designing a suboptimal control that minimizes the effects of the external disturbance on the output. In other words, the problem can be explained as follows: Given a dynamical time delay system with exogenous input that belongs to G₂[0, oo], design a controller that minimizes the 7-1_ß-norm of the transfer function between the controlled output and the external disturbance, or at least guarantees that the W_oo-norm will not exceed a given level γ > 0.