Robust Control Design with Application to a Seeker Scan Loop System

Abstract

A new method for designing a two-degree-of-freedom robust controller is formulated in the framework of the standard H_∞ optimization problem. The method can deal with the time domain requirements such as transient response characteristics and multivariable interaction between output channels by introducing a desired closed-loop model into the problem formulation, and produces a low order two-degree-of-freedom controller because the feedback and feedforward controllers share the same state space. The method is applied to design a robust controller of a seeker scan loop system. It is illustrated that the proposed two-degree-of-freedom control system satisfies design requirements, and shows good scanning performance for conical, rosette, and spiral scan patterns.