Robust Optimal Control for Flexible Space Structures by Gain and Phase Compensation Using Displacement Output

This paper considers position and attitude control of flexible space structures. It is assumed that sensors and actuators are collocated in the structure. The purpose of this paper is to propose a control method by a controller compensating for gain reduction and phase lag in a loop transfer function using only displacement output. We show that the proposed controller makes a closed-loop system not only robustly stable against uncertainty of characteristic parameters such as mass, damping, and stiffness, but also optimal for a quadratic cost function.