Dynamic Positioning Control of Floating Platform using <TEX>$H_{infty}$</TEX> Control Method

J. Ocean Eng. Technol. 1996;10(3):153-161.

Dynamic Positioning Control of Floating Platform using $H_{infty}$ Control Method

$H_{infty}$ 제어법을 이용한 부유식 플랫폼의 동위치 제어

유휘룡,김환성,김상봉

부경대학교 기계공학과 대학원,부경대학교 기계공학과 대학원,부경대학교 기계공학과 대학원

Keywords: Dynamic Positioning System, Mixed Sensitivity Problem, Semi-submergible Platform, Multiplicatve Perturbation

핵심용어: 동의치 제어 시스템, 혼합 감도 문제, 반잠수식 작업선, 승법적 섭동

Abstract

This paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{infty}$ control technique. The norm band of uncertainty is captured by multiplicative perturbation between nominal model and reduced order model. A controller robust to the uncertainty is designed applying $H_{infty}$ synthesis. The control law satisfying robust stabillity and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{infty}$ synthesis is done through simulations of the closed loop system. The results of $H_{infty}$ synthesis are compared to those of the traditional LQ synthesis method.