Performance Estimation for Shipboard Directional Pedestal by Using M&S Methodologies

M&S기법을 활용한 선박용 지향성 요동보상장치 성능 분석

Abstract

Recently, the tasks assigned to surface ship are becoming diverse and important. In this trend, shipboard directional pedestals are widely used for surveillance and electronic warfare because ships are always under angular motion such as rolling, pitching and yawing. To estimate the performance of pedestal, the motion responses of vessel as well as mechanical characteristics of pedestal should be considered. In this study, both the motion responses of vessel which the pedestal will be mounted and the behavior of 3-axis pedestal are considered. Numerical analysis based on potential theory is used to obtained motion characteristics of vessel and then 6-DOF motions of vessel are simulated under operational condition. 1st-order time delay model and LQR control algorithm are used for modeling of pedestal drive model and control model, respectively. By using coordinate transform, the angular motions which the pedestal should compensate are calculated from the vessel's angular motion. Through these M&S methodologies, time history of pedestal behavior and maximum angular error of each pedestal axis are obtained. Overall M&S results show that 3-axis pedestal compensate the angular motion induced by vessel, efficiently.

그림 1. ITTC 파 스펙트럼 Fig. 1 ITTC Wave Spectrum

그림 2. 파 입사각 정의 Fig. 2 Definition of incident wave angle

그림 3. 선체와 자유표면의 패널 격자 Fig. 3 Panels on the hull and free surface

그림 4. 병진운동 RAO Fig. 4 RAO in translation motion

그림 5. 회전운동 RAO Fig. 5 RAO in angular motion

그림 6. 수상함 운동응답 (해상상태6, 선수파) Fig. 6 Motion response of vessel (Sea state6, Head sea)

그림 7. 3축 구동 페데스탈 Fig. 7 3-axis mount pedestal

그림 8. 페데스탈 구동모델 입출력 Fig. 8 Input/Output signal of drive model

그림 9. 페데스탈 모델 입출력 Fig. 9 Input/Output signal of pedestal model

그림 10. 좌표계 정의 Fig. 10 Definition of coordinate system

그림 11. 표적 지향 방위각 정의 Fig. 11 Definition of pointing azimuth angle

그림 12. 수상함 회전운동응답 (해상상태6, 우현파) Fig. 12 Angular motion response of vessel (Sea state6, Beam sea)

그림 13. 페데스탈 운동응답 (Case1) Fig. 13 Motion response of pedestal (Case1)

그림 14. 페데스탈 운동응답 (Case2) Fig. 14 Motion response of pedestal (Case2)

표 1. 해상상태 등급표 Table 1. Sea State Table

표 2. 대상 수상함 제원 Table 2. Main particulars of surface vessel

표 3. 구동모델 변수 Table 3. Parameters for pedestal drive model

표 4. 시뮬레이션 조건 Table 4. Simulation conditions

표 5. 페데스탈 요동보상 최대오차 Table 5. Maximum error of directional pedestal