반잠수식 해양구조물의 동적위치유지 성능 시험 연구

Abstract

This paper shows a development of DPS(Dynamic Positioning System) for semi-submersible model and an experimental result of using the DPS in ocean engineering basin of KORDI/MOERI. The developed DPS consists of 4 azimuth thruster. Each azimuth thruster is small enough to be equipped in a column of semi-submersible model. To estimate the low frequency motion of platform Kalman filter is applied. Wave drift force and current force cause the drift motion in very low frequency region. The conventional PD or RMA(Resolved Motion and Acceleration) controller could not cancel this kind of steady state error without I controller. And this kind of I controller often cause divergence. So in this paper we suggest a modified I controller which feedback the accentuated error time mean value and show the effectiveness of this suggested modified I controller in experiment.