Chang Min Lee

A Simplified Horizontal Maneuvering Model of a RIB-Type Target Ship

AbstractA Rigid Inflatable Boat (RIB) is now widely used for commercial and military purpose. In this paper, it is supposed that seven-meter-class RIB be used a s an unmanned target ship for naval training. In order to develop many tactical maneuvering patterns of a target ship, a simple horizontal maneuvering model of a RIB is needed. There fore, models of speed and yaw rate are constructed as the first-order differential equati ons based on Lewandowskis empirical formula for steady turning circle diameter of a conve ntional planning hull. Some parameters in the models are determined using the results of se a trial tests. Finally, proposed models are validated through the comparison of the sim ulation result with the sea trial result for a specific scenario. Even though a simple model does not represent the horizontal motion of a RIB precisely, however, it can be used enough to develop tactical trajectory patterns. ※Keywords: RIB(고형부력선), Unmanned target ship(무인 표적정), Maneuvering model(조종모델), Sea trial(실선 시운전), Tactical pattern(전술 패턴)

Implementation of multi-vessel tracking algorithm using multiple marine radar systems

To prevent marine casualties, marine radars are widely used for tracking vessels near coast and, in general, multiple marine radars are applied to cover wide coastal area. Therefore their cooperative operation is very important for effective vessel traffic control. This work introduces implementation of a multivessel, multiradar tracking algorithm which can be used for such purpose. The implemented algorithm is based on the sensor-level tracking with centralized track file architecture which maintains a sensor-level (local) track file at each local radar site and integrate them into one central-level (global) track file using cross-correlation of the sensor-level tracks. The sensor-level tracking at each local radar site employs the conventional global nearest neighbor (GNN) approach which uses the auction algorithm for data association. The sensor-level tracks formed at each radar site are transmitted to data fusion center and combined by a track-to-track fusion algorithm to give central-level tracks. The resulting central-level tracks are also correlated against time to give a continuous track file for each target vessel even though it goes through the border of different radars scan area. To validate the algorithm, a simulation was fulfilled and it showed that it operated properly as intended.

Modeling and Simulation of a Ship with Anti-Rolling Devices in Waves

Wave exciting force and moment generate the motions of a ship in waves. Since ship motion exerts the negative influences on a crew`s operability, the safety of cargos, passenger`s comfort, etc, the anti-rolling devices may be required to reduce such motion In this paper, the dynamics of the anti-rolling devices such as passive and active moving weight stabilizer and anti-rolling tank, and fin stabilizer are mathematically modeled While the effect of the motion of the anti-rolling device on a ship was taken into consideration in roll mode only in the past, the 6 DOF coupled equations of motion between a ship and the anti-rolling devices are constituted Finally the motion of a ship with anti-rolling devices in waves is simulated through the developed simulation program