• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.5
• /
• pp.507-512
• /
• 2007

This paper presents a tracking filter with ship's motion compensation for a ship-borne radar tracking system. The ship's maneuver is described by displacement and rotational motions in the ship-centered east-north frame. The first order Taylor series approximation of the measurement error covariance of the converted measurement is derived in the ship-centered east-north frame. The ship's maneuver is compensated by incorporating the measurement error covariance of the converted measurement and displacement of the position state in the tracking filter. The simulation results via 500 Monte-Carlo runs show that the proposed method follows the target successfully and provides consistent tracking performance during ship's maneuvers while the conventional tracking filter without ship motion compensation fails to track during such periods.

• Journal of the Korean Institute of Navigation
• /
• v.20 no.1
• /
• pp.11-26
• /
• 1996

On this paper, the traditional methods for the measurement of ship's maneuverabilities during the sea-trial of newly built ship are summarized and new methods for the same measurement using Integrated Navigation System and GPS are introduced. After various sea-trials of training ship "HANNARA" which are equipped with modern INS and GPS system, the results are compared and analysed. The purpose of this paper is to present more accurate methods of measurement of ship's maneuverabilities during sea-trial using INS and GPS which are gradually becoming the basic navigational equipments on many newly constructed vessels.d vessels.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.4
• /
• pp.429-436
• /
• 2018

The RCS value of maritime ship is indicator of ship's stealth performance and it should be particularly measured for navy ship to ensure survivability on the battlefield. In the design phase of the navy ship, a RCS prediction should be performed to reduce RCS value and achieve ROC(Required Operational Capability) of the ship through configuration control. In operational phase, the RCS value of the ship should be measured for verifying the designed value and obtaining tactical data to take action against enemy missile. During the measurement of RCS for the ship, ship motion can be affected by roll and pitch in accordance with sea state, which should be analyzed into threat elevation from view point of enemy missile. In this paper, we propose a method to measure and analyze RCS of ship in 3-dimensions using a ship motion measuring instrument and a fixed RCS measurement system. In order to verify the proposed method, we conducted a marine experiment using a test ship in sea environment and compared the measurement data with RCS prediction value which is carried by prediction SW($CornerStone^{TM}$) using CAD model of the ship.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.11a
• /
• pp.270-270
• /
• 2019

Although the Inertial Measurement Unit is applied to a variety of applications such as ships, submarines, and aircrafts, it is mainly used in the attitude measurement area. But since such equipment is expensive, it has been used only in special fields. In this study, the ship's seaworthiness is verified by measuring the speed, direction, gravity, and acceleration of the ship in real time using a low-cost Inertial Measurement Unit. A research method for estimating fIuid force coefficients was devised. Therefore, this study measured ship motion factors at sea, processed and analyzed the measured data, and evaluated the overall safety of the ship and estimated the resistance and steering performance of the ship.

• Journal of Ocean Engineering and Technology
• /
• v.36 no.1
• /
• pp.50-60
• /
• 2022

The deep ocean engineering basin (DOEB) of the Korea Research Institute of Ship and Ocean Engineering (KRISO) is equipped with an extreme-environment reproduction facility that can analyze the motion characteristics of offshore structures and ships. In recent years, there have been requirements for a wide range of six-degree-of-freedom (6-DOF) motion measurements for performing maneuvering tests and free-running tests of target objects (offshore structures or ships). This study introduces the process of developing a wide-area motion measurement technology by incorporating the auto-tracking technology of the towing carriage system to overcome the existing 6-DOF motion measurement limitation. To realize a wide range of motion measurements, the automatic tracking control system of the towing carriage in the DOEB was designed as a speed control method. To verify the control performance, the characteristics of the towing carriage according to the variation in control gain were analyzed. Finally, a wide range of motions was tested using a model test object (a remotely operated vehicle (ROV)), and the wide-area motion measurement technology was implemented using an automatic tracking control system for a towing carriage.

• Journal of Navigation and Port Research
• /
• v.38 no.6
• /
• pp.577-583
• /
• 2014

A ship-to-ship (STS) lightering operation takes place in order to transfer cargo (e.g. crude oil or petroleum products) between an ocean-going ship and a service ship alongside it. Instrumental measurements to accurately determine the relative speeds and distances during the approach between the vessels would benefit the operational safety and efficiency. A velocity information GPS (VI-GPS) system, which uses the instantaneous velocity measures from carrier-phase Doppler measurement, has been applied in a field observation onboard a service ship (Aframax tanker) approaching a ship-to-be-lightered (VLCC) in open waters. This article proposes to apply VI-GPS as the input sensor to a guidance and decision-support system aiming to provide accurate velocity information to the officer in charge of an STS operation. A method for precise velocity measurement using VI-GPS was described and the measurement results were compared each other with the results of Voyage Data Recorder (VDR) and VI-GPS that showed the concept of a guidance and decision-support system applying VI-GPS with the field test results during STS operations. Also, it turned out that VI-GPS has sufficient accuracy to serve as an input sensor from the field test results.

• Korean Journal of Computational Design and Engineering
• /
• v.20 no.3
• /
• pp.281-290
• /
• 2015

The specific goal of the SMS (Ship Management System) is to increate ship safety and decrease maintenance fee. Equipment of ship is managed by PMS (Planned Management System), subsystem of SMS. But hull has not managed by ship manager. So, the Classes have developed the system for hull maintenance. Recently, the ship maintenance system has been developed for satisfying operator's requirements such as managing maintenance data as integrated platform, intuitive manipulation and design for ease of use. To reflect such requirement, 3D Model based maintenance system was introduced for ship in operation stage. Hull items that have to be inspected, repaired, replaced, are stored in integrated data platform with drawing, reports, and etc. and completely linked to 3D product Model. This system is specially developed for measurement and maintenance of hull thickness.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.16 no.1
• /
• pp.135-140
• /
• 2010

Vibration on the ship was generated mainly by main engine and propeller. The vibration which is generated from the ship has an effect on durability of ship's machinery and it also has an evil influence on the working conditions for crew. In this research, vibration measurement system to measure ship's vibration was built and vibration signals using acceleration sensors were measured from an accomodation space of training ship. An evaluation of vibration with regard to habitability was also discussed and the evaluation process followed the guidelines ISO6954:2000E.

• Journal of the Society of Naval Architects of Korea
• /
• v.48 no.4
• /
• pp.336-341
• /
• 2011

Ship infrared signature is the cause of detection and tracking by infrared sensor and anti-ship missile seeker. Recent warships have been applied the infrared stealth technology to reduce own ship infrared signature and tested to validate own ship infrared signature level. This study describes the two issues. Firstly, we describe the infrared measurement concept and infrared signature level establishment method that have been performed. Secondly, we compare and analyze the error components between the infrared measurement and simulation result.

• Journal of the Society of Naval Architects of Korea
• /
• v.40 no.4
• /
• pp.66-74
• /
• 2003

In non-contact underwater explosion shock test of a real naval ship, measurement of shock loadings and responses should require onboard system to be able to safely trigger an explosive and to simultaneously and successfully measure scores of shock signals in the deteriorated environment. For this purpose, we have developed a shock-hardened measurement system resistible to 170g peak acceleration having 4 msec duration by resiliently mounting general purpose measurement instruments in racks. The system can simultaneously measure and record 200 signals to evaluate shock leadings and responses of the test ship by triggering an explosive and measurement instruments at the same time. We prove the performance of the developed system by introducing the signal acquisition results from of a real ship underwater shock test, firstly performed in Korea.