• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.5
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• pp.331-341
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• 2017

This paper presents the sea-trial results of Crabster CR6000 which is a deep-sea walking robot developed by KRISO in 2016. Crabster CR6000 is designed to inspect deep-sea environment rejecting the disturbance on the silent and calm abyssal area. The sea-trial was conducted at the East Sea and the Philippine Sea on December 2016. The Crabster CR6000 undocked successfully from the Shuttle after touchdown on the sea-bed and walked out on the soft sediment soil of the 4,743m seafloor at the fourth diving in the Philippine Sea. The advanced technologies and capabilities of CR6000 were verified from the operational and functional test conducted in the sea-trial. The experimental data acquired from the sea-trial were summarized and the first experience of the deep-sea walking robot was presented in this paper.

• Journal of Korea Multimedia Society
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• v.20 no.10
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• pp.1637-1645
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• 2017

Target/Nontarget classification can be divided into the study of shape estimation of the target analysing reflected echo signal and of type classification of the target using acoustical features. In active sonar system, the feature vectors are extracted from the signal reflected from the target, and an classification algorithm is applied to determine whether the received signal is a target or not. However, received sonar signals can be distorted in the underwater environments, and the spatio-temporal characteristics of active sonar signals change according to the aspect of the target. In addition, it is very difficult to collect real sea-trial data for research. In this paper, target/non-target classification were performed using real sea-trial data. Feature vectors are extracted using MFCC(Mel-Frequency Cepstral Coefficients), filterbank energy in the Fourier spectrum and wavelet domain. For the performance verification, classification experiments were performed using backpropagation neural network classifiers.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.1-8
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• 2012

To correctly estimate ice load and ice resistance for a ship's hull, it is essential to understand the material properties of sea ice during ice field trials and to use the proper experimental procedure for gathering ice strength data. The first Korean-made icebreaking research vessel (IBRV), ARAON, had her second sea ice trial in the Arctic Ocean during July and August of 2010. This paper describes the test procedures used to properly obtain sea ice strength data, which provides the basic information on the ship's performance in an ice-covered sea and can be used to estimate the correct ice load and ice resistance on the IBRV ARAON. The data gathered from three sea ice field trials during the Arctic voyage of the ARAON includes the ice compressive strength, flexural strength, and failure strain of sea ice. This paper analyzes the gathered sea ice data in comparison with data from the first voyage of the ARAON during her Antarctic Sea ice trial in January 2010.

• Journal of Ship and Ocean Technology
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• v.5 no.4
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• pp.44-50
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• 2001

Large container carriers are suffering from lack of knowledge on reliable correlation allowances between model tests and full-scale trials, especially at fully loaded condition, Careful full-scale sea trial with a full loading of containers both in holds and on decks was carried out to clarify it. Model test results were analyzed by different methods but with the same measuring data to figure out appropriated correlations factors for each analysis methods, Even if it is no doubt that model test technique is one of the most reliable tool to predict full scale powering performance, its assumptions and simplifications which have been applied on the course of data manipulation and analysis need a feedback from sea trial data for a fine tuning, so called correlation factor. It can be stated that the best correlation allowances at fully loaded condition for both 2-dimensional and 3-dimensional analysis methods are fecund through the careful sea trial results and relevant study on the large size container carriers.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.55-61
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• 2011

A field trial in an ice-covered sea is one of the most important tasks in the design of icebreaking ships and offshore structures. To correctly estimate the ice load and ice resistance of a ship's hull, it is essential to understand the material properties of sea ice during ice field trials and to use the proper experimental procedure for gathering effective ice data. The first Korean-made icebreaking research vessel, "ARAON," had her second sea ice trial in the Arctic Ocean during the summer season of 2010. This paper describes the test procedures used to obtain proper sea ice data, which provides the basic information for the ship's performance in an ice-covered sea and is used to estimate the correct ice load and ice resistance of the IBRV ARAON. The data gathered from the sea ice in the Chukchi Sea and Beaufort Sea during the Arctic voyage of the ARAON includes the temperature, density, and salinity of the sea ice, which was believed to be from two-year old ice floes. This paper analyses the gathered sea ice data in comparison with data from the first voyage of the ARAON during her Antarctic Sea ice trial.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.3
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• pp.208-215
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• 2011

A full-scale field trial in ice-covered sea is one of the most important tasks in the design of icebreaking ships. The first Korean icebreaking research vessel 'ARAON', after her delivery in late 2009, had a sea ice field trial in the Arctic Sea during July-August, 2010. This paper describes the test procedures and data analysis on the icebreaking performance of the IBRV ARAON. The data gathered from the icebreaking performance test in the Chukchi Sea and the Beaufort Sea during the Arctic voyage of ARAON includes the speed and engine power of the ship as well as sea ice thickness and strength data. The air temperature, wind speed and heading of the ship were also measured during each sea ice trial. The ARAON was designed to break 1 m thick level ice with a flexural strength of 630kPa at a continuous speed of 3knots. She is registered as a KR POLAR 10 class ship. The principal dimensions of ARAON are 110 m, 19 m and 6.8 m in length, breadth and draft respectively. She is equipped with four 3,500kW diesel-electric main engines and two Azipod type propulsion motors. Four sea ice trials were carried out to understand the relationship between the engine power and the ship speed, given the Arctic ice condition. The analysis shows that the ARAON was able to operate at 1.5knots in a 2.5m thick medium ice floe condition with the engine power of 5MW, and the speed reached 3.1 knots at the same ice floe condition when the power increased to 6.6MW. She showed a good performance of speed in medium ice floe compared to the speed performance in level ice. More detailed analysis is summarized in this paper.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.2
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• pp.29-37
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• 1998

Linear equations of motion for submersibles are one of the rest important design parameters, which are used as a governing equation for the shape design and the controller design. But, the estimated maneuvering coefficients in equations of motion by using empirical formulae, theoretical calculations or model tests might have some errors. Therefore the maneuvering coefficients should be verified from sea trial test. In this study, parallel extended Kalman filter method, Nelder & Mead Simplex method and genetic algorithm were applied to the parameter identification of roll maneuvering coefficients based on sea trial data. As a result, it was verified that Nelder & Mead Simplex method gave the most satisfactory results for the mathmatical models and the sea trial data used in this study.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.3
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• pp.254-259
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• 2011

The first Korean-made icebreaking research vessel "ARAON" had her second sea ice trial in the Arctic Ocean in Aug. 2010 after her first voyage to Antarctic Ocean in Jan. 2010 to gather various material and strength characteristics of sea ice. This is a detail report of ARAON 2010 summer Arctic voyage and this paper describes a standard test procedure to obtain proper sea ice data which provide basic information to estimate ice loads and icebreaking performance of the ship. The data gathered from sea ice in the Chukchi Sea and Beaufort Sea during the Arctic voyage of the ARAON includes ice temperature/salinity and the compressive/flexural strength of sea ice. This paper analyses the gathered sea ice data in comparison with data from the first voyage of the ARAON during her Antarctic Sea ice trial.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.5
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• pp.457-464
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• 2011

This paper deal with the validation of correction method of ice strength and thickness to the sea trial condition based on the ice model test results. It is very difficult to conduct the model test corresponding to the sea trial condition exactly. In addition, the available sea trial data is not sufficient for the validation of correction method. In the present study, the model test results of Terry-Fox ice breker have been used to compare the corrected results of sea trial test by varying its thickness and strength of model ice. The HSVA and ITTC methods have been applied to the present comparisions and the required power has been also validated by using the HSVA method. There are rather good agreement between the sea trial result and model test corrected by the HSVA and ITTC method. The more comparisons are expected to be carried out in near future.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.1
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• pp.8-14
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• 2011

RIB(Rigid Inflatable Boat) is widely used for coastal transportation in the commercial use and for ISR(Intelligence, Surveillance, Reconnaissance) in the military use. Since RIB is around 10 meters in length and over 30 knots in speed, its motion characteristics in waves is quite different from a large scale ship. When it turns, large roll occurs and heeling direction is opposite to the large ship's case. Currently, many countries are developing USV(Unmanned Surface Vehicle) of which type is RIB. In order to develop high performance autopilot and way point controller, it is very important to identify RIB's motion characteristics. In this paper, sea trial test results of a 7-meter RIB such as speed, turning, zig-zag, and way point control tests were represented and its resistance and propulsion model was identified by using sea trial data and Savitsky's formula. In addition, the state space model which will be used in the identification of the four-degree-of-freedom dynamics in the next step was formulated and the identification procedure was proposed.