• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.39 no.1
• /
• pp.1-7
• /
• 2003

When a ship is course-keeping in the open seas, autopilot system is adapted. The design of autopilot system is very important for improvement of ship′s element research. Automatic steering system consists of autopilot device, power unit, steering gear, magnetic or gyro compass and ship dynamics. In order to evaluate automatic steering system of ships in open seas. we need to know the characteristics of each component of the system, and also to know the characteristics of disturbance to ship dynamics. In this paper, I provide evaluation method of autopilot navigation system of the fishing ship. Prediction method based on the principle of linear superposition is introduced for irregular disturbance. For the evaluation of automatic steering system of a ship, "performance index" is introduced from the viewpoint of energy saving and calculation method is frequency response analysis. Finally, I carried out calculation of sensitivity of control constants of autopilot with various conditions of ocean environments.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.2
• /
• pp.118-124
• /
• 2008

Recently fishing industry is interested in efficiency and automation to acquire the international competitive power of national fishing industry. As an automation device of fishing boat, there are electric compasses using GPS and terrestrial magnetic sensor. Electric compass can be minimum size, high effectiveness with keeping the characteristic of a magnetic compass. This can be used a heading angle sensor to construct auto-navigation system in a small size ship. This paper develop electronic compass system that has serial output signal in NMEA 0183 and demonstrates the possibility of the electronics compass in navigation system for a small sized ship.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.349-350
• /
• 2015

소형 어선들은 디젤유를 주 동력원으로 사용하여 모터를 구동시킨다. 이때 사용되는 모터는 배에 필요한 동력 및 전력을 공급해 주는데 리터당 효율을 계산할 경우 효율이 매우 낮다. 그렇기 때문에 전력 변환 효율이 높음에도 불구하고 전체 시스템의 관점에서는 효율이 매우 낮음을 보인다. 본 논문에서는 어선의 전력 계통도를 전기적으로 모델링하여 실제로 일어날 수 있는 모든 시나리오를 시뮬레이션을 통해 확인 할 수 있도록 구성하였다. 또한 낮은 효율의 문제를 해결하기 위하여 태양광 발전 시스템을 도입하여 디젤 모터에 걸리는 부하를 줄여 전체 시스템의 효율이 증가하는 것을 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.110-111
• /
• 2019

본 논문은 DC 배전 전기 추진 시스템으로 건조된 10톤급 소형 어선을 운항하며 계측한 실험 결과를 제시한다. DC 배전 선박과 모의된 AC 배전 선박을 일반적인 10톤급 소형 어선의 운용 패턴에 따라 운항하였고, 각 경우의 연료소모량을 유량계로 측정하였다. DC 배전 시스템은 가변속으로 인한 엔진의 효율적인 운전과 전기설비 무게 감소로 인한 추진 부하 감소의 효과로 AC 배전 시스템에 비하여 연료사용량이 약 20% 가량 절감된다. 실험 결과, DC 배전 전기 추진 선박을 적용할 시 연간 약 18,500L (22.0%)의 연료가 절감되어 연료비가 매년 약 1400만원 가량 절약될 것으로 예상된다.

• Journal of Power System Engineering
• /
• v.21 no.2
• /
• pp.77-82
• /
• 2017

In the fishing boat, freshwater ice is loaded on the fishroom in advance and it is used for storage of fishes. However, it causes degradation of catches' freshness. Therefore, seawater ice machine on board is necessary for the fishing industry. In this study, seawater ice machine with drum type evaporator was manufactured, and the system was tested under various operating conditions having an influence on the COP and amount of ice produced. The main results are as follow : The COP of the system gets larger when the evaporation temperature and rotation speed of the drum in the evaporator increases. The most effective refrigerant is R22 and the value of the COP was 1.43 times higher than that of R404A. The amount of produced ice increases with respect to increment of the evaporation temperature, while that decreases with respect to increment of the evaporator drum rotation speed.

• Journal of Advanced Marine Engineering and Technology
• /
• v.28 no.2
• /
• pp.382-392
• /
• 2004

The usage of constant velocity (CV) joint is effective for motorboats on gliding regime of the motion. During transition on the gliding when angle of the CV differs from null on driving and driven composite shafts there are moments of the second order. Excitation of oscillations of the second order moments occurs when driving shafts transmits a variable torque. which generates through CV joint a lateral moment acting on the bearing. As a result of oscillations from a resonating harmonic of a shafting the harmonic with the greater or periodically varying amplitude for power condition trough transferring to nominal power 144kW. Beating conditions coincide with third mode having frequency 45.486 Hz. In that case there is high increasing of the equivalent stresses. The forming of the stiffness of the composite material is concerned to use most orientation of the layer angle in the range of $\pm$60 degrees relatively of shaft axis. Application of that angles for layer orientation gives possibility to avoid high disturbance of the shafting for motorboat transition regime.

• Journal of Engineering Education Research
• /
• v.12 no.2
• /
• pp.89-95
• /
• 2009

This thesis investigated way of employment, education course of a training school of Programmable Logic Controller a Field. I inquired into a demand of an engineer and a necessary level of professional education. As a result, I have a purpose in what offer the information that cared for a beginning to work elevation and education training and boat development of a student more than. Faced a human power demand in an education demand and a field rehearsal student demand and analyzed it. The sample extraction used industrial classification, work of scale, Assignment sample extraction way (quota sampling). All data called at a silver phone and the investigated, The data parser analyzed the statistics that used Microsoft Excel.

• Journal of Engineering Education Research
• /
• v.11 no.3
• /
• pp.90-95
• /
• 2008

This thesis investigated way of employment, education course of a training school of electrical company. I inquired into a demand of an engineer and a necessary level of professional education. As a result, I have a purpose in what offer the information that cared for a beginning to work elevation and education training and boat development of a student more than. Faced a human power demand in an education demand and a field rehearsal student demand and analyzed it. The sample extraction used industrial classification, work of scale, Assignment sample extraction way (quota Sampling). All data called at a silver phone and the investigated, The data parser analyzed the statistics that used Microsoft Excel.

• Journal of Power System Engineering
• /
• v.22 no.1
• /
• pp.41-47
• /
• 2018

This paper analyzes the output characteristics of a self excited induction generator with isolated mode according to change of its speeds and loads for building a hybrid electric propulsion system in special purpose ships by using power take off. The induction generators are being considered as an alternative choice to the well-developed generators because of their lower unit cost, inherent ruggedness, operational and maintenance simplicity. However, the generator working by stand alone has a few problems that the reactive power is required to establish the air gap magnetic flux, and the induced voltage and magnetizing current fluctuate when the load is varied. In spite of its advantages, basic design data of the capacitor bank and behaviors of the output characteristics of the generator are not sufficient for the system. Based on the operating condition(speed range of main engine) of the target boat, a reduced experimental equipment system was constructed to analyze the output characteristics of the SEIG. And a suitable capacitor bank of a stand-alone generator and its output characteristics under various loads was investigated in detail through these experiments. According to the experimental result, it was confirmed that the capacitor bank should be $70{\mu}F{\sim}100{\mu}F$, and the proper SEIG induced voltage should be DC 80 V ~ 250 V in order to storage electrical energy into a battery.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.4
• /
• pp.347-355
• /
• 2016

In this study, a new designed propeller was applied on 24 ton class squid jigging vessel to reduce of fuel consumption. The selected squid jigging boat was under construction at the shipyard to determine the resistance of the hull through the model experiment. The propeller design was carried out by using the experimental data and ITTC procedures. Sea trials were performed by measuring the speed and the horsepower required by the condition of five power levels of engine load, namely 70%, 80%, 90%, MCR and maximum engine power. The speed and delivered horse power were compared between the conventional propeller and the new design propeller. Delivered horse power by installing the new propeller takes 90% engine load at start-up conducted by decreased 9.06%. The measuring speed is increased up to the 0.6 knots in the low-speed range to high range. This study showed that only the design and installation of a new propeller can improve the propulsion efficiency of the boats; furthermore, reduce fuel costs can be achieved at the same time by improving the increased cruising speed.