• Title/Summary/Keyword: Course keeping

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A Study on the Maneuverabilities of the M . S . Pusan 404-Tests by a Series of Turning Circles , New Course Keeping and Spiral (부산 404호의 조종성능에 관한 연구)

  • 김민석
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.28 no.1
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    • pp.21-26
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    • 1992
  • Generally a navigator evaluated the maneuverability of his ship by the scale of turning circle which was described only by the largest rudder angle of the port and starboard sides. But to have the sufficient knowledge of his ship's maneuvering characteristics he should consider the data about the new course keeping test, the spiral test, and the turning circle tests in accordance with the rudder angles together. In this paper the author performed the above tests to study the maneuverability of the stern trawler M.S. Pusan 404 which is a training ship of the National Fisheries University of Pusan. The obtained results are summarized as follows: 1. When the rudder angles being 5。, 10。, 20。, 30。, 35。 the advances of the starboard side turning circles were 12.8, 8.2, 4.8, 2.9, 2.7 times as large as the length of the ship, and of the port side turning circles were 13.3, 8.7, 5.4, 3.5, 2.9, time as large as the large as it. Under the same conditions the tactical diameters were 15.1, 9.7, 5.2, 3.1, 2.8 times as large as the length of the ship, for starboard side, and 17.2, 12.4, 6.4, 3.7, 3.2 times as large as it for port side. 2. As the rudder angle being increased the ratio of the advance to the tactical diameter was nearly 1 and her obeying ability was better than that of the small angle. 3. The mean values of the rates of speed reduction during the steady turning motion were 0.96, 0.92, 0.82, 0.71, 0.65 in accordance with the rudder angles. 4. The relative formulas between the distance to the new course y and the altering course x were as follows: When rudder angles being 10。, 20。, 30。, y=52.2222+1.6133x, y=48.750+0.9383x, y=39.250+0.655x respectively. 5. There was little difference of the distance to the new course between rudder angle 20。and 30。, and so it is desirable for a navigator to a navigator to use the small rudder angles unless sudden emergencies. 6. Though her rudder angle being small her course stability was good according to the spiral tests.

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Textural Changes of Cooked-Rice during Warm Keeping in Electrical Rice Cooker (전기밥솥에서 보온중인 밥의 조직감 변화)

  • Lee, Y.J.;Hwang, S.W.;Kim, S.K.;Park, Y.S.;Chun, J.K.
    • Applied Biological Chemistry
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    • v.38 no.5
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    • pp.422-424
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    • 1995
  • In order to investigate the textural changes of cooked rice in a home electrical rice cooker during warm keeping period, rice was cooked and stored at $73^{\circ}C$ for 42 hours. The time course changes of hardness and adhesiveness of cooked rice were measured with the specimen prepared as a cylindrical rice block(H/D= 15 mm/20 mm). At the initial stage of warm keeping period the hardness was 1.61 kg and it was increased steadily to 1.95 kg up to 12 hours. And it was rapidly dropped to 1.57 kg within 3 hours, and thereafter gradually decreased to 1.44 kg. The adhesiveness was steadily declined with warm keeping period from 0.51 to 0.323kg set The cohesiveness and chewiness were also changed in the similar pattern to that of hardness while the springiness remained unchanged throughout the whole warm keeping period.

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Design the Autopilot System of using GA Algorithm

  • Lee, Sang-Min;Choo, Yeon-Gyu;Lim, Young-Do
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.699-703
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    • 2004
  • The autopilot system targets decreasing labor, working environment, service safety security and elevation of service efficiency. Ultimate purpose is minimizing number of crew for guarantee economical efficiency of shipping service. Recently, being achieving research about Course Keeping Control, Track Keeping Control, Roll-Rudder Stabilization, Dynamic ship Positioning and Automatic Mooring Control etc. which compensate nonlinear characteristic using optimizing control technique. And application research is progressing using real ship on actual field. Relation of Rudder angle which adjusted by Steering Machine and ship-heading angle are non-linear. And, Load Condition of ship acts as non-linear element that influence to Parameter of ship. Also, because the speed of a current and direction of waves, velocity and quantity of wind etc. that id disturbance act in non-linear form, become factor who make service of shipping painfully. Therefore, service system of shipping requires robust control algorithm that can overcome nonlinearity. In this paper, Using GA algorithm,design autopilot system of ship that could overcome the non-linear factor of ship and disturbance and examined result through simulation.

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A study on the Manoeuvring Motion Under the Condition of External Forces in Restricted Waterways

  • Lee Chun Ki;Kang Il Kwon;Yoon Jeom Dong
    • Proceedings of KOSOMES biannual meeting
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    • 2003.11a
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    • pp.123-126
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    • 2003
  • In the present paper, the analysis is on the safe navigation between ships moving each other in restricted waterways under the external force, such as wind or current The numerical simulation of manoeuvring motion was carried out to propose an appropriate safe speed and distance between ships, which is required to avoid marine disasters from the viewpoint of marine safety. From the inspection q this investigation, it indicates the following result In case of proximal navigation between ships under the wind and current, the low-speed vessel is potentially hazardous because the rudder force if low-speed vessel needed for steady-state course-keeping is not sufficient, compared to the high-speed vessel The manoeuvring characteristic based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in restricted waterways.

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Airport Noise Reduction based on Track Keeping (항로제한을 통한 공항주변 소음피해 영향검토)

  • Min, Ji-Hoon;Kim, Jung-Tae;Son, Jung-Gon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.65-70
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    • 2000
  • Flying an aircraft is not like driving a train along a railway track. There are many factors that may affect an aircraft's course, including the wind speed and direction relative to the aircraft's intended flight path. This paper investigates noise exposed area by using INM. Especially, effect on aircraft route to minimise the number of people overflown by departing aircraft is evaluate. The result shows that track keeping scheme is effective to reduce the noise area. On the other track at 4000ft is negligible to the noise contour.

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Route Analysis Algorithm using Fuzzy Reasoning in Route Planning (항로 계획시의 퍼지 항로분석 알고리즘)

  • 구자윤
    • Journal of the Korean Institute of Navigation
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    • v.20 no.3
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    • pp.65-71
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    • 1996
  • Recently, the Track Control System which was separated from the Course Control System so-called Auto-Pilot has been developed for track-keeping in coastal area. From this year, the NAV Sub-committee in IMO commenced to consider the Performance Standard for the Track Control System vigorously. This system will be integrated with ECDIS and IBS so that captain/officers should analysis ship's motion characteristics accurately in the route planning using the electronic nautical charts. In this paper, a new Route Analysis Algorithm using fuzzy reasoning in route planning was proposed for 2, 700 TEU container ship. In order to verify the track-keeping, the author established a ship mathematical model and executed the simulation of the Route Analysis Algorithm at on-line condition with Pentium PC. The results of ship trajectories of the Route Analysis Algorithm were found to be effective to get track control automatically.

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An Analysis of Major Maritime Casualty from Bridge Resource Manage

  • Kim, Thi Thu Lan;Jeong, Jae-Yong;Jeong, Jung-Sik
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2011.11a
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    • pp.13-15
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    • 2011
  • This report represents analysis of the maritime casualty in terms of Bridge Resource Management. We evaluate the attitudes and knowledge of bridge officer regarding human factors issues that have been identified as causal to mishaps in high-risk situations. So to reduce human errors our goal is to establish effective officer resource management (ORM) program which is based on all subjects for cadets in IMO model course. In harmonization with STCW(The International Convention on Standards of training, Certification and Watch-keeping for Seafarers), as the result, the curriculumss in the maritime education institutions is surveyed to improve our education system and then reduce the human errors by mariners at sea.

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Study on a New and Effective Fuzzy PID Ship Autopilot

  • Le, Minh-Duc;Nguyen, Lan-Anh
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1628-1631
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    • 2005
  • Ship Autopilots are usually designed based on the PD and Pill controllers because of simplicity, reliability and easy to construct. However their performance in various environmental conditions is not as good as desired. This disadvantage can be overcome by adjusting works or constructing adaptive controllers. But those methods are complex and not easy to do. This paper presents a new method for constructing a Ship Autopilot based on the combination of Fuzzy Logic Control (FLC) and Linear Control Theory (Pill control). The new Ship Autopilot has the advantages of both the Pill and FLC control methodologies: easy to construct, and optimal control laws can be established based on ship masters' knowledge. Therefore, the new ship autopilot can be well adapted with parameter variations and strong environment effects. Simulation using MATLAB software for a ship with real parameters shows high effectiveness of the Fuzzy Pill autopilot in course keeping and course changing manoeuvres in comparison with the ordinary Pill ship autopilots.

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A Study on Rudder-Roll Stabilization System Design for Ship with Varying Ship Speed (선박 주행속도 변화를 고려한 Rudder-Roll Stabilization System 설계에 관한 연구)

  • Kim, Young-Bok;Chea, Gyu-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.5
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    • pp.363-372
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    • 2002
  • In ship operation, the roll motions can seriously degrade the performance of mechanical and personnel effectiveness. So many studies for the roll stabilization system design have been performed and good results have been achieved. In many studies, the stabilizing fins are used. Recently rudders, which have been extensively modified, have been used exclusively to stabilize the roll. But, in the roll stabilization control system, the control performance is very sensitive to the ship speed. So, we can see that it is important to consider the ship speed in the rudder roll control system design. The gain-scheduling control technique is very useful in the control problem incorporating time varying parameters which can be measured in real time. Based on this fact, in this paper we examine the;$H_{\infty}$-Gain Scheduling control design technique. Therefore, we assume that a parameter, the ship speed which can be estimated in real time, is varying and apply the gain-scheduling control technique to design the course keeping and anti-rolling control system far a ship. In this control system, the controller dynamics is adjusted in real-time according to time-varying plant parameters. The simulation result shows that the proposed control strategy is shown to be useful for cases when the ship speed is varying and robust to disturbances like wind and wave.

Design the Autopilot System of using Fuzzy Algoritim

  • Kim, Young-Hwi;Bae, Gyu-Han;Park, Jae-Hyung;Kang, Sin-Chool;Lee, Ihn-Yong;Lim, Young-Do
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.296-300
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    • 2003
  • The autopilot system targets decreasing labor, working environment improvement, service safety security and elevation of service efficiency. Ultimate purpose is minimizing number of crew for guarantee economical efficiency of shipping service. Recently, being achieving research about Course Keeping Control, Track Keeping Control, Roll-Rudder Stabilization. Dynamic Ship Positioning and Automatic Mooring Control etc. which compensate nonlinear characteristic using optimizing control technique. And application research is progressing using real ship on actual field. Relation of Rudder angle which adjusted by Steering Machine and ship-heading angle are non-linear. And Load Condition of ship as non-linear element that influence to Parameter of ship. Also, because the speed of a current and direction of waves, velocity and quantity of wind etc. that is disturbance act in non-linear from, become factor who make serv ice of shipping painfully. Therefore, service system of shipping requires robust control algorithm that can overcome nonlinearity. In this paper, Using fuzzy algorithm ,Design autopilot system of ship that could overcome the non-linear factor of ship and disturbance and examined result through simulation.

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