• Journal of Advanced Marine Engineering and Technology
• /
• 제22권6호
• /
• pp.920-927
• /
• 1998

This paper presents a synthetic control algorithm that generates the rudder command angle to track the optimal route which is composed of straight-lines among way-points with keeping a required error limit. The control algorithm comprises three main lgorithms that is a course-keeping algorithm that eliminates the yaw angle difference between optimal route and current route a track-keeping algorithm that tracks the optimal route among way-points and a turning-control algorithm that includes the generation of optimal turning routes and control method. The effectiveness of the proposed control algorithm is assured through computer simulation.

• 한국항해학회지
• /
• 제20권3호
• /
• pp.65-71
• /
• 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.

• 수산해양기술연구
• /
• 제23권2호
• /
• pp.47-53
• /
• 1987

충무권의 선로내에 관측선을 정하고 통항선박의 선적을 연속측정한 자료로서 항행중의 위험성과 조선상의 여유와 부담에 관하여 연구한 결과를 요약하면 다음과 같다. 1. 항행중의 위험성은 동항할 때 모두 항로의 동부보다 중앙부와 서부에서 비교적 높았다. 2. 조선상의 여유는 동항할 때는 선로의 서부, 서항할 때는 선로의 중앙부에서 가장 높았다. 그러나 서부입구에서는 동항할 때나 서항할 때 모두 가장 낮았다. 3. 조선상의 여유는 동항할 때나 서항할 때 모두 항로의 서부에서 높았고 동부에서 낮았다. 4. 조종성지수 T', K'는 모두 좌초위험지수 R에 영향을 미치나 T'가 K'보다 더 많은 영향을 미치는 것으로 나타났다

• 수산해양기술연구
• /
• 제23권2호
• /
• pp.1-1
• /
• 1987

충무권의 선로내에 관측선을 정하고 통항선박의 선적을 연속측정한 자료로서 항행중의 위험성과 조선상의 여유와 부담에 관하여 연구한 결과를 요약하면 다음과 같다. 1. 항행중의 위험성은 동항할 때 모두 항로의 동부보다 중앙부와 서부에서 비교적 높았다. 2. 조선상의 여유는 동항할 때는 선로의 서부, 서항할 때는 선로의 중앙부에서 가장 높았다. 그러나 서부입구에서는 동항할 때나 서항할 때 모두 가장 낮았다. 3. 조선상의 여유는 동항할 때나 서항할 때 모두 항로의 서부에서 높았고 동부에서 낮았다. 4. 조종성지수 T', K'는 모두 좌초위험지수 R에 영향을 미치나 T'가 K'보다 더 많은 영향을 미치는 것으로 나타났다

• International Journal of Aerospace System Engineering
• /
• 제2권1호
• /
• pp.31-37
• /
• 2015

Passenger plane flying motion graphics is very important for route, control of the flight altitude and passenger safety. For all that, it is quite useful for route away from the disruptive influences such as vibrations caused by storms or turbulence during the flight and in processes such as re-arrest of the specified route. Therefore, the response time against the adverse effects of the shape and the system is so necessary for both safety and comfort. In this study motion and route graphics were obtained under the control of an airliner C # interface with the program. In this way, graphics were obtained in solving the equations of motion in short time and design time was shortened.

• Journal of Advanced Marine Engineering and Technology
• /
• 제25권1호
• /
• pp.199-208
• /
• 2001

In this paper, an automatic route tracking algorithm using the position variables and the yaw angle of a ship is suggested, Since most autopilot systems paly only a role of course-keeping by integrating the gyrocompass output, they cannot cope with position errors between the desired route and real route of the ship resulted from a drifting and disturbances such as wave, wind and currents during navigation. In order for autopilot systems to track the desired route, a method which can reduce such position errors is required and some algorithms have been proposed[1,2]While such were turned out effective methods, they have a shortage that the rudder control actions for reducing the position errors are occurred very frequently. In order to improve this problem it is necessary to convert that error into the corresponding yaw angle and necessary to treat only yaw angle control problem. To do this a command generation algorithm which converts the rudder angle command reducing the current position error into they yaw angle command is suggested. To control the ship under disturbances and nonlinearities of the ship dynamics, the adaptive fuzzy controller is developed. Finally, through computer simulations for two ship models, the effectiveness of the suggested method and the possibility of the automatic route tracking are assured.

• Journal of Communications and Networks
• /
• 제7권3호
• /
• pp.325-336
• /
• 2005

Mobile ad hoc networks (MANET) are composed of moving wireless hosts which, within range of each other, form wireless networks. For communication to occur between hosts that are not within each other's range, routes involving intermediate nodes must be established; however, since the hosts may be in motion, a host that was part of a route may move away from its upstream and downstream partners, thus breaking the route. In this paper, we propose anticipated route maintenance (ARM) protocol with two extensions to route discovery based routing scheme: Extend the route when nodes on a link move apart from each other and they have common neighbor that can be 'inserted' in the path, and shrink route when a node discovers that one of its neighbor which is not the next hop is also on the same route several hops later on. By utilizing only local geographic information (now a part of some route finding algorithms), a host can anticipate its neighbor's departure and, if other hosts are available, choose a host to bridge the gap, keeping the path connected. We present a distributed algorithm that anticipates route failure and performs preventative route maintenance using location information to increase a route lifespan. The benefits are that this reduces the need to find new routes (which is very expensive) and prevents interruptions in service. As the density of nodes increases, the chance to successfully utilize our route maintenance approach increases, and so does the savings. We have compared the performance of two protocols, pure dynamic source routing (DSR) protocol and DSR with ARM. The simulation results show how ARM improves the functionality of DSR by preventing the links in the route from breaking. Packets delivery ratio could be increased using ARM and achieved approximately $\100%$ improvement. The simulations clarify also how ARM shows a noticeable improvement in dropped packets and links stability over DSR, even though there is more traffic and channel overhead in ARM.

• 대한산업공학회지
• /
• 제20권4호
• /
• pp.5-21
• /
• 1994

We have described the optimal process route selection model for the PCB(printed circuit board) auto-insertion line. This PCB assembly line is known as a FFL(flexible flow line) which produces a range of products keeping the flow shop properties. Under FFL environments, we have emphasized the balancing of work-loads in order to maximize total productivity of PCB auto-insertion line. So we have developed a heuristic algorithm based on a work-order selection rule and min-max concept for the job route selection model.

• 한국통신학회논문지
• /
• 제35권9A호
• /
• pp.844-851
• /
• 2010

최근 AODV 라우팅 프로토콜은 무선센서네트워크에서 노드 간에 데이터 전송방식을 추구하므로 요구기반방식중 가장 널리 사용되고 있다. AODV는 활성화 경로(activity route)만 라우팅 테이블을 유지하기 때문에 라우팅 패킷의 오버헤드가 적고, 경로 단절시 경로 복구를 재설정할 수 있는 장점을 가지고 있다. 하지만 경로 복구를 위해 네트워크 대역폭의 낭비가 과다하고, 경로 복구 시간이 오래 걸린다는 단점을 가지고 있다. 따라서 본 논문에서는 AODV기반 무선센서네트워크 환경에서 경로 단절이 발생한 경우에 저-재전송을 위한 효율적인 경로 복구방법을 제안한다. 제안한 방법은 지역경로복구의 영역을 확대하고, 확대된 지역경로복구 영역을 제한하기 위하여 노드간의 거리, 에너지량을 고려하여 RREQ 메시지의 개수를 제한하여 경로를 효율적으로 복구한다. 실험결과, 제안한 AODV 방법은 기존 방법보다 패킷 폐기율이 15.43% 감소하고, 경로 재설정시 지연시간은 평균적으로 0.20sec 단축되었다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2004년도 Asia Navigation Conference
• /
• pp.167-176
• /
• 2004

The authors have newly developed the “Port Traffic Management System (PTMS)”. The PTMS provides each ship with the detailed planned routes of all the ships entering/leaving the port. This system also has a function to predict the encounter situations between own ship and other ships in the future. Based on information of the present positions, speeds and planned routes of the own ship and other ships, it is possible to predict when and where the own ship will have dangerous encounters with other ships in the future. The software of PTMS was developed from 2001. Then onboard experiments using small training ships equipped with actual AIS were performed in June 2003. From the results of these onboard experiments, the usefulness of PTMS was clarified. In addition to these onboard experiments, the effectiveness of PTMS was confirmed by comprehensive simulator experiments. In the simulator experiments, captains/pilot maneuvered a training ship/container ship in congested waters using PTMS. [t was assumed that all ships have PTMS and send their planned routes. After the simulator experiments, captains/pilot suggested that it is very beneficial if the optimal route of own ship can be automatically calculated. In response to this suggestion, software to calculate the optimal route of own ship using Dynamic Programming was developed. This software calculates the minimum time route from the present position to the destination keeping the danger of collision against other ships under predetermined level. From the result of calculations for multi-encounter situations, it was confirmed that the developed software can provide safe and time-saving route.