• 한국산학기술학회논문지
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• 제16권6호
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• pp.3680-3684
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• 2015

조선소에서 데크 크레인은 지상에 설치된 타워 크레인이나 해상 크레인을 사용하여 리프팅 설치 방법에 의해 선박에 탑재된다. 데크 크레인의 두 점 리프팅 설치 작업 시에는 임시 고정 지그 등을 사용하는데, 안전한 리프팅 작업을 위해서는 고정 지그의 형상 및 설치 위치를 고려한 리프팅 안전성 평가가 선행되어야 한다. 본 연구에서는 데크 크레인 및 고정 지그에 해당하는 유한요소해석 모델을 각각 생성하고, 리프팅 반력 및 경계 조건을 적용한 구조 해석을 수행하여 리프팅 설치 작업에 대한 안전성을 평가하였다. 본 연구에서 제시한 안전성 평가 방법은 다양한 데크 크레인의 리프팅 설치 작업 시에 보다 안전한 리프팅 작업 가이드를 제공할 수 있는 해석적 툴로 활용될 수 있다.

• 한국해양공학회지
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• 제17권3호
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• pp.33-38
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• 2003

This study focuses on an analytical approach to calculate crane-lifting forces for a sunken ship, with consideration to elongation of crane ropes. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the ship's hull, including the effect of lug positions. For lifting analysis, the Euler angles are defined to represent the inclination of a sunken ship in developing the static force and moment equations. An additional compatibility condition is introduced in order to solve an indeterminate lifting analysis problem with 4 cranes. A set of lifting forces along the 4 crane ropes is calculated. A 3-dimensional example of the G/T 1500 oil tanker is analyzed. The results show that the information obtained by the method could be useful to engineers when conducting salvage work.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.563-570
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• 2022

Industrialized and modular construction is a growing construction technique that can transfer a large portion of the construction process to off-site fabrication yards. This method of construction often involves the fabrication, pre-assembly, and transportation of massive and long volumetric modules. The module weight keeps increasing as the modules become more complete (with infill) to minimize the work at the site and, as higher productivity can be achieved at the fabrication shop. Thus, a volumetric module delivery gets more challenging and risky. Despite its importance, past research paid relatively insufficient attention to the problem related to the lifting of heavy modules. This can be a complex and time-consuming problem with multiple lifting for transportation-and-installation operations both in fabrication yard and jobsite, and require complex crane operations (sometimes, more than one crane) due to crane load capacity and load balance/stability. This study investigates this problem by focusing on the structural perspective of lifting such long volumetric modules through simulation studies. Various scenarios of lifting a weighty module from the top using four lifting cables attached to crane hooks (either a single crane or double crane) are simulated in SAP software. The simulations account for various factors pertaining to structural indices, e.g., bending stress and deflection, to identify a proper method of module lifting from a structural point of view. The method can identify differences in structural indices allowing identification of structural efficiency and safety levels during lifting, which further allows the selection of the number of cranes and location of lifting points.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.179-184
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• 2003

This study focuses on an analytical approach to calculate crane lifting forces for a sunken ship in consideration oj elongation of crane ropes. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the ship's hull including the effect of lug positions. For lifting analysis, the Euler angles are defined to represent the inclination of a sunken ship in developing the static force and moment equations. An additional compatability condition is introduced in order to solve an indeterminate lifting analysis problem with 4 cranes and a set of lifting forces along the 4 crane ropes is calculated. A 3-dimensional example of the G/T 1500 oil tanker is analyzed and the results show that the information obtained by the method could be useful to engineers to conduct salvage work.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.321-323
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• 2015

Monitoring crane motion in real time is the first step to identifying and mitigating crane-related hazards on construction sites. However, no accurate and reliable crane motion capturing technique is available to serve this purpose. The objective of this research is to explore a method for real-time crane motion capturing and investigate an approach for assisting hazard detection. To achieve this goal, this research employed various techniques including: 1) a sensor-based method that accurately, reliably, and comprehensively captures crane motions in real-time; 2) computationally efficient algorithms for fusing and processing sensing data (e.g., distance, angle, acceleration) from different types of sensors; 3) an approach that integrates crane motion data with known as-is environment data to detect hazards associated with lifting tasks; and 4) a strategy that effectively presents crane operator with crane motion information and warn them with potential hazards. A prototype system was developed and tested on a real crane in a field environment. The results show that the system is able to continuously and accurately monitor crane motion in real-time.

• 대한조선학회논문집
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• 제41권2호
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• pp.98-105
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• 2004

This study focuses on an analytical approach to calculate four crane lifting forces for heavy ship hull blocks considering elongations of lilting slings. Four-crane-lifting is a redundant problem. During lifting procedures, in addition to the force and moment equilibrium equations, a compatibility condition is introduced to determine 4 unknown lifting forces. For verification of the method, a ship hull block with field measurements data is analyzed and the result shows that the information obtained by current method could be useful to engineers to conduct lifting work at shipyards.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.198-201
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• 1999

An automated storage and retrieval machinery for high rack warehouse systems is developed in order to stack the various kinds of productions. However, according to increase in the rack height, the long lead time should be taken. In stacker crane systems, the variations of the lifting height and the load generate the vibration of lifting machine, and it makes a Position control to be difficult Therefore, the reduction of vibration will be important factor for saving the lead time and the damage of Productions. This paper deals with a position control of stacker crane in automated high rack warehouse system by using a gain-scheduled control algorithm via a LMI method, where the variations of elastic coefficient of the stacker crane's post are considered.

• 한국해양공학회지
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• 제14권1호
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• pp.17-22
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• 2000

This study focuses on a simple analytical approach to calculate crane lifting forces for a sunken ship. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the vessel including the effect of lug positions. The importance of the sunken ship salvage is explained from the statistics of ship casualties during last 15 years. Euler angles are introduced to represent the inclination of a sunken ship in developing the static force and moment equations,. Three dimensional examples with one redundant degree of freedom for a GT1500 oil tanker are analyzed and the results show that the information obtained by the method could be useful to salvors to conduct salvage work.

• 한국건축시공학회지
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• 제10권3호
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• pp.65-70
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• 2010

철골공사는 고소에서 작업을 하며 많은 위험요소가 따르며, 안전성과 생산성을 향상시키기 위해 로보틱 크레인개발을 위한 프로젝트가 진행되었다. 그 첫 번째 단계로서 실시간 양중위치를 추적하는 시스템을 개발하였는데, 본 연구에서는 이를 위하여 x, y, z 좌표를 쉽게 얻을 수 있는 GPS 센서를 사용하였다. 또한, 본 연구에서는 데이터의 정확도를 향상시키기 위해 2대의 GPS센서를 사용하였으며, RF모뎀을 이용한 무선인식 태그와 함께 통합된 양중경로 추적 시스템을 개발하였다. 개발된 무선인식 태그와 RF모뎀 기반의 GPS 센서는 함께 최대 1 km까지 안정적으로 신호를 전송할 수 있으며, GPS의 상대측위기법을 사용하여 그 오차를 평균 0.61 m까지 줄일 수 있다.

• 대한조선학회 특별논문집
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• 대한조선학회 2009년도 특별논문집
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• pp.97-106
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• 2009

Many production methods are tried to enhance the productivity efficiency. Parallel connected floating cranes are one of the examples to lift mega-blocks quickly and efficiently. However, a general operation manual to operate parallel connected floating cranes and a method to consider risks during lifting operation are not confirmed. And if each floating crane is operated by itself, it is very hard to cooperate. Therefore, Synchronized operation system is installed to control parallel connected floating cranes simultaneously and to be informed of each floating cranes data. And weighting factor is calculated by considering all hazards during the operation and the general operation manual is confirmed based on the factor. This paper introduces the procedure for lifting operations by parallel Connected Floating Cranes using synchronized operation system, and its applications to lifting operation of a heavy cargo such as barge lifting test, floating dock installation and 900 ton goliath crane replacement operation, etc.