• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.428-431
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• 2002

Yard cranes are very useful equipments for handling of heavy containers. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. But control algorithm of trolley speed is not practical in windy weather. In this paper, we are going to propose a new structure for anti-sway. This structure uses aux. ropes. The control strategy with auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And main schemes are introduced and explained briefly.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.197-205
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• 2000

Productivity of container cranes and gantry cranes is influenced by the performance of crane hardware and cycle time. Cycle time in container handling is influenced by the path of containers and relative positioning of containers. So we have to minimize the sway of containers and spreaders to minimize relative positioning time. And sway minimization is influenced by the skill of workers in manual gantry cranes. In this paper, we will survey some anti-sway systems. Each system has some merits and some shortages. And we will show our choice and its experimental equipment which is under construction.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1287-1294
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• 2004

Automated container terminals have been being developed over the world for recent years and many countries are interested in it because the amount of containers exported or imported is rapidly increasing. The conventional container terminals were not designed to control this kind of heavily many containers. They would face many structural problems soon or later, although they have managed to do well so far. One of the most important things in developing automated container terminal is to develop the equipment able to handle many containers efficiently. Those are maybe automated transfer cranes, automatic guided vehicles, and automated quay-side cranes. The word 'automated' means the equipment is operated without drivers and those equipments are able to work without any interruption in working schedule. Through the researches on the conventional transfer cranes, we decided that the structure of the conventional transfer cranes is not efficient in automated container terminal and it's not possible to handle so many containers in limited time. Therefore we have been studying on the proper structure of the automated container crane for past several years and a new type of transfer crane has been developed. Design concept and control method of a new type of transfer crane had been presented in the previous paper: Part Ⅰ. Experimental features will be presented with a model transfer crane in this paper: Part Ⅱ.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.2
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• pp.83-90
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• 1994

The container crane is still operated by skillfull human operators. So an automatic crane operation system is strongly required. In this paper, the digital control method is applied to position an anti-swing control for container crane. Two methods of digital optimal regulator control and digital redesign control are used for experiment. From these experimental results, it is respected that both methods can be applied effectively to an actual container crane operation.

• Journal of Ship and Ocean Technology
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• v.3 no.2
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• pp.27-48
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• 1999

The paper is concerned with application to develop the expert system, which structural analysis and design process for tower cranes. The system is organized into three groups. One is pre-processor for creating input data files, another is `model former' which combines knowledge-base with inference engine for automatic generating structural analysis models, a third is application group for final analysis checks. In this study, geometric subroutine of `model former' designates node positions, nodes, elements numbers and element types. Load data subroutine computes weight of tower crane and device, slewing force, cargo load, wind force form rules or equations in knowledge-base. Also, Property and boundary subroutine applies element properties and boundary conditions to suitable elements and nodes. Design and analysis expert system for tower crane integrates these subroutine, `model former' and pre-processor. RBR(Rule-Base Reasoning) was adopted for a reasoning strategy of this expert system. And this expert system can produce structural analysis model and data, which can be used in ordinary structural analysis program (SAP, ADINA or NASTRAN, etc.). In this paper, this expert system produces format of the analysis model data, which are used in MSC/NASTRAN. The main discussions included in the paper are introduction of the tower crane and structural analysis, composition of the design expert system for tower crane and structural analysis using the expert system.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1224-1227
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• 2002

In this paper, we propose a composition method of the template image whose detection performance does not have incorrect detection and improves also on the tough photography conditions of the outdoors, rainy weather and night. This research was done to measure a relative position between a spreader and a target container with image processing to realize full-automatic quayside gantry cranes. By the proposal method, we confirmed that the template image for object detection has a contour image more effective than a gray image.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.293-296
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• 1999

In conventional automatic container-terminal, the gantry cranes are operated manually or semi-automatically. But UGC is an unmanned-operated gantry crane and the positioning information for UGC is supplied only by position-measuring devices. In order to enhance the operation efficiency of UGC, it is required that the position-measuring devices have long maintenance period and are not sensitive to the weather and environment condition. And in order to be used practically in container terminal, the cost of position-measuring devices is not higher than currently used measuring devices. In the study, it is discussed the requirements for position-measuring devices in UGC, And it is studied on the measuring devices suitable to UGC. From this study, it is expected that the combination of a rotary encoder and a ferrous metal detector is useful for position-measuring devices in UGC.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1679-1684
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• 2004

This paper introduces a novel approach that can provide the three dimensional information on the movement of a spreader by using two CCD cameras and a laser distance sensor, which enables an ALS (Automatic Landing System) to be used for yard cranes at a harbor. So far a kind of 2D Laser scanner sensor or laser distance measuring units are used as corner detectors for the geometrical matching between the spreader and a container, which provides only 2D information which is not enough for an accurate and fast ALS system required presently. In addition to this deficiency in performance, the price for the system is too high to be adopted widely for the ALS. Therefore, to overcome these defects, a novel method to acquire the three dimensional information for the movement of a spreader including skew and sway angles is proposed using two CCD cameras and a laser distance sensor. To show the efficiency of proposed algorithm, real experiments are performed to show the accuracy improvement in distance measurement by fusing the sensory information of CCD camera and laser distance sensor.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.126-133
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• 2004

Lots of researches and applications on the automated overhead cranes in shops have been done for some decades, but a few successful results are reported. Integrated crane control systems designed by famous engineering companies are still expensive and are not satisfactory in view of maintenance and reliability. A more reasonable control system fit to requirements of manufacturing industries is suggested in the study. The new deigned system has superior capabilities for anti-sway of rope and position control. The controller for automated operations is composed of a Linux-based PC for non real-time control and a high-speed PLC for hard real-time control. Some algorithms required for coil yard operations as well as main control algorithms such as reference position generation, position control and anti-sway control have been designed and fully tested on the new crane simulator. The designed crane control system showed satisfactory performance on position control accuracy and anti-sway of rope. The maximum positional error is 8mm and the maximum sway error is 0.1 degrees. The suggested control strategies have been successfully applied to the 10-1 crane in No. 4 CGL of in the Kwangyang Steel Works and in commercial operation.

• Journal of Power System Engineering
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• v.2 no.1
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• pp.67-72
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• 1998

In crane control system, it is required that the travelling time of crane must be reduced as much as possible and there is no the swing of load at the end and starting points. In this paper, we present a hybrid control method which includes two control methods of the optimal regulator and the velocity pattern control in order to realize high performance of the anti-sway. To implement the control algorithm, the dynamic equation is linearlized at an equilibrium point, so that the linear time invariant state equation can be obtained. A 1/10 sized model crane of the usual gantry cranes is made and used to show the applicability of the developed hybrid control method. The effectiveness of developed hybrid control method is proved by experimental results which show us good performance for anti-sway control comparing to conventional velocity pattern control. Practically, it is expected that the proposed control system will make an important contribution to the automatic crane control system of the industrial fields.