• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.165-169
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• 2008

In other side the recent construction industry is a skyscraper, a large scale and a sophistication, a construct site have many problems that an aging of worker and shortage of work force. The purpose of this study was to develop the location of tower crane and the simulation technology of tover crane. The automation of tower carne is a important component in skyscrapers. Specially, this study suggested that it was to develop the exact location system through GPS(Global Positioning System) better than former times.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.20-22
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• 2005

In this study, deformation of flange of pedestal crane due to Lug welding and lifting. Thermo elasto-plastic analysis was performed using commercial FE code MSC/MARC. The accuracy control of roundness is critical to the final product assembly. Deformation is mainly occurs during Lug welding. So, we determine welding sequence and Lug space in order to reduce deformation. And we also investigate safety of lifting Lug during crane lifting.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.498-504
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• 1998

This paper presents an optimal control algorithm for the overhead crane. To control the swing motion and the position tracking of the payload of the overhead crane a state feedback control algorithm is applied. by using a hybrid genetic algorithm the feedback gains of the state feedback is optimized to minimize the cost function composed of position errors and payload swing angle under unknown constant disturbances. Computer simulation is performed to demonstrate the effectiveness of the proposed control algorithm.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.5
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• pp.527-535
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• 2009

This paper describes the control system to suppress the load pendulation using tagline for the floating crane. Dynamic equation of motion of the floating crane and the load is derived using Newton's 2nd law and free body model. The floating crane and the load are assumed that they move in center plane. Each rigid body has 3 DOF (surge, heave, pitch), because it moves in two directions and rotates. Then, this system, which is composed of two rigid bodies, has 6 DOF. The gravitational force, the hydrostatic force, the hydrodynamic force and the tension of the wire rope are considered as external forces, which affect to the floating crane. To suppress the pendulation of the load, the tagline, which connects between the load and the float crane, is applied to the system. The tagline is composed of the spring and the wire rope. Proportional and Derivative control is used as a linear control algorithm. The results of the numerical analysis of the 3,600 ton floating crane show that the tagline system is effective to suppress the load pendulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.77-82
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• 2010

This study evaluated the characteristics and reliability of an auger crane with a built-in hydraulic extender. The field test of the hydraulic extender was performed with the hydraulic lines filled with hydraulic fluid and free of air. The pressure generated during the test was measured with a digital pressure gauge. The crane was considered to have undergone one cycle of the excavation process after it had performed excavation under three conditions at the same location. This process was performed three times in total. From the results of the excavation using the hydraulic extender, it was found that the maximum pressure and torque measured were 19.9 [MPa] and 895.4 [$kgf{\cdot}m$], respectively. The rotation force of the auger crane generated at this time signifies a horizontal force. If the excavation diameter of the auger crane is increased, the rotation speed is reduced causing the circumferential speed to also be reduced. The torsional shear stress of the extendable auger crane was calculated to be approximately 23.5 [MPa]. However, the rotation shaft material used for this system was carbon steel for machine structural use (SM45C). Since the minimum torsional yield stress is greater than 150 [MPa] according to KS D 3752, it means the equipment has secured a safety factor greater than 6. Therefore, it was found that when performing work using the extendable auger crane, it exhibited no problems with the safety and reliability of its shaft.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.525-531
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• 2006

In the port, the yard crane is very important. If a container crane or a transfer crane is broken down, it costs a lot because of the delay of work during the period of repair or reorder. But, we don't have enough spare parts because of the high cost. It is necessary to maintain high reliability of the crane through effective preventive maintenance and failure analysis. In this paper, we analyse the function and failure mechanism of the transfer crane which is a main equipment in the yard Also, we standardize failures and maintenance works using the historical data of failure and maintenance. This study which is a basic work for effective equipment operation and maintenance will support reliability engineers to decide the optimal design of the next generation equipment and operational policy of equipment.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.379-384
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• 2014

This article describes the dynamic behaviors of a rubber tired gantry crane(RTGC) under typical load conditions which are used in the design of gantry cranes. In order to investigate the dynamic characteristics of an RTGC, we developed a finite element crane model for its huge structure. The finite element model was validated with the modal test results, e.g., natural frequencies and normal modes. And other components of RTGC were converted into detailed 3D CAD models and finally transformed to rigid body models in a dynamic simulation program ADAMS. The load conditions considered in this paper were a normal operating condition(OP1) and container hanging condition with no external loads. As a result, we could find there was large influence of crane's vibration owing to its structural stiffness and deformation. And the vibration of crane could made the movements of RTGC, which occurs crash or malfunction of crane works.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.5
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• pp.552-567
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• 2017

The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. The dynamic tension induced by the lifted object also affects the motion responses of the floating crane vessel in return. In this study, coupled motion responses of a floating crane vessel and a lifted subsea manifold during deep-water installation operations were investigated by both experiments and numerical calculations. A series of model tests for the deep-water lifting operation were performed at Ocean Engineering Basin of KRISO. For the model test, the vessel with a crane control system and a typical subsea manifold were examined. To validate the experimental results, a frequency-domain motion analysis method is applied. The coupled motion equations of the crane vessel and the lifted object are solved in the frequency domain with an additional linear stiffness matrix due to the hoisting wire. The hydrodynamic coefficients of the lifted object, which is a significant factor to affect the coupled dynamics, are estimated based on the perforation value of the structure and the CFD results. The discussions were made on three main points. First, the motion characteristics of the lifted object as well as the crane vessel were studied by comparing the calculation results. Second, the dynamic tension of the hoisting wire were evaluated under the various wave conditions. Final discussion was made on the effect of passive heave compensator on the motion and tension responses.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.445-457
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• 2007

This report studied the individual number, their favorite habitat, and change pattern of family and group number in Cheolwon Basin, starting in the early Oct. 2004 until late March. 2005 to investigate the ecological features of the Red-crowned Crane and the White-naped Crane. The Cranes arrived Cheolwon Basin in mid-October until next mid-March, and passed the winter in mid-November until next late-February The most visiting number amounted to 550 individuals and, that period was the most frosting mid-January to mid-February. The White-naped Crane visited Cheolwon Basin in autumn, the early winter and spring. Approximately, the wintering-number is 550 individuals, also, the mid-March was the peak-period of arrival and, the number amounted to 2,162 individuals. The cranes chose the farming area around mountains as their wintering habitat and were less likely to choose the farming area around lake as habitat. The Red-crowned Crane and the White-naped Crane showed the different periodical pattern in familial and group numbers. In case of the crane, the familial pattern was stable, but varied in grouping number, and this pattern was similar to the variation of overall individual number. And, also, the most grouping number was shown in the most freezing period of wintering period. The White-naped Crane showed the similar pattern of the Red-crowned Crane that is, stable family number and varying group number, this pattern affected the total number of entire individuals. Grouping number increased in migration period. Parasite infection rate is G japonensis 35.0%, G vipio 38.7%.