• Journal of Institute of Control, Robotics and Systems
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• v.3 no.2
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• pp.132-138
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• 1997

Six different types of velocity profiles of trolley movement of a container crane are investigated for the minimal sway angle at the target trolley position. Three velocity patterns which include trapezoidal, stepped and notched-type velocity patterns are obtained assuming constant rope length. The notched type velocity pattern is shown to be derived from the time-optimal bang-bang control. The stepped type velocity pattern can be shown to be derived as bang-off bang control as well. Considering the damping effect due to hoist motion a double stage acceleration pattern is also analyzed. The main objective of the paper is to show how much time-reduction can be obtained among several velocity patterns appearing in the literature.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.9-16
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• 1994

In the discrete optimum design, occasionally, the solutions oscillate between the feasible and the infeasible resions during the series of redesigns of members with discrete sections. This phenomenon may be caused inherently by the discontinuity of variables of commercially available sections in the database. In this paper, in-depth investigation into the oscillation in the discrete optimization and its control has been conducted. When the structure is optimized through element optimization, the oscillation can be divided into two categories, local and global oscillations. An algorithm which controls these phenomena is suggested and numerical examples demonstrate the oscillation in optimum solutions and the effectiveness of the control strategy suggested here.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.6
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• pp.1391-1401
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• 1995

This paper addresses design procedure and testing results of a closed-loop motion control of the cranes. When the object is stopped at the desired position, swinging occurs, and such swinging deteriorates the safety and efficiency of the operation of the crane. Therefore, in this paper, the cascade anti-swing and trolley position feedback controller are designed. Anti-swing controller rapidly eliminates swinging of object and position feedback controller reduces the trolley position error. The performance of this controller is investigated through the computer simulation and experiment. From the results of a series of computer simulations and experiments it can be concluded that proposed controller effectively reduces swinging of the object and trolley position error, which shows this controller can be used as an effective tool for the precise control of overhead cranes.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.2
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• pp.89-94
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• 2016

Equipments to influence by external force have to take effect mechanical oscillation. These equipments regardless of the movement on the external force such as roll, pitch and heave etc, worked to keep the height of tote are required for activeness and needed a device as equipment's fluctuation for rapidly compensation. Because the actual development of these devices is difficult to cost-effectively, we were developed to compensation simulator scaled down 1/50. In this paper, we were studying kinematic characteristics, designed the simulator to grasp the point and manufactured. This paper was analyzed for confirming the superiority of compensation simulator and set up 50 ton crane in practice.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.153-158
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• 2000

The sway motion of the spreader during and after movement causes an efficiency problem of position control in unmaned gantry crane. The objective of this research is to investigate the phenomenon that the load is taken by the sway motion of crane. For deriving the dynamic equations related to the swing motion of crane, we introduced a conception of spring and damper in the upper part of the crane. During the crane and trolley is driving along the velocity profile, the swing motion of the spreader and crane will be simulated. The simulation result of the equation of motion using the Runge-Kutta method is presented in this paper. And we will show an effect of the swing of the crane in this research.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.16-21
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• 2000

In this paper we design a GA-fuzzy controller for position control and anti-swing at the destination point. Applied genetic algorithm is used to complement the demerit such as the difficulty of the component selection of fuzzy controller namely scaling factor membership function and control rules. lagrange equation is used to represent the motion equation of trolley and load in order to obtain mathematical modelling. Simulation results show that the proposed control technique is superior to a conventional optimal control in destination point moving and modification.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.23-29
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• 1997

In the control of crane system, the traversing time of the trolley must be reduced as much as possible and the swing must be stopped at the end point. To design the minimum time control system, Pontryagim maximum principle is applied. In order 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. The overall performance of the closed loop system is evaluated by means of computer simulations and practical experiments in a broad range of working conditions. The effectiveness is proved through the experimental results for the anti-sway control of the load and the position control of trolly. It is expected that the proposed system will make an important contribution to the industrial fields.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.363-365
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• 2013

최근 3D산업의 급성장으로 인해 3D콘텐츠 제작에 대한 관심이 확산되고 있다. 지금까지는 3D콘텐츠 제작을 영화나 애니메이션 같은 자연영상을 3D변환하는 것에 초점이 맞추어져 있었다. 자동 3D변환에서는 window 영상처럼 텍스트, 이미지, 로고 등의 혼합되어 있는 영상을 처리하는데 어려움이 있다. 특히 텍스트는 동일한 깊이맵을 얻지 못하면, 깨짐, 흔들림 등의 문제점이 발생한다. 해결방법으로 혼합 영상을 구분하고 영상 영역만을 탐색해서, 3D변환을 하고, 다른 영역은 2D로 처리함으로써 상기 문제점을 극복할 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.366-367
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• 2013

3D Conversion은 3DTV 및 3D Display에 장착되어 제공되고 있다. 이외에도 다양한 변환 방법이 제안되어 왔다 기존 방법들은 영화나 애니메이션 같은 자연영상을 3D로 변환하는 것에 초점이 맞추어져 있었다. 따라서 자동 3D변환에서는 webpage영상처럼 텍스트, 이미지, 로고 등의 혼재되어 있는 영상을 처리하는데 어려움이 있다. 특히 텍스트는 동일한 깊이맵을 얻지 못하면, 깨짐, 흔들림 등의 문제점이 발생한다. 해결방법으로 webpage에서 image region만을 탐색해서, 3D변환을 하고, 다른 영역은 2D로 처리함으로써 상기 문제점을 극복할 수 있다. 이를 위해 본 논문에서는 변환하려는 영상 영역을 탐색하고 이 탐색된 영상들을 단순하게 픽셀의 수평이동이 아닌, 양선형 보간으로 변환하여 홀채움 문제를 극복할 수 있는 변환방법을 제안한다.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.281-285
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• 1997

We developed the system which could trace the hand and arm motion to test the product usability by integrating a wired-glove and a magnetic position sensing system. The magnetic position sensing system traces the position and orientation of the arm while the sired-glove measures 18 phal angeal joint angles. A case study was performed on two different camcorders in weight. The heavier camcorder was more stable than the lighter one. Also the recording task is more stable than the zoom-in and zoom-out tasks. This system could be used to monitor and quantify the hand and arm motion in real time and also could be used to test the product usability where the hand motion is important.