• Journal of Institute of Control, Robotics and Systems
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• v.16 no.12
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• pp.1212-1219
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• 2010

The most important thing in the container terminal is to handle the cargo effectively in the limited time. To achieve this object, many strategies have been introduced and applied to. If we consider the technical trends and environment of the automated container terminal, it is necessary that the systems for cargo handling are equipped with more intelligent control technologies. To cope with this tendency, from the middle of the 1990's, the automated RMGC (Rail-Mounted Gantry Crane) and RTGC (Rubber-Tired Gantry Crane) have been developed and widely used to handle containers in the yards. Recently, in these cranes, the many equipments like CCD cameras and sensors are mounted to cope with the automated terminal environment. If we want to obtain more efficient handling performance, the modelling, tracking control, anti-sway system design, skew motion suppressing and complicated motion control problems must be considered in the control system design and application process. Considering these problems, in this paper, the system modelling with the tire slip and a tracking control approach are proposed. Especially, we design the tracking control system based on the 2DOF servosystem design approach to cope with undesirable disturbance input. The experiment results show the desirable performance and usefulness of the designed control system.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.114-122
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• 2006

The most important thing in the container terminal is to handle the cargo effectively in a limited time. To achieve this objective, many strategies have been introduced and applied. If we consider the automated container terminal, it is necessary that the cargo handling equipment is equipped with more intelligent control systems. From the middle of the 1990s, an automated rail-mounted gantry crane (RMGC) and rubber-tired gantry crane (RTG) have been developed and widely used to handle containers in the yards. Recently, in these cranes, equipment like CCD cameras and sensors have been mounted to cope with the automated terminal environment. In this paper, we try to support the development of more intelligent automated cranes that make the cargo handling be performed effectively in the yards. For this plant, we ought to consider modeling, tracking control, anti-sway system design, skew motion suppressionand complicated motion control and suppressing problems. In this paper, the system modeling and a tracking control approach are discussed, based on a two-degree-of-freedom (2DOF) servo-system design. From the simulation results, the good control performance of the designed control system is evaluated.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.485-488
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• 2006

The most important thing in the container terminal is to handle the cargo effectively in the limited time. To achieve this object, many strategies have been introduced and applied to. If we consider the automated container terminal, it is necessary that the cargo handling equipments are equipped with more intelligent control systems. From the middle of the 1990's, an automated rail-mounted gantry crane(RMGC) and rubber-tired gantry crane(RTG) have been developed and widely used to handle containers in the yards. Recently, in these cranes, the many equipments like CCD cameras and sensors are mounted to cope with the automated terminal environment. In this paper, we try to support the development of more intelligent automated cranes which make the cargo handling be performed effectively in the yards. For this plant, the modelling, tracking control, anti-sway system design, skew motion suppressing and complicated motion control and suppressing problems must be considered. In this paper, the system modelling and a tracking control approach are discussed based on two-degree-of-freedom (2DOF) servosystem design.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.1
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• pp.26-32
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• 2007

The most important thing in the container terminal is to handle the cargo effectively in the limited time. To achieve this object, many strategies have been introduced and applied to. If we consider the automated container terminal, it is necessary that the cargo handling equipments are equipped with more intelligent control systems. From the middle of the 1990's, an automated rail-mounted gantry crane(RMGC) and rubber-tired gantry crane(RTG) have been developed and widely used to handle containers in the yards. Recently, in these cranes, the many equipments like CCD cameras and sensors are mounted to cope with the automated terminal environment. In this paper, we try to support the development of more intelligent automated cranes which make the cargo handling be performed effectively in the yards. For this plant, the modelling, tracking control, anti-sway system design, skew motion suppressing and complicated motion control and suppressing problems must be considered. In this paper, the system modelling and a tracking control approach are discussed. And, we design the tracking control system incorporating an observer based on the 2DOF servosystem design approach to obtain the informations of the states. The experiment results show the usefulness of the designed control system.

• Wind and Structures
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• v.19 no.1
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• pp.1-14
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• 2014

Rail-mounted cranes can be easily damaged by a sudden gust of wind while working at a running speed, due to the large mass and high barycenter positions. In current designs, working rail-mounted cranes mainly depend on wheel braking torques to resist large wind load. Regular brakes, however, cannot satisfactorily stop the crane, which induces safety issues of cranes and hence leads to frequent crane accidents, especially in sudden gusts of wind. Therefore, it is necessary and important to study the braking performance of working rail mounted cranes under wind load. In this study, a simplified mechanical model was built to simulate the working rail mounted gantry crane, and dynamic analysis of the model was carried out to deduce braking performance equations that reflect the qualitative relations among braking time, braking distance, wind load, and braking torque. It was shown that, under constant braking torque, there existed inflection points on the curves of braking time and distance versus windforce. Both the braking time and the distance increased sharply when wind load exceeded the inflection point value, referred to as the threshold windforce. The braking performance of a 300 ton shipbuilding gantry crane was modeled and analyzed using multibody dynamics software ADAMS. The simulation results were fitted by quadratic curves to show the changes of braking time and distance versus windforce under various mount of braking torques. The threshold windforce could be obtained theoretically by taking derivative of fitted curves. Based on the fitted functional relationship between threshold windforce and braking torque, theoretical basis are provided to ensure a safe and rational design for crane wind-resistant braking systems.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.91-96
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• 2011

The handling ability of containers at the terminal strongly depends on the performance of the cargo handling system such as RTGC(Rubber Tired Gantry Crane) and RMGC(Rail Mounted Gantry Crane). This paper introduces a guide line measurement system on the operating condition, in which two camera are installed to detect the guide line. Because the line tracking is the basic technique for control system design of RTGC, it is necessary to develop a useful and reliable measurement system. If the displacement and angle of the RTGC relative to a guide line as the trajectory to follow is obtained, the position of RTGC is automatically calculated. Therefore, in this paper, a camera-based measurement system is introduced. The proposed measurement system is robust against light fluctuation and cracks of the guide line. This system consists of two camera and a PC which are installed at the lower side of the RTGC. Two edges of the guide line are detected from an input image taken by the cameras in the moving state, and these positions are determined in a Hough parameter space by using the Hough transformation method. From the experimental results, the accuracy and usefulness of the proposed system is evaluated by comparing other instruments.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.42-49
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• 2008

The most important job in the container terminal area is to handle the cargo effectively in the limited time. To achieve this object, many strategies have been introduced and applied to. If we consider the automated container terminal, it is necessary that the cargo handling equipments are equipped with more intelligent control systems. From the middle of the 1990's, an automated rail-mounted gantry crane(RMGC) and rubber-tired gantry crane(RTG) have been developed and widely used to handle containers in the yards. Recently, in these cranes, the many equipments like CCD cameras and sensors are mounted to cope with the automated terminal environment. In this paper, we try to support the development of more intelligent automated cranes which make the cargo handling be performed effectively in the yards. For this plant, the modelling, tracking control, anti-sway system design, skew motion suppressing and complicated motion control and suppressing problems must be considered. Especially, in this paper, the system modelling and tracking control approach are discussed. And, we design the tracking control system incorporating an observer based on the 2DOF servo system design approach to obtain the desired state informations. In the case of observer design, a weighted $H_{\infty}$ error bound approach for a state estimator is considered. Based on an algebraic Riccati equation(inequality) approach, a necessary and sufficient condition for the existence of a full-order estimator which satisfies the weighted $H_{\infty}$ error bound is introduced. Where, the condition for existence of the estimator is denoted by a Linear Matrix Inequality(LMI) which gives an optimized solution and observer gain. Based on this result, we apply it to the tracking control system design for the transfer crane.

• Journal of Ocean Engineering and Technology
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• v.20 no.5 s.72
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• pp.57-62
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• 2006

The most important thing in acontainer terminal is to handle the cargo effectively in the limited time available. To achieve this objective, many strategies have been introduced and applied. To create an automated container terminal, it is necessary for the cargo handling equipment to be equipped with more intelligent control systems. From the middle of the 1990's, automated rail-mounted gantry cranes (RMGC) and rubber-tired gantry cranes (RTG) have been widely used to handle containers in yards. Recently, many pieces of equipment, like CCD cameras and sensors, have beenmounted in these cranes to cope with the automated terminal environment. In this paper, we try to support the development of more intelligent automated cranes, which allow for more effective cargo handling in yards. For this purpose, the modeling, tracking control, anti-sway system design, skew motion suppressing, and complicated motion control and suppressing problems must be considered. Especially, in this paper, the system modeling and a new tracking control approach are discussed, and an experimental study is performed based on a two-degree-of-freedom (2DOF) servosystem design.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.1
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• pp.110-125
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• 2007

Various different types of yard cranes are used in container terminals. Examples are rubber tired gantry cranes,rail mounted gantry cranes, overhead bridge cranes, dual rail-mounted gantry cranes, and automated stacking cranes. The kinematics and handling characteristics of these yard cranes are different from each other. Ttiis study analyses charactehstics of generic types of yard cranes which represent various yard cranes m practice Demg used in several types of block layouts, Considering specifications of yard cranes and block layouts, expected cycle times and variances of the cycle time are estimated for different handling activities.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.79-90
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• 2009

The main function of a container terminal is to load container freights into vessels and discharge them from vessels. The container terminal needs to utilize its resources effectively in order to improve the productivity of it. This study deals with the deployment model for yard cranes whose type is RMGC (rail mounted gantry crane). We develop a mathematical model for the deployment of yard cranes. The model considers not only the deployment but also the storage plans. It could be divided into two cases according to whether inter-block movements of yard cranes are allowed or not, during the same period Numerical examples are solved and analyzed to validate the model. Then, additional experiments are performed to compare the performance of the model with that of a previous model without the re-deployment of yard cranes.