• Journal of Navigation and Port Research
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• v.34 no.6
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• pp.479-485
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• 2010

To handle container effectively is one of the most important factors in a port because working time is linked soon into cost. Since the middle of 1990s, RMGC(Rail-Mounted Gantry Crane) and RTGC(Rubber-Tired Gantry Crane) have been developed and widely used to operate containers in the yard. The RTGC is more difficult than RMGC in the automatic control system design. Although, the RTGC is largely advantaged to free driving environment, it has some considerable disadvantages in the system operating. In general, the problems are due to tire slip and lack of tire pressure etc. Therefore, a desirable research result has not been shown in this time. So, in this paper, we propose a new approach to design tracking control system for the RTGC in which the mathematical modeling is included. From the simulation results, the control performance of the designed control systems is evaluated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.905-912
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• 2013

Rubber is one of the most commonly used materials in various fields because of its unique viscoelastic properties. Friction occurs when a tire constantly makes contact with the ground. As a result, friction causes wear. The frictional energy caused by friction is a primary factor in the wear mechanism. The frictional energy is affected by various conditions (temperature, roughness of ground, shape of rubber, load, and materials). In this study, the analysis was preceded by considering the vertical load and the horizontal velocity to the rubber using ABAQUS/explicit. The contact pressure, and friction energy are derived using the shear force and slip distance. The actual behavior of the rubber test data were compared with the analysis results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.12
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• pp.997-1003
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• 2014

This paper describes modeling process to obtain precise landing gear model which is necessary to design a control law for ground auto-taxi, auto take-off/landing of UAV. In this paper, landing gear side force modeling is studied to complete a landing gear model of UAV. Side force modeling is performed by calculating cornering angle including steering angle. And ground directional controller is designed by using nose wheel steering and rudder steering at the same time to control course angle error. Accuracy of landing gear side force modeling and ground directional controller is proved by comparing of auto-taxi test results with simulation results.