• Proceedings of the KSR Conference
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• 2011.05a
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• pp.671-679
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• 2011

Now, for the continuous location detection of train, The method which the moving distance and speed of vehicles are detected using an odometer mounted within railway vehicle, is used in railway domain generally. There are some problems that the train's positioning errors are accumulated as the moving distances increase. To solve this problems, The Train-borne Positioning System is being developed at Korea Railroad Research Institute. It is required to evaluate exactly a positioning performance of The Train-borne Positioning System for improvement of performance. Therefore, in this paper, we review the CDGPS methods to acquire reference position for performance evaluation of Train-borne Positioning System and verify the accuracy of the reference position through the static test and the vehicle test.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.138-145
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• 2013

A sweep-based heuristic using common area is developed for multi-vehicle VRPs under time various and unsymmetric forward and backward vehicle moving speed. One depot and 2 delivery vehicle are assumed in this research to make the problem solving strategy simple. A common area is held to make adjustment of possible unbalance of between two vehicle delivery completion times. The 4 time zone heuristic is used to solve for efficient delivery route for each vehicle. The current size of common area needs to be studied for better results, but the suggested problem solving procedures can be expanded for any number of vehicles.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1416-1418
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• 2004

This paper proposes an image processing algorithm for detecting obstacles on road-lane using DLI(disparity of lane-related information) that is generated by stereo images acquired from dual cameras mounted on a moving vehicle. The DLI is a disparity that is acquired using single lane information from road lane detection. For the purpose to reduce processing time, we use small blocks obtained by edge-histogram based blocking logic. This algorithm detects moving objects such as preceding vehicles and obstacles. The proposed algorithm has been implemented in a personal computer with the road image data of a typical highway. We successfully performed experiments under a wide variety of road conditions without changing parameter values or adding human intervention. Experimental results also showed that the proposed DLI is quite successful.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.413-416
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• 2004

The tracking antenna system must be always pointed to a satellite for data link among moving vehicles. Especially, for an antenna mounted on a moving vehicle, it needs the stabilized the antenna system. So, software and hardware, signal processing of motion detection sensors, real-time processing of vehicle dynamics, trajectory estimation of satellite, antenna servo mechanism, and tracking algorithm, are unified in the antenna system. The purpose of this paper is to design the embedded tracking antenna control system for satellite communication. The embedded OS(Operating System) based stabilization and tracking algorithm was implemented. The performance of the designed embedded control system was verified by the real satellite communication test.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.1
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• pp.20-29
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• 2009

There are concerns about the influence of the gust wind caused by helicopters affecting the moving vehicles while hovering over the road during rescue activities. For the understanding of such complicated flow. numerical simulation of a rotor hovering above the ground has been carried out, changing the rotor/ground clearances. The rotor thrust is kept constant. and the rotor control is determined by trim adjustments incorporated into the CFD algorithm. Collective pitch angle and the required power decreases with the rotor/ground clearance which agrees with experience. Changes of the flowfield near the rotor with regard to the rotor height are investigated based on the calculated results.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.525-528
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• 2005

The tracking antenna system must be always pointed to target moving vehicle. Especially, for an antenna mounted on a movable vehicle, it needs the stabilized antenna system. In this paper, two types of fuzzy controller were derived and applied to a data link antenna system and the altitude control of unmanned helicopter, respectively. A simplified Fuzzy-PID controller was designed for 2-axes antenna stabilization and tracking system and the performance was verified by simulations and experiments. Computer simulations were performed by Matlab and SIMULINK. A 2-Axes antenna (SeaTel 1898 model) was selected as test platform of this research. The antenna was modified by using two Blushless Direct Current motors and an embedded DSP controller. To verify the performance of designed antenna servo control system, the performance of the conventional PID controller and that of the Fuzzy-PID controller, designed by the same PID control gains, were compared.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.5
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• pp.496-502
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• 2008

In this study, supersonic and hypersonic flutter characteristics have been analyzed for the various typical section shapes of missile fin configurations. Nonlinear flutter analyses are conducted considering the effect of moving shock waves. Computational fluid dynamic method is applied to accurately predict unsteady aerodynamic loads due to structural motions for the solution of aeroelastic governing equations. Commonly used typical section shapes of supersonic and hypersonic launch vehicles are considered in the present numerical study. Detailed flutter responses for four different typical section models are presented and the flutter characteristics are physically investigated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.447-450
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• 2003

This paper concerns on application of active magnetic bearing(AMB) system to levitate the elevation axis of an electro-optical sight mounted on moving vehicles. In such a system. it is desirable to retain the elevation axis within the predetermined air-gap while the vehicle is moving. A disturbance compensation control is proposed to reduce the base motion response. In the consideration of the uncertainty of the system model, a filtered-x least-mean-square(FXLMS) algorithm is used to estimate adaptively the frequency response function of the feedforward control which cancels disturbance responses. The frequency response function is fitted to an optimal feedforward control. Experimental results demonstrate that the proposed control reduces the air-gap deviation to 27.7% that by feedback control alone.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.10
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• pp.1712-1719
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• 2003

This paper concerns on application of active magnetic bearing(AMB) system to levitate the elevation axis of an electro-optical sight mounted on moving vehicles. In such a system, it is desirable to retain the elevation axis within the predetermined air-gap while the vehicle is moving. An optimal base acceleration feedforward control is proposed to reduce the base motion response. In the consideration of the uncertainty of the system model, a filtered-x least-mean-square(FXLMS) algorithm is used to estimate the frequency response function of the feedforward control which cancels base motions. The frequency response function is fitted to an optimal feedforward control. Experimental results demonstrate that the proposed control reduces the air-gap deviation to 27.7% that by feedback control alone.

• Interaction and multiscale mechanics
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• v.2 no.3
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• pp.263-276
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• 2009

This paper is intended to investigate interaction response of a train running over a suspension bridge undergoing support settlements. The suspension bridge is modeled as a single-span suspended beam with hinged ends and the train as successive moving oscillators with identical properties. To conduct this dynamic problem with non-homogeneous boundary conditions, this study first divides the total response of the suspended beam into two parts: the static and dynamic responses. Then, the coupled equations of motion for the suspended beam carrying multiple moving oscillators are transformed into a set of nonlinearly coupled generalized equations by Galerkin's method, and solved using the Newmark method with an incremental-iterative procedure including the three phases: predictor, corrector, and equilibrium-checking. Numerical investigations demonstrate that the present iterative technique is available in dealing with the dynamic interaction problem of vehicle/bridge coupling system and that the differential movements of bridge supports will significantly affect the dynamic response of the running vehicles but insignificant influence on the bridge response.