• Structural Engineering and Mechanics
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• v.13 no.5
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• pp.505-532
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• 2002

In this study, the analysis of high-speed vehicle-bridge interactions by a simplified 3-dimensional finite element model is performed. Since railroads are constructed mostly as double tracks, there exists eccentricity between the vehicle axle and the neutral axis of cross section of a railway bridge. Therefore, for the more efficient and accurate vehicle-bridge interaction analysis, the analysis model should include the eccentricity of axle loads and the effect of torsional forces acting on the bridge. The investigation into the influences of eccentricity of the vehicle axle loads and vehicle speed on vehicle-bridge interactions are carried out for two cases. In the first case, only one train moves on its track and in the other case, two trains move respectively on their tracks in the opposite direction. From the analysis results of an existing bridge, the efficiency and capability of the simplified 3-dimensional model for practical application can be also verified.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.754-758
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• 2002

In the fuel-cell electric vehicle system, the low-voltage output of unit fuel-cell demands a number of cells to be stacked In series to produce a DC link voltage which is high enough to drive the vehicle inverter system. However, this increases the complexity of the fuel-cell control system. This paper presents a design of high-efficiency boost converter employing the average current-mode control, which is able to convert a low voltage of a fuel-cell generator with a small number of unit cells to a stable and high DC link voltage for electric vehicle applications.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.26-32
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• 2008

This research presents a simulation for the fuel economy of parallel diesel hybrid vehicle. Diesel engines compared to gasoline engines have the advantages of higher fuel economy and lower $CO_2$ emission. One of the most ways to meet future fuel economy and emissions regulation is to combine diesel engine technology with a hybrid electric vehicle. The simulation of HEV is growing need for rapid analysis of the many configurations and component options. WAVE, a one-dimensional engine analysis tool, was used to a 2.7L diesel engine. ADVISOR, designed for rapid analysis of the performance and fuel economy of vehicle models, was used to conventional and hybrid electric vehicle by the use of output file from WAVE as the input engine data file for ADVISOR. A parallel diesel HEV is at least $19.7{\sim}36%$ higher fuel economy and improved acceleration ability compared to a conventional diesel vehicle. The energy loss of the parallel diesel HEV is $23{\sim}38%$ less than the conventional vehicle using regeneration.

• Journal of Auto-vehicle Safety Association
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• v.8 no.2
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• pp.30-36
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• 2016

According to revolutionary developments in automobile technologies, various electronically controlled components of vehicles are rapidly increasing. A variety of advanced vehicles (hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc.) using electrical energy source are increasing, too. The electromagnetic compatibility is getting more important for development of a vehicle because those advanced vehicles are equipped with more new electronic systems. In general, electromagnetic compatibility tests consist of an electromagnetic interference (EMI) test and an electromagnetic susceptibility (EMS) test. In this paper, in order to investigate the electromagnetic interference in the cabin of vehicle by various electric and electronic components of vehicles, a series of narrowband electromagnetic emission tests are conducted. For comparison, the several digital home appliances (smartphone under charging, laptop compuer and digital camera), which are used a lot in daily lives, are tested.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.9
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• pp.723-734
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• 2018

A structural weight estimation methodology for the multicopter design process is presented. In general, a multicopter is composed of an airframe, motors, propellers, battery and so on. Among these, the weight of motors, propellers and battery can be obtained from the weight trends with respect to design parameters. However, the structural weight is hard to be estimated due to the various configurations and design concepts of multicopters. Moreover, the airframe weights of most commercial multicopter products are not provided. Thus, an accurate airframe weight model is required for the reliable mutlcopter design process. Firstly, the standard configuration of multicopters is defined. Then, we proposed the structural weight estimation method using the number and diameter of propellers determined from the initial step of sizing process. Finally, we validated our suggested method using the commerical products.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.7
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• pp.664-668
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• 2012

Hierarchical IPP (Integrated Path Planning) combining the GPP (Global Path Planner) and the LPP (Local Path Planner) is interesting the researches who study about the mobile vehicle in recent years. However, in this study, there is the path mismatch problem caused by the difference in the map information available to both path planners. If ever a part of the path that was found by the GPP is available to mobile vehicle, the part may be unavailable when the mobile vehicle generates the local path with its built-in sensors while the vehicle moves. This paper proposed the TWR (Temporal Waypoint Reviser) to solve the path mismatch problem of the hierarchical IPP. The results of simulation provide the performance of the IPP with the TWR by comparing with other path planners.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.1
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• pp.42-48
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• 2008

The architecture of WSN based Vehicle Speed Measurement System is presented in this paper from Telematics Sensor Network(TSN) to Management System. To verify the feasibility of the system, we implemented the vehicle speed measurement system and evaluated the accuracy of velocity measured by the system in our testbed, an old highway located near Kyungbu highway. The system performed over 95% of accuracy at 80kmph from the measurement. In addition, the battery life time of the sensor node was evaluated by simulation analysis with real measured current consumption profiles. Assuming the maximum average daily traffic in 2005, the battery life time is expected to be over 1.6 year from the simulation result.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.2
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• pp.69-79
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• 2010

This paper describes the experimental framework for the control system design and validation of a rotorcraft unmanned aerial vehicle (UAV). Our approach follows the general procedure of nonlinear modeling, linear controller design, nonlinear simulation and flight test but uses an indoor-installed multi-camera system, which can provide full 6-degree of freedom (DOF) navigation information with high accuracy, to overcome the limitation of an outdoor flight experiment. In addition, a 3-DOF flying mill is used for the performance validation of the attitude control, which considers the characteristics of the multi-rotor type rotorcraft UAV. Our framework is applied to the design and mathematical modeling of the control system for a quad-rotor UAV, which was selected as the test-bed vehicle, and the controller design using the classical proportional-integral-derivative control method is explained. The experimental results showed that the proposed approach can be viewed as a successful tool in developing the controller of new rotorcraft UAVs with reduced cost and time.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.694-701
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• 2016

According to revolutionary developments in automobile technologies, eco-friendly advanced vehicles (hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc.) are rapidly increasing. The electromagnetic compatibility is getting more important for development of a vehicle because those advanced vehicles are driven by electric energy and equipped with more electric systems. In general, electromagnetic compatibility tests consist of an electromagnetic interference(EMI) test and an electromagnetic susceptibility(EMS) test. EMI test of the electric vehicles are needed not only in driving mode but also in charging mode because they must be recharged by much electric energy for driving. Depending on vehicle manufacturers, the charging device type and the location of charging device inlet in electric vehicles are various. In this paper, in order to investigate EMI of electric vehicles in charging mode in consideration of the direction of measuring antenna and the location of charging device inlet, a series of electromagnetic emission tests are conducted using three electric vehicles (neighborhood electric vehicle, electric vehicle and electric vehicle-bus). The test results show that electromagnetic emission measurements in charging mode are dependent on the direction of measuring antenna and the location of charging device inlet.

• Journal of Auto-vehicle Safety Association
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• v.4 no.1
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• pp.12-17
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• 2012

ADAS(Advanced Driver Assistance System) which is developed for alleviating driver's load has become improved with extending it's role. Previously, ADAS offered simple function just to make driver's convenience. However, nowadays ADAS also acts as Active Safety system which is made to release and/or prevent accidents. Longitudinal control system, as one of major parts of Active Safety System, is assessed as doing direct effect on avoiding accidents. Therefore, many countries such as Europe and America has pushed longitudinal control system as a government-wide project. In this paper, it covers the result of evaluation system and vehicle evaluation for development study in FCW, ACC and AEB.