• Journal of Mechanical Science and Technology
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• v.14 no.10
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• pp.1028-1040
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• 2000

A numerical method is presented for the dynamic analysis of military tracked vehicles of high mobility. To compute the impulsive dynamic contact forces which occur when a vehicle passes on a ground obstacle, the track is modeled as the combination of elastic links interconected by pin joints. The mass of each track link, the elastic elongation of a track link between pin joints by the track tension, and the elastic spring effects on the upper and lower surfaces of each track link have been considered in the equations of motion. And the chassis, torsion bar arms, and road wheels of the vehicle are modeled as the rigid multi bodies connected with kinematic constraints. The contact positions and the contact forces between the road wheels and track, and the ground and the the track are simultaneously computed with the solution of the equations of motions of the vehicle consisting of the multibodies. The iterative scheme for the solution of the multi body dynamics of the tracked vehicle is presented and the numerical simulations are conducted.

• Journal of Auto-vehicle Safety Association
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• v.14 no.2
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• pp.83-89
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• 2022

Recently, the use of ATV (All-Terrain Vehicle) has increased due to increase in leisure activities, and the awareness of safety and traffic accidents has improved, but it still insignificant compared to other transportation. Therefore, in this study, the current status and characteristics of traffic accidents related to ATVs were investigated, and actual ATV accident was analyzed. As a result, it was confirmed that the condition of the braking system directly connected to the safety of the ATV was not well maintained. For driver safety in the future, it is considered that it is necessary to strengthen safety regulations related to experience centers and rental companies handling AVTs and to conduct regular inspections in accordance with the Motor Vehicle Management Act.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.924-930
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• 2011

Maglev vehicle has two parts a vehicle body and a series of bogies. The vehicle body is connected through a pneumatic suspension on the bogie frame operating loads, vehicle weight and passengers, repeatedly during the service life. The bogie frame plays an important role in sustaining the weight of the vehicle body and controlling the magnets in the correct alignment to meet requirements of stable running on railway. It is also subjected to the levitation and guidance force and propulsion force generated by electromagnets and linear induction motor (LIM) respectively. To guarantee a vehicle system, it is necessary to identify a load test method with proper loads that the vehicle is expected to experience while in service. In this paper, a test method was proposed to verify the structural safety of vehicle body and bogie frame that are applied to an EMS(electromagnetic suspension)-type urban Maglev vehicle considering in case of not only running on the ground but also levitated running.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1234-1242
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• 2013

To verify the effectiveness of the proposed system, the charges in power demand are analyzed for an AC and DC distribution system for the existing V2G concept and electric vehicle charging stations connected to a Battery Energy Storage System. In addition, since many power-converter-based chargers are operated simultaneously in an EV charging station, the change in the system harmonics when several EV chargers are connected at a single point is analyzed through simulations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.75-80
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• 1998

Statistical Energy Analysis(SEA) has been considered as a possible method for predicting responses of complex structures, especially at higher frequencies. In this paper, an SEA model of vehicle was built using 138 energy storing subsystems connected together using 1019 junctions. SEAM software program was used to build and calculate the model. To demonstrate the accuracy of the SEA model, predicted response levels were compared with measured levels. The source input levels were measured at the engine mounting parts. For the vibration levels, the agreement between the calculation results and the experimental ones was found to be good. The energy flow between connected subsystems can be presented, because the analysis method is based on the estimation of the power flow between subsystems. This paper also identifies some dominant energy flow paths from sources. It is finally presented that the SEA model can optimize the design parameters of vehicles using model parameters and energy flow paths.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.52-68
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• 2019

Aiming at the optimal placement of communication relay nodes (OPCRN) problem in manned/unmanned aerial vehicle cooperative engagement system, this paper designed a kind of fully connected broadband backbone communication topology. Firstly, problem description of OPCRN was given. Secondly, based on problem analysis, the element attributes and decision variables were defined, and a bi-level programming model including physical layer and logical layer was established. Thirdly, a hierarchical artificial bee colony (HABC) algorithm was adopted to solve the model. Finally, multiple sets of simulation experiments were carried out to prove the effectiveness and superiority of the algorithm.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.27-33
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• 2018

The recent efforts in academia and industry represent a paradigm shift that will extend the IoT from the home environment so that it is interoperable with the Internet of Vehicles (IoV). IoV is a special kind of IoT. It allows to connect between vehicle and things located in infrastructure. Furthermore, IoV enable to create new intelligent services through collaboration with existing various services such as smart city and connected home. In this paper, we develop a service in order to realize IoV. To this end, we design a novel vehicle service platform which could automatical controlling the IoT device according to drivers' voice. To show practical usability of our proposed platform, we develop a prototype service could be call car-to-thing (C2T). We expect that our proposed platform could eventually contribute to realizing IoV.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.841-846
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• 2008

Recently the LNG(liquified natural gas) public buses have been introduced to prevent the air pollution in metropolitan areas. As the LNG temperature in fuel tank is as low as $-162^{\circ}C$. the thermal and structural effects of tank components need to be studied for safe introduction in the market. Especially the support system of LNG fuel tank in vehicle, which has connected with inside and outside of tanks, should put attention to reduce the structural stress due to cryogenic temperature and to restrict the heat flux from ambient. There are two supporting systems in the tank, that one is connected between inside and outside tanks by welding, and the other is the inserted support system which is a cylindrical SUS bar inserted in a hole of the supporting plate. In this study the temperature distribution and thermal stress of the inserted support system were evaluated by using the utility program as ANSYS. The results showed that the rate of heat transfer to inner tank through this support system was quite small due to limited contact of support bar with plate. but the thermal stress of support plate was obtained beyond the limited tensile value of SUS304. The cautious design for the support plate part, therefore, should be given to make the safe support system of LNG vehicle fuel tank.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.215-221
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• 2022

In the manufacturing process of the bus treated as the commercial vehicle, after making the bare chassis which is the basic frame of the vehicle body, the part in which passengers ride is connected. In addition, the necessary parts such as the engine and transmission required for the operation of the bus are connected to the bare chassis. The element connecting the parts such as the boarding part of the passengers, the engine, the suspension and the transmission is the bracket. The device required for driving and operating the vehicle is mounted on the bare chassis using the bracket, which should ensure stability during bus operation. In this study, we were performed stress analysis to evaluate the stability of three types of brackets connecting the bare chassis of a new type of 30-seater bus in the development process and components required for driving and operation. The stress analysis should be preceded by the analysis of boundary conditions considering the loads applied to the brackets according to the material of the bracket to be analyzed and the driving type of the bus. The finite element model for structural analysis of brackets according to the driving type of the bus was used by Altair's Hypermesh 2017, and the solver used for structural analysis was Altair's Optistruct. The stress analysis was performed to present the safe and vulnerable parts of the three brackets.

• Structural Engineering and Mechanics
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• v.11 no.2
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• pp.133-149
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• 2001

A high-fidelity model of a tracked vehicle traversing a flexible ground terrain with a varying profile is presented here. In this work, we employed a recursive formulation to model the track subsystem. This method yields a minimal set of coordinates and hence, computationally more efficient than conventional approaches. Also, in the vehicle subsystem, the undercarriage frame is assumed to be connected to the chassis by a revolute joint and a spring-damper unit. This increase in system mobility makes the model more realistic. To capture the vehicle-ground interaction, a Winkler-type foundation with springs-dampers is used. Simulation runs of the integrated tracked vehicle system for vibrations for four varying ground profiles are provided.