• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1207-1212
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• 2009

The flexible multibody dynamic model of an EMS-type Maglev vehicle is necessary in design stage to predict its behavior, load history and levitation performance. Especially in EMS-type Maglev vehicle, the body flexibility of its bogie with electromagnets affects the levitation performance because its feedback control system is more sensitive to vibration of bogie structure. The flexible multibody dynamic model of a 1/2 Maglev vehicle under test is presented. The basic modeling procedure is almost the same as in other applications. However, the feedback control system model unique in EMS-type maglev vehicle must be included in the model. With the model proposed in this study, the dynamic behavior, load history and levitation performance are more precisely predicted. This model could realize the virtual prototyping in EMS-type Maglev vehicle area.

• Journal of Auto-vehicle Safety Association
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• v.15 no.2
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• pp.21-27
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• 2023

This paper presents a simulation tool for developing and evaluating automated driving systems' lane change algorithm in urban congested traffic. The behavior of surrounding vehicles was modeled based on driver driving data measured in urban congested traffic. Surrounding vehicles are divided into aggressive vehicles and non-aggressive vehicles. The degree of aggressiveness is determined according to the lateral position to initiate interaction with the vehicle in the next lane. In addition, the desired velocity and desired time gap of each vehicle are all randomly assigned. The simulation was conducted by reflecting the cognitive limitations and control performance of the autonomous vehicle. It was possible to confirm the change in the lane change performance according to the variation of the lane change decision algorithm.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3187-3194
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• 2011

Vehicle dynamic behavior should be investigated to establish the track irregularity criteria because they have an impact on vehicle dynamic behavior. The tilting train which have been developed in Korea will be operated on the conventional line. Therefore, it should be checked that the track irregularity criteria of conventional line is still available for the new vehicle. In this paper, the influence of alignment on running behavior and safety for tilting train was instigated by numerical analysis. The wavelength and amplitude of alignment were considered in scenario of this numerical analysis. This research is based on just numerical analysis and the final result which include measurement will be published in the future.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1937-1942
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• 2010

Vehicle dynamic behavior should be investigated to establish the track irregularity criteria because they have an impact on vehicle dynamic behavior. The tilting train which have been developed in Korea will be operated on the conventional line. Therefore, it should be checked that the track irregularity criteria of conventional line is still available for the new vehicle. In this paper, the influence of vertical alignment on running behavior and safety for tilting train was instigated by numerical analysis. The wavelength and amplitude of vertical alignment were considered in scenario of this numerical analysis. This research is based on just numerical analysis and the final result which include measurement will be published in the future.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.603-608
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• 2006

As an important and relatively easy to implement technology for realizing Intelligent Transportation Systems(ITS), Adaptive Cruise Control(ACC) automatically adjusts vehicle speed and distance to a preceding vehicle, thus enhancing driver comfort and safety. One of the key issues associated with ACC development is usability and user acceptance. Control parameters in ACC should be optimized in such a way that the system does not conflict with driving behavior of the driver and further that the driver feels comfortable with ACC. A driving simulator is a comprehensive research tool that can be applied to various human factor studies and vehicle system development in a safe and controlled environment. This study investigated driving behavior with ACC for drivers with different driving styles using the driving simulator. The ACC simulation system was implemented on the simulator and its performance was evaluated first. The Driving Style Questionnaire(DSQ) was used to classify the driving styles of the drivers in the simulator experiment. The experiment results show that, when driving with ACC, preferred headway-time was 1.5 seconds regardless of the driving styles, implying consistency in driving speed and safe distance. However, the lane keeping ability reduced, showing the larger deviation in vehicle lateral position and larger head and eye movement. It is suggested that integration of ACC and lateral control can enhance driver safety and comfort even further.

• Journal of the Society of Disaster Information
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• v.13 no.2
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• pp.258-266
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• 2017

Cable-stayed bridges are bridges with long spans for special purposes. Due to the long span, the dynamic response of the vehicle to the moving load is very special. The behavior also has nonlinear, which makes it difficult to design. In this study, the responses of cable - stayed bridges are considered considering various vehicle loads and the behavior of long - span bridges under moving loads is investigated. Especially, when the loads for one direction and for both directions move with speed, the behavior of the bridges is found to be due to the flexibility of the cable. It can be seen that the analysis including the dynamic behavior of the cable and the top plate is more effective because the influence of the vehicle load tends to amplify the vertical deformation together with the vibration of the cable.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.95-103
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• 2016

PURPOSES : Permitted left turn is a turning maneuver in which a vehicle turns left using a gap between oncoming vehicles, called gap acceptance, and it enables for more efficient traffic operation at intersections. In Korea, the permitted left turn has not been a common maneuver at signalized or un-signalized intersections. However, many experts and the Police Agency tried to apply this effective turning maneuver at intersections in Korea since 2010. Though the investigation of gap acceptance is significantly important in understanding a driver's behavior at intersections, there have not been many studies about this topic, specifically a study to develop probability models of gap acceptance behavior. METHODS : In this study, the probability model of gap acceptance behavior for a permitted left turn was developed based on observational field studies. To develop the model, seven variables were analyzed including gap, waiting time, traffic volume, conflict-flow vehicle type, left-turning vehicle type, the number of lane, and time. RESULTS : In the final model, gap and left-turning vehicle type were found to be significant influencing factors. CONCLUSIONS : Through this model development, it was concluded that as the gap size increased, the probability of gap acceptance was higher. Moreover, when a left-turning vehicle was a passenger car, the probability of gap acceptance was higher than compared to large size buses or freight cars.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.727-736
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• 2000

The present study investigates the influences of vehicle induced loads on the thermal buckling behavior of straight and curved continuous welded rail (CWR) tracks. Quasi-static loads model is assumed to determine the uplift region, which occurs due to the vertical track deflection induced by wheel loads of vehicle. The lateral loads of vehicle induced by weight, the speed, the superelevation and curvature of track, and other dynamic vehicle track interaction, are included in the ratio of lateral to vertical vehicle load. Parametric numerical analyses are perfomed to calculate the upper and lower critical buckling temperatures of CWR tracks, and the comparison between the results of this work and the previous results without vehicle is also included.

• Journal of the Society of Disaster Information
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• v.7 no.3
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• pp.190-197
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• 2011

In this paper, an analytical and experimental study is performed in order to determine the effects of interaction between a vehicle and a structure. For this purpose, a wheel tracking machine and an adequate single span bridge are designed. Results presented in the paper show that the real vehicle tracking accelerations including the interaction between the vehicle and the structure produce additional effects on the dynamic behavior of the structure including reversal and contrary behavior. Also, the interaction between the vehicle and the bridge is reproduced by applying the identified real vehicle tracking accelerations to a general finite element analysis program.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.1-9
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• 1998

The analysis concerns collapse behavior of framed vehicle models with the change of design parameters at the initial stage of conceptual design. Collapse analysis of a vehicle model with framed structures has been carried out using finite element limit analysis. The analysis makes sequential changes of design parameters from an initial model with frames of uniform section so as to stage then weak parts. As a result of those design changes, the collapse load of a model has been increased and the deflection toward a passenger room has been reduced. The results demonstrate the versatility of finite element limit analysis as a tool that confirms the safety of vehicle models.