• 한국지진공학회논문집
• /
• 제15권3호
• /
• pp.1-9
• /
• 2011

자기부상열차가 중 저속 및 초고속 주행 시 차량의 주행특성 및 교량의 동적 응답 결과를 제시하고자 한다. 수직 자유도 및 회전 자유도를 포함한 10자유도 자기부상열차에 대한 운동방정식을 유도하고, 모드 중첩법을 이용하여 교량의 운동방정식을 구성하였다. 또한 제어 방법으로 UTM01제어기법을 적용하여 수치해석을 수행하였다. 해석 예제로 노면조도, 가이드웨이의 처짐비, 차량 속도 등이 교량의 처짐과 차량의 부상공극 및 여러 가지 변수에 미치는 영향을 파악하였다. 부상공극은 조도의 조건에 따라 그 차이가 확연히 드러나고 또한 자기부상열차의 속도가 증가함에 따라 부상공극이 증가함을 알 수 있었다. 그리고 자기부상열차가 중, 저속 주행 시에는 교량에 대한 영향이 미비하지만 초고속 주행 시 교량에 대한 동적확대계수가 큰 값을 보여주었다.

• 자동차안전학회지
• /
• 제10권2호
• /
• pp.6-12
• /
• 2018

Optimized section shape of aluminum bumper backbeam for enhancing the front high speed crashworthiness was investigated. Front body analysis model of a convertible vehicle was built up and parameter studies were carried out with changing the inner rib shape and the section thickness distribution. First an inner rib shape displaying most efficient structural performance was selected. Next, for the selected section the effect of section thickness combination was examined. Also, a light weighed backbeam section displaying crash performance over the current design was suggested. Finally RCAR front low speed impact analyses were carried out for the optimized models.

• 한국자동차공학회논문집
• /
• 제12권4호
• /
• pp.191-197
• /
• 2004

This paper presents experimental results for human drivers' driving patterns and an Adaptive Cruise Control(ACC) strategy. Analyses have shown that female drivers' driving characteristic values such as time-gap and minimum clearance are larger than those of male drivers'. Human drivers tend to have more clearance margins at high speed than at low speed. At low speed, drivers are much more sensitive to the desired clearance than at high speed. A multi-vehicle detection method is presented to improve ride quality of an ACC. Simulation results have shown that the proposed ACC can provide superior performance compared to the ACC strategy which uses a single-vehicle detection method.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.107-118
• /
• 2011

최근 차량이나 철도 혹은 화재관련 장거리 터널 내 해석이 증가하고 있다. 그러나 기존의 터널 내 유동해석은 수십 km의 터널 전체를 3차원 해석을 진행하는 것으로 비효율 적이다. 또한 터널 내 압력파해석을 위해서 1차원 해석을 많이 진행하지만 유동장을 볼 수 없는 단점이 있고, 3차원으로 확장할 경우 격자수가 기하급수적으로 증가하는 문제가 있다. 이에 본 논문에서는 1차원 3차원 혼합격자기법을 사용하여서 터널 내 운송체 주변의 유동해석과 압력파 해석을 수행하였다. 20km가 넘는 장거리 터널내 에서 운송체의 고속이동과 이에 따른 유동의 해석을 위하여 운송체 주변은 3차원 격자를 사용하여 유동을 해석 후 공력저항을 계산하였고, 유동장 변화가 거의 없는 나머지 지역에 대하여는 1차원 격자를 사용하여서 터널 내 압력파 문제를 확인하였다. 유동은 비정상상태로 해석되었고 Solver는 사용툴인 Ansys vr. 12.0을 사용하였다.

• 한국정밀공학회지
• /
• 제31권9호
• /
• pp.759-764
• /
• 2014

Lateral force of wheel is important parameter when we evaluate the safety of a railway vehicle on curved track. The lateral force of wheel is influenced by the steering performance of wheelsets. Generally, in passive type vehicles, the steering performance of wheelsets is influenced by the parameters like primary spring stiffness, wheel base, conicity of the wheel profile, etc. But, the steering performance of passive type vehicle has its limit. To overcome the limit of the steering performance of passive type vehicle, active steering technology is being developed. In this paper, we analyze the lateral force of wheel and the safety of the railway vehicle on curved track by adopting the active steering technology. As results of dynamic analysis for vehicle model equipped with active steering system, the lateral force of wheel is reduced and the safety is improved remarkably.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.378-382
• /
• 2005

The opening of high speed railway upgraded our land transportation speed limit, causing lots of changes including living and culture and also paving the way for stepping up the railway technology. However, it is also true that we had a limit to adopt the existing railway system structured for 150km/h to the new structure requiring a higher speed of approximate 300km/h due to technological, based on the time and experience. More importantly, heading toward a step of operating such a high speed railway system, it has been practically and quickly proposed that the railway needs high speed railway engineering, maintenance technology of parts of the vehicles to have a stable maintenance foundation and localization of major parts. Therefore, this study was intended to research the actual displacement characteristics in runningg on an actual track for the purpose of developing the protective and maintenance technology of springs and dampers, which are core parts among suspension elements of a high speed railway vehicle. For this, it was researched the actual vehicle test and its interpretation centered on primary spring, which is used for the suspension system of a bogie, body-body dampers and body-bogie yaw damper. Also, to analyze the displacement characteristics of suspension system in the actual conditions of high speed railway vehicles, a vehicle‘s dynamic characteristics was analyzed and interpreted. At the same time, a tester for measuring the actual displacement of such suspension elements was designed and attached to actual vehicles, to measure the displacements that occur in running it on the Seoul-Busan line, one of major lines serviced by KTX. The displacement data gained from the test with actual vehicles was analyzed for its displacement distribution depending on the service sections and frequency, with which the valuable data necessary for any potential breakdown or maintenance in the future could be obtained.

• International Journal of Automotive Technology
• /
• 제6권4호
• /
• pp.351-357
• /
• 2005

Development of a real-time simulation model for high-speed and multibody tracked vehicles is difficult because they involve hundreds of highly nonlinear equations. In the development of a reliable tracked vehicle model for real-time simulation, it is helpful to use an off-line tracked vehicle model developed by considering all the degrees of freedom of each element. This paper presents a step-by-step procedure for the development of a real-time simulation model based on the off-line tracked vehicle model. The road input data, Profile IV, is used for the real time simulation and simulation results are compared with vehicle test results obtained in the military test field. It is noted that the simulation results are quite close to the test results.

• 한국멀티미디어학회논문지
• /
• 제24권12호
• /
• pp.1632-1640
• /
• 2021

In order to improve target tracking performance of the conventional electro-optical tracking system (EOTS) in the high speed and high maneuvering vehicle, an EOTS navigation algorithm is proposed, in which an inertial measurement unit(IMU) is included and navigation results of the vehicle are used. The proposed algorithm integrates vehicle's navigation results and the IMU and the time-delay and the scale factor errors are augmented into the integrated Kalman filter. In order to evaluate the proposed navigation algorithm, a land vehicle navigation experiments were performed a navigation grade navigation system, TALIN4000 and a tactical grade IMU, LN-200 and a equipment for roll motion were loaded on the land vehicle. The performance evaluation results show that the proposed algorithm effecting works in high maneuvering environment and for the time-delay.

• Journal of Electrical Engineering and Technology
• /
• 제6권1호
• /
• pp.81-85
• /
• 2011

The end effect of a linear induction motor (LIM) has been known for several decades, especially in high speed operation. The exit part of the primary is not dealt as extensively as the entry part because of its minor effect. However, the exit part is one of the keys to weaken the dolphin effect, which occurs in high speed operation. In this paper, the concept of the virtual primary core is introduced, and chamfering of the primary outlet teeth is proposed to minimize the longitudinal end effect at the exit zone. For this, LIM for the high-speed train is designed and analyzed by using finite element method. Results confirm that chamfering can improve thrust performance effectively.

• International Journal of Precision Engineering and Manufacturing
• /
• 제3권3호
• /
• pp.21-27
• /
• 2002

In this paper, a simple test rig of high-speed crash for the front members of vehicles was developed for the improvement of crashworthiness of vehicle's side rail. The cart hanging the specimen is accelerated up to 35 mph by the traction wire and by the force of freely dropping weight and 1:3 accelerating pulleys. The cart with shock absorbers travels on the rail roads, so it does not transfer any additional vibration to the specimen. In order to measure the energy absorbed by the specimen when it collapse to the wall and during it deform, the two strain gage type load cells are used at the wall place. The test rig rated good to test the specimen like a side rail of vehicle as developing the vehicle's structures in the early design stage.