• 한국산학기술학회논문지
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• 제19권7호
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• pp.275-282
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• 2018

산악트램은 기존 산악 도로에 매립형 궤도를 설치하여 무가선으로 주행할 수 있는 친환경 교통 시스템으로서, 결빙시에도 운행할 수 있는 장점이 있으나, 산악 도로의 급곡선과 급경사 구간을 주행해야 하는 어려움이 따르게 된다. 본 연구에서는 산악트램이 도로에 설치된 급곡선 급경사 궤도를 주행할 때의 기술적인 문제를 정의하고, 이 문제를 해결하기 위한 대차와 차체 연결 구조의 설계 방안을 제시하였으며, 시작품 제작 및 성능 시험을 통해 설계 방안의 효용성을 입증하였다. 급곡선 구간에서 내외 레일의 주행거리 차이가 심하게 발생하여 주행이 곤란해질 수 있으므로 좌우 차륜이 별개의 속도로 회전하는 독립구동 차륜을 개발하여 적용하였다. 기존 2대차-1차체 차량에서 발생할 수 있는 곡선구간에서의 공격각 및 횡압 증가에 따른 탈선을 방지하기 위해 1대차-1차체 차량을 설계하여 실제 적용하였다. 독립 구동차륜과 1대차-1차체 구조의 시험 차량 시작품을 제작하였고, 소형 궤도에서 시험 운행을 실시하여 성능을 검증하였다. 산악트램이 곡선과 경사를 통과할 시에 차체 간에 발생하는 3방향 회전 대변형을 흡수하기 위해 연결기를 설계하여 축소 시작품을 제작하였으며, 작동 시험을 실시하여 성능을 검증하였다.

• 전기학회논문지
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• 제58권3호
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• pp.598-604
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• 2009

This paper proposes a vehicle detector with an anisotropic magnetoresistive (AMR) sensor and addresses experimental results to show the detector's performance. The detector consists of an AMR sensor and mechanical and electronic apparatuses. The AMR sensor, composed of four magnetoresistors, senses disturbance of the earth's magnetic field caused by a vehicle moving over the sensor and then produces an output indicative of the moving vehicle. This paper verifies performance of the detector on the basis of experimental results obtained from the field tests carried under the two traffic conditions on local highways in Korea. First, I show the vehicle counting performance on a low speed congested highway by comparing the vehicle counts measured by the detector with the exact counts. Second, both vehicle counts and average speeds calculated from the measured point-occupancy on another continuously free running highway are compared with the reference values obtained from a loop detector which has two independent loop coils, where I have used several performance indices including mean absolute percentage error (MAPE) to show the performance consistency between the two types of detectors.

• 한국철도학회논문집
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• 제10권4호
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• pp.431-437
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• 2007

This paper describes the dynamic modeling of a railway vehicle when it is under braking force. It is important for the enhancement of braking performance to establish a proper dynamic model of a railway vehicle because the braking performance is affected by some dynamic forces generated by a railway vehicle when it undergoes braking. In this paper, a dynamic model for one vehicle is suggested to compute the dynamic behavior of a railway vehicle in the HILS(Hardware In-the-loop Simulation) system for the railway vehicle braking devices. To simplify the dynamic model, friction between a wheel and a rail is assumed that there exist only the static and the dynamic friction forces. Static friction coefficient is also assumed to be a function of the running speed. Some simulations are carried out with various braking forces, and the braking characteristics according to the change of the braking force are discussed. This study can provide some fundamental results to construct the HILS system for braking devices of a railway vehicle.

• 전기학회논문지
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• 제60권3호
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• pp.600-605
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• 2011

This paper shows field test and evaluation results for a wireless vehicle detector with anisotropic magneto-resistive (AMR) sensors. The detector consists of two AMR sensors and mechanical and electronic apparatuses. The AMR sensor senses disturbance of the earth magnetic field caused by a vehicle moving over the sensor and then produces an output indicative of the moving vehicle. In this paper, vehicle speeds are calculated by using two AMR sensors fixed on a board, with constant distance. To test and evaluate the accuracy of the detector in real traffic situations, the detector was installed on a local highway and vehicle speeds and volumes were measured both in a free running and a highly congested traffic. The measurements from the detector are compared with the reference measurements obtained from a traffic camera with the Mean Absolute Percentage Errors (MAPE), which has proved the usefulness of the detector in the field.

• International Journal of Automotive Technology
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• 제7권4호
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• pp.449-457
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• 2006

The driver model during drift cornering was examined, and a technique to improve vehicle movement performance during drift cornering was investigated. Based on the results obtained, the driver was found to steer using feedback of the body slip angle and the body slip angle velocity during drift cornering. Moreover, improvement of the cornering force characteristic, at which exceeded the maximum cornering force calm as much as possible is important.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.47-52
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• 1996

Interior noise, engine speed and vehicle speed are measured under road-load condition and interior noise signal is transformed by using the transient signal analysis methods such as the spectrogram and wavelet transform. Using the analyzed results, subjective noise criteria such as the loudness, noisiness and articulation index at each vehicle speed can be estimated and characteristics of interior noise for various running mode can be discussed in the viewpoint of noise quality.

• 소음진동
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• 제6권4호
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• pp.499-502
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• 1996

Interior noise, engine speed and vehicle speed are measured under transient road-load condition and interior noise signal is transformed by using the transient signal analysis methods, such as the spectrogram and wavelet transform. Using the analyzed results, subjective noise metrics such as the loudness, sharpness and articulation index at each vehicle speed can be estimated and characteristics of interior noise for various running modes can be discussed in the viewpoint of noise quality.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.573-578
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• 2004

Rotem has chosen ADAMS/Rail as the next generation analysis tool, to improve the capability and accuracy of the analysis ability. The dynamic performances of the railway vehicle, which is designed and manufactured by Rotem, have been analyzed and simulated using ADAMS/Rail. In this paper, Dynamic stress of bogie frame on running track is analyzed and compared with the data of real vehicle test. It is performed using ADAMS/AutoFlex and ADAMS/Durability.

• Wind and Structures
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• 제20권2호
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• pp.143-168
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• 2015

A numerical model for analyzing air-train-track interaction is proposed to investigate the dynamic behavior of a high-speed train running on a track in crosswinds. The model is composed of a train-track interaction model and a train-air interaction model. The train-track interaction model is built on the basis of the vehicle-track coupled dynamics theory. The train-air interaction model is developed based on the train aerodynamics, in which the Arbitrary Lagrangian-Eulerian (ALE) method is employed to deal with the dynamic boundary between the train and the air. Based on the air-train-track model, characteristics of flow structure around a high-speed train are described and the dynamic behavior of the high-speed train running on track in crosswinds is investigated. Results show that the dynamic indices of the head car are larger than those of other cars in crosswinds. From the viewpoint of dynamic safety evaluation, the running safety of the train in crosswinds is basically controlled by the head car. Compared with the generally used assessment indices of running safety such as the derailment coefficient and the wheel-load reduction ratio, the overturning coefficient will overestimate the running safety of a train on a track under crosswind condition. It is suggested to use the wheel-load reduction ratio and the lateral wheel-rail force as the dominant safety assessment indices when high-speed trains run in crosswinds.

• 인터넷정보학회논문지
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• 제12권6호
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• pp.73-82
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• 2011

지금까지의 위치인식 환경은 사람이나 사물 또는 이동체 자체에 대해서만 연구되어 왔다. 그러나 본 연구에서는 주행 중인 차량에 있는 여러 탑승자의 위치를 실시간으로 식별하고 추적하는 서비스에 대한 위치인식 모델을 제안하였다. 탑승자의 위치를 식별하려면 GPS기능이 탑재된 고가형 단말기를 이용하는 경우와 GPS기능이 없는 저가형 소형단말기를 이용하는 경우로 구분할 수 있다. 본 연구에서는 단순한 소형단말기가 GPS를 탑재한 차량용 인터페이스와 센서네트워크로 메시지를 전송하게 함으로써 탑승상황에 따른 효율적인 위치인식을 제공하도록 하였다. 이 기법은 먼저 차량의 상태(정차, 주행)를 감지하고, 주행상태라면 탑승자가 탑승이나 하차를 할 수 없기 때문에 굳이 위치정보를 송수신할 필요가 없어 트래픽을 감소시킬 수 있다. 이것은 전력소모를 줄여 배터리 수명을 늘릴 수 있도록 한다. 이에 본 연구에서는 제안한 차량정차 감지알고리즘을 탑승자 위치추적 시스템으로 구현하여 그 효용성을 확인하기 위해 실험하였다. 또한 설계하여 구현한 시스템을 이용하여 실험한 결과 최대수신거리는 12m로 측정되었으며, 200회의 실험을 통해 탑승인식과 하차인식이 모두 성공했음을 알 수 있었다. 또한 주행인식 측정실험에서는 차량정차 알고리즘을 적용한 경우가 그렇지 않은 경우에 비해서 41.6%의 전송트래픽을 감소시킬 수 있었다.