• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.42-60
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• 2024

This study analyzed the characteristics of mixed traffic flows with autonomous vehicles on highway weaving sections and assessed the safety of vehicle-following pairs based on surrogate safety indicators. The intelligent driver model (IDM) was utilized to emulate the driving behavior of autonomous vehicles, and the weaving sections were divided into lengths of 300 and 600 meters for analysis within a micro-traffic simulation (VISSIM). Although significant differences were found in the average speed, density, and headway between the two sections through t-test results, no significant differences were observed when comparing the number of conflicts per indicator and the vehicle-following pair. Four safety indicators were selected for the mixed traffic evaluation based on their ability to represent risk levels similar to those perceived by drivers. The safety analysis, based on the selected four indicators, determined that autonomous vehicles following other autonomous vehicles were the safest pairing. Future research should focus on integrating these indicators into a single comprehensive index for analysis.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.859-864
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• 2009

When the vehicle passes through turnout, the design is required to minimize the change of lateral force. Therefore, in case the vehicle passed the through turnout, we ought to execute dynamic analysis of the interaction between the vehicle and turnout in order to make an estimate of the lateral force and the derailment coefficient on the turnout. In this paper, we established the analytical model of the vehicle and turnout and analysed running safety when the vehicle passes through turnout in order to improve running safety of the vehicle on turnout. Also, to verify the vehicle and turnout model, we analysed reaction force and running behavior between wheel and rail, and running safety of the vehicle by changing cradle part and the tongue rail when the vehicle passes through turnout.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.110-116
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• 2013

Track irregularities is one of the key factors influencing the running behavior of trains. In order to ensure safety and ride comfort of train, the criteria for track irregularities should be adequately established regarding vehicle velocity, vehicle characteristics, characteristics of the track recording car, and measurement interval. Also, track maintenance should be carried out thoroughly according to the criteria for managing track irregularities. Numerical analysis was conducted to investigate the influence of track alignment on the running behavior of Korean high speed train(KTX). Various wavelengths and amplitudes of lateral alignment were considered as parameters for this study using the Vampire program, a vehicle dynamics modeling package in railway environment. Derailment, lateral load, bogie acceleration and body acceleration of numerical analysis results due to alignment were investigated. Finally, the influence of the alignment on safety and ride comfort for the KTX was evaluated. This study indicates that alignment irregularities have significant impacts on running safety, and that the criteria used to manage alignment irregularities should be restrictive to ensure the running safety of the KTX.

• Tunnel and Underground Space
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• v.16 no.4 s.63
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• pp.288-295
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• 2006

In this study, dynamic behavior of the vehicles is analyzed, while the track is subjected to lateral vibrations due to earthquake and blasting load. A computer program(WERIA, Wheel Rail Interaction Analysis) is used, which can simulate dynamic responses of vehicles subjected to lateral vibrations. The analysis considers two types of vehicles: I.e. power cars of KTX and Busan subway train. It can also consider the interaction with sub-structures such as tracks and soil. The creep force module is considered, and the running safety of railway vehicles subjected to earthquake and blasting loading is studied. Based on the results of this study, the running safety of the vehicles can be confirmed against lateral vibration.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.864-867
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• 2009

고속도로를 주행하는 차량에 작용하는 순간적인 강풍은 차량의 주행경로이탈, 차체의 수평회전 과다와 전도를 발생시키는 원인이 되며, 이로 인한 교통사고는 치명적인 대형사고로 이어질 가능성이 높다. 최근에 건설되거나 추진중인 고속도로는 고속운행에 필요한 도로선형을 확보하기 위해 계곡부를 통과하는 높은 위치에 교량을 건설하거나 산악터널을 내는 경우가 많으며, 지형적인 특성으로 발생하는 국지적인 강풍의 영향이 매우 크기 때문에 적극적인 강풍저감대책이 필요하다. 본 연구에서는 강풍 발생지역을 주행중인 차량의 안전성 및 쾌적성확보를 위하여 차량의 동역학적 거동을 규명하고 차종별 주행속도와 순간풍속의 상관관계를 정립하였다. 또한 차량사고의 영향인자별 분석을 통하여 기존에 제시된 연구결과와 기준안에 대한 고찰을 실시하였고, 강풍발생 지역을 통과하는 차량에 대한 규제와 운영방법에 대해 위험풍속을 정의하고 차량속도규제(안)을 제시하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.299-312
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• 2021

Autonomous vehicles using V2X can drive safely information on areas outside the sensor coverage of autonomous vehicles conventional autonomous vehicles. As V2X technology has emerged as a key component of autonomous vehicles, research on V2X security is actively underway research on risk analysis due to failure of V2X communication is insufficient. In this paper, the service scenario and function of autonomous driving system V2X were derived by presenting the intersection scenario of the autonomous vehicle, the malfunction was defined by analyzing the hazard of V2X. he ISO26262 Part3 process was used to analyze the risk of malfunction of autonomous vehicle V2X. In addition, a fault injection scenario was presented to verify the fail-safe of the simulation-based intersection scenario.

• Information and Communications Magazine
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• v.34 no.5
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• pp.10-18
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• 2017

본고에서는 자율주행 완성차와 자율주행 융합 부품 관련 기술과 국내외의 자율주행자동차 산업정책과 기술 개발 동향을 살펴본다. 자율주행 차량은 고안전, 고편의, 친환경, 신생태계의 자동차 산업에서의 4가지 미래 키워드를 만족시키는 기술로서 국가차원의 전략적 양성이 필요하다. 자율주행자동차 산업은 자동차 산업 생산기반 및 우리나라의 IT, 반도체 등의 기술 활용이 가능하며, 아직 상용화 되지 않은 분야로서 자율주행 분야의 상용화 기술 조기 확보 시 세계시장을 선점 할 수 있다. 따라서 자율주행 완성차 및 부품업체 등의 복수 수요기관이 참여하여 중소, 중견 부품업체 수요처 다각화 및 생태계 체질 개선, 자율주행 핵심부품 및 제어를 위한 SW 등 원천기술 확보 및 수입대체, 자율주행 기술과 관련 센서 선도기술 개발 및 글로벌 중견기업 육성을 기대 할 수 있다. 또한 빠르게 자율주행자동차 관련 기술개발이 진행되고 전장 부품이 자동차에서 차지하는 비중이 커짐에 따라 서로 연결되어 동작하는 전기전자 시스템의 기능안전 확보의 필요성이 대두되고 있다. 이미 해외에서는 자동차 전자제어 시스템 의무 장착을 강화시키는 추세이며 차량 안전 확보를 위해 전자제어장치의 기능 안정성의 중요성과 기술 표준의 필요성을 기반으로 자동차 기능 안전선 국제 표준을 규격화하고 있다. 따라서 본고에서는 국내외의 자율주행차량 분야의 산업 현황과 기술 동향을 살펴봄으로써 시장의 현황을 파악하고 자동차 기능 안전성 국제 표준에 관하여 알아본다.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.909-914
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• 2009

A suspension is the most prior apparatus to decide vehicle's running safety and ride comfort, also the suspension stiffness is the most important parameter for the designing of the vehicle. Providing the strong stiffness with the primary suspension in order to improve the running safety with high speed, but it causes a problem with a curve running performance of a railway vehicle. Therefore, many studies deal with the optimal value of suspension stiffness. In this paper, we aim to optimize the suspension system to improve running safety by varying stiffness values of railway vehicle suspension. We have proceeded an analysis by design variables which are position, length, width, stiffness and damping coefficients of primary and secondary suspension to optimize the suspension characteristics. As a result of the optimization, we verified that the derailment coefficients of inside and outside of wheel are decreased in comparison with initial model.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.95-100
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• 2019

In this paper, autonomous vehicles of service with existing vehicle accident for the prevention of the vehicle communication technology, self-driving techniques, brakes automatic control technology, artificial intelligence technologies such as well and developed the vehicle accident this occur to death or has been techniques, can prepare various safety cases intended to minimize the injury. In this paper, it is a study to secure safety in autonomous vehicles. This is determined according to spatial factors such as chip signals for general low-power short-range wireless communication and micro road AI. On the other hand, in this paper, the safety of boarding is improved by checking the signal from the electronic chip, up to "recognition of the emotion from residence time in the sensing area" to the biological electronic chip. As a result of demonstrating the reliability of the world countries the world, inducing safety autonomous system of all passengers in terms of safety. Unmanned autonomous vehicle riding and commercialization will lead to AI systems and biochips (Verification), linked IoT on the road in the near future, and the safety technology reliability of the world will be highlighted.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.67-85
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• 2018

Vehicle platooning through wireless communication and automated driving technology has become realized. Platooning is a technique in which several vehicles travel at regular intervals while maintaining a minimum safety distance. Truck platooning is of keen interest because it contributes to preventing truck crashes and reducing vehicle emissions, in addition to the increase in truck flow capacity. However, it should be noted that interactions between vehicle platoons and adjacent manually-driven vehicles (MV) significantly give an impact on the performance of traffic flow. In particular, when vehicles entering from on-ramp attempt to merge into the mainstream of freeway, proper interactions by adjusting platoon size and inter-platoon spacing are required to maximize traffic performance. This study developed a methodology for establishing operational strategies for truck platoonings on freeway on-ramp areas. Average speed and conflict rate were used as measure of effectiveness (MOE) to evaluate operational efficiency and safety. Microscopic traffic simulation experiments using VISSIM were conducted to evaluate the effectiveness of various platooning scenarios. A decision making process for selecting better platoon operations to satisfy operations and safety requirements was proposed. It was revealed that a platoon operating scenario with 50m inter-platoon spacing and the platoon consisting of 6 vehicles outperformed other scenarios. The proposed methodology would effectively support the realization of novel traffic management concepts in the era of automated driving environments.