• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.4
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• pp.75-85
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• 2002

The introduction of GPS technique in transportation study make real time tracking of driving vehicle's position possible. Position information data gauged with three dimension(X, Y, Z) can be achieved with time-continuity and from more than two driving vehicles. For this field of study, in past day, there were many difficulties in collecting real time data, but now, it becomes easy thanks to this. But for the resonable result analysis, fully understanding of GPS data-accuracy must be proceeded. Because accompanied magnitude of error depends on the study's accuracy. For this reason, this study surveyed the GPS data's error and suggest calibrate technique. This study's result will be helpful for following studies using DGPS data. For this, this study takes two types study in road, and set triangulation coordinates, and compare it with GPS data. DGPS data contains less than 0.6m's error.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.931-940
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• 2017

This paper describes a predictive fault diagnosis algorithm for autonomous vehicles based on a kinematic model that uses a sliding mode observer. To ensure the safety of autonomous vehicles, reliable information about the environment and vehicle dynamic states is required. A predictive algorithm that can interactively diagnose longitudinal environment and vehicle acceleration information is proposed in this paper to evaluate the reliability of sensors. To design the diagnosis algorithm, a longitudinal kinematic model is used based on a sliding mode observer. The reliability of the fault diagnosis algorithm can be ensured because the sliding mode observer utilized can reconstruct the relative acceleration despite faulty signals in the longitudinal environment information. Actual data based performance evaluations are conducted with various fault conditions for a reasonable performance evaluation of the predictive fault diagnosis algorithm presented in this paper. The evaluation results show that the proposed diagnosis algorithm can reasonably diagnose the faults in the longitudinal environment and acceleration information for all fault conditions.

• 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.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.35-44
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• 2006

Acceleration and deceleration curves have been used for design purposes worldwide. The curve in design level has been regarded as an single deterministic curve to be used for design of climb lanes. It should be noted that the curve was originally made using ideal driving truck and that the curve is applied during design based on the assumption of no difference between ideal and real driving conditions. However. observations show that aged vehicles and lazy behavioring drivers nay make lower performance of vehicles than the ideal performance. The present paper provides the results of truck speeds at climbing lanes then probabilistic variation of acceleration and deceleration corves. For these purposes. a study about identification of vehicle makers, and weights for trucks at freeway toll gates and then observation of vehicle-following speed were performed. The 85%ile results obtained were compared with the deterministic performance curves of 180, 200, and 220 Ib/hp. It was identified that the performance of 85%ile results obtained from vehicle-following-speed observations were lower than one from deterministic performance curves. From these results, it may be concluded that at the beginning Point of climbing lanes additional $16.19{\sim}67.94m$ is necessary and that at the end point of climbing lanes $53.12{\sim}103.24m$ of extension is necessary.

• Proceedings of the KOR-KST Conference
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• 2003.02a
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• pp.3-18
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• 2003

본 논문은 ATMS와 ATIS에서 요구되는 교통관리 및 정보제공의 효과분석을 위해, 운전자의 주행 및 경로선택 의사결정과 교통제어에 대한 반응등 운전자 행태를 모의실험에 반영함으로써 교통시스템의 실시간 특성을 모사할 수 있는 모형을 구축하고 이를 기반으로 하는 미시적 교통 모의실험기를 개발하는 것을 목적으로 하였다. 본 연구에서는 운전자, 차량, 교통망, 검지 및 신호시스템, 교통정보제공시스템 등을 교통시스템의 주요 구성요소로 설정하였으며 운전자 및 차량특성, 차두시간분포와 차량발생모형, 차량주행모형, 차로변경 및 간격수락모형, 경로선택모형을 주모의실험모형을 구성하는 부모형으로 결정하였다. 따라서 본 논문에서는 각각의 부모형들에 대한 최근의 연구결과들을 검토하고, 현실모사 능력과 함께 다른 부모형들과의 연계, 모의실험기의 구현상에서의 적합성 등을 고려하여 적정모형의 선정 및 수정, 새로운 부모형의 구축을 수행하였다. 구축된 부모형을 통합하여 교통모의실험기를 개발하였으며 구축된 모형의 타당성 및 적용성 검토를 위해 현장자료 및 가상자료를 이용한 검증을 수행하였다. 검증결과 모형의 목적인 교통제어 및 정보제공등의 시스템 대안의 평가에 이용 가능한 것으로 나타났다. 또한 본 논문의 연구결과는 교통제어 및 정보제공전략 대안의 평가뿐만 아니라 차량추종 및 차로변경 등의 미시적 교통모형 연구, 동적기종점 통행량 추정, 동적통행배정의 연구에도 활용할 수 있을 것으로 판단된다. 본 논문의 연구모형은 현단계에서는 현실의 모사 및 분석을 위한 도구보다는 새로운 대안들간의 비교평가를 위한 도구로 활용할 수 있을 것으로 판단된다. 이에 따라 현실모사의 정확도를 확보하기 위한 검증 및 개선이 필요할 것이며, 각 부모형들에 대한 계속적인 연구와 새롭게 발표되는 연구결과를 수용한 지속적인 개발이 필요할 것이다.유기적인 연계에 있음을 밝히고 있다. 건설을 위한 정책적 시사점과 동북아 연구개발정보 Portal 및 APEC APGrid 연구망 등의 구체적인 정보인프라 구축방안을 도출하였다.술 주기를 도출하고, 산업 내 평균 권리 청구 항목 수를 이용하여 각 산업의 기술 범위를 비교하였다. 각각의 동적 분석을 통해 시간에 따른 변화 양상이 관찰하였고, ANOVA 분석을 이용하여 통계적 유의성을 검증하였다. 본 연구는 현재의 기술 패러다임 내에서 Pavitt이 제시한 산업 분류의 근거를 보충 설명하였고 특허 정보를 이용하여 기술혁신의 산업별 유형에 대한 폭넓은 분석방법을 제시하였다.별 시간대별 효과분석을 통하여 정책의 시행여부가 결정되어야 할 것이다. 한편, 화물전용차선의 설치로 인한 물류비용의 절감을 보다 효과적으로 달성하기 위해서는 종합류류 전산망의 시급한 구축과 함께 화물차의 적재율을 높이고 공차율을 낮출 수 있는 운송체계의 수립이 필요한 것으로 판단된다. 그라나 이러한 화물전용차선의 효과는 단기적인 치유책일 수밖에 없기 때문에 물류유통 시설의 확충을 위한 사회간접자본의 구축을 서둘러 시행하여야 할 것이다.으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압주입시험에서도 확인된다.. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9%

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.709-716
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• 2007

An active steering bogie has been theoretically proved to improve both stability and steering performance remarkably. However, It has not been commercialized yet even though many researchers have been trying to develop it because some technical difficulties still exist such as information acquisition fer active control, increasing mechanical components, high energy consumption, fail-safe problem and so on. To solve those problems, an advanced active steering mechanism is proposed in this paper. With this mechanism, required control force is small enough to use direct drives. Therefore, the number of additional mechanical components can be minimized since mechanical transducers like gears are not necessary. Fail-safe function can be also inserted easily. In this paper, concept design of the proposed active steering bogie is introduced and the possibility is verified through computer simulation using linear dynamic model.

• Spatial Information Research
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• v.23 no.4
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• pp.79-89
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• 2015

This study aims to design and implement a traffic model that can simulate the traffic behavior on the microscopic level by using the GIS. In the design of the model, the vehicle in the simulation environment recognizes the GIS road centerline data as road network data reflecting number of lanes, speed limit and so on. In addition, the behavior model was designed by dividing functions into the environmental perception model, time headway distribution model, car following model, and lane changing model. The implemented model was applied to Jahamun-road of Jongno-gu district to verify the accuracy of the model. As a result, the simulation results on the Jahamun-road had no great error compared with the actual observation data. In the aspect of usability of model, it is judged that this model will be able to effectively contribute to analysis of amount of carbon emission by traffic, evaluation of traffic flow, plans for location of urban infrastructure and so on.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.609-617
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• 2013

This paper presents a near-minimum time path planning algorithm for autonomous driving. The problem of near-minimum time path planning is an optimization problem in which it is necessary to take into account not only the geometry of the circuit but also the dynamics of the vehicle. The path planning algorithm consists of a candidate path generation and a velocity optimization algorithm. The candidate path generation algorithm calculates the compromises between the shortest path and the path that allows the highest speeds to be achieved. The velocity optimization algorithm calculates the lap time of each candidate considering the vehicle driving performance and tire friction limit. By using the calculated path and velocity of each candidate, we calculate the lap times and search for a near-minimum time path. The proposed algorithm was evaluated via computer simulation using CarSim and Matlab/Simulink.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.187-196
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• 2014

In this paper, Minimize driving energy for operation within a defined distance yeokgan fixed time-resolved and determine the nature of the train is traveling, and to model mathematically. Urban rail car cruise in general by the PID controller is used instead of automatically tracking a target value while traveling in energy consumption to be minimized by using optimal control model railroad charyangreul was designed under real operating conditions the same. The actual track conditions apply to the minimum value or a separate listing of cars around the track facility without a driving energy of the automatic operation and to reduce the driving energy. Therefore, actual route chosen straight line 8 / gradient segment / curve for the measured data analysis, such as sections within the city-minute drive each section and presented how the trains to save energy, depending on the pattern of the train station in the region.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.219-230
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• 2017

This paper proposes a vehicle to road tracking algorithm based on vision sensor by using EKF(Extended Kalman Filter). The lateral offset, heading angle, and curvature which are obtained from vehicle to road tracking might be used as inputs to steering controller of LKAS(Lane Keeping Assist System) or for the warning decision logic of LDWS(Lane Departure Warning System). To the end, in this paper, the yaw rate, steering angle, and vehicle speed as well as lane raw points together with considering of vehicle lateral dynamics are utilized to improve the exactness and convergence of the vehicle to road tracking. The proposed algorithm has been tested at a proving ground that consists of straight and curve sections and compared with GPS datum using DGPS-RTK equipment to show the feasibility of the proposed algorithm.