• 한국정밀공학회지
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• 제31권3호
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• pp.233-241
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• 2014

This paper contributes to development of a new method for detecting rear-side vehicles and estimating the positions for blind spot region or providing the lane change information by using vision systems. Because the real image acquired during car driving has a lot of information including the target vehicle and background image as well as the noises such as lighting and shading, it is hard to extract only the target vehicle against the background image with satisfied robustness. In this paper, the target vehicle has been detected by repetitive image processing such as sobel and morphological operations and a Kalman filter has been also designed to cancel the background image and prevent the misreading of the target image. The proposed method can get faster image processing and more robustness rather than the previous researches. Various experiments were performed on the highway driving situations to evaluate the performance of the proposed algorithm.

• 한국도로학회논문집
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• 제15권6호
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• pp.135-141
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• 2013

PURPOSES : The lack of details of design guideline for zig-zag shaped section approaching central bus stop leads an traffic accident proneness. So, this study analysed the geometric elements of central bus stop area in terms of vehicle dynamics and suggested design alternatives. METHODS : The study analysed a dynamic behaviour of bus moving in and out of zig-zag shaped section using Auto-Turn under scenarios. Based upon dynamic analysis, the study found out the width of overtaking lane is the most influential factor for a safe moving at zig-zag alignment. RESULTS : The width of overtaking lane at design speed of 40, 50, and 60 km/h respectively was suggested given taper ratio of 1 to 10 required for Bus Rapid Transit (BRT), and the lane width is not wider than 4.0m which possibly makes two vehicles using the same lane. Also, the width of overtaking lane which mitigates the taper ratio was suggested with the same restriction about the maximum lane width. CONCLUSIONS : The results of the study can be used to prepare a design guideline on zig-zag shaped alignment of central bus exclusive lanes. The more stable moving is expected by applying the design alternatives suggested, therefore the lower rate of traffic crashes at the vicinity of central bus stops.

• 한국도로학회논문집
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• 제15권1호
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• pp.163-169
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• 2013

PURPOSES: The urban traffic problems can be defined as general problems for smooth traffic flow including maintenance of mass transportation system according to suddenly increased population, traffic regulations for vehicles and pollution problem. As a method for solving traffic jams, one of the traffic problems of late, interest in Intelligent Traffic System(ITS) is increasing sharply, which is a system managing traffic demand by providing passers with information on traffic state of path and road conditions before they pass the road through ATIS, a field of ITS. METHODS: Variable message signs(VMS) is used on the roads as a method for providing information to promote smooth traffic flow and safety and prevent traffic accidents in advance by providing drivers with various information while driving. RESULTS: Recently, as ITS industry has been vitalized and technical factors of VMS have developed, various kinds of information is provided but the effect of VMS has not been maximized due to its limited type. CONCLUSIONS: Therefore, this study intends to provide methods for effective information transfer by analyzing driver's visual behavior characteristics for VMS and presenting a basis for maximizing VMS effect after considering read by expression type.

• 한국도로학회논문집
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• 제15권6호
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• pp.61-68
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• 2013

PURPOSES : The purpose of this study is to study the noise reducing effect of Micro Surfacing by comparing general asphalt, longitudinal tining and Slurry Seal. METHODS : This study measures vehicles' noise of each section by the NCPX method that can measure noise between the road surface and the tire at the field. Total sound pressure and sound pressure level by the 1/3 octave band frequency are calculated through the field data of each section. Total sound pressure level is compared by ANOVA test statistically. After ANOVA test, post-hoc test is conducted to know mean difference of surface type by Tukey. RESULTS : As the result of CPB analysis to confirm sound pressure levels by frequency, it was shown that sound pressure levels by frequency are totally similar except for those of frequency bands between 100Hz and 500Hz. The result of ANOVA test and post-hoc test, it was shown that sections of surface type have a difference. The result of Micro Surfacing was lower 2~5dB(A) than other surface type. CONCLUSIONS : It is found that the noise reduction performance of Micro Surfacing was better than other surface type.

• 자동차안전학회지
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• 제13권4호
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• pp.53-59
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• 2021

According to the Korean Traffic Accident Analysis System (TAAS), more than 200,000 traffic accidents occur every year. Also, the statistics including auto insurance companies data show 1.3 million traffic accidents. In the case of TAAS, the types of traffic accidents are simply divided into four; frontal collision, side collision, rear collision, and rollover. However, more detailed information is needed to assess for advanced driver assist systems at intersections. For example, directional information is needed, such as whether the vehicle in the car accident way in a straight or a left turn, etc. This study intends to redefine the type of accident with the more clear driving direction and path by referring to the Negligence standards used in automobile insurance accidents. The standards largely divide five categories of car-to-car/motorcycle /pedestrian/cyclist, and highway, and the each category is classified into dozens of types by status of the traffic signal, conflict situations. In order to present more various accident types for auto insurance accidents, the standards are reclassified driving direction and path of vehicles from crash situations. In results, the car-to-car accidents are classified into 33 accident types, car-to-pedestrian accidents have 19 accident types, car-to-motorcycle accidents have 38 accident types, and car-to-cyclist accidents are derived into 26 types.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3369-3385
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• 2019

There are various research challenges in vehicular ad hoc networks (VANETs) that need to be focused until an extensive deployment of it becomes conceivable. Design and development of a scalable routing algorithm for VANETs is one of the critical issue due to frequent path disruptions caused by the vehicle's mobility. This study aims to provide a novel road-aware routing protocol for vehicular networks named as Two-level hierarchical Hybrid Road-Aware (THERA) routing for vehicular ad hoc networks. The proposed protocol is designed explicitly for inter-vehicle communication. In THERA, roads are distributed into non-overlapping road segments to reduce the routing overhead. Unlike other protocols, discovery process does not flood the network with packet broadcasts. Instead, THERA uses the concept of Gateway Vehicles (GV) for the discovery process. In addition, a route between source and destination is flexible to changing topology, as THERA only requires road segment ID and destination ID for the communication. Furthermore, Road-Aware routing reduces the traffic congestion, bypasses the single point of failure, and facilitates the network management. Finally yet importantly, this paper also proposes a probabilistical model to estimate a path duration for each road segment using the highway mobility model. The flexibility of the proposed protocol is evaluated by performing extensive simulations in NS3. We have used SUMO simulator to generate real time vehicular traffic on the roads of Gangnam, South Korea. Comparative analysis of the results confirm that routing overhead for maintaining the network topology is smaller than few previously proposed routing algorithms.

• 한국산업정보학회논문지
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• 제24권2호
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• pp.25-31
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• 2019

최근 인공지능 기술이 급격히 발전하면서 첨단 운전자 지원 시스템 분야에 딥러닝 기술을 접목하여 기존의 기술보다 뛰어난 성능을 보여주기 위한 여러 연구들이 진행 되고 있다. 이러한 동향에 맞춰 본 논문 또한 첨단 운전자 지원 시스템의 핵심 요소 중 하나인 차로이탈 경고시스템에 딥러닝 기술을 접목한 방법을 제안한다. 제안하는 방법과 기존의 차선검출 기반의 경고시스템과의 비교 실험을 통해 그 성능을 평가 하였다. 고속도로 주행영상과 시내 주행영상을 이용한 두 가지의 서로 다른 환경에서 모두 제안하는 방법이 정확도 및 정밀도 부분에서 더 높은 수치를 보여주었다.

• 자동차안전학회지
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• 제14권3호
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• pp.65-70
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• 2022

Lane change in urban environments is a challenge for both human-driving and automated driving due to their complexity and non-linearity. With the recent development of deep-learning, the use of the RNN network, which uses time series data, has become the mainstream in this field. Many researches using RNN show high accuracy in highway environments, but still do not for urban environments where the surrounding situation is complex and rapidly changing. Therefore, this paper proposes a lane change possibility decision network by adopting Attention layer, which is an SOTA in the field of seq2seq. By weighting each time step within a given time horizon, the context of the road situation is more human-like. A total 7D vectors of x, y distances and longitudinal relative speed of side front and rear vehicles, and longitudinal speed of ego vehicle were used as input. A total 5,614 expert data of 4,098 yield cases and 1,516 non-yield cases were used for training, and the performance of this network was tested through 1,817 data. Our network achieves 99.641% of test accuracy, which is about 4% higher than a network using only LSTM in an urban environment. Furthermore, it shows robust behavior to false-positive or true-negative objects.

• 한국도로학회논문집
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• 제13권3호
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• pp.131-137
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• 2011

근래의 폭발적인 차량의 증가와 지가 상승, 도시부 시가지 내에서의 지상공간의 공급한계, 자연환경 및 경관에 대한 사용자 요구수준의 증대 등 여러 이유로 지하공간 개발의 필요성이 증대되고 있다. 지하공간의 개발은 필연적으로 건설비의 증가로 이어지며 대형 구조물의 설치는 도시 미관을 저해하는 요인으로 작용하기 때문에 최근에 가능하면 도심 구조물의 경우 경량화, 소형화 하려는 경향이 있다. 따라서 본 연구에서는 효율적인 지하공간의 개발을 위해 대구광역시의 도시부 도로에 설치되어 운영 중인 지하차도 구조물을 대상으로 미시적 소프트웨어인 VISSIM 5.20을 이용하여 소형차 전용 지하차도 도입에 따른 지체시간의 변화를 분석하였다. 소형차 전용 지하차도 도입 시 운영 방식의 변화를 반영하기 위해 대형차량을 지하차도를 통해 통행시키지 않고 지하차도 상부 평면교차로를 이용해 통행하도록 하였으며, 교통특성에 따른 영향을 분석하기 위해 접근로의 포화도(v/c)와 대형차량 혼입률을 순차적으로 증가시켜 통행시간의 변화를 알아보고 기존 지하차도와 비교 분석하였다. 본 연구의 결과로 미루어 볼 때 소형차 전용 지하차도의 도입은 토지매입에 따른 경제적 손실, 구조물의 대형화에 따른 환경훼손 및 친환경적 녹색교통 측면에서도 유리할 것으로 판단된다.

• 한국도로학회논문집
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• 제10권2호
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• pp.159-166
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• 2008

최근 교통감시시스템은 실시간의 영상검지시스템(VIPS)을 가장 선호하고 있으며, 그 수요는 매년 증가하고 있는 추세이다. 일반적으로 영상검지시스템은 공간기반의 검지알고리즘을 사용하고 있으며, 교통량, 속도, 점유율 등의 교통정보를 제공하고 있다. 현재 전 세계적으로 이미 상용화되어 있는 대부분의 영상검지시스템들은 Tripwire기반의 검지영역 내 차량의 존재유무를 판단하여 교통정보를 수집하는 알고리즘으로 구성되어 있으나, 개별차량에 대한 걸지는 불가능한 한계를 갖고 있다. 반면 개벽차량의 추적시스템은 보다 구체적인 공간적 교통정보를 제공할 수 있어 사고검지, 급차선 변경 등 교통정보를 보다 다양화 할 수 있다는 장점이 있으나 추적길이가 불과 100미터이내이면, 그 이상 관측하기 위해서는 운영자가 카메라를 줌인을 하여 영상을 확대하여야 한다. 따라서 본 논문에서는 차량 추적의 효과를 높이기 위해서 기존의 100미터 이내 추적거리를 여러 대의 CCTV시스템을 이용하더라도 200미터이상으로 확대함으로써 사고 또는 비정상적 차량흐름을 검지할 수 있는 알고리즘을 제안한다.