• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.134-140
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• 2008

Preceding vehicle detection is a crucial issue for driver assistance system as well as for autonomous vehicle guidance function and it has to be performed with high reliability to avoid any potential collision. The vision-based preceded vehicle detection systems are regarded promising for this purpose because they require little infrastructure on a highway. However, the feasibility of these systems in passenger car requires accurate and robust sensing performance. In this paper, an preceded vehicle detection system is developed using stereo vision sensors. This system utilizes feature matching, epipoplar constraint and feature aggregation in order to robustly detect the initial corresponding pairs. After the initial detection, the system executes the tracking algorithm for the preceded vehicles including a leading vehicle. Then, the position parameters of the preceded vehicles or leading vehicles can be obtained. The proposed preceded vehicle detection system is implemented on a passenger car and its performances is verified experimentally.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1071-1078
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• 2018

In this paper, we implemented community driving system for auto-vehicles as a preceding research of drone's community flight. We used ultrasonic sensors in order to measure the distance between vehicles, and designed each vehicles to maintain specific distance to each other, by making the following vehicle to stop moving when the distance is closed to less than 20cm, to start moving when the distance increases to more than 30cm. We have also designed vehicle to accelerate until the distance is closed to 30cm when they are apart for more than 40cm due to contingencies during driving.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.5
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• pp.487-493
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• 2014

A geographic survey, which requires much of working hours in the digital mapping process, is consisted with the complementary survey and the attribute survey of topography and topographic features, and depended on the field survey. In previous research, using the location-based image had been recommended for diminishing the workload of field survey and post processing. For this research, we have developed the hardware and software for gathering and processing the location-based images with referencing results from the previous research. Those Geographic surveys were performed using developed system on 1/5,000 map sheets for Si and Gun area, respectively. The results have been evaluated as the mobile geographic survey system were able to replace the large part of field survey, and also the working hours were decreased by 37.5% at Si area. However, the complementary survey was needed for the attributes of topography and topographic features that were occluded by the parked vehicles or located in the areas without entry of vehicles.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.107-118
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• 2010

Wireless communication technologies including vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) enable the development of more sophisticated and effective traffic information systems. This study presents a method to estimate vehicular travel times in a vehicular ad hoc network (VANET) environment. A novel feature of the proposed method is estimating individual vehicle travel times through advanced on-board units in each vehicle, referred to as self-estimated travel time in this study. The method uses travel information including vehicle position and speed at each given time step transmitted through the V2V and V2I communications. Vehicle trajectory data obtained from the VISSIM simulator is used for evaluating the accuracy of estimated travel times. Relevant technical issues for successful field implementation are also discussed.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.64-73
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• 2012

In this paper, a new land preview system using laser range finder based on heave estimation algorithm is proposed. The proposed land preview system is an equipment which measures the shape of forward topography for autonomous vehicle. To implement this land preview system, the laser range finder is generally used because of its wide measuring range and robustness under various environmental condition. Then the current location of the vehicle has to be known to generate the shape of forward topography and sensors based on acceleration such as IMU and accelerometer are generally utilized to measure heave motion in the conventional land preview system. However the drawback to these sensors is that they are too expensive for low-cost vehicle such as mobile robot and their measurement error is increased for mobile robot with abrupt acceleration. In order to overcome this drawback, an algorithm that estimates heave motion using the information of odometer and previously measured topography is proposed in this paper. The proposed land preview system based on the heave estimation algorithm is verified through simulation and experiments for various terrain using a simulator and a real system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.90-100
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• 2017

The purpose of this study is to detect and label the vehicles using the drone images as a way to overcome the limitation of the existing point and section detection system and vehicle gap estimation on Arterial road. In order to select the appropriate time zone, position, and altitude for the acquisition of the drone image data, the final image data was acquired by shooting under various conditions. The vehicle was detected by applying mixed Gaussian, image binarization and morphology among various image analysis techniques, and the vehicle was labeled by applying Kalman filter. As a result of the labeling rate analysis, it was confirmed that the vehicle labeling rate is 65% by detecting 185 out of 285 vehicles. The gap was calculated by pixel unitization, and the results were verified through comparison and analysis with Daum maps. As a result, the gap error was less than 5m and the mean error was 1.67m with the preceding vehicle and 1.1m with the following vehicle. The gaps estimated in this study can be used as the density of the urban roads and the criteria for judging the service level.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1436-1445
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• 1990

Performance of vehicles depends mainly on engine performance, transmission gear ration and shifting pattern. In this paper, determination method of gear ratios and shifting pattern for automatic transmission equipped vehicles has been proposed. Computer programs for gear ratio determination and shifting pattern decision using optimal design technique have been developed for the purpose of increasing vehicle acceleration performance. For preceding study, computer simulation of vehicle performance is carried out using numerical technique.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.48-56
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• 2009

Regulation of Visible Light Transmission Percentage (VLT%) has been argued because it was known that the degree of darkness of tinted vehicle can affect to driving maneuver. Previously, it was proven that low level of VLT affects capacity reduction. But, due to lack of field data they could not analyze the effect of Car-Following model parameters. This study focuses on the effect of a tinted vehicle on following traffic flow. RTK GPS receiving data through field experiment analyzed based on headway distance, acceleration noise, sensitivity, and reaction time. As a result of analysis through GM 1st Model and 3rd Model, influence of following vehicle vary inversely with VLT and risk according as tinting of lead vehicle is third vehicle bigger than second vehicle. Also the results patterns of GM 3rd model include distance-headway are same with GM 1st Model. In the further need to research for influence analysis of traffic flow stability by the level of VLT.

• Journal of the KSME
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• v.35 no.8
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• pp.709-715
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• 1995

날로 그 중요성이 대두되고 있는 환경보존 문제에 능동적으로 대응하고 여러 계층 소비자의 안 전도, 쾌적성 등에 관련된 요구, 성능의 수준향상에 효과적으로 대처하기 위해서는 차량의 경량화 기술이 가장 먼저 선행되어야 할 과제이다. 경량화를 추구하는 방법은 최적설계 개념을 이용한 구조합리화에 의한 방법과 알루미늄, 강화 플라스틱 등 신소재 대체에 의한 방법이 병행 연구 되고 있다. 이 글에서는 구조합리화를 통한 경량화 목표를 달성하기 위해 설계 초기 단계에 활용 가능한 단순 보 모델 개발의 필요성에 관해 언급하고 실차의 도어 측면 붕괴강도(door side intrusion strength), 루프 붕괴강도 (roof crush strength) 해석을 위한 단순 보 모델 개발에 관해 소개하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1309-1312
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• 2015

본 논문에서는 현대 자율 주행 차량 경진대회에 적용되었던 LIDAR 기반의 다중 물체 추적 알고리즘을 소개한다. 물체 추적은 자율 주행 차량이 외부 환경을 인지하는데 중요한 역할을 한다. 본 논문의 물체 추적 알고리즘은 동시에 여러 개의 물체를 추적할 수 있도록 Multiple Data Association 방식을 사용하였고 순수하게 LIDAR만으로 동작하기 때문에 밤과 낮 모든 경우에 적용 가능하다. 알고리즘은 Clustering, Data Association, State Estimation, Data Arrangement 총 4단계로 이루어져 있으며 본 논문에서는 각 단계별로 알고리즘의 동작 방식을 소개한다. 실제 구현에는 Velodyne사의 HDL-32e이 사용되었고 실제 주행에서 교차로 내의 차량 추적 및 선행 차량의 동향을 추적하는데 적용되었다.