• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.636-644
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• 2010

A method for the detection of on-road succeeding vehicles using visual characteristic features like horizontal edges, shadow, symmetry and intensity is proposed. The proposed method uses the prominent horizontal edges along with the shadow under the vehicle to generate an initial estimate of the vehicle-road surface contact. Fast symmetry detection, utilizing the edge pixels, is then performed to detect the presence of vertically symmetric object, possibly vehicle, in the region above the initially estimated vehicle-road surface contact. A window defined by the horizontal and the vertical line obtained from above along with local perspective information provides a narrow region for the final search of the vehicle. A bounding box around the vehicle is extracted from the horizontal edges, symmetry histogram and a proposed squared difference of intensity measure. Experiments have been performed on natural traffic scenes obtained from a camera mounted on the side view mirror of a host vehicle demonstrate good and reliable performance of the proposed method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6090-6097
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• 2013

A pneumatically-driven driving simulator that provides a realistic representation of the driving environment was developed. The motion platform for the driving simulator is a mechatronic device that gives a driver the realistic feeling of an actual vehicle. The cost of the motion platform comprises the largest part of the expenses in developing a driving simulator. In this project, to develop a low-cost motion platform, the self-built motion platform based on the Stewart platform configuration that is constructed by six pneumatic cylinders was used as its actuator. The Stewart platform that moves in response to the operating signals of the joystick showed satisfactory tracking performance. We confirmed the possibility of the driving simulator using rFactor that is a commercially available racing game software.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.107-112
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• 2001

본 연구는 FTMS와 TCS를 실시간으로 통신하여 톨게이트 운영에 관련된 다양한 교통정보를 제공하는 교통상황 모니터링과 미래의 교통상황을 예측하고 이를 바탕으로 톨게이트 교통상황을 예측하는 톨게이트 시뮬레이션 시스템(TGSS)을 개발하는 것이다. 교통상황 모니터링은 실시간 교통자료를 통계처리하고 분석하여 사용자에게 그래픽하게 교통정보를 제공하고 교통류의 예측은 톨게이트에 도착하는 교통류를 60분 후까지 예측하여 톨게이트 운영자에게 제공한다. 또한 톨게이트 예측시스템은 서울톨게이트에 도착하는 교통류 패턴을 이용하여 미래 톨게이트 교통상황을 시뮬레이션하고 이에 대한 톨게이트 운영 대안을 제시하는 기능을 수행한다. FTMS 및 TCS와 실시간으로 통신하기 위하여 별도의 통신프로그램을 작성하였고 통신에 의해 수집된 실시간 교통자료들은 모니터링 시스템과 연계하여 서울 톨게이트 주변구간의 교통상황과 톨게이트 운영 현황을 제공한다. 교통류 예측 시스템에 사용되는 모형은 거시적 교통류 모형인 Simple Continuum 모형과 시계열 모형을 이용하였고 이를 통해 서울 톨게이트에 도착하는 미래 교통류를 예측 할 수 있다. 톨게이트의 교통상황을 구현하기 위하여 미시적 모형인 차량추종모형과 차로변경모형을 톨게이트 예측 시스템에 반영하였고 현재의 톨부스 운영안과 사용자가 입력하는 톨부스 운영대안에 따라 시뮬레이션 함으로써 미래 톨 플라자내 교통상황을 톨게이트 운영자에게 애니메이션으로 보여줄 수 있다. 톨게이트 시뮬레이션 시스템을 이용하여 현재의 톨게이트 운영안과 최적화된 운영안을 상호 비교함으로써 톨게이트 운영자는 좀더 과학적인 톨게이트 운영을 모색할 수 있을 것으로 생각된다. 실용적 측면에서 볼 때, 톨게이트 시뮬레이션 시스템(TGSS)은 실시간 통신을 통한 모니터링과 교통류 예측으로 톨게이트 상황을 시뮬레이션하고 톨게이트 운영 대안을 제시·평가함으로써 서울톨게이트 운영을 효율화하고 이로 인한 고속도로 소통 증대를 도모할 수 있을 것으로 기대된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1804-1809
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• 2015

The study in railway system to apply a fuel cell system with high efficiency and mobility than other renewable energy is being actively conducted. It is needed a analysis on load characteristics and control method of rolling stock in order to apply to rolling stock. This paper presents study on control small-scale prototype power converter electric railway vehicle using fuel cell generation system. Experiment is conducted through real fuel cell generation system and reference speed applying the driving curve of the actual electric railway vehicle was applied. Also, output voltage of boost converter is controlled considering characteristic of fuel cell. And it was confirmed characteristic according to powering and regeneration of inverter.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.113-130
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• 2002

In this paper, we developed DNL(Dynamic Network Loading) model based on Moving cell theory to analyze the dynamic characteristics of traffic flow in congested network. In this paper vehicles entered into link at same interval would construct one cell, and the cells moved according to Cell following rule. In the past researches relating to DNL model a continuous single link is separated into two sections such as running section and queuing section to describe physical queue so that various dynamic states generated in real link are only simplified by running and queuing state. However, the approach has some difficulties in simulating various dynamic flow characteristics. To overcome these problems, we present Moving cell theory which is developed by combining Car following theory and Lagrangian method mainly using for the analysis of air pollutants dispersion. In Moving cell theory platoons are represented by cells and each cell is processed by Cell following theory. This type of simulation model is firstly presented by Cremer et al(1999). However they did not develop merging and diverging model because their model was applied to basic freeway section. Moreover they set the number of vehicles which can be included in one cell in one interval so this formulation cant apply to signalized intersection in urban network. To solve these difficulties we develop new approach using Moving cell theory and simulate traffic flow dynamics continuously by movement and state transition of the cells. The developed model are played on simple network including merging and diverging section and it shows improved abilities to describe flow dynamics comparing past DNL models.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.133-144
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• 2004

A model and a measure which can evaluate the risk of rear end collision are developed. Most traffic accidents involve multiple causes such as the human factor, the vehicle factor, and the highway element at any given time. Thus, these factors should be considered in analyzing the risk of an accident and in developing safety models. Although most risky situations and accidents on the roads result from the poor response of a driver to various stimuli, many researchers have modeled the risk or accident by analyzing only the stimuli without considering the response of a driver. Hence, the reliabilities of those models turned out to be low. Thus in developing the model behaviors of a driver, such as reaction time and deceleration rate, are considered. In the past, most studies tried to analyze the relationships between a risk and an accident directly but they, due to the difficulty of finding out the directional relationships between these factors, developed a model by considering these factors, developed a model by considering indirect factors such as volume, speed, etc. However, if the relationships between risk and accidents are looked into in detail, it can be seen that they are linked by the behaviors of a driver, and depending on drivers the risk as it is on the road-vehicle system may be ignored or call drivers' attention. Therefore, an accident depends on how a driver handles risk, so that the more related risk to and accident occurrence is not the risk itself but the risk responded by a driver. Thus, in this study, the behaviors of a driver are considered in the model and to reflect these behaviors three concepts related to accidents are introduced. And safe stopping distance and accident occurrence probability were used for better understanding and for more reliable modeling of the risk. The index which can represent the risk is also developed based on measures used in evaluating noise level, and for the risk comparison between various situations, the equivalent risk level, considering the intensity and duration time, is developed by means of the weighted average. Validation is performed with field surveys on the expressway of Seoul, and the test vehicle was made to collect the traffic flow data, such as deceleration rate, speed and spacing. Based on this data, the risk by section, lane and traffic flow conditions are evaluated and compared with the accident data and traffic conditions. The evaluated risk level corresponds closely to the patterns of actual traffic conditions and counts of accident. The model and the method developed in this study can be applied to various fields, such as safety test of traffic flow, establishment of operation & management strategy for reliable traffic flow, and the safety test for the control algorithm in the advanced safety vehicles and many others.

• Korean Security Journal
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• no.54
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• pp.149-179
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• 2018

October 31, 2017, a man named Saipov who follows ISIS killed 8 people and injured nearly 20 others by driving his truck to the riverside bicycle path in Manhattan, New York, in an act of terror. June 5, 2017, the Islamic extremist Yacqub Khayre held a woman hostage in a suburb of Melbourne, Australia, before being killed by the police. Various countries around the world including the UK, France, and Germany are in war against terrorism. The terrorists change their target from hard targets such as government officials to vulnerable soft target, intensifying the public's fear, and, unlike in the past when they were organized by governments or organizations, extremists such as ISIS followers are now acting on their own in the act of terrorism. Also, as they use vehicles, pressure cooker, and other objects that can be easily found for terrorism, it is becoming more difficult for the police to prepare against terrorist attacks. Meanwhile, some terrorism researchers argue that conversational techniques (negotiation) used by the police are now of no use, as shown in the cases like 9/11 attacks in 2001 and 2016 Nice attack in France in which the suspects committed terrorist attacks without leaving enough time for the police to take action and that, therefore, tactical suppression techniques need to be developed. Therefore, this study suggested police negotiation techniques are necessary not only for terrorist attacks but also for overall police work, including handling intoxicated people at police station, and proposed ways to activate conversational techniques for police organizations.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.72-81
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• 2013

Many articles have been published about a 2-degree of freedom model that includes the lateral and yaw motions for controller synthesis in intelligent transport system applications. In this paper, a 3-degree of freedom linear model that includes the roll motion is developed to design a robust steering controller for lane following maneuvers using ${\mu}$-synthesis. This linear perturbed system includes a set of parametric uncertainties in cornering stiffness and unmodelled dynamics in steering actuators. The state-space model with parametric uncertainties is represented in linear fractional transformation form. Design purpose can be obtained by properly choosing the frequency dependent weighting functions. The objective of this study is to keep the tracking error and steering input energy small in the presence of variations of the cornering stiffness coefficients. Furthermore, good ride quality has to be achieved against these uncertainties. Frequency-domain analyses and time-domain numerical simulations are carried out in order to evaluate these performance specifications of a given vehicle system. Finally, the simulation results indicate that the proposed robust controller achieves good performance over a wide range of uncertainty for the given maneuvers.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.2
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• pp.195-202
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• 2016

In this study, a concept of active sound enrichment (ASE) control system was implemented and demonstrated for improving engine sound quality inside the cabin of a passenger car during acceleration. Unlike the active noise control cancels the noise for disturbance rejection, the ASE adds additional sound to the noise for tracking control. This approach requires a new algorithm to provide additional artificial sound to the original engine sound using active control strategy to achieve a target sound profile, which is predefined to satisfy required interior sound quality. The ASE algorithm was implemented in a digital controller dSPACE DS1401 and real-time control experiment was accomplished in an actual car. The ASE control results show that the actively enriched sound of each engine order against RPM tracks the target profiles precisely and quickly and improves the discontinuity, the level ratios and the sound pressure level of each engine order. Thus it is anticipated the ASE system can be applied for the improvement of the engine sound quality inside the cabin during acceleration.