• International Journal of Automotive Technology
• /
• 제6권1호
• /
• pp.29-35
• /
• 2005

The structural integrity of either a passenger car or a light truck is one of the basic requirements for a full vehicle engineering and development program. The results of the vehicle product performance are measured in terms of ride and handling, durability, Noise/Vibration/Harshness (NVH), crashworthiness, and occupant safety. The level of performance of a vehicle directly affects the marketability, profitability and, most importantly, the future of the automobile manufacturer. In this study, the Virtual Proving Ground (VPG) approach has been developed to simulate dynamic nonlinear events as applied to automotive ride & handling. The finite element analysis technique provides a unique method to create and analyze vehicle system models, capable of including vehicle suspensions, powertrains, and body structures in a single simulation. Through the development of this methodology, event-based simulations of vehicle performance over a given three-dimensional road surface can be performed. To verify the predicted dynamic results, a single lane change test was performed. The predicted results were compared with the experimental test results, and the feasibility of the integrated CAE analysis methodology was verified.

• 한국ITS학회 논문지
• /
• 제10권6호
• /
• pp.24-31
• /
• 2011

본 연구는 회전교차로의 운영효과를 다루고 있다. 회전교차로는 신호교차로에 비해 지체감소와 친환경적이라는 기존 연구결과에 따라 우리나라에서 설치가 고려되는 실정이다. 본 연구의 목적은 보행교통량을 고려한 회전교차로의 운영효과를 분석하는데 있다. 이를 위해 이 연구는 교차로 네트워크를 구성하고 보행교통량과 진입교통량에 따른 분석시나리오를 설정하고, 차량당 평균제어지체 비교 분석에 중점을 두고 있다. 이 연구에서는 VISSIM 프로그램이 교통 시뮬레이션 도구로 사용된다. 분석된 주요결과는 다음과 같다. 첫째, 보행교통량에 근거하여 지체를 분석한 결과, 보행교통량이 회전교차로의 운영에 큰 영향을 미치는 것으로 분석되었다. 둘째, 보행교통량이 증가할수록 회전교차로의 지체도 증가하여, 보행교통량 1,000인/시 일 때 1차로 회전교차로에서는 총 진입교통량 800pcph, 2차로 회전교차로에서는 1,600pcph 이상 진입 시 신호교차로가 회전교차로보다 운영효율이 높게 평가되었다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.696-701
• /
• 2004

A vehicle cruise control algorithm using an Interacting Multiple Model (IMM)-based Multi-Target Tracking (MTT) method has been presented in this paper. The vehicle cruise control algorithm consists of three parts; track estimator using IMM-Probabilistic Data Association Filter (PDAF), a primary target vehicle determination algorithm and a single-target adaptive cruise control algorithm. Three motion models; uniform motion, lane-change motion and acceleration motion, have been adopted to distinguish large lateral motions from longitudinal motions. The models have been validated using simulated and experimental data. The improvement in the state estimation performance when using three models is verified in target tracking simulations. The performance and safety benefits of a multi-model-based MTT-ACC system is investigated via simulations using real driving radar sensor data. These simulations show system response that is more realistic and reflective of actual human driving behavior.

• 한국자동차공학회논문집
• /
• 제3권3호
• /
• pp.97-108
• /
• 1995

A 3-dimensional double track vehicle model, that has 12-degress-of-freedom, was proposed to analyze handling and riding behaviours of an automotive car. Nonlinear characteristics of the suspension and steering systems of the vehicle model were considered in its equations of motion, which were solved by using the 4th-order Runge-Kutta integration method. Computer simulations for lane change, steady-state handling, and running-over-bump manoeuvres were made and verified by vehicle tests on proving ground. The computed results of the proposed model showed better agreement with test results than those of the conventional 2-dimensional single track model did. Especially they showed good accuracy near the characteristic speed and in high lateral accelerated manoeuvres.

• 한국자동차공학회논문집
• /
• 제13권1호
• /
• pp.166-173
• /
• 2005

A vehicle stability control logic for 4WD hybrid electric vehicle is proposed using the regenerative braking of the rear motor and electronic brake force distribution module. Performance of the stability control logic is evaluated for J-turn and single lane change. It is found from the simulation results that the regenerative braking at rear motor is able to provide improved stability compared with the vehicle performance without my stability control. Additional improvement can be achieved by applying the regenerative braking plus electronic brake farce distribution control. It is expected that the regenerative braking offers additional improvement of the fuel economy as well as the vehicle stability control.

• 대한기계학회논문집A
• /
• 제29권1호
• /
• pp.139-144
• /
• 2005

A vehicle cruise control algorithm using an Interacting Multiple Model (IMM)-based Multi-Target Tracking (MTT) method has been presented in this paper. The vehicle cruise control algorithm consists of three parts; track estimator using IMM-Probabilistic Data Association Filter (PDAF), a primary target vehicle determination algorithm and a single-target adaptive cruise control algorithm. Three motion models; uniform motion, lane-change motion and acceleration motion. have been adopted to distinguish large lateral motions from longitudinal motions. The models have been validated using simulated and experimental data. The improvement in the state estimation performance when using three models is verified in target tracking simulations. The performance and safety benefits of a multi-model-based MTT-ACC system is investigated via simulations using real driving radar sensor data. These simulations show system response that is more realistic and reflective of actual human driving behavior.

• 대한전자공학회논문지TC
• /
• 제43권9호
• /
• pp.49-59
• /
• 2006

운전자 보조시스템은 운전자가 좀 더 편리하고 안전하게 주행할 수 있도록 주행 정보나 위험 경보를 주거나 적극적인 개입을 통해서 안전사고를 방지할 수 있는 시스템이다. 차선이탈경보, 전후방 충돌경보와 같이 특정한 기능을 갖는 현재의 운전자 보조시스템은 비젼과 거리 센서의 가격 대비 처리성능의 향상으로 통합된 기능성과 HMI (Human-Machine Interface)를 갖는 지능형 운전자 보조시스템으로 발전할 것이다. 본 논문은 2대의 카메라와 8대의 초음파센서를 각각 차량의 전후방과 주변에 설치하여 주행 중인 차량의 환경정보인 실선과 점선의 차선 정보, 사각을 제거한 전방향의 차량의 위치정보를 추출하여 운전자가 전방향의 주행상황을 쉽게 인지할 수 있는 조감영상과 음성충돌경보를 제공하는 지능형 운전자 보조시스템을 제안한다.

• 로봇학회논문지
• /
• 제12권3호
• /
• pp.297-305
• /
• 2017

As the development of autonomous vehicles becomes realistic, many automobile manufacturers and components producers aim to develop 'completely autonomous driving'. ADAS (Advanced Driver Assistance Systems) which has been applied in automobile recently, supports the driver in controlling lane maintenance, speed and direction in a single lane based on limited road environment. Although technologies of obstacles avoidance on the obstacle environment have been developed, they concentrates on simple obstacle avoidances, not considering the control of the actual vehicle in the real situation which makes drivers feel unsafe from the sudden change of the wheel and the speed of the vehicle. In order to develop the 'completely autonomous driving' automobile which perceives the surrounding environment by itself and operates, ability of the vehicle should be enhanced in a way human driver does. In this sense, this paper intends to establish a strategy with which autonomous vehicles behave human-friendly based on vehicle dynamics through the reinforcement learning that is based on Q-learning, a type of machine learning. The obstacle avoidance reinforcement learning proceeded in 5 simulations. The reward rule has been set in the experiment so that the car can learn by itself with recurring events, allowing the experiment to have the similar environment to the one when humans drive. Driving Simulator has been used to verify results of the reinforcement learning. The ultimate goal of this study is to enable autonomous vehicles avoid obstacles in a human-friendly way when obstacles appear in their sight, using controlling methods that have previously been learned in various conditions through the reinforcement learning.

• 한국도로학회논문집
• /
• 제10권3호
• /
• pp.19-31
• /
• 2008

영상처리시스템(VIPS: Video Image Processing System)은 실시간으로 들어오는 영상정보를 분석하여 유용한 정보를 제공하며, 하나의 카메라로 여러 차로를 동시에 감시할 수 있는 알고리즘으로 교통량, 속도뿐만 아니라 밀도 및 점유율 등 다양한 정보를 제공한다. 영상검지시스템으로 상용화 제품은 Tripwire시스템으로 검지영역의 픽셀 변화량으로 차량검지를 하나, 이는 교통량, 속도 등 단편적인 정보에 국한될 수 밖에 없다. 반면, 영상검지시스템이 개별차량에 대한 추적시스템으로 개발할 경우 사고 및 차로 변경의 위험요소 감지 등 보다 다양한 정보를 제공할 수가 있다. 본 논문은 컴퓨터비전 기술을 이용하여 Tripwire에서 수집할 수 있는 교통정보와 동일한 정보를 제공하는 개별차량의 추적시스템을 개발하였으며 이 시스템을 실제 도로영상에 적용하여 상용화된 시스템과 결과를 비교함으로써 성능검증을 하였다.

• 한국도로학회논문집
• /
• 제16권5호
• /
• pp.173-182
• /
• 2014

PURPOSES : The purpose of the study is to a) explore the operating speed of trucks on rural highways affected by road geometry, and thereby b) develop a predictive model for the operating speed of trucks on rural highways. METHODS : Considering that most of the existing studies have focused on cars, the current study aimed to predict the operating speed of trucks by conducting linear regression analysis on the speed data of trucks operating on the linear-curved-linear portions of the road as a single set. RESULTS : The operating speed in the plane curve portion increased with the length of the curve, and decreased with a lower vertical grade and a smaller curve radius. In the straight plane portion, the operating speed increased with a larger curve radius(upstream), and decreased with an increase in the change of the vertical grade, depending on the length of the vertical curve. CONCLUSIONS : This study developed estimation models of truck for operational speed and evaluated the degree of safety for horizontal and vertical alignments simultaneous. In order to represent whole area of the rural highway, the models should be ew-analyzed with vast data related with road alignment factor in the near future.