• 한국도로학회논문집
• /
• 제10권2호
• /
• pp.57-67
• /
• 2008

현재 우리나라에서 도로 평면선형 설계를 위해 도로설계속도 개념을 사용하고 있다. 도로설계속도 개념은 단 한 개 도로 설계속도를 사용하기 때문에 도로 기하구조 수준이 일정해진다는 강점을 갖고 있으나, 도로 건설 후 그 도로를 주행하는 실제 차량 속도가 설계속도와 달리 나타날 수 있다는 약점을 갖고 있기도 하다. 본 연구에서는 이 약점을 보완하기 위해, 이미 여러 나라에서 사용 중인 주행속도 예측모형에 근거한 평면 선형설계기법을 제안한다. 본 연구에서는 이를 위해 우리나라 전역에서 표본을 선택하여 차량 속도조사를 수행했고, 속도에 영향을 미치는 도로설계요소를 통계분석을 통해 선정하여 양방향 2차로와 4차로 일반국도에 대한 차량 주행속도 모형을 제시했으며, 그 모형을 도로 평면선형설계에 적용하는 과정을 제시했다. 한편 새로운 기법에 대한 유효성을 밝히기 위한 실제 사례분석에서 새로운 기법은 기존 기법이 갖고 있는 약점을 해소하는 것으로 밝혀졌다. 향후 우리나라 도로 건설 사업에서 본 연구에서 제안한 평면선형 설계기법을 적용하면 도로 투자 효율성이 높아지고, 더 높은 설계일관성을 확보할 수 있을 것으로 판단한다.

• 산업경영시스템학회지
• /
• 제36권4호
• /
• pp.138-145
• /
• 2013

A sweep-based heuristic using common area is developed for multi-vehicle VRPs under time various and unsymmetric forward and backward vehicle moving speed. One depot and 2 delivery vehicle are assumed in this research to make the problem solving strategy simple. A common area is held to make adjustment of possible unbalance of between two vehicle delivery completion times. The 4 time zone heuristic is used to solve for efficient delivery route for each vehicle. The current size of common area needs to be studied for better results, but the suggested problem solving procedures can be expanded for any number of vehicles.

• 자동차안전학회지
• /
• 제4권1호
• /
• pp.27-32
• /
• 2012

Recently, in order to reduce traffic accident related fatalities, increasing number of studies are conducted regarding the vehicle safety enhancement devices. But very few studies about test procedures and requirements for vehicle safety systems are being carried out. Since BSD, as one of the most important safety features, is installed on a new vehicle, its performance test method has to be evaluated. Independent factors irrelevant to the device types including collision position, vehicle speed and closing speed are used to calculate test distance away from the current vehicle. Effect of roadway geometry as radius of curvature is introduced to propose possible misjudgement of following vehicle as adjacent one. The study results would be utilized to enhance the test procedure of BSD performance.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.420-423
• /
• 2003

This paper addresses the results of experimental and analytical study on the effects of dynamic interaction between vehicle and bridge on modal properties of bridge. Based on ambient vibration test and vehicle impact test on a bridge, it is found that the natural frequencies of bridge are varied by vehicle passing. Analytical studies for the effects of vehicle position, speed, damping, mass ratio and frequency ratio on bridge-vehicle interaction are carried out using complex eigenvalue analysis and numerical integration in time domain. The results show that vehicle properties except speed cause significant change of natural frequency as well as damping of bridge.

• 자동차안전학회지
• /
• 제13권4호
• /
• pp.114-122
• /
• 2021

In this paper, an automated vehicle intersection collision accident was analyzed through simulation. Recently, the more automated vehicles are distributed, the more accidents related to automated vehicles occur. Accidents may show different trends depending on the sensor characteristics of the automated vehicle and the performance of the accident prevention system. Based on NASS-CDS (National Automotive Sampling System-Crashworthiness Data System) and TAAS (Traffic Accident Analysis System), four scenarios are derived and simulations are performed. Automated vehicles are applied with a virtual system consisting of an autonomous emergency braking system and algorithms that predict the route and avoid collisions. The simulations are conducted by changing the sensor angle, vehicle speed, the range of the sensor and vehicle speed range. A range of variables considered vehicle collision were derived from the simulation.

• Wind and Structures
• /
• 제6권5호
• /
• pp.325-346
• /
• 2003

High-sided road vehicles are susceptible to a sharp-edged crosswind gust, which may cause vehicle accidents such as overturning, excessive sideslip, or exaggerated rotation. This paper thus investigates the dynamic behaviour and possible accidents of high-sided road vehicles entering a sharp-edged crosswind gust with road surface roughness and vehicle suspension included. The high-sided road vehicle is modelled as a combination of several rigid bodies connected by a series of springs and dampers in both vertical and lateral directions. The random roughness of road surface is generated from power spectral density functions for various road conditions. The empirical formulae derived from wind tunnel test results are employed to determine aerodynamic forces and moments acting on the vehicle. After the governing equations of motion are established, an extensive computation work is performed to examine the effects of road surface roughness and vehicle suspension on the dynamic behaviour and vehicle accidents. It is demonstrated that for the high-sided road vehicle and wind forces specified in the computation, the accident vehicle speed of the road vehicle running on the road of average condition is relatively smaller than that running on the road of very good condition for a given crosswind gust. The vehicle suspension system should be taken into consideration, and the accident vehicle speed becomes smaller if the vehicle suspension system has softer springs and lighter dampers.

• 제어로봇시스템학회논문지
• /
• 제18권1호
• /
• pp.1-6
• /
• 2012

In this paper, an adaptive fuzzy control system is proposed for the speed control of the ASV (Autonomous Surface Vehicle) with nonaffine nonlinear system dynamics. We consider the turning speed of the screw propeller to be the control input instead of thrust so that we do not have to know the exact function between turning speed and thrust. But in this case, the ASV becomes a nonaffine nonlinear system because thrust is a nonlinear function of the turning speed. To solve this problem, we propose a Takagi-Sugeno fuzzy-model-based control system and simulation studies are performed. Simulation results show the effectiveness of the proposed control scheme.

• International Journal of Safety
• /
• 제9권1호
• /
• pp.47-53
• /
• 2010

The speed difference in mountainous area is known causing traffic conflicts and accidents. Thus, climbing lanes have popularly been installed in mountainous roads around the world. In the present paper, vehicle speeds within and around climbing lanes of Ho-nam and Jung-ang expressway were collected and evaluated. The evaluation was performed in terms of coefficient of variations which represent dispersion of vehicle speed in climbing lanes. Results show that speed dispersion is more significant at segments before and after climbing lanes than those within climbing lanes. The estimated accident risk was evaluated using The Solomon's u-shaped curve. It was identified that the accident risk is also a lot significant at the same segments as much as 2.2 times greater than those of climbing lanes.

• 한국철도학회논문집
• /
• 제3권1호
• /
• pp.12-18
• /
• 2000

This paper addresses the experimental study on the nonlinear critical speed and the validity of simple prediction formulation. The experiment on nonlinear critical speed is carried out using roller rigs, which has been impossible on track because of a possibility of an accident. In addition, experiment for a bogie is performed to check the difference in modeling a full railway vehicle and a bogie. It is found that nonlinear critical speed proves to be an inherent phenomenon of a railway vehicle itself and the difference of test results between a full railway vehicle and a bogie is comparatively negligible. Finally. the accuracy of simple prediction formulation for outbreak velocity and response frequency in hunting is investigated.

• Design & Manufacturing
• /
• 제14권4호
• /
• pp.40-45
• /
• 2020

In a vehicle-to-vehicle accident, the impact posture, braking status, final stopping position, collision point and collision speed are important factors for accident reconstruction. In particular, the speed of collision is the most important issue. In this study, the collision speed and the final stopping position in the tunnel were estimated using PC-CRASH, a vehicle crash analysis program used for traffic accident analysis, and the final stopping position of the simulation and the final stopping position of the traffic accident report were compared. When the Pride speed was 0km/h or 30km/h and the Sorento speed was 100m/h, the simulation results and reports matched the final stopping positions and posture of the two vehicles. As a result of the simulation, it can be estimated that Pride was collided in an almost stationary state.