The aim of this study is to evaluate the possibility of damage to cultural assets resulting from vibrations generated by construction vehicle traffic. The cultural heritage's natural vibration frequency was determined to be 150Hz by measurement. The damping ratios were calculated as 4.7% using the logarithmic decrement approach and 4.3% using the half-power method. The vibration measurements obtained during vehicle operation indicated that, despite an increase in vehicle velocity of up to 15 km/h, the vibrations remained below the detectable level of 0.13 mm/sec. When the road is curved and the terrain is sloped, a suitable speed for vehicle operation was found to be around 17 km/h, at which point vibrations were seen. The highest recorded vibration amplitude at this velocity was 0.217 mm/sec, which remains below the stringent regulation limit of 2 mm/sec. Thus, it can be concluded that there is no actual harm caused by vibrations.

PURPOSES: A hard shoulder lane (HSL) is a method of solving severe traffic congestion on an expressway. Recently, it has been applied to several expressways in Korea, and there have been numerous positive effects, which include increasing the road capacity and reducing traffic congestion. However, these effects have been limited due to tunnels which created a‘ bottle-neck’effect in HSL application for longer road segments. In the tunnel sections, an HSL is generally not operational owing to problems such as narrow roads and the risk of accidents. If an HSL can be extended to tunnel segments, great positive effects can be achieved. Therefore, this study was conducted to evaluate driver behavior and stability to investigate the risk of HSL in tunnels. METHODS: The Driving Simulator experiments were conducted using some scenarios for the Geumnam and Seojong tunnels on the Seoul- Chuncheon Highway. Based on data from the experiments such as running speed, lateral replacement, and steering handling, the running stabilities of participants were analyzed. In addition, traffic flow data from VDS(Vehicle Detection System) were analyzed as before-after studies. RESULTS: Although there were some differences in driving behaviors, most participants showed safe driving behavior at a speed of less than 50 km/h. CONCLUSIONS : Based on driving behaviors and traffic flow analyses, it is concluded that HSL in tunnels can be an alternative to increase efficiency based on safe driving environments for speeds of below 50 km/h.

본 논문은 인체에 영향을 미치는 진동에 따라 도로노면의 주행성을 정량화하고 향후 공용중인 도로 및 신설도로의 주행 안전성 평가에 적용할 수 있는 방법론을 정립하는 것이 주요 목적이다. 이를 위해 평탄성 및 인체 피로도 관련 조사를 수행하여 이론적 근거를 수립하였고 다양한 고속도로 표본 구간을 선정하여 차량 내 3축 가속도를 측정하였다. 도로 상태별로 ISO-2631에 준한 주파수별 가속도 값을 분류화함으로써 노면상태에 따른 인체에 미치는 진동 가속도 수준을 정량화할 수 있었다. 연구 결과, 전반적으로 인체에 미치는 피로도는 IRI가 높은 콘크리트 포장이 크게 유발시키는 것으로 나타났으며, SMA 포장과 다이아몬드그라인딩이 적용된 콘크리트 포장은 상대적으로 피로도가 낮은 것으로 나타났다.

본 연구에서는 강풍시 차량의 주행안정성을 확보하기 위하여 분출형 방풍벽을 고안하였으며 풍동실험을 통하여 그 유효성을 검증하였다. 풍동실험에서는 4종류의 분출형 방풍벽과 기존의 다공형 수직방풍벽 2종류에 대해서 간이차량모형의 표면압을 측정하였으며 방풍벽으로부터 차량의 이격거리 및 성토부의 유무에 따라 방풍벽의 성능을 고찰하였다. 실험결과, 본 연구에서 고안된 분출형 방풍벽은 충실율 25%~50% 사이의 수직방풍벽과 동등한 방풍효과를 가지는 것을 확인하였으며 운전자의 시야확보에 유리하며 교량구조물에 적용시에는 기존의 방풍벽에 비하여 수풍면적이 감소하여 공기력을 저감시킬 수 있는 신개념의 방풍시설이 될 수 있을 것으로 기대된다.

본 연구에서는 교량을 통과하는 차량의 주행안정성확보를 위하여 기존의 강성방호책 상면에 부착 가능한 방풍펜스를 고안하여 풍동실험을 통하여 그 유효성을 검증하였다. 실험결과로서, 경사판을 경사도 1:0.5로 하향으로 설치한 방풍펜스 F3(-)가 1차로에서 가장 효과적이며 영각 0o 및 5o에서 50%이상의 횡력 및 전도모멘트의 감소효과가 있었으며 -5o에서는 20%내외의 감소효과가 있었다. 2차로에서는 경사도 1:0.5로 상향으로 설치한 F3(+)가 F3(-)에 비하여 풍력 저감효과가 더 크게 나타났으나, 차량에 작용하는 풍력은 풍하측으로 갈수록 그 크기가 감소하는 면에서 볼 때, 방풍펜스 F3(-)를 대안으로 제시 한다.

The robot mechanisms that were previously researched had only been conducted for the purpose of overcoming the obstacles stably at low speed driving and enhancing the stability against high speed circuitous driving, and yet, the mechanism satisfying two purposes. However, in order to stably drive with high speed on rough terrain, there is a need for satisfying both of these purposes, as well as testing the efficiency of the mechanisms at high speed driving. There, this paper simulated some of the passive mechanisms and focused on checking the performances of passive mechanisms through simulations and analyzing each mechanism on the basis of an evaluation index. The simulation was conducted by Adams (The Multi-body Dynamics Simulation Solution) and used various types of passive mechanisms which were introduced in the robotics field. As a result, the study confirmed that passive mechanisms have a number of situations that affect the driving stability on each direction of roll and pitch. Further study is needed about active mechanism.

Methods for measuring or estimating of ground shape by a laser range finder and a vision sensor(exteroceptive sensors) have critical weakness in terms that these methods need prior database built to distinguish acquired data as unique surface condition for driving. Also, ground information by exteroceptive sensors does not reflect the deflection of ground surface caused by the movement of UGVs. Thereby, UGVs have some difficulties regarding to finding optimal driving conditions for maximum maneuverability. Therefore, this paper proposes a method of recognizing exact and precise ground shape using Inertial Measurement Unit(IMU) as a proprioceptive sensor. In this paper, firstly this method recognizes attitude of a robot in real-time using IMU and compensates attitude data of a robot with angle errors through analysis of vehicle dynamics. This method is verified by outdoor driving experiments of a real mobile robot.

To evaluate the traffic safety of PSC box bridge for increasing speed 450km/h of KTX, a dynamic analysis of KTX wheel force spectrum is needed concurrently with existing design requirements. The wheel force spectrum are considered the dynamic PSC box bridge behaviors as well as KTX running movements with advanced numerical model. KTX power train is modeled one body, two bogies and four wheel axis as 38 degree of freedoms. The difference of each wheel forces are evaluated for running speed on the bridge upto the increasing target speed to propose new evaluation standards of traffic safety.