• Title, Summary, Keyword: Collision Speed

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The Estimation of Collision Speed at the Intersection using Simulation (시뮬레이션을 통한 교차로 충돌 속도 추정)

  • Han, Chang-Pyoung;Cheon, Jeong-Hwan;Choi, Hong Ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.514-521
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    • 2021
  • When calculating an intersection collision speed using a formula, it is very difficult to grasp the degree of deceleration of a vehicle after the collision unless there is road surface trace in the entire section where each vehicle moved from the point of collision to their final positions after the collision. A vehicle's motion trajectory shows an irregular curve after a collision due to the effects of inertia based on the driving characteristics of the vehicle, the eccentric force according to the collision site, and the collision speed. Therefore, it is very important to set the appropriate departure angle after a collision for accurate collision speed analysis. In this study, based on experimental collision data using a computer simulation (PC-Crash), the correlation between an appropriate vehicle departure angle and the post-collision speed was analyzed, and then, a regression analysis model was derived. Through this, we propose a method to calculate collision speed by applying only the vehicle departure angle in some types of collisions for traffic accidents at intersections.

A method of inferring collision ratio based on maneuverability of own ship under critical collision conditions

  • You, Youngjun;Rhee, Key-Pyo;Ahn, Kyoungsoo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.2
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    • pp.188-198
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    • 2013
  • In constructing a collision avoidance system, it is important to determine the time for starting collision avoidance maneuver. Many researchers have attempted to formulate various indices by applying a range of techniques. Among these indices, collision risk obtained by combining Distance to the Closest Point of Approach (DCPA) and Time to the Closest Point of Approach (TCPA) information with fuzzy theory is mostly used. However, the collision risk has a limit, in that membership functions of DCPA and TCPA are empirically determined. In addition, the collision risk is not able to consider several critical collision conditions where the target ship fails to take appropriate actions. It is therefore necessary to design a new concept based on logical approaches. In this paper, a collision ratio is proposed, which is the expected ratio of unavoidable paths to total paths under suitably characterized operation conditions. Total paths are determined by considering categories such as action space and methodology of avoidance. The International Regulations for Preventing Collisions at Sea (1972) and collision avoidance rules (2001) are considered to solve the slower ship's dilemma. Different methods which are based on a constant speed model and simulated speed model are used to calculate the relative positions between own ship and target ship. In the simulated speed model, fuzzy control is applied to determination of command rudder angle. At various encounter situations, the time histories of the collision ratio based on the simulated speed model are compared with those based on the constant speed model.

Reconstruction Analysis of Vehicle-pedestrian Collision Accidents: Calculations and Uncertainties of Vehicle Speed (차량-보행자 충돌사고 재구성 해석: 차량 속도 계산과 불확실성)

  • Han, In-Hwan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.5
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    • pp.82-91
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    • 2011
  • In this paper, a planar model for mechanics of a vehicle/pedestrian collision incorporating road gradient is derived to evaluate the pre-collision speed of vehicle. It takes into account a few physical variables and parameters of popular wrap and forward projection collisions, which include horizontal distance traveled between primary and secondary impacts with the vehicle, launch angle, center-of-gravity height at launch, distance from launch to rest, pedestrian-ground drag factor, the pre-collision vehicle speed and road gradient. The model including road gradient is derived analytically for reconstruction of pedestrian collision accidents, and evaluates the vehicle speed from the pedestrian throw distance. The model coefficients have physical interpretations and are determined through direct calculation. This work shows that the road gradient has a significant effect on the evaluation of the vehicle speed and must be considered in accident cases with inclined road. In additions, foreign/domestic empirical cases and multibody dynamic simulation results are used to construct a least-squares fitted model that has the same structure of the analytical one that provides an estimate of the vehicle speed based on the pedestrian throw distance and the band within which the vehicle speed would be expected to be in 95% of cases.

A Study on the Ship Collision Avoidance Model considered Speed (속력을 고려한 선박충돌회피모델에 관한 연구)

  • Yang, Hyoung-Seon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.23-29
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    • 2006
  • From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But with respect to the establishment of Safe-Guard Ring of Ship Collision Avoidance Support Model in Close Quarters Situation that had been newly studied to avoid ship's collision, the ratio of own ship' speed to a target ship's speed was limited to about less than 1.7. Therefore in this paper, as doing a study concerned with the establishment of Safe-Guard Ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.

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A framework for carrying out train safety evaluation and vibration analysis of a trussed-arch bridge subjected to vessel collision

  • Xia, Chaoyi;Zhang, Nan;Xia, He;Ma, Qin;Wu, Xuan
    • Structural Engineering and Mechanics
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    • v.59 no.4
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    • pp.683-701
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    • 2016
  • Safety is the prime concern for a high-speed railway bridge, especially when it is subjected to a collision. In this paper, an analysis framework for the dynamic responses of train-bridge systems under collision load is established. A multi-body dynamics model is employed to represent the moving vehicle, the modal decomposition method is adopted to describe the bridge structure, and the time history of a collision load is used as the external load on the train-bridge system. A (180+216+180) m continuous steel trussed-arch bridge is considered as an illustrative case study. With the vessel collision acting on the pier, the displacements and accelerations at the pier-top and the mid-span of the bridge are calculated when a CRH2 high-speed train running through the bridge, and the influence of bridge vibration on the running safety indices of the train, including derailment factors, offload factors and lateral wheel/rail forces, are analyzed. The results demonstrate that under the vessel collision load, the dynamic responses of the bridge are greatly enlarged, threatening the running safety of high-speed train on the bridge, which is affected by both the collision intensity and the train speed.

High-speed Railway Vehicle Collision and Derailment Safety Evaluation Research (고속철도차량 충돌 및 탈선 안전도 평가 연구)

  • Lee, Chan-Woo
    • Proceedings of the KSR Conference
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    • pp.245-250
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    • 2006
  • From the research which it sees the safety regarding a high-speed railway vehicle collision and a derailment evaluation research it an example and executed. Japan, France, Germany and Spain, Italy and with our country together it compared a high-speed railway vehicle collision of the high-speed railroad operating nation and derailed relation safety standard and safety against the evaluation system trade name comparison it analyzed. The research which it sees it led and the accident instance against the hazard analysis against the collision and a derailment of the high-speed railway vehicle and a risk evaluation together and a high-speed vehicle collision and derailed it cannot prevention plan from hereafter domestic comparison it analyzed forecast it presented.

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An Estimating Algorithm of Vehicle Collision Speed Through Images of Blackbox (블랙박스 영상 분석을 통한 차량 충돌 속도 연산 알고리즘에 대한 융복합 연구)

  • Ko, Kwang-Ho
    • Journal of Digital Convergence
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    • v.16 no.9
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    • pp.173-178
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    • 2018
  • The vehicle collision speed in mid and high range can be checked by EDM(Event Driven memory) data recorded when the air bag works. But it's difficult to estimate the low speed of vehicle collision. And estimating the speed is important because the injury level can be changed by the impact speed. The study proposed an estimating algorithm by analysing the images recorded in car blackbox instrument. Low speed rear collision accidents simulated with wire winding motor for various vehicle types. The study estimated the impact speed with the ratio of the distance change between two vehicles and the length change of the number plate of front vehicle. The closer the vehicles are, the larger the plate length is. You can estimate the impact speed with the ratio. The impact speed is calculated with the initial distance for a specific length of number plate in the algorithm. The results can be applied to the linear rear collision because the angle of impact was not considered in this study.

A Study on the Ship Collision Avoidance Model considered Speed (속력을 고려한 선박충돌회피모델에 관한 연구)

  • Yang, Hyoung-Seon
    • Journal of Navigation and Port Research
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    • v.30 no.10
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    • pp.779-785
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    • 2006
  • From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But the new safe-guard ring of ship's collision avoidance support model in the close quarters is established assuming that the ratio of own ship' speed to a target ship's speed is less than about 1.7. Therefore in this paper, as doing a study concerned with the establishment of safe-guard ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.

A study on the estimation of impact velocity of crashed vehicles in tunnel using computer simulation(PC-CRASH) (컴퓨터 시뮬레이션(PC-CRASH)을 이용한 터널 내 피추돌 차량의 충돌 속도 추정에 관한 연구)

  • Han, Chang-Pyoung;Choi, Hong-Ju
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.14 no.4
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    • pp.40-45
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    • 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.

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A Study on the Threshold of Avoidance Sector in the New Evaluation of Collision Risk

  • Jeong Tae-Gweon
    • Journal of Navigation and Port Research
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    • v.28 no.9
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    • pp.799-802
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    • 2004
  • Evaluation of the quantitative risk of collision plays a key role in developing the expert system of navigation and collision avoidance. This study analysed thoroughly how to determine the threshold of avoidance sector as described in the new evaluation of collision risk, and suggested the collision risk obtained by the alteration of course and/or speed in order to pass clear qf each danger zone as the threshold of avoidance sector.