• Title, Summary, Keyword: Collision Angle

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A Study on the Side Collision Accident Reconstruction Using 3-Dimensional Crash Analysis (3차원 충돌해석 정보를 이용한 측면 충돌 사고 재구성)

  • Jang, In-Sik;Kim, Il-Dong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.52-63
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    • 2008
  • The side collision reconstruction algorithm is developed using three dimensional car crash analysis. Medium size passenger car is modeled for finite element analysis. Total 24 side collision configurations, four different speed and six different angle, are set up for making side collision database. Deformation index and degree index are built up for each collision case. Deformation index is a kind of deformation estimate averaging displacement of side door of crashed car from finite element analysis result. Angle index is constructed measuring deformed angle of crashing car. There are two kinds of angle index, one is measured at driver's side and the other is measured at passenger's side. Also a collision analysis information in side of cars is used for giving a basis for scientific and practical reason in a reconstruction of the car accident. The analysis program, LS-DYNA3D is utilized for finite element analysis program for a collision analysis. Those database are used for side collision reconstruction. Side collision reconstruction algorithm is developed, and applied to find the collision conditions before the accident occurs. Three example collision cases are tried to check the effectiveness of the algorithm. Deformation index and angle index is extracted for the case from the analysis result. Deformation index is compared to the established database, and estimated collision speed and angle are introduced by interpolation function. Angle index is used to select a specific collision condition from the several available conditions. The collision condition found by reconstruction algorithm shows good match with original condition within 10% error for speed and angle. As a result, the calculation from the reconstruction of the situation is reproducing the situation well. The performance in this study can be used in many ways for practical field using deformation index and degree index. Other different collision situations may be set up for extending the scope of this study in the future.

Experimental Study of Collision Angle Effects on Heat Transfer During Droplet-wall Collision in Film Boiling Regime (막비등 영역에서 액적-벽면 충돌 시 충돌각도가 열전달에 미치는 영향에 관한 실험적 연구)

  • Park, Junseok;Kim, Hyungdae
    • Journal of ILASS-Korea
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    • v.22 no.3
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    • pp.129-136
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    • 2017
  • Effects of collision angle on heat transfer characteristics of a liquid droplet impinging on a heated wall above the Leidenfrost point temperature were experimentally investigated. The heated wall and droplet temperatures were $506^{\circ}C$ and $100^{\circ}C$, respectively, and the impact angle varied from $20^{\circ}$ to $90^{\circ}$ while the normal collision velocity was constant at 0.27 m/s. The droplet collision behaviors and the surface temperature distribution were measured using synchronized high-speed video and infrared cameras. The major physical parameters influencing upon droplet-wall collision heat transfer, such as residence time, wall heat flux, effective heat transfer area, heat transfer amount, were analyzed. It was found at the constant normal collision velocity that the residence time, wall heat flux and effective heat transfer area were hardly not changed, resulting in the almost constant heat transfer amount.

Development of Lane Change System considering Acceleration for Collision Avoidance (충돌회피를 위한 가속도를 고려한 차선 변경 시스템 개발)

  • Kang, Hyunkoo;Lee, Donghwi;Huh, Kunsoo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.2
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    • pp.81-86
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    • 2013
  • This paper presents the lane change system for collision avoidance. The proposed algorithm for the collision avoidance consists of path generation and path following. Using a calculated TTC (Time to Collision), partial braking is operated and collision avoidance path is generated considering relative distance, velocity and acceleration. Based on the collision avoidance path, desired yaw angle and yaw rate are calculated for the automated path following. The lateral controller is designed by a Lyapunov function approach using 3 D.O.F vehicle model and vehicle parameters. The required steering angle is determined from wheel velocity, longitudinal and lateral velocity in order to follow the desired yaw angle and yaw rate. This system is developed MATLAB/Simulink and its performance is evaluated using the commercial software CarSim.

Damage Evaluation of Flexible Concrete Mattress Considering Steel Reinforcement Modeling and Collision Angle of Anchor (철근의 영향과 앵커 충돌각도를 고려한 유연콘크리트 매트리스의 손상평가)

  • Ryu, Yeon-Sun;Cho, Hyun-Man;Kim, Seo-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.30 no.2
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    • pp.109-116
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    • 2016
  • A flexible concrete mattress (FCM) is a structural system for protecting submarine power or communication cables under various load types. To evaluate its of protection performance, a numerical analysis of an FCM under an anchor collision was performed. The explicit dynamics of the finite element analysis program ANSYS were used for the collision analysis. The influences of the steel reinforcement modeling and collision angle of the anchor on the collision behavior of the FCM were estimated. The FCM damage was evaluated based on the results of the numerical analysis considering the numerical modeling and collision environment.

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 Study on the Side Collision Accident Reconstruction Using Database of Crush Test of Model Cars (모형자동차 충돌시험의 데이터베이스를 이용한 측면 충돌사고 재구성)

  • Sohn, Jeong-Hyun;Park, Seok-Cheon;Kim, Kwang-Suk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.2
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    • pp.49-56
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    • 2009
  • In this study, a side collision accident reconstruction using database based on the deformed shape information from the collision test using model cars is suggested. A deformation index and angle index related to the deformed shape is developed to set the database for the collision accident reconstruction algorithm. Two small size RC cars are developed to carry out the side collision test. Several side collision tests according to the velocity and collision angles are performed for establishing the side collision database. A high speed camera with 1000fps is used to capture the motion of the car. A side collision accident reconstruction algorithm is developed and applied to find the collision conditions before the accident occurs. Two collision cases are tested to validate the database and the algorithm. The results obtained by the reconstruction algorithm show good match with original conditions with regard to the velocity and angle.

Multi-Mobile Robot System with Fuzzy Rule based Structure in Collision avoidance (충돌회피환경에서의 퍼지 규칙 기반 멀티 모바일 로봇 시스템)

  • Kim, Dong-W.;Yi, Chong-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.3
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    • pp.233-238
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    • 2010
  • This paper describes a multi-mobile robot system with fuzzy rule based structure in collision avoidance. Collision avoidance is an important function to perform a given task collaboratively and cooperatively in multi-mobile robot environments. So the important but challenging problem is handled in this paper. Considered obstacles for collision avoidance between multi mobile robots are static, dynamic, or both of them at the same time. Using the fuzzy rule based structure, distance and angle from a robot to obstacles are described as fuzzy linguistic values and steering angle for the robot are updated from the collision environments. As a result, the multi-mobile robot can modify a global path from a robot itself to its own target. In addition, avoiding collision with static or dynamic obstacles for the robot system can be achieved. Simulation based experimental results are given to show usefulness of this method.

Investigation Into Protection Performance of Projectile Using Flying Plate (판재를 이용한 초고속 위협체의 방호성능에 대한 해석적 연구)

  • Choi, Hyoseong;Shin, Hyunho;Yoo, Yo-Han;Park, Jahng Hyon;Kim, Jong-Bong
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.12
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    • pp.1039-1045
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    • 2016
  • We investigated the protection capability of a plate against high speed projectiles demonstrating collision and penetration behaviors by finite element analysis. The element erosion method was used for penetration analysis, which showed that the speed of the projectile was slightly reduced by the collision with the protection plate. Protection capability was measured by the projectile's attitude angle change because the damage of our tanks by projectiles was also dependent on the projectile-tank collision angle. When the length of the protection plate was sufficiently long, the projectile was severely deformed and incapacitated. In the case of a small plate, the projectile was deformed only in the collision region. Thus, projection capability was investigated by the change of attitude angle. The effect of collision angle, velocity, and length of the plate on the rotational and vertical velocities of the projectile was investigated.

Study on the Travel and Tractive Characteristics of The Two-Wheel Tractor on the General Slope Ground (II)-Dynamic Side-overturn of the Tiller-trailer System- (동력경운기의 경사지견인 및 주행특성에 관한 연구 (II)-동력경운기-트레일러계의 욍골동 및 동횡전도한계)

  • 송현갑;정창주
    • Journal of Biosystems Engineering
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    • v.3 no.1
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    • pp.1-19
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    • 1978
  • Power tiller is a major unit of agricultural machinery being used on farms in Korea. About 180.000 units are introduced by 1977 and the demand for power tiller is continuously increasing as the farm mechanization progress. Major farming operations done by power tiller are the tillage, pumping, spraying, threshing, and hauling by exchanging the corresponding implements. In addition to their use on a relatively mild slope ground at present, it is also expected that many of power tillers could be operated on much inclined land to be developed by upland enlargement programmed. Therefore, research should be undertaken to solve many problems related to an effective untilization of power tillers on slope ground. The major objective of this study was to find out the travelling and tractive characteristics of power tillers being operated on general slope ground.In order to find out the critical travelling velocity and stability limit of slope ground for the side sliding and the dynamic side overturn of the tiller and tiller-trailer system, the mathematical model was developed based on a simplified physical model. The results analyzed through the model may be summarized as follows; (1) In case of no collision with an obstacle on ground, the equation of the dynamic side overturn developed was: $$\sum_n^{i=1}W_ia_s(cos\alpha cos\phi-{\frac {C_1V^2sin\phi}{gRcos\beta})-I_{AB}\frac {v^2}{Rr}}=0$$ In case of collision with an obstacle on ground, the equation was: $$\sum_n^{i=1}W_ia_s\{cos\alpha(1-sin\phi_1)-{\frac {C_1V^2sin\phi}{gRcos\beta}\}-\frac {1}{2}I_{TP} \( {\frac {2kV_2} {d_1+d_2}\)-I_{AB}{\frac{V^2}{Rr}} \( \frac {\pi}{2}-\frac {\pi}{180}\phi_2 \} = 0 $$ (2) As the angle of steering direction was increased, the critical travelling veloc\ulcornerities of side sliding and dynamic side overturn were decreased. (3) The critical travelling velocity was influenced by both the side slope angle .and the direct angle. In case of no collision with an obstacle, the critical velocity $V_c$ was 2.76-4.83m/sec at $\alpha=0^\circ$, $\beta=20^\circ$ ; and in case of collision with an obstacle, the critical velocity $V_{cc}$ was 1.39-1.5m/sec at $\alpha=0^\circ$, $\beta=20^\circ$ (4) In case of no collision with an obstacle, the dynamic side overturn was stimu\ulcornerlated by the carrying load but in case of collision with an obstacle, the danger of the dynamic side overturn was decreased by the carrying load. (5) When the system travels downward with the first set of high speed the limit {)f slope angle of side sliding was $\beta=5^\circ-10^\circ$ and when travels upward with the first set of high speed, the limit of angle of side sliding was $\beta=10^\circ-17.4^\circ$ (6) In case of running downward with the first set of high speed and collision with an obstacle, the limit of slope angle of the dynamic side overturn was = $12^\circ-17^\circ$ and in case of running upward with the first set of high speed and collision <>f upper wheels with an obstacle, the limit of slope angle of dynamic side overturn collision of upper wheels against an obstacle was $\beta=22^\circ-33^\circ$ at $\alpha=0^\circ -17.4^\circ$, respectively. (7) In case of running up and downward with the first set of high speed and no collision with an obstacle, the limit of slope angle of dynamic side overturn was $\beta=30^\circ-35^\circ$ (8) When the power tiller without implement attached travels up and down on the general slope ground with first set of high speed, the limit of slope angle of dynamic side overturn was $\beta=32^\circ-39^\circ$ in case of no collision with an obstacle, and $\beta=11^\circ-22^\circ$ in case of collision with an obstacle, respectively.

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