• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.149-154
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• 2002

A simplified 3D dynamic model of tracked vehicle crawling on cohesive soft soil is investigated. The vehicle is assumed as rigid body with 6-dof. Cohesive soft soil is modeled through relations: pressure to sinkage, shear displacement to shear stress, and shear to dynamic sinkage. Equations of motion of vehicle are derived with respect to the body-fixed coordinates. In order to investigate 3D transient dynamics of tracked vehicle, Newmark's method is employed based on incremental-iterative algorithm. 3D dynamic simulations are conducted for a tracked vehicle model and steering performance is investigated.

• 한국자동차공학회논문집
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• 제25권3호
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• pp.374-379
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• 2017

In vehicle to pedestrian accidents, cracks occur in the vehicle laminated glass due to impact of a pedestrian's head. In this study, FMH(Free Motion Headform) was used to experiment on and analyze the crack patterns on a vehicle laminated glass that collides with an adult headform at speeds of 20 km/h, 30 km/h, and 40 km/h, respectively. Applying the acquired experimental data and material property of the vehicle laminated glass to the structural analysis program LS-Dyna, we could develop the FE model of vehicle laminated glass similar to real vehicle laminated glass. We could estimate the head impact velocity and pedestrian's vehicle impact velocity using the Madymo program.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.316-320
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• 2003

This paper introduces an autonomous underwater vehicle (AUV) model, ASUM, equipped with a visual servo control system to dock into an underwater station with a camera and motion sensors. To make a visual servoing AUV, this paper implemented the visual servo control system designed with an augmented state equation, which was composed of the optical flow model of a camera and the equation of the AUV's motion. The system design and the hardware configuration of ASUM are presented in this paper. ASUM recognizes the target position by processing the captured image for the lights, which are installed around the end of the cone-type entrance of the duct. Unfortunately, experiments are not yet conducted when we write this article. The authors will present the results for the AUV docking test.

• Journal of Information Processing Systems
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• 제15권5호
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• pp.1218-1230
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• 2019

This study proposes a novel video traffic flow detection method based on machine vision technology. The three-frame difference method, which is one kind of a motion evaluation method, is used to establish initial background image, and then a statistical scoring strategy is chosen to update background image in real time. Finally, the background difference method is used for detecting the moving objects. Meanwhile, a simple but effective shadow elimination method is introduced to improve the accuracy of the detection for moving objects. Furthermore, the study also proposes a vehicle matching and tracking strategy by combining characteristics, such as vehicle's location information, color information and fractal dimension information. Experimental results show that this detection method could quickly and effectively detect various traffic flow parameters, laying a solid foundation for enhancing the degree of automation for traffic management.

• 자동차안전학회지
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• 제5권1호
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• pp.25-30
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• 2013

The main purpose of this research is to predict dynamic behavior of door locking system for side impact safety and the design process to avoid door opening is introduced. The equations of motion that represent the system are obtained from the energy equation. From them, the motion of door handle is predicted by using Runge-Kutta $4^{th}$ order method and the simulation result is compared with the real crash data. Also, the design guide to define the properties of door locking system from the standpoint of avoiding door opening phenomenon is introduced.

• Structural Engineering and Mechanics
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• 제88권5호
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• pp.405-417
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• 2023

This paper reveals theoretical research to the nonlinear dynamic response and initial geometric imperfections sensitivity of the spinning graphene platelets reinforced metal foams (GPLRMF) cylindrical shell under different boundary conditions in thermal environment. For the theoretical research, with the framework of von-Karman geometric nonlinearity, the GPLRMF cylindrical shell model which involves Coriolis acceleration and centrifugal acceleration caused by spinning motion is assumed to undergo large deformations. The coupled governing equations of motion are deduced using Euler-Lagrange principle and then solved by a combination of Galerkin's technique and modified Lindstedt Poincare (MLP) model. Furthermore, the impacts of a set of parameters including spinning velocity, initial geometric imperfections, temperature variation, weight fraction of GPLs, GPLs distribution pattern, porosity distribution pattern, porosity coefficient and external excitation amplitude on the nonlinear harmonic resonances of the spinning GPLRMF cylindrical shells are presented.

• 한국컴퓨터정보학회논문지
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• 제12권1호
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• pp.261-267
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• 2007

최근 교통문제 해결을 위한 하나의 방안으로 첨단교통체계(ITS)에 관한 연구가 활발히 진행 중이다. 또한 도로 상에서 차량을 검출하기 위한 다양한 방법들이 제시되고 있다. 본 논문에서는 영상처리 기술을 이용하여 이동하는 차량을 검출하는 차량검지 시스템을 개발하여 도로 이용자에게 신속한 정보를 제공하고자 한다. 또한 차량을 검출하기 위해 효율적이고 하드웨어로 구현이 쉬운 알고리즘을 개발하는데 목적이 있다. CCD 카메라를 이용하여 도로 영상을 촬영하고, 모폴로지 기법을 적용하여 영상으로부터 특징점을 추출하고, 추출된 특징점 간의 이동벡터를 구하여 움직이는 차량영역을 검출한다. 제안된 알고리즘을 실제 도로 영상에서 실험한 결과 처리시간이 단축되었으며, 차량 검출에서 좋은 결과를 얻을 수 있었다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.387-392
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• 2006

컨테이너 터미널과 같이 다수의 AGV(Automated Guided Vehicle)를 한정된 공간에서 동시에 운용하는 환경에서는 AGV의 작업생산성에 악영향을 주는 충돌, 데드락(deadlock), 라이브락(livelock)이 발생할 확률이 높다. 또한, AGV의 가/감속 운동은 AGV의 주행시간을 예측하기 어렵게 만들기 때문에 AGV 라우팅을 더욱 어렵게 만드는 요인이다 . 본 연구에서는 AGV 사이의 충돌, 데드락, 라이브락을 방지하기 위해 점유영역 예약테이블(Occupancy Area Reservation table; OAR table)을 이용하는 방법과 최적주행경로를 선택하기 위해 가감속 운동을 고려하여 AGV의 주행시간을 추정하는 방법을 제안한다. 시간중심 시뮬레이션(time-driven simulation)을 통해 제안방안을 실험한 결과 제안방안의 효과를 확인하였다.

• 한국항공우주학회지
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• 제34권5호
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• pp.46-55
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• 2006

비행체의 궤적 최적화를 위해서는 비행체의 특성을 반영한 3차원 운동방정식이 유도되어야 하며, 비행선과 같이 공기보다 가벼운 비행체의 경우는 일반 고정익 항공기와는 다른 특성들을 반영하여야 한다. 본 연구에서는 중고도 무인비행선의 궤적 최적화를 위해 비행선의 운동방정식을 유도하고, 이를 이용한 최소시간 문제를 다루었다. 최적 궤적을 얻기 위하여 최적 궤적 문제를 제어입력 파라미터화를 이용한 비선형 프로그래밍 문제로 변환한 후 연속 2차 계획법을 이용하여 궤적을 산출하였으며, 이에 대한 수치결과를 나타내었다.

• Structural Engineering and Mechanics
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• 제31권6호
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• pp.737-749
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• 2009

The problem of estimating the dynamic response of a distributed parameter system excited by a moving vehicle with random initial velocity and random vehicle body mass is investigated. By adopting the Galerkin's method and modal analysis, a set of approximate governing equations of motion possessing time-dependent uncertain coefficients and forcing function is obtained, and then the dynamic response of the coupled system can be calculated in deterministic sense. The statistical characteristics of the responses of the system are computed by using improved perturbation approach with respect to mean value. This method is simple and useful to gather the stochastic structural response due to the vehicle-passenger-bridge interaction. Furthermore, some of the statistical numerical results calculated from the perturbation technique are checked by Monte Carlo simulation.