• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.14-21
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• 2019

Axial piston pump is a significant part in wheeled armored vehicle, for generating hydraulic power of vehicle power system. The Axial Piston Pump is a high-performer, core functional item that is developed and applied to most of the military models in the development of military weapon systems. However, in the case of military equipment, there are conditions of limited size and weight required depending on the operating conditions and the operating environment. Under these conditions, it is required that the performance and the environmental resistance are verified to exert the required output. A unique technology is needed for the development of such equipment both in the present and in the future. Therefore, in this study, mathematical modeling of an axial piston pump is presented as a basic data for securing proprietary technology. In addition, a simulation model is designed and compared with the models of six kinds of pistons through simulation. It was established that when the number of pistons of the axial piston pump, which is the development objective, is seven, the model is suitable for the wheeled armored vehicle.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.158-168
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• 2000

Vehicle driving simulators can provide engineers with benefits on the development and modification of vehicle models. One of the most important factors to realistic simulations is the fidelity given by a motion system and a real-time visual image generation system. Virtual reality technology has been widely used to achieve high fidelity. In this paper the virtual environment including a visual system like a head-mounted display is developed for a vehicle driving simulator system by employing the virtual reality technique. virtual vehicle and environment models are constructed using the object-oriented analysis and design approach. Accordint to the object model a three dimensional graphic model is developed with CAD tools such as Rhino and Pro/E. For the real-time image generation the optimized IRIS Performer 3D graphics library is embedded with the multi-thread methodology. Compared with the single loop apprach the proposed methodology yields an acceptable image generation speed 20 frames/sec for the simulator.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.201-211
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• 2002

In this research, we are trying to research about hydraulic system design and vehicle dynamic modeling far the development of the tire roller. The reason why we would like develop it is that tire roller is one of the most useful machine for the road construction site and application other construction equipments. Here, we conceptualize the new hydraulic system and derive the equations of motion fur dynamic analysis and also investigate system modeling by using a DAQ board. We design the hydraulic circuit of steering and traction mechanism system. This design can be used to create virtual prototypes of construction equipment. So, we studied tire roller to integrate development technology. In system analysis, we formulate hydraulic traction system model and hydraulic steering system model. Also, we integrate DAQ system to acquire experimental results in real tire roller equipment.

• 대한교통학회지
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• 제31권6호
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• pp.90-105
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• 2013

자동차는 다양한 차속, 가감속도 및 출력의 변화를 겪게 된다. 이와 같은 동적 주행 특성에 의한 온실가스 배출특성은 현행 평균속도 기반의 방법만으로는 정확히 추정하기 어려운 것으로 알려져 있다. 본 연구에서는 미시적 주행 특성의 변화를 고려하는 국외의 미시 기반 배출량 산정방법론 중에서 MOVES를 국내에 도입하기에 가장 적합한 모형으로 선정하여 국내 적용 가능한 미시기반 온실가스 배출량 산정 모형을 개발하였다. 개발 모형에는 MOVES의 배출량 산정 개념을 도입하고, MOVES의 기본 배출율 맵을 활용하여 국내 차량 구분에 맞는 미시 배출맵을 추정하여 적용하였다. 본 개발 모형을 기존 우리나라 배출계수 산정 체계와 연계시켜 비교한 결과 MOVES로부터 추정한 미시 배출율 맵을 국내에 적용하는 것이 타당하나 양국간의 차량규모의 차이를 고려할 필요성이 있음을 발견하였다. 이에, 차종별로 미시배출맵 보정계수를 추정하여 적용함으로써 우리나라 대표 차종에 대응하는 미시기반 배출율 맵을 추정하여 개발모형을 실제로 국내에 활용할 수 있도록 하였다.

• Structural Engineering and Mechanics
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• 제91권2호
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• pp.227-238
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• 2024

Sparse regularization methods have proven effective in addressing the ill-posed equations encountered in moving force identification (MFI). However, the complexity of vehicle loads is often ignored in existing studies aiming at enhancing MFI accuracy. To tackle this issue, a double 𝑙₁ regularization method is proposed for MFI based on a response spectrum-based weighted dictionary in this study. Firstly, the relationship between vehicle-induced responses and moving vehicle loads (MVL) is established. The structural responses are then expanded in the frequency domain to obtain the prior knowledge related to MVL and to further construct a response spectrum-based weighted dictionary for MFI with a higher accuracy. Secondly, with the utilization of this weighted dictionary, a double 𝑙₁ regularization framework is presented for identifying the static and dynamic components of MVL by the alternating direction method of multipliers (ADMM) method successively. To assess the performance of the proposed method, two different types of MVL, such as composed of trigonometric functions and driven from a 1/4 bridge-vehicle model, are adopted to conduct numerical simulations. Furthermore, a series of MFI experimental verifications are carried out in laboratory. The results shows that the proposed method's higher accuracy and strong robustness to noises compared with other traditional regularization methods.

• 한국강구조학회 논문집
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• 제12권6호
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• pp.727-736
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• 2000

본 연구에서는 궤도의 좌굴해석 및 그 결과를 통해 열차하중이 직선 및 곡선 장대레일 궤도의 온도좌굴 거동에 미치는 영향에 대해 평가하였다. 차량을 고려한 온도좌굴 해석은 바퀴하중하에서 장대레일 궤도의 수직 처짐에 기인한 상향처짐을 결정하기 위해 유사정적 하중모델을 가정하였으며, 차량의 무게와 속도, 궤도의 곡률, 캔트, 그외의 열차와 궤도의 동적인 상호작용으로 인한 횡방향하중은 열차의 수직하중에 대한 수평하중 비에 포함하여 수행하였다. 수치적 해석을 통해 장대레일의 상부 및 하부좌굴온도를 구하였고, 이런 해석결과들을 기존의 열차하중을 포함하지 않은 정적 좌굴해석결과들과 비교하였다.

• 한국정밀공학회지
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• 제21권4호
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• pp.88-94
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• 2004

Recently, vehicle simulators are widely used to evaluate driver's responses and driver assistance systems. It needs much effort to construct the virtual driving environment for a vehicle simulator. In this study, it is described how to make effectively the roads and the driving environment for a vehicle simulator. The GIS (Geographic Information System) is used to construct the roads and the environment effectively. Because the GIS is the integrated system of geographical data, it contains useful data to make virtual driving environment. First, the outline and centerline of roads is abstracted from the GIS. From the road outline, the road width is calculated. Using the centerline, the grid model of roads is constructed. The final graphic model of roads is constructed by mapping road image to the grid model according to the number of lanes and the kind of surface. Data of buildings from the GIS are abstracted. Each shape and height of buildings is determined according to kind of buildings, the final graphic model of buildings is constructed. Then, the graphic model of roadside tree is also constructed. Finally, the driving environment for driving simulator is constructed by converting the three graphic models with the graphic format of Direct-X and by joining the three graphic models.

• 한국산업융합학회 논문집
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• 제6권4호
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• pp.339-345
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• 2003

The purpose of this thesis is to develop a simulation model to estimate link travel speed applicable to urban street transportation planning for interrupted traffic flow, influenced by signalized intersection. This link travel speed model is expected to be a better and more than previous studies.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.671-672
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• 2015

Due to harsh conditions of disaster areas, understanding of current feature of collapsed buildings, terrain, and other infrastructures is critical issue for disaster managers. However, because of difficulties in acquiring the geographical information of the disaster site such as large disaster site and limited capability of rescue workers, comprehensive site investigation of current location of survivors buried under the remains of the building is not an easy task for disaster managers. To overcome these circumstances of disaster site, this study makes use of an unmanned aerial vehicle, commonly known as a drone to effectively acquire current image data from the large disaster areas. The framework of 3D model reconstruction of disaster site using aerial imagery acquired by drones was also presented. The proposed methodology is expected to assist rescue workers and disaster managers in achieving a rapid and accurate identification of survivors under the collapsed building.

• 한국강구조학회 논문집
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• 제23권3호
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• pp.397-404
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• 2011

본 연구에서는 4축 단일차량에 타이어의 접지폭을 고려한 새로운 3차원 차량모델을 개발하여 도로교의 동적응답을 구할 수 있는 수치해석방법을 개발하였다. 3차원 차량모델에는 타이어의 접지폭과 텐덤 스프링 차륜축의 피칭을 고려하고 4축 단일차량을 10-자유도를 갖는 차량으로 모델링하였다. 차량의 운동방정식은 Lagrange방정식을 사용하여 유도하였으며 Newmark-${\beta}$법을 사용하여 그 해를 계산하였다. 본 연구에서 개발한 3차원 차량모델을 이용하여 구한 수치해석 결과와 실제 교량에서 실시한 실험값을 비교 검토하여 그 타당성을 입증하였다. 수치해석으로 구한 해석값은 실험값과 매우 유사한 경향을 나타내었다. 차량의 동적 해석에서는 4축 단일차량인 24톤 덤프트럭이 여러 가지 스텝 범프를 통과할 때 발생하는 타이어력의 최대 충격계수를 구하였다.