• 제목/요약/키워드: virtual Manufacturing

검색결과 440건 처리시간 0.021초

Effects of Form Errors of a Micromirror Surface on the Optical System of the TMATM(Thin-film Micromirror ArrayTM) Projector

  • Jo, Yong-Shik;Kim, Byoung-Chang;Kim, Seung-Woo;Hwang, Kyu-Ho
    • International Journal of Precision Engineering and Manufacturing
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    • 제1권1호
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    • pp.98-105
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    • 2000
  • The projectors using liquid crystal display(LCD) have faults such as low optical efficiency, low brightness and even heat generation. To solve these problems reflective-type spatial light modulators based on MEMS (Microelectromechanical Systems) technology have emerged. Digital Micromirror DeviceTM(DMDTM), which was already developed by Texas Instruments Inc., and Thin-film Micromirror ArrayTM(TMATM), which has been recently developed by Daewoo Electronics Co., are the representative examples. The display using TMATM has particularly much higher optical efficiency than other projectors. But the micromirrors manufactured by semiconductor processes have inevitable distortion because of the limitations of the manufacturing processes, so that the distortions of their surfaces have great influence on the optical efficiency of the projector. This study investigated the effects of mirror flatness on the optical performance, including the optical efficiency, of the TMATM projector. That is to say, as a part of the efforts to enhance the performance of the TMATM projector, how much influence the form errors of a micromirror surface exert on the optical efficiency and the modulation of gray scale of the projector were analyzed through a pertinent modeling and simulations.

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분해 모델을 이용한 자동차 차체의 틈새 탐색 시스템 개발 (Development of Gap Searching System for Car Body Assembly by Decomposition Model Representation)

  • 배원중;이승훈;박성배;정융호
    • 한국자동차공학회논문집
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    • 제20권4호
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    • pp.109-118
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    • 2012
  • Large number of part design for aircraft and automobile is preceded by functional or sectional design groups for efficiency. However, interferences and gaps can be found when the parts and sub-assemblies by those design groups are to be assembled. These interferences and gaps cause design changes and additional repair processes. While interference problem has been resolved by digital mockup and concurrent engineering methodology, gap problem has been covered by temporary treatment of filling gap with sealant. This kind of fast fix causes fatal problem of leakage when the gap is too big for filling or the treatment gets old. With this research, we have developed a program to find the gap automatically among parts of assembly so that users can find them to correct their design before manufacturing stage. By using decomposition model representation method, the developed program can search the gap among complex car body parts to be visualized with volumetric information. It can also define the boundary between the gap and exterior empty space automatically. Though we have proved the efficiency of the developed program by applying to automobile assembly, application of the program is not limited to car body only, but also can be extended to aircraft and ship design of large number of parts.

E-Business and Simulation

  • Park, Sung-Joo
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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    • pp.9-10
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    • 2001
  • Simulation has been evolved with the advance of computer and technique of modeling application systems. Early simulations were numerical analysis of engineering models known as continuous simulation, analysis of random events using various random number generators thus named as Monte Carlo simulation, iud analysis o(\\\\`queues which are prevalent in many real world systems including manufacturing, transportation, telecommunication. Discrete-event simulation has been used far modeling and analyzing the systems with waiting lines and inefficient delays. These simulations, either discrete-event, continuous, or hybrid, have played a key role in industrial age by helping to design and implement the efficient real world systems. In the information age which has been brought up by the advent of Internet, e-business has emerged. E-business, any business using Internet, can be characterized by the network of extended enterprises---extended supply and demand chains. The extension of value chains spans far reaching scope in business functions and space globally. It also extends to the individual customer, customer preferences and behaviors, to find the best service and product fit for each individual---mass customization. Simulation should also play a key role in analyzing and evaluating the various phenomena of e-business where the phenomena can be characterized by dynamics, uncertainty, and complexity. In this tutorial, applications of simulation to e-business phenomena will be explained and illustrated. Examples are the dynamics of new economy, analysis of e-business processes, virtual manufacturing system, digital divide phenomena, etc. Partly influenced by e-business, a new trend of simulation has emerged called agent-based simulation, Agent-based simulation is a technique of simulation using software agent that have autonomy and proactivity which are useful in analyzing and integrating numerous individual customer's behavior. One particular form of agent-based simulation is swarm. This tutorial concludes with the illustration of swarm or swarm Intelligence applied to various e-business applications, and future directions and implications of this new trend of simulation.

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3D 시뮬레이션을 활용한 렌즈모듈 자동화조립시스템 개발 (Developing Automatic Lens Module Assembly System Using 3D Simulation)

  • 문덕희;이준석;백승근;장병림;김영규
    • 한국시뮬레이션학회논문지
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    • 제16권2호
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    • pp.65-74
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    • 2007
  • 가상생산기술은 신제품의 개발, 새로운 장비 개발 및 새로운 제조시스템 개발에 유용한 도구이며, 특히 3D 시뮬레이션 기술은 가상생산의 핵심기술이다. 3D 시뮬레이션 기술은 기계적 시뮬레이션 기술과 이산사건 시뮬레이션 기술로 구분할 수 있다. 본 논문에서는 휴대폰 카메라에 장착되는 렌즈모듈 조립을 생산하는 국내 회사의 사례를 소개한다. 이 회사에서는 렌즈모듈 조립공정을 현재 수작업으로 하고 있는데 자동화시스템을 개발하기로 결정하였으며 이를 위해 3D 시뮬레이션 기술을 도입하기로 하였다. 3D 시뮬레이션 기술은 시스템 개념설계단계에서부터 적용이 되었는데, 단위 장비 개발을 위해서는 $CATIA^{(R)}$$IGRIP^{(R)}$이 활용되었으며, 시스템 설계를 위해서는 이산사건 시뮬레이션 도구인 $QUEST^{(R)}$가 활용되었다. 논문의 목적은 새로운 자동화 설비의 기술적. 경제적 타당성을 검증하는 것이다. 개발결과 takt time 이 기존의 수작업에 비해 4분의 1 수준으로 감소되었으며, 이에 따른 작업자 인원도 대폭 감소되었다.

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LED 융합조명 모듈 자동화 조립 시스템의 피더에 관한 구조해석 및 동특성 해석 (Structural and Dynamic Characteristic Analysis of a Feeder for an Automatic Assembly System of an LED Convergent Lighting Module)

  • 추세웅;정상화
    • 한국기계가공학회지
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    • 제16권1호
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    • pp.124-133
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    • 2017
  • In the current lighting market, LEDs that have a high luminous efficiency, a long life and consume less power have emerged as next generation lighting. Owing to various designs and sizes of LEDs, the production process of existing LEDs involves many tasks that require manual labor; hence, the assembly of LEDs necessitates manpower. Because of the use of manpower, the production costs of LEDs increases and production efficiency decreases. Recently, the assembly parts of LEDs have been standardized for minimizing manual labor, and an LED is developed as an LED panel. The automatic assembly system produces LED convergent lighting by assembling two LED panels and one diffusion cover. To increase the production efficiency of the LED convergent lighting module, it is important that the development of a feeder can continuously supply the LED panels is required, and whose design has sufficient stability. The automatic assembly system of the LED convergent lighting module consists of two feeders, which convey LED panels and diffusion covers to a main conveyor, which assembles the lifted panels and covers. In this study, structural analysis and fatigue life for forced loads on the conveyer line of the feeder in the process of lifting LED panels and diffusion covers of each feeder, is analyzed. In addition, the drive of the belt constituting the conveyor line of each feeder is simulated, and the dynamic characteristics of the belt is analyzed using the virtual engineering method.

Three-dimensional evaluation of the transfer accuracy of a bracket jig fabricated using computer-aided design and manufacturing to the anterior dentition: An in vitro study

  • Park, Jae-Hyun;Choi, Jin-Young;Kim, Seong-Hun;Kim, Su-Jung;Lee, Kee-Joon;Nelson, Gerald
    • 대한치과교정학회지
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    • 제51권6호
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    • pp.375-386
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    • 2021
  • Objective: To evaluate the accuracy of a one-piece bracket jig system fabricated using computer-aided design and manufacturing (CAD/CAM) by employing three-dimensional (3D) digital superimposition. Methods: This in vitro study included 226 anterior teeth selected from 20 patients undergoing orthodontic treatment. Bracket position errors from each of the 40 arches were analyzed quantitatively via 3D digital superimposition (best-fit algorithm) of the virtual bracket and actual bracket after indirect bonding, after accounting for possible variables that may affect accuracy, such as crowding and presence of the resin base. Results: The device could transfer the bracket accurately to the desired position of the patient's dentition within a clinically acceptable range of ± 0.05 mm and 2.0° for linear and angular measurements, respectively. The average linear measurements ranged from 0.029 to 0.101 mm. Among the angular measurements, rotation values showed the least deviation and ranged from 0.396° to 0.623°. Directional bias was pronounced in the vertical direction, and many brackets were bonded toward the occlusal surface. However, no statistical difference was found for the three angular measurement values (torque, angulation, and rotation) in any of the groups classified according to crowding. When the teeth were moderately crowded, the mesio-distal, bucco-lingual, and rotation measurement values were affected by the presence of the resin base. Conclusions: The characteristics of the CAD/CAM one-piece jig system were demonstrated according to the influencing factors, and the transfer accuracy was verified to be within a clinically acceptable level for the indirect bracket bonding of anterior teeth.

냉장고 캐비닛 벽면에서 발생하는 박리현상 예측을 위한 평가 기준 개발에 관한 연구 (Development of Criteria for Predicting Delamination in Cabinet Walls of Household Refrigerators)

  • 박진성;김성익;이건엽;조종래
    • 한국기계가공학회지
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    • 제21권4호
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    • pp.1-13
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    • 2022
  • Household refrigerator cabinets must undergo cyclic testing at -20 ℃ and 65 ℃ for quality control (QC) after their production is complete. These cabinets were assembled from different materials, including acrylonitrile butadiene styrene (ABS), polyurethane (PU) foam, and steel plates. However, different thermal expansion values could be observed owing to differences in the mechanical properties of the materials. In this study, a technique to predict delamination on a refrigerator wall caused by thermal deformation was developed. The mechanical properties of ABS and PU foams were tested, theload factors causing delamination were analyzed, delamination was observed using a high-speed camera, and comparison and verification in terms of stress and strain were performed using a finite element model (FEM). The results indicated that the delamination phenomenon of a refrigerator wall can be defined in two cases. A method for predicting and evaluating delamination was established and applied in an actual refrigerator. To determine the effect of temperature changes on the refrigerator, strain measurements were performed at the weak point and the stress was calculated. The results showed that the proposed FEM prediction technique can be used as a basis for virtual testing to replace future QC testing, thus saving time and cost.

자동차 패널 자동창고 시스템의 PLC 시뮬레이션 적용 연구 (A Study of PLC Simulation for Automobile Panel AS/RS)

  • 고민석;구락조;곽종근;홍상현;왕지남;박상철
    • 한국시뮬레이션학회논문지
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    • 제18권3호
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    • pp.1-11
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    • 2009
  • 본 논문에서는 자동차 패널 자동창고 시스템의 PLC 시뮬레이션 적용 연구 사항에 관해 소개한다. 자동차 차종의 증가에 따라 차종 별 패널 공급의 복잡도가 향상되었다. 이를 해결하기 위해 AS/RS 시스템을 사용하지만, 내부 시스템 로직의 복잡성으로 인해 사전에 검증하는 것이 매우 어렵다. 특히 AS/RS시스템 제어의 중추적 역할을 하는 PLC는 하위 레벨의 언어로 기술되기 때문에, 사용자가 정확히 이해하고 검증을 수행하기 힘든 것이 현실이다. 본 논문에서는 이 같은 논리적 복잡성과 언어적 한계를 극복하고자 PLC 와 3D 모델을 연동하는 시뮬레이션 환경을 제안하였다. 특히 차체 조립라인의 설비 및 패널 데이터를 실측치를 기반으로 하였고, 실제 PLC 신호를 이용하여 환경을 구축함으로써 시스템 구축 이전에 시운전 환경을 완벽히 구현하였다. 사용자는 제안된 시뮬레이션 환경에서 AS/RS 로직을 시운전 할 수 있게 되었고, 이를 통해 경제적, 시간적 이득을 얻게 되는 장점을 갖는다.

스마트 공장의 디지털 트윈을 위한 XR기술에 관한 연구 (A Study on XR Technology for Digital Twin of Smart Factory)

  • 이석희
    • 실천공학교육논문지
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    • 제16권1_spc호
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    • pp.1-9
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    • 2024
  • 스마트공장의 디지털 트윈에 대한 도입은 이미 CPS(Cyber Physics System)을 통하여 제조산업에 생산성을 높이고자 제안되었던 개념으로 특정한 산업 공정의 단계에 적용되거나 시뮬레이션이 필요한 단계에서 부분적으로 도입되고 있었다. 그러나 최근 4차산업혁명기술 발전을 통해서 XR(Extended Reality) 기술과 함께 다시 주목을 받고 있다. 하지만 실효성 있는 사례가 많지 않기 때문에 본 연구에서는 제조공정을 장치와 장비 그리고 기술을 분석하여 디지털 쓰레드를 적용한 디지털 트윈을 구축하였고 신호와 정보의 동기화하며 이를 통해서 지능형 공정자동화 장비의 관제와 원격제어와 생산정보의 분석이 가능할 수 있는 플랫폼을 제안하고 이를 개발하였다. 이로써 기존에 제조업에서 활용되어지고 있는 자동화 설비공정 및 장비들에 대한 고장 발생 시 원활한 대처의 어려움과 정확한 고장 발생지점에 대한 확인의 어려움, 그리고 생산설비장비의 고장시점 관리의 어려움, 불량에 대한 원인 및 문제 분석과 대처의 어려움을 해결하는데 도움을 줄 수 있는 제안 내용을 다루었다. 향후 본 연구를 통해서 많은 사례들의 선행 연구에 도움이 되길 기대하고 향후에는 지능형 모델을 통해서 공정 및 생산의 부분별 생산성 증가에 대한 확장 연구가 필요하다.

3차원 가상도시 모델에서 높이맵을 이용한 CNN 기반의 그림자 탐지방법 (CNN-based Shadow Detection Method using Height map in 3D Virtual City Model)

  • 윤희진;김주완;장인성;이병대;김남기
    • 인터넷정보학회논문지
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    • 제20권6호
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    • pp.55-63
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    • 2019
  • 최근 교육, 제조, 건설 등 다양한 응용 분야에서 사실적인 가상환경을 표현하기 위하여 실세계 영상데이터를 활용하는 사례가 증가하고 있다. 특히, 스마트 시티 등 디지털 트윈에 대한 관심이 높아지면서, 항공 영상 등 실제 촬영한 영상을 이용하여 현실감 있는 3D 도시 모델을 구축하고 있다. 그러나, 촬영된 항공 영상에는 태양에 의한 그림자가 포함되어 있으며, 그림자가 포함된 3D 도시 모델은 사용자에게 정보를 왜곡시켜 표현하는 문제를 안고 있다. 그림자를 제거하기 위하여 그동안 많은 연구가 진행되었지만, 아직까지 해결하기 어려운 도전적인 문제로 인식되고 있다. 본 논문에서는 VWorld에서 제공하는 3차원 공간정보를 이용하여 건물의 높이 맵을 포함한 가상환경 데이터 셋을 구축하고, 높이맵과 딥러닝을 이용한 새로운 그림자 탐지 방법을 제안한다. 실험 결과에 의하면, 높이맵을 사용했을 때 기존 방법보다 그림자 탐지 에러율이 감소한 것을 확인할 수 있다.