• 제목/요약/키워드: Mechanical engineering

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A Fault Isolation Filter Design Using Left Eigenstructure Assignment Scheme

  • Choi, Jae-Weon;Lee, Shi-Bok;Lee, Dae-Young;Park, Un-Sik;Suh, Young-Soo
    • Journal of Mechanical Science and Technology
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    • 제14권6호
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    • pp.583-589
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    • 2000
  • This paper presents a novel fault isolation filter design method using left eigenstructure assignment scheme proposed by the first author et al. The proposed method shows good performance of fault isolation with an exact eigenstructure assignment and guarantees that the corrupted ${\gamma}$ faults can be isolated simultaneously when the number of available output measurements are equal to or larger than (${\gamma}+1$). A numerical example for the fault isolation filter is also included.

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화학기상증착법에 의하여 제조된 그래핀 성장층의 기계적 마모 특성 (Tribological Properties of Chemical Vapor Deposited Graphene Coating Layer)

  • 이종훈;김선혜;조두호;김세창;백승국;이종구;강준모;최재붕;석창성;김문기;구자춘;임병수
    • 대한금속재료학회지
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    • 제50권3호
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    • pp.206-211
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    • 2012
  • Graphene has recently received high attention as a promising material for various applications, and many related studies have been undertaken to reveal its basic mechanical properties. However, the tribological properties of graphene film fabricated by the chemical vapor deposition (CVD) method are barely known. In this study, the contact angle and frictional wear characteristics of graphene coated copper film were investigated under room temperature, normal air pressure, and no lubrication condition. The contact angle was measured by sessile drop method and the wear test was carried out under normal loads of 660 mN and 2940 mN, respectively. The tribological behaviors of a graphene coating layer were also examined. Compared to heat treated bare copper foil, the graphene coated one shows a higher contact angle and lower friction coefficient.

기계적 메타물질 설계 및 제조방안 (Design and Manufacturing of Mechanical Metamaterials: A Review)

  • 김민겸;김승현;윤재원;정효균;곽민준;안예린;박찬욱;김윤철;서종환
    • Composites Research
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    • 제34권4호
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    • pp.199-211
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    • 2021
  • 적층제조 기술의 발전으로 복잡한 구조의 제조가 용이해짐에 따라, 기존에 존재하지 않은 특성을 지닌 메타물질에 대한 관심이 커지고 있다. 기존에 존재하지 않은 기계, 음향, 열, 전자기 및 광학 특성을 지닌 메타물질은 높은 공학응용(Engineering applications) 가능성을 보여, 새로운 메타물질 개발 및 설계방안에 대한 연구를 지속적으로 진행하고 있다. 이에 본 논문에서는 메타물질의 여러 특성 중 기존에 존재하지 않은 기계적 특성을 지닌 메타물질의 특성, 거동 및 물성을 소개하고 설계방안을 제시하고자 한다. 또한 설계한 메타물질을 제조하기 위해 여러 적층제조 방식별 메타물질 제조특성 들을 검토하여, 메타물질의 산업에서의 활용 가능성을 제시하고자 한다.

금속 나노 파티클의 레이저 플라즈모닉 어닐링을 통한 메탈메쉬 전극 형성과 이를 활용한 유연 터치 센서 (Formation of Metal Mesh Electrodes via Laser Plasmonic Annealing of Metal Nanoparticles for Application in Flexible Touch Sensors)

  • 정성민;황윤식;우유미;조용준;김찬혁;안민기;서호석;양찬현;박귀일;박정환
    • 한국전기전자재료학회논문지
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    • 제37권2호
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    • pp.223-229
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    • 2024
  • Laser-induced plasmonic sintering of metal nanoparticles (NPs) holds significant promise as a technology for producing flexible conducting electrodes. This method offers immediate, straightforward, and scalable manufacturing approaches, eliminating the need for expensive facilities and intricate processes. Nevertheless, the metal NPs come at a high cost due to the intricate synthesis procedures required to ensure long-term reliability in terms of chemical stability and the prevention of NP aggregation. Herein, we induced the self-generation of metal nanoparticles from Ag organometallic ink, and fabricated highly conductive electrodes on flexible substrates through laser-assisted plasmonic annealing. To demonstrate the practicality of the fabricated flexible electrode, it was configured in a mesh pattern, realizing multi-touchable flexible touch screen panel.

Effects of Rotor Misalignment in Airgap on Dynamic Response of an Eccentric Rotor in BLDC Motor

  • Kim, Tae-Jong;Kim, Kyung-Tae;Hwang, Sang-Moon;Park, No-Gill;Lee, Shi-Bok
    • Journal of Mechanical Science and Technology
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    • 제16권12호
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    • pp.1576-1582
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    • 2002
  • Vibration of a BLDC motor is a coupled phenomenon between mechanical characteristics and magnetic origins which takes place through the motor airgap. When relative misalignment of a rotor in the airgap is introduced during assembly, the dynamic characteristics of the motor system are affected. The rotor-motor system used in a washing machine is modeled using FETM and magnetic forces in a BLDC motor with radial rotor eccentricity are determined analytically The transient whirl responses of a rotor system supported on two roller bearings with relative misalignment in the motor airgap are investigated by considering mechanical and magnetic coupling effects. Results show that rotor misalignment in the airgap considerably affects the vibration of the rotor-motor system.

자율주행자동차 PHAROS (Introduction to Autonomous Vehicle PHAROS)

  • 유지환;박장식;;;김혁;송영욱;윤문영;김재석;강전진
    • 제어로봇시스템학회논문지
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    • 제18권8호
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    • pp.787-793
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    • 2012
  • This paper introduces the autonomous vehicle Pharos, which participated in the 2010 Autonomous Vehicle Competition organized by Hyundai-Kia motors. PHAROS was developed for high-speed on/off-road unmanned driving avoiding diverse patterns of obstacles. For the high speed traveling up to 60 km/h, long range terrain perception, real-time path planning and high speed vehicle motion control algorithms are developed. This paper describes the major hardware and software components of our vehicle.

무기체계의 상세설계 단계에 적용을 위한 한국형 정비도 예측 S/W 개발 (Development of Korean Maintainability-Prediction Software for Application to the Detailed Design Stages of Weapon Systems)

  • 권재언;김수주;허장욱
    • 한국기계가공학회지
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    • 제20권10호
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    • pp.102-111
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    • 2021
  • Maintainability is a major design parameter that includes availability as well as reliability in a RAM (reliability, availability, maintainability) analysis, and is an index that must be considered when developing a system. There is a lack of awareness of the importance of predicting and analyzing maintainability; therefore, it is dependent on past-experience data. To improve the utilization rate, maintainability must be managed as a key indicator to meet the user's requirements for failure maintenance time and to reduce life-cycle costs. To improve the maintainability-prediction accuracy in the detailed design stage, we present a maintainability-prediction method that applies Method B of the Military Standardization Handbook (MIL-HDBK-472) Procedure V, as well as a Korean maintainability-prediction software package that reflects the system complexity.