• Title/Summary/Keyword: non-contacting

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A Study of Non-contacting Ultrasonic Technique for Evaluation of Fiber Reinforced Composite Materials (섬유강화 복합재료의 비접촉식 초음파 평가 기법 연구)

  • Choi Sang-Woo;Seo Kyeong-Cheol;Lee Joon-Hyun;Byun Joon-Hyun
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.10a
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    • pp.268-271
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    • 2004
  • Non-contact technique should be developed for receiving ultrasonic wave for on-line monitoring of processing defects of fiber reinforced composites, since couplant must be applied on composite materials when conventional ultrasonic testing technique was used. Restriction of conventional ultrasonic testing technique was proven by transmitting and receiving ultrasonic wave on CFRP in various direction of wave propagation with various incident angle of ultrasonic beam. Air-coupled transducer and laser interferometer were applied for non-contacting reception of ultrasonic wave in fiber reinforced composite materials. Air-coupled transducer has optimal sensitivity and frequency band of 300kHz has homogeneous characteristics on direction of wave propagation.

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Vibration experiment of precision stage that use laser vibrator (비접촉식 진동측정 장치를 이용한 정밀 스테이지의 진동특성 평가시험)

  • Lee, Jae-Woo;Lee, Kang-Wook;Yim, Hong-Jae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1224-1230
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    • 2007
  • In this study, a new modal test method is presented to evaluate vibration characteristic of the nano imprint stage system. Since it is difficult to measure vibration level without contacting the machine component, non contacting modal test method, laser scanning system is ultrared. Finite element analysis results are compared with the modal test results.

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Finite Element Analysis on the Thermal Behaviors of Non-Contact Type Mechanical Seals Depending on Contacting Face Geometry (접촉면 형상에 따른 비접촉식 기계시일의 열거동 특성에 관한 유한요소해석)

  • Cho, Seung-Hyun;Kim, Chung-Kyun
    • Tribology and Lubricants
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    • v.18 no.1
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    • pp.34-41
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    • 2002
  • This paper presents the contact thermal behaviors of mechanical seals depending on the contacting face geometry. Using the finite element analysis, the temperature distribution, thermal distortion and leakage have been analyzed as functions of sealing gap and rotating speed of the seal ring shaft. The FE results indicate that the inclined contacting face may be more effective and stable based on the results of thermal characteristic analysis if the seal ring has been designed with a same thermal capacity between conventional rectangular sealing faces and inclined seating surface of seal rings.

LCD 팬널의 임프린트 공정을 위한 접촉 평평도 증진 연구

  • Gang Yun-Seok;Jang Si-Yeol;Im Hong-Jae;Sin Dong-Hun;Jeong Jae-Il
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2006.05a
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    • pp.269-272
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    • 2006
  • Surface contacts between mold and target should be in parallel for the imprinting mechanism. However, the size of contacting area makes it difficult for both mating surfaces to be in all contact because of precision level of the imprinting machine and the waviness of mold and target. The gripping force for both mold and target with the vacuum chuck is also major effect to interrupt the full contact, which must be avoided in imprinting mechanism. In this study, the preliminary study for the causes of non-uniformity of contacting surfaces such as mold and target is performed with $470{\times}370mm^2$ LCD panel size.

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A Study on the Calibration of Shape Measurement System Using Digital moire (Digital moire 형상측정 시스템의 보정에 관한 연구)

  • 유원재;김도훈;안재웅;강영준;노형민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.199-202
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    • 2002
  • Moire topography method is a well-known non-contacting 3-D measurement method. Recently, the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using digital projection moire topography is very attractive because of its high measuring speed and high sensitivity. In this paper, using different N-bucket algorithm method of digital projection moire topography is tested to measuring object with the 2$\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding measurement errors that decreased more by using the flour-three step algorithm method than the same step in the phase shifting of different pitchs.

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A Study on the Virtual Grating Projection Moire Topography for the Shape Measurement of Human Face (인체형상 측정을 위한 가상격자 영사식 무아레 방법에 관한 연구)

  • 유원재;최정표;안중근;강영준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.49-52
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    • 2001
  • Moire topography method is a well-known non-contacting 3-D measurement method. Recently, the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using projection moire topogrphy is very attractive because of it s high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the $2\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the $2\pi$-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

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Precise in situ Measurement using Non-Contacting Capacitive Sensor with 4-Electrodes (비접촉식 4-전극형 전기용량 센서를 이용한 in situ 정밀측정)

  • 이래덕
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.93-98
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    • 1999
  • Non-contacting capacitive sensors, based on principle of the cross capacitor, for measuring small displacement less than 1.95$\pm$0.5 mm have been fabricated and characterized. To overcome disadvantages of the existed capacitive sensors, the new sensor is consisted of 4-electrodes which are formed 2 active electrodes and 2 guard electrodes on a sapphire plate with diameter 17mm and thickness 0.7 mm, and are symmetrically situated with constant gap of 0.2 mm among the electrodes. The sensor is evaluated to be correlation coefficient of 0.9987 for the range of 1.95$\pm$0.5 mm and that of 0.9995 for 1.95$\pm$0.25 mm range. This sensor can be used for in situ measurements in the mechanical mirror polishing with precision less than $\pm$1${\mu}{\textrm}{m}$.

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Comparison of PID and Feedback Linearization Control for Magnetic Levitation System (자기부상 시스템의 PID 제어와 Feedback Linearization 제어와의 성능비교)

  • 박종석;김동환
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.263-263
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    • 2000
  • Electromagnetic Suspension(EMS) System produces no noise, friction and heat through non-contacting operation Therefore, the applicable device using EMS system has a lot of attraction in case of the high-speed and non-contacting transmission EMS with nonlinear properties requires a precise airgap position control and stable kinematics characteristics under the disturbances, In this study, the nonlinear system was linearized by a Nonlinear Feedback Lineariztion(NFL) method. The NFL method requires that the modelling should be exact, and the state variables should be measured and a rapidly operating controller be necessary on account of a heavy data calculating In the experiments. the ideal control characteristics of the NFL was acquired through simulation at first. then the characteristics of the actual system were compared with those of simulation. In addition, the results by NFL were examined and analysed considering the characteristics of the PID control. The Control by NFL shows much stable control characteristics than the PID control. Whereas, the steady state errors occur for various disturbances. hence a robust control design is remained for a further study.

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2중파장 영사식 무아레의 N-Buckets 알고리즘 오차비교에 관한 실험적 연구

  • 유원재;박낙규;강영준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.181-181
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    • 2004
  • 3 차원 형상측정기술(3-D Profile Measurement Method)은 가공품의 치수검사 및 형상측정 등의 공학분야뿐만 아니라 최근에는 의류산업 및 의학산업은 물론 오락산업의 가상현실 구현 등 여러 분야로 점차 사용이 확대되고 있다. 이러한 요구를 만족시킬 수 있는 광학을 바탕으로 한 비접촉 3 차원 형상측정방법(Non-contacting 3-D Profile Measuring Method)은 고속, 고정밀도 측정이 가능하기 때문에 활발히 연구되고 있다. 광학을 이용한 대표적인 3 차원 비접촉 측정방법의 하나인 영사식 무아레는 그림자식 무아레의 단점인 격자의 크기가 측정물체보다 커야 한다는 점과 측정물체와 격자사이의 거리 제한 문제를 해결하였으며, 위상이동법을 사용함으로서, 무아레 무늬 형태의 영향을 받지 않고 측정이 가능해졌다.(중략)

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A study on the Mathematical Tension Model for a Non-contact Transfer of a Moving Web in R2R e-Printing Systems (롤투롤 시스템에서의 비 접촉 이송 시스템을 위한 수학적 장력 모델에 관한 연구)

  • Lee, Chang-Woo;Kim, Ho-Joon;Kang, Hyun-Kyoo;Shin, Kee-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.9
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    • pp.894-898
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    • 2009
  • In a post printing section of roll to roll printing systems, scratch problem is the major defects. The functional qualities such as conductivity, mobility could deteriorate because of the scratch defect. In general, the scratch of the printed pattern on the flexible substrate was induced from a contact between rolls and printed pattern in the post printing section. In this paper, for non-contacting transfer of a moving web, a mathematical tension model has been developed considering strain due to air floatation and the proposed mode has been validated by numerical simulation. Additionally, the correlation between floatation height and speed compensation to control the tension and register are investigated. On the basis of the proposed model, a guide line of speed control in R2R printing system is presented to guarantee the non-contact between rolls and R2R printed pattern on the flexible substrate.