• Title/Summary/Keyword: Contact pair

검색결과 119건 처리시간 0.021초

한쌍의 6축 전기유압 매니퓰레이터를 이용한 힘 제어 (너트의 장착 및 체결 작업에의 응용) (Force Control of One Pair of 6-Link Electro-Hydraulic Manipulators (Application to the Approaching of a Bolt and the Wrenching of a Nut Tasks))

  • 안경관;양순용
    • 제어로봇시스템학회논문지
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    • 제8권1호
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    • pp.15-20
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    • 2002
  • An electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the automatic assembly tasks using hydraulic manipulators. In this manuscript, we applied a compliance control, which is based on the position control by a disturbance observer for our manipulator system. A reference trajectory modification method is proposed in order to achieve accurate force control even though the stiffness and the position of the environment change. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved under various environment conditions. The proposed force control algorithm is applied to the approaching of bolt and the wrenching of nut tasks as one typical task in the maintenance work of live power electric line and is experimentally confirmed very effective for the task.

다이아프램 구조를 이용한 탄소나노튜브 가스 센서의 가스감응특성 (Gassensing characteristics of carbon nanotube gas sensor using a diaphragm structure)

  • 김성운;한재천;조우성;주병권;조현섭;김영조
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2006년도 춘계학술발표논문집
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    • pp.203-206
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    • 2006
  • The sensor consists of a heater, an insulating layer, a pair of contact electrodes, and CNT-sensing film on a micromachined diaphragm. The heater plays a role in the temperature change to modify sensor operation. Gas sensor responses of CNT-film to $NO_2$ at room temperature are reported. The sensor exhibits a reversible response with a time constant of a few minutes at thermal treatment temperature of $130^{\circ}C$.

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다이아프램 구조를 이용한 탄소나노튜브 가스 센서의 제작 (Fabrication of carbon nanotube gas sensor using a diaphragm structure)

  • 김성운;한재천;조우성;주병권;조현섭;김영조
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2006년도 춘계학술발표논문집
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    • pp.223-226
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    • 2006
  • The micro-gas sensor based on carbon nanotubes (CNTs) was fabricated and its gas sensing characteristics on nitrogen dioxide ($NO_2$) have been investigated. The sensor consists of a heater, an insulating layer, a pair of contact electrodes, and CNT-sensing film on a micromachined diaphragm. The heater plays a role in the temperature change to modify sensor operation. Gas sensor responses of CNT-film to $NO_2$ at room temperature are reported. The sensor exhibits a reversible response with a time constant of a few minutes at thermal treatment temperature of $130^{\circ}C$.

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유한요소해석에 의한 헤밍 공정 변수연구 (A Parametric Study of the Hemming Process by Finite Element Analysis)

  • 김형종;최원목;임재규;박춘달;이우홍;김헌영
    • 대한기계학회논문집A
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    • 제28권2호
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    • pp.149-157
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    • 2004
  • Implicit finite element analysis of the flat surface-straight edge hemming process is performed by using a commercial code ABAQUS/Standard. Methods of finite element modeling for springback simulation and contact pair definition are discussed. An optimal mesh system is chosen through the error analysis that is based on the smoothing of discontinuity in the state variables. This study has focused on the investigation of the influence of process parameters in flanging, pre-hemming and main hemming on final hem quality, which can be defined by turn-down, warp and roll-in. The parameters adopted in this parametric study are flange length, flange angle, flanging die corner radius, face angle and insertion angle of pre-hemming punch, and over-stroke of pre-hemming and main hemming punches.

근접센서를 이용한 차량 도어 제어 충돌 방지 시스템 (Car-door-controlled collision protection system using proximity sensor)

  • 이석희;조한석;허종규;이정헌;김희국
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.971-975
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    • 2005
  • In this study, a car-door-controlled collision protection system using proximity sensor is proposed and its preliminary analysis and several preliminary experiments are conducted. The proposed system has three additional sub-components on the car-door that is, a pair of extra electro-magnetic actuator that are attached to the sliding bar of the open/close car-door four-bar mechanism, a proximity sensor that would be attached to the outside surface of the door which is likely to frequently contact to the object and a driving control circuit of the whole system. A proximity sensor is used to detect object close to the car-door, the driving control circuit provides actuating power command to the electro-magnets to generate braking force to stop the swing motion of the car-door. It is verified through kinematic analysis of the four-bar car-door open/close mechanism and through experiments that the magnitude of maximum electronic magnetic force could provide the braking force enough for this application. For this purpose, an electro-magnet driving circuit is implemented and tested. And also to increase the safety of the system a time delay circuit is implemented and tested.

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토크 변동에 의한 백래시를 가진 헬리컬 기어의 비선형 동적 해석 (Nonlinear Dynamic Analysis of Helical Gears with Backlash by Torque Fluctuation)

  • 박찬일
    • 한국소음진동공학회논문집
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    • 제20권7호
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    • pp.677-684
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    • 2010
  • Backlashes of gears provide gears for good lubrication and for removal of the interference between teeth by the wear and manufacturing errors. The backlash is the strong nonlinear factor to gears. This study deals with nonlinear modeling of helical gears with backlash. Excitation of helical gears comes from torque variation, the tooth surface error, and the periodical change of mesh stiffness. To study the effect of torque fluctuation, equation of motion for the single degree of freedom torsional model of helical gears with the periodical change of mesh stiffness and the backlash was derived. The Newmark beta method and the Newton-Raphson method were used to obtain the nonlinear behaviors of mesh forces of helical gears. All excitation frequencies initially caused the tooth separation and single-sided impacts of the gear pair and eventually led to the normal tooth contact. However, some special excitation frequencies caused the single-sided impacts in the entire time as well as the initial time. Damping increase reduced the duration of single-sided impacts, and the backlash increase caused those in the entire time domain.

헬리컬기어의 동적해석을 통한 전달오차 예측 (Prediction of Transmission Error Using Dynamic Analysis of a Helical Gear)

  • 이정석;윤문영;부광석;김흥섭
    • 대한기계학회논문집A
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    • 제40권12호
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    • pp.1005-1011
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    • 2016
  • 기어소음의 근본적인 원인은 전달오차로 인해 발생하게 된다. 전달오차는 기어가 맞물릴 때 발생하는데 크게 정적전달오차와 동적전달오차가 있다. 이러한 오차들은 기어 이빨의 처짐 또는 치면 마찰에 의해 발생하고 이 요인들이 원인이 되어 기어 시스템에 진동이 발생하게 된다. 그리고 이 진동이 기어의 축으로 이동하게 되어 축을 떠받치고 있는 베어링에 전달되고 베어링에 전달된 가진은 최종적으로 기어의 케이싱으로 이동하게 되어 소음을 방출하게 된다. 본 논문에서는 이러한 전달오차에 의해 발생하는 최대 굽힘응력을 가지는 롤각을 찾기 위한 응력해석을 수행되었다. 본 논문에서는 이론적 바탕으로 설계되어 인볼류트 곡선을 가진 기어와 수정된 치형을 가진 기어의 전달오차에 대한 해석을 진행하였다. 또한, 급작스러운 작동이나 큰 백래쉬로 인해 발생하는 충격강도에 대한 영향을 알아보기 위해 유한요소해석을 통해 각각 정적 최대굽힘응력과 동적 최대굽힘응력의 결과를 이용하여 충격인자 값을 예측해 보았다.

한국형 봅슬레이화 개발을 위한 구간 시간과 족저압력 분석 (The Analysis of Foot Pressure and Lap Time for the Development of Korean Bobsleigh Shoes)

  • 박종진;김경훈;박승범
    • 한국운동역학회지
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    • 제25권4호
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    • pp.465-474
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    • 2015
  • Objective : A study and development of Korean Bobsleigh athletes's shoe which considers their physical condition has yet to be completed. So this study examines the effects of running shoes used by athletes based on plantar pressure and sprint time in order to provide raw data for the development of bobsleigh shoes suitable for Koreans. Method : The study selected seven bobsleigh athletes as subjects and selected three pairs of spiked running shoes from three companies, which will be referred to as Company N (Type A), Company A (Type B), and Company M (Type C). To analyze sprint time and plantar pressure for each shoe, the subject of the study were instructed to wear the selected shoes and to drag a sled at maximum sprint for 15 meters for 15 meters for in each condition that would be in real bobsleigh competitions. Results : The average sprint intervals for each athlete in each pair of shoes revealed Type C produce the fastest sprint in the order of Type C < Type A< Type B. Shoe Type C also had the largest contact area in order of Type C > Type B > Type A (p<.01). None of the three shoe types seem to yield a distinct advantage in terms of maximum average pressure or maximum pressure. Conclusion : In the future, functional analysis should be carried out by comparing the material properties, hardness, and toe spring of shoes based on the Type C shoe from Company M in order to develop bobsleigh shoes suitable for Koreans.

On Fiber Orientation Characterization of CERP Laminate Layups Using Ultrasonic Azimuthal Scanners

  • Im Kwang-Hee;Hsu, David K.;Sim Jae-Gi;Yang, In-Young;Song, Sung-Jin
    • 비파괴검사학회지
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    • 제23권6호
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    • pp.566-576
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    • 2003
  • Carbon-fiber reinforced plastics (CFRP) composite laminates often possess strong in-plane elastic anisotropy attributable to the fiber orientation and layup sequence. The layup orientation thus greatly influences its properties in a composite laminate. It could result in the part being rejected or discarded if the layup orientation of a ply is misaligned. A nondestructive technique would be very beneficial, which could be used to test the part after curing and to require less time than the optical test. In this paper, ultrasonic scanners were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. The motorized scanner was built first for making transmission measurements using a pair of normal-incidence shear wave transducers. Another scanner was then built fer the acousto-ultrasonic configuration using contact transducers. A ply-by-ply vector decomposition model has been developed, simplified, and implemented for composite laminates fabricated from unidirectional plies. We have compared the test results with model data. It is found that strong agreement are shown between tests and the model developed in characterizing cured layups of the laminates.

Organic/Organic Core-Shell 아크릴 접착바인더의 플라즈마 처리영향 (II) (Plasma Treatment Effect of Organic/Organic Core-Shell Acrylic Adhesive Binder (II))

  • 설수덕
    • 폴리머
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    • 제34권2호
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    • pp.89-96
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    • 2010
  • Methyl methacrylate(MMA), ethyl acrylate(EA), n-butyl acrylate(BA), styrene(St) 단량체를 수용성 개시제인 ammonium persulfate(APS)와 음이온 유화제인 sodium dodecyl benzene sulfonate(SDBS)를 사용하여 organic/organic core-shell 구조의 접착바인더를 중합 후 부직포와 피혁에 함침시키고 플라즈마 표면 처리 후 속도론적인 해석과 기계적인 물성을 평가하였다. Core-shell 바인더 중합시 전환율은 단량체의 조성이 등몰에서 MMA/EA, MMA/BA core-shell 복합입자 모두 90% 이상이 되었다. 등몰에서 부직포/부직포에 core-shell 복합입자를 함침시키고 플라즈마 처리 후의 상태접착 박리강도는 MMA/St, EA/BA, BA/MMA, EA/St, EA/MMA의 순으로 되었고, 또한 부직포/피혁에 core-shell 복합입자를 함침시키고 플라즈마 처리 후의 상태접착 박리강도는 MMA/BA, BA/EA, MMA/EA, St/MMA, EA/St의 순으로 되었다.