• 제목/요약/키워드: Open loop

검색결과 852건 처리시간 0.024초

개루프 제어의 실린더 진동형 자이로 구현 및 실험 (The Implementation and Experiments of Open-Loop Cylindrical Vibratory Gyroscope)

  • 공형직;김정엽;홍성경
    • 제어로봇시스템학회논문지
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    • 제10권8호
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    • pp.669-672
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    • 2004
  • This paper considers the implementation and experiments of an open-loop Cylindrical Vibratory Gyroscope(CGV). An open-loop CGV composed of thin cylindrical vibrating element, electromagnetic drive and pick-off element with open-loop control was designed and fabricated. The experimental performance tests of the open-loop CGV were done using a temperature chambered rate table. Also, the limitations of open-loop CGV were analyzed and the solution for the limitations was proposed.

Multibody Dynamics of Closed, Open, and Switching Loop Mechanical Systems

  • Youm, Youn-Gil
    • Journal of Mechanical Science and Technology
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    • 제19권spc1호
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    • pp.237-254
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    • 2005
  • The vast mechanical systems could be classified as closed loop system, open loop system and open & closed (switching) system. In the closed loop system, the kinematics and dynamics of 3-D mechanisms will be reviewed and closed form solutions using the direction cosine matrix method and reflection transformation method will be introduced. In the open loop system, kinematic & dynamic analysis methods regarding the redundant system which has more degrees of freedom in joint space than those of task space are reviewed and discussed. Finally, switching system which changes its phase between closed and open loop motion is investigated with the principle of dynamical balance. Among switching systems, the human gait in biomechanics and humanoid in robotics are presented.

복소 매칭을 이용한 Open Loop Resonator 다이플렉서 (Open loop resonator diplexer applying conjugate matching)

  • 백현;한형석;김형석
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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    • pp.425-428
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    • 2008
  • A new type of cross-coupled planar microwave filter using coupled microstrip square open-loop resonators diplexer pro-posed. A method for the rigorous calculation of the coupling coefficients of basic four pole electric and magnetic coupling structures encountered. Simple empirical models are derived for estimation of the coupling coefficients. Experiments are performed to verify the theory. And a method for diplexer matching is conjugate matching that has characteristic better than open matching method.

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무금형 성형장치를 이용한 폐루프 판재성형 (Closed-loop Sheet Metal Forming Using Dieless Forming Apparatus)

  • 양승훈;박종우;홍예선;양현석
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 춘계학술대회 논문집
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    • pp.62-65
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    • 2002
  • A dieless forming system which consists of hydraulic punch elements and elastomer/fluid pads, was developed for sheet metal forming. 2-D curved surface forming was carried out using open-loop, closed-loop, and repeated forming method. Closed-loop exhibited higher decision than open-loop forming. Repeated forming also showed reduced spring back and possibility of high precision.

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기체 탄화수소 연료 연소시험에서 연소불안정의 개루프 제어 (Open-Loop Control of Combustion Instability in Hot-Firing Test Using Gaseous Hydrocarbon Fuel)

  • 황동현;안규복
    • 한국추진공학회지
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    • 제22권6호
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    • pp.28-36
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    • 2018
  • 기체 탄화수소 연료를 사용하는 덤프 연소기의 연소불안정에 개루프 제어를 적용하는 연구를 수행하였다. 연료들의 특성화학시간이 유사한 연소조건에서 음향 발생기를 이용하여 제어 출력과 주파수를 변화시켰다. 연소불안정 주파수와 동일한 주파수의 개루프 제어에서는 음향 발생기의 출력이 제어성능에 영향을 주었다. 연소불안정 주파수와 다른 주파수의 개루프 제어결과로부터 개루프 제어주파수는 연소불안정 주파수와 유사하게 설정하는 것이 효과적임을 알 수 있었다.

변환요소에 따른 LOOPED WIRE의 탄성 변화에 관한 연구 (A STUDY ON THE CHANGES OF THE ELASTIC PROPERTIES TN LOOPED WIRES BY VARIABLE FACTORS)

  • 나용인;김상철
    • 대한치과교정학회지
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    • 제25권3호
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    • pp.263-271
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    • 1995
  • Canine retraction spring과 같은 looped wire에서, 각 변환요소에 따라 변하는 탄성 정도를 알아보기 위하여, wire의 재료, 굵기, loop에 소요된 길이, loop의 모양, gabling의 여부 등 5가지의 변환요소를 설정하여, 각 wire activation시의 탄성을 range, force, stiffness등의 면에서 알아보고자 하였다. wire의 재료적인 면에서 Hi-T (Unitek Co.)와 blue Elgiloy (Rocky Mountain Orthodontics)를 선택하였으며, 굵기로는 .016"$\;\times\;$.022" 와 .018"$\;\times\;$.025"를 선택하였다. loop 자체에 소요된 wire 길이를 15mm와 20mm의 두가지로, loop의 모양을 vertical open loop과 vertical closed loop의 두가지로, gabling의 양을 $0\circ$$30\circ$의 두가지로 하여 각각 제작하였다. 따라서 wire의 재료와 굵기, loop의 길이와 모양, gabling의 5가지 변환요소에 따라 32개군으로 구분되었으며, 각 군의 시료수는 8개씩으로, 총 256개의 시료를 대상으로 하였다. Instron(4202, Instron Co, USA)을 사용하여 각 시료의 하중변형 곡선을 얻었으며 elastic limit에서의 하중과 변형을 계측하고, 그때의 stiffness(force/range)를 산출하여, ANOVA 등의 통계처리로 32개군 간의 상관성을 조사하였다. 그 결과 wire의 재료, 굵기, loop의 길이, 모양, gabling모두가 looped wire의 하중 변형도에 유의한 영향을 미치는 것을 관찰할 수 있었으며, 탄성범위에서의 force는 Hi-T, .016"$\;\times\;$.022", loop 길이 20mm, open loop, non-gable군에서 가장 적었으며, blue Elgiloy, .018"$\;\times\;$.025", loop 길이 15mm, closed loop, non-gable군에서 가장 컸다. 탄성범위에서의 range는 Hi-T, .018"$\;\times\;$.025", loop길이 15mm, open loop, non-gable군이 가장 적었으며, Hi-T, .016"$\;\times\;$.022", loop길이 20mm, closed loop, gable군에서 가장 컸다. 또한 Looped wire의 탄성에 가장 큰 영향을 미치는 변환요소는 loop의 모양과 길이였으며, gabling의 영향이 가장 적었다.

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Microstrip Slow-Wave Open-Loop Resonator Filters with Reduced Size and Improved Stopband Characteristics

  • Akkaraekthalin, Prayoot;Jantree, Jaruek
    • ETRI Journal
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    • 제28권5호
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    • pp.607-614
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    • 2006
  • This paper presents a new class of microstrip slow-wave open-loop resonator filters with reduced size and improved stopband characteristics. A comprehensive treatment of both ends loaded with triangular and rectangular ends is described, leading to the invention of a microstrip slow-wave open-loop resonator. Two-resonator and four-resonator bandpass filters are designed at the operating frequency of about 2 GHz, and a bandwidth of 60 MHz. The size of the slow-wave open-loop resonator is optimized from the standpoint of the unloaded Q-factor. The filters are not only compact in size due to the slow-wave effect, but also have a wider upper stopband resulting from the dispersion effect. The filter designs of this type are described in details. The experimental results are demonstrated and discussed.

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An Open-Loop Method for Point-to-Point Positioning of a Piezoelectric Actuator

  • Henmi, Nobuhiko;Tanaka, Michihiko
    • International Journal of Precision Engineering and Manufacturing
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    • 제8권2호
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    • pp.9-13
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    • 2007
  • We describe how to control a piezoelectric actuator using the open-loop method for point-to-point positioning. Since piezoelectric actuators have nonlinear characteristics due to hysteresis and creep between the input voltage and the resulting displacement, a special method is required to eliminate this nonlinearity for an open-loop drive. We have introduced open-loop driving methods for piezoelectric actuators in the past, which required a large input voltage and an initializing motion sequence to reset the state of the actuator before each movement. In this paper, we propose a new driving method that uses the initializing state. This method also utilizes the overshoot from both the upward and downward stepwise drives. Applying this method., we obtained precise point-to-point positioning without the influence of hysteresis and creep.

Development of a full-scale magnetorheological damper model for open-loop cable vibration control

  • Zhang, Ru;Ni, Yi-Qing;Duan, Yuanfeng;Ko, Jan-Ming
    • Smart Structures and Systems
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    • 제23권6호
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    • pp.553-564
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    • 2019
  • Modeling of magnetorheological (MR) dampers for cable vibration control to facilitate the design of even more effective and economical systems is still a challenging task. In this study, a parameter-adaptive three-element model is first established for a full-scale MR damper based on laboratory tests. The parameters of the model are represented by a set of empirical formulae in terms of displacement amplitude, voltage input, and excitation frequency. The model is then incorporated into the governing equation of cable-damper system for investigation of open-loop vibration control of stay cables in a cable-stayed bridge. The concept of optimal voltage/current input achieving the maximum damping for the system is put forward and verified. Multi-mode suboptimal and Single-mode optimal open-loop control method is then developed. Important conclusions are drawn on application issues and unique characteristics of open-loop cable vibration control using MR dampers.

지하수 수위가 개방형 지열시스템 성능에 미치는 영향에 관한 연구 (A Study of the Influence of Groundwater Level on the System Performance of Open Loop Geothermal System)

  • 김진상;남유진
    • 한국지열·수열에너지학회논문집
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    • 제9권3호
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    • pp.1-10
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    • 2013
  • Open loop geothermal heat pumps have great potential where the groundwater resources are sufficient. Performance of open loop geothermal heat pump systems is considered higher than that of ground source heat pumps. Head and power calculation of submersible pumps, heat pump units, and piping are numerically based on regression data. Results shows that the system performance drops as the water level drops, and the lowest flow rates generally achieve the highest system COPs. The highest achievable cooling system COPs become 6.34, 6.12, and 5.95 as the groundwater levels are 5m, 15m, and 25m. The highest heating system COPs also become 4.59, 4.37, and 4.20. Groundwater level and submersible pump selection greatly influence the system performance of open loop geothermal heat pumps. It needs to be analysed during the design process of open loop geothermal heat pump system, possibly with analysis tools that include wide range of pump product data.