• Title/Summary/Keyword: Force Display

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Fabrication of Fine Organic Thin-Film Stripes Using a Hydrophobic Needle (소수성 Needle을 이용한 미세 유기 박막 Stripe 제작)

  • Kim, Jongmyeong;Lee, Jinyoung;Shin, Dongkyun;Park, Jongwoon
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.1
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    • pp.73-78
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    • 2020
  • There appears lateral capillary force in a hydrophilic flat needle employed for the fabrication of fine organic thin-film stripes, bringing in an increase of the stripe width. It also causes the stripe thickness to increase with increasing coating speed, which is hardly observed in a normal coating process. Through computational fluid dynamics (CFD) simulations, we demonstrate that the lateral capillary flow can be substantially suppressed by increasing the contact angle of the needle end. Based on the simulation results, we have coated the outer surface of the flat needle with a hydrophobic material (polytetrafluoroethylene (PTFE) with the water contact angle of 104°). Using such a hydrophobic needle, we can suppress the lateral capillary flow of an aqueous poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) to a great extent, rendering the stripe narrow (63 ㎛ at 30 mm/s). Consequently, the stripe thickness is decreased as the coating speed increases. To demonstrate its applicability to solution-processable organic light-emitting diodes (OLEDs), we have also fabricated OLED with the fine PEDOT: PSS stripe and observed the strong light-emitting stripe with the width of about 68 ㎛.

Sensor-less Speed Control of PMSM for Driving Oil-free Air Compressor (무급유식 공기압축기 구동을 위한 영구자석 동기 모터의 센서리스 속도제어)

  • Kin, Min Ho;Yang, Oh;Kim, Youn Hyun
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.3
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    • pp.45-50
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    • 2015
  • This paper suggests the sensor-less speed control of PMSM (Permanent Magnet Synchronous Motor) without the position sensor of oil-free air compressor. It estimated d and q axis back electro motive force using Back-EMF (Electro motive Force) observer to control sensor-less speed of PMSM. Also it used the method that tracks the information of rotor position and speed using PLL (Phase Locked Loop) based on estimated d and q axis Back-EMF. The sensor-less speed control of PMSM for oil air compressor application is carried out with the introduced rotor position and speed tracking method. In this paper, the experimental characterization of the sensor-less drive is provided to verify the accuracy of the estimated position and the performance of sensor-less control is analyzed by results obtained from the experiment. Moreover, the potential of PMSM sensor-less drive in industrial application such as compressor drive is also examined.

Improvement of Mchanical Property of Indium-tin-oxide Films on Polymer Substrates by using Organic Buffer Layer

  • Park, Sung-Kyu;Han, Jeong-In;Moon, Dae-Gyu;Kim, Won-Keun
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.2
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    • pp.32-37
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    • 2002
  • This paper gives the basic mechanical properties of indium-tin-oxide (ITO) films on polymer substrates which are exposed to externally and thermally induced bending force. By using modified Storney formula including triple layer structure and bulge test measuring the conductive changes of patterned ITO islands as a function of bending curvature, the mechanical stability of ITO films on polymer substrates was intensively investigated. The numerical analyses and experimental results show thermally and externally induced mechanical stresses in the films are responsible for the difference of thermal expansion between the ITO film and the substrate, and leer substrate material and its thickness, respectively. Therefore, a gradually ramped heating process and an organic buffer layer were employed to improve the mechanical stability, and then, the effects of the buffer layer were also quantified in terms of conductivity-strain variations. As a result, it is uncovered that a buffer layer is also a critical factor determining the magnitude of mechanical stress and the layer with the Young's modulus lower than a specific value can contribute to relieving the mechanical stress of the films.

Induction Mechanism of Planar Arrangement in Cholesteric Liquid Crystals (콜레스테릭 액정의 Planar 배열 유도 메카니즘)

  • Jung, Gap-Ha;Lee, Mong-Ryong;Seo, In-Seon;Song, Ki-Gook
    • Polymer(Korea)
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    • v.35 no.3
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    • pp.272-276
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    • 2011
  • The induction mechanisms of planar arrangements in cholesteric liquid crystals (CLC) which showed selective reflections of visible light were investigated by measuring the selective reflectivity and FTIR peak intensity of $C{\equiv}N$ stretching band. Although the planar arrangement of CLC was not as perfectly induced as the cases prepared with using alignment layers, it could be also induced by stretching polymer substrate or by applying shear forces. The planar arrangements were induced by forming CLC helical structures on top of liquid crystal molecules which were in contact with the substrate and oriented all in the same direction.

Force Display Based on Simultaneous Actuation of Motors and Brakes

  • Kwon, Tae-Bae;Song, Jae-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1131-1135
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    • 2004
  • In the virtual environment, force feedback to the human operator makes virtual experiences more realistic. However, the force feedback using active actuators such as motors can make the system active and sometimes unstable. To ensure the safe operation and enhance the haptic feeling, stability should be guaranteed. Both motors and brakes are commonly used for haptic device. A brake can generate a torque only against its rotation, but it is intrinsically stable. Consequently, motors and brakes are complementing each other. In this research, a two degree-of-freedom (DOF) haptic device equipped with both motors and brakes has been developed to provide better haptic effects. Each DOF is actuated by a pair of motor and brake. Modeling of the environment and the control method are needed to utilize both actuators. For various haptic effects, contact with the virtual wall and representation of friction effect are extensively investigated in this paper. It is shown that the hybrid haptic system is more suited to some applications than the motor-based active haptic system.

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Optimized Design of a Planar Haptic Device Using Passive Actuators

  • Kim, Tae-Woo;Cho, Chang-Hyun;Kim, Mun-Sang;Song, Jae-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1565-1570
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    • 2003
  • Passive Haptic Devices have more benefit than the active in Stability. But Apart from benefits, it shows poor performance in haptic display. The author proposed the passive FME(Force Manipulability Ellipsoid) which can graphically show force generating ability of a passive haptic device. In this paper, performance indexes for the force approximation and pseudo friction cone are obtained with the passive FME and an optimized planar device with the indexes is proposed. Based on the above theory, experiment is conducted.

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Haptic Interaction with Objects Displayed in a Picture based on Surface Normal Estimation (사진 속 피사체의 법선 벡터 예측에 기반한 햅틱 상호 작용)

  • Kim, Seung-Chan;Kwon, Dong-Soo
    • The Journal of Korea Robotics Society
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    • v.8 no.3
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    • pp.179-185
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    • 2013
  • In this paper we propose a haptic interaction system that physically represents the underlying geometry of objects displayed in a 2D picture, i.e., a digital image. To obtain the object's geometry displayed in the picture, we estimate the physical transformation between the object plane and the image plane based on homographic information. We then calculate the rotated surface normal vector of the object's face and place it on the corresponding part in the 2D image. The purpose of this setup is to create a force that can be rendered along with the image without distorting the visual information. We evaluated the proposed haptic rendering system using a set of pictures of objects with different orientations. The experimental results show that the participants reliably identified the geometric configuration by touching the object in the picture. We conclude this paper with a set of applications.

Simulation of the control force of the light aircraft using flight test data (비행시험 자료를 이용한 경항공기의 조종력 시뮬레이션)

  • 김정환;황명신;이정훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.203-206
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    • 1996
  • The purpose of this paper is to find how to determine the parameters of the basic control system design such as hinge moment coefficients and to display the controllability of the ChangCong-91. Since the estimation from the flight test of real aircraft is the most reliable, we performed the flight test of ChangGong-91 to get the various parameters such as velocity, height, control force, control surface deflection, 3 axis acceleration, 3 axis angular rate, pitch angle, angle of attack temperature and so on. We recorded the flight test data in VHS tapes and stored them to personal computer using A/D(analog to digital) converter. Flight test was done in various conditions, and the acquired data was processed with parameter identification method such as least square method. These data will be utilized for the development of Autopilot System design and Control Loading System design.

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Design of A Force-Reflecting 3DOF Interface using Phase-Difference Control of Ultrasonic Motors (초음파 모터의 위상차 제어를 이용한 3자유도 힘반영 촉각장치 설계)

  • 오금곤;조진섭;김동옥;김영동;김재민
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.84-87
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    • 1999
  • This paper proposes an interfaces control system to drive a ultrasonic motors(USMs). To touch surfaces and objects created within a virtua environment, the 3 DOF force-reflecting interfaces provides force feedback to users, so to feel touching real things. To effectively display the mechanical impedance of the human hand we need a device with specific characteristics, such as low inertia almost zero friction and very high stiffness. As an actuator for direct drive method, the USMs have many good advantages satisfied these conditions over conventional servo motors. To estimate capability of this interface, we did an experiment. The device works very well, as user are able to detect the edge of the wall and the stiffness of the button.

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Graphic Deformation Algorithm for Haptic Interface System (촉각시스템을 위한 그래픽 변형 알고리즘)

  • Kang, Won-Chan;Jeong, Won-Tae;Kim, Young-Dong;Shin, Suck-Doo
    • Proceedings of the KIEE Conference
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    • 2002.06a
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    • pp.67-71
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    • 2002
  • In this paper, we propose a new deformable model based on non-linear elasticity, anisotropic behavior and the finite element method and developed the high-speed controller for haptic control. The proposed controller is based on the PCI/FPGA technology, which can calculate the real position and transmit the force data to device rapidly, The haptic system is composed of 6DOF force display device, high-speed controller and HIR library for 3D graphic deformation algorithm & haptic rendering algorithm. The developed system will be used on constructing the dynamical virtual environment. we demonstrate the relevance of this approach for the real-time simulating deformations of elastic objects. To show the efficiency of our system, we designed simulation program of force-reflecting, As the result of the experiment, we found that the controller has much higher resolution than some other controllers.

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