• Title/Summary/Keyword: linear system

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Development of OHS System Driven by Linear Motor for Automatic Transfer of LCD Panels (선형전동기를 적용한 LCD 패널 자동반송용 순환궤도차량 시스템 개발)

  • Kim, Won-Gon;Yun, Jong-Bo;Park, Gun-Woo;Hwang, Gye-Ho
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.3
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    • pp.11-16
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    • 2008
  • The authors investigated an overhead shuttle (OHS) system for automatic transferring the liquid crystal display (LCD) panels. The constructed tracks of OHS system include the linear and curve regions and have been installed on the ceiling to transfer the cassette of LCD glass along the closed-loop and open-loop tracks. In this study, the OHS system was implemented by a proposed linear motor to solve encoder installation and the system cost problems of the long distance transfer system. In addition, we utilized a new algorithm of the position detection and a new control algorithm for driving linear motor. The newly developed control algorithm was demonstrated from both a computer simulation and an experimentation, indicating that the highly reliable and speedy transfer system can enhance the LCD panel productivity of commercial OHS system.

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A Study on Intelligent Decentralized Active Suspension Control System with Descriptor LMI Design Method

  • Park, Jung-Hyen
    • Journal of information and communication convergence engineering
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    • v.6 no.2
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    • pp.198-203
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    • 2008
  • An Intelligent optimal control system design algorithm in active suspension equipment adopting linear matrix inequalities control system design theory with representing by descriptor system form is presented. The validity of the linear matrix inequalities intelligent decentralized control system design with representing by descriptor system form in active suspension system through the numerical examples is also investigated.

DS-PAM UWB System Using Non-linear Chirp Waveform

  • Shen, Hanbing;Zhang, Weihua;An, Xizhi;Kwak, Kyung-Sup
    • ETRI Journal
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    • v.29 no.3
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    • pp.322-328
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    • 2007
  • We propose a direct-sequence pulse-amplitude modulation (DS-PAM) ultra-wideband (UWB) system which employs a non-linear chirp waveform instead of the conventional Gaussian monocycle in this paper. In the approved frequency for UWB, there exist myriad narrowband interferers. Specifically, we focus on the mutual interference between UWB systems and 802.11a WLAN. This paper offers a method to suppress this in-band narrowband interference by introducing a kind of non-linear chirp waveform. Using the proposed non-linear chirp waveform, the effects of one or more narrowband interference sources with different frequencies can be suppressed. System performance of UWB systems in the narrowband interference environment can be improved. Computer simulations with additive white Gaussian noise successfully demonstrate an increase in performance with the proposed system as compared to traditional linear chirp systems.

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Methods to Obtain Approximate Responses of a Non-Linear Vibration Isolation System (비선형 진동절연 시스템의 근사적 응답을 구하는 방법)

  • Lee, Gun-Myung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.6
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    • pp.23-28
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    • 2020
  • A non-linear vibration isolation system composed of a non-linear spring and a linear damper was presented in a previous study. The advantage of the proposed isolator is the simple structure of the system. When the base of the isolator is harmonically excited, the response component of the mass at the excitation frequency was approximated using three different methods: linear approximation, harmonic balance, and higher-order frequency response functions (FRFs). The method using higher-order FRFs produces significantly more accurate results compared with the other methods. The error between the exact and approximate responses does not increase monotonously with the excitation amplitude and is less than 2%.

Development of Elevator Door System with Linear Induction Motor (리니어모터를 적용한 엘리베이터 도어시스템 개발)

  • Kim, Youn-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3617-3625
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    • 2011
  • This paper introduces new concept elevator door system with linear induction motor(LIM) featuring simple structured and direct drive mechanism, which makes up for the weak points of the conventional complex structured door system. The optimal configuration of linear door system and the design results of linear LIM will be proposed in this paper and the validation of LIM design results will be investigated through the test. In this study, high performance of drive controller applied vector control and optimum drive pattern also are suggested. In addition, this paper describes details of designing and manufacturing process of linear door system and investigates the performance by analysis and test. The analytical and experimental results of this paper are considered as the productive data for the development of new elevator door system.

The use of the semi-empirical method to establish a damping model for tire-soil system

  • Cuong, Do Minh;Ngoc, Nguyen Thi;Ran, Ma;Sihong, Zhu
    • Coupled systems mechanics
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    • v.7 no.4
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    • pp.395-406
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    • 2018
  • This paper proposes a linear damping model of tire-soil system using semi-empirical method. A test rig was designed and developed to measure the vertical equivalent linear damping ratio of tire only and tire-soil system using Free-Vibration Logarithmic Decay Method. The test was performed with two kinds of tractor tires using a combination of five inflation pressure levels, two soil depths and four soil moisture contents in the paddy soil. The results revealed that the linear damping ratio of tires increased with decreasing tire inflation pressure; the linear damping ratio of tire-soil system also increased with decreasing tire inflation pressure and increased with the increasing soil depth (observed at 80 and 120 mm). It also increased with a relative increase of soil moisture contents (observed at 37.9%, 48.8%, 66.7% and 77.4%). The results also indicated that the damping ratio of tire-soil system was higher than that of tire only. A linear damping model of tire-soil system is proposed as a damping model in parallel which is established based on experimental results and vibration theory. This model will have a great significance in study of tractor vibration.

A Study on the Feed Rate Optimization of a Linear Motored Feed Drive System for Minimum Vibrations (Linear Motor 이송계의 진동 최소화를 위한 이송속도 최적화)

  • 최영휴;홍진현;최응영;김태형;최원선
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.321-325
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    • 2004
  • Linear motor feed drive systems have been broadly used in machine tools or precision automatic feed systems. Recently, modem machine tools require high speed and high precision feed drive system to achieve high productivity. Unfortunately, a feed drive system, even though it was optimum designed, may experience severe transient vibrations during high-speed operation if its feed rate control is unsuitable. A rough feed rate curve having discontinuity in its acceleration profile causes a serious vibration problem in the feed slides system. This paper presents a feed rate optimization of a machine tool feed slide system, which is driven by a linear motor, for its minimum vibrations. Firstly, a 4-degree-of-freedom lumped parameter model is proposed for the vibration analysis of a linear motor driven machine tool feed drive system. Next, a feed rate optimization of the feed slide is carried out for minimum vibrations. The feed rate curve optimization strategy is to find out the most appropriate acceleration profile with jerk continuity. Of course, the optimized feed rate should approximate to the desired one as possible. A genetic algorithm with variable penalty function was used in this feed rate optimization.

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A Study on the Cooling Parameter Decision of Linear Motor System by Finite Volume Method (유한체적법을 이용한 리니어모터 시스템의 냉각조건 선정에 관한 연구)

  • Hwang Y.K.;Eun I.E.;Lee C.M.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.449-450
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    • 2006
  • Development of a feed drive system with high speed, positioning accuracy and thrust has been an important issue in modern automation systems and machine tools. Linear motors can be used as an efficient system to achieve such technical demands. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. In this paper presents an investigation into a thermal behavior of linear motor cooling plate. FVM employed to analyze the thermal behavior of the linear motor cooling plate, using the ANSYS-CFX.

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Design of Rotary Inverted Pendulum applying an Embedded System and Implementation by PID (Embeded system을 적용한 Rotary Inverted Pendulum 설계 및 PID에 의한 구현)

  • 김영춘;김정훈;김영탁;김동한
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.5-8
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    • 2002
  • In this paper, we applied a PC interface and an embedded system in order to design a non-linear system and implement the PID algorithm as our control one. We used the inverted pendulum, one of the most generally used non-linear system models, to control uncertain factors in the environment. This paper showed how to use this non-linear system model to control the factors completely as well as to understand the PID algorithm. Furthermore, this paper applied and understood the embedded system.

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Analysis and Experiments of the Linear Electrical Generator in Wave Energy Farm utilizing Resonance Power Buoy System

  • Park, Sang-Shin;Park, Se Myung;Jung, Jongkyo;Kim, Jin Ho
    • Journal of Magnetics
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    • v.18 no.3
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    • pp.250-254
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    • 2013
  • In this research, the linear electrical generator in wave energy farm utilizing resonance power buoy system is studied. The mechanical resonance characteristics of the buoy and the wave are analyzed to maximize the kinetic energy in a relatively small wave energy area where WRPS is operated. In this research, we chose an analog model of the linear electrical generator of which size is one-hundredth of an actual size of it in WPRS (Wave energy farm utilizing Resonance Power buoy System) prior to verifying the characteristics of actual model of linear electrical generator in WRPS. In addition, the finite element analysis is conducted using commercial electromagnetic analysis software named MAXWELL to examine the electric characteristic of linear generator. Finally, for the verification of dynamic and electric characteristics of linear generator, the prototype was manufactured and the experiments to measure the displacement and the output electric power were performed.