• Title/Summary/Keyword: Pendulum 장치

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Fuzzy Control of Smart Base Isolation System using Genetic Algorithm (유전자알고리즘을 이용한 스마트 면진시스템의 퍼지제어)

  • Kim, Hyun-Su;Roschke, P.N.
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.2 s.42
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    • pp.37-46
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    • 2005
  • To date, many viable smart base isolation systems have been proposed and investigated. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively, of the smart base isolation system. A fuzzy logic controller (FLC) is used to modulate the MR damper because the FLC has an inherent robustness and ability to handle non linearities and uncertainties. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. This method is efficient in improving local portions of chromosomes. Neuro fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find optimal fuzzy rules and the GA optimized FLC outperforms not only a passive control strategy but also a human designed FLC and a conventional semi active control algorithm.

A Proof of Concept Investigation on a Pendular Power Take-Off System of Horizontal Wave Power Generator (수평파력 발전장치의 진자형 1차 에너지 추출 시스템에 대한 기초 모형실험 및 시뮬레이션)

  • Park, Yong-Kun;Lim, Chae Gyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.68-75
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    • 2017
  • This paper presents the experimental and theoretical results of the dynamic responses of a pendular energy extractor in a two-dimensional wave channel. By adopting a wave maker with varying wave height and period, the dynamic responses of the pendular buoy were experimentally obtained. Furthermore, with the aid of the co-simulation of moving particle analysis and rigid dynamic analysis, the dynamic responses of the pendular system were evaluated. In order to validate the feasibility of the proposed wave power generator, the force tuning of the pendular system with restoring energy was carried out. The results provide proof of concept data for the development and design of a commercial model for horizontal wave power generators in the shoreline area.

Exploring Structural Stability using Arduino for the Prevention of Tower Cranes' Safety Accident : focused on ardu (타워크레인의 안전사고 예방을 위한 아두이노 기반 구조적 안정성 탐색)

  • Kim, Jun-Seok;Lee, Won-Hee;Kim, Sungae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.27-31
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    • 2019
  • Various safety accidents occur frequently at construction sites due to poor operation of construction machines and insufficient safety facilities. Among them, safety accidents on the Tawerkrain have resulted in massive casualties and property damage. Therefore, the purpose of this study is to develop safety devices to prevent safety accidents in the Tower Crane. To this end, the existing safety device was explored and the model of the Tower Crane was constructed using Arduino. The weight of the object, the weight of the pendulum, and the distance from the center axis, as well as the equation of turning and experimentation, suggested mobile weights as a safety device to identify and resolve problems with existing safety devices. This is expected to minimize the limit on the salvage distance of the tower crane, thus providing a safer working environment away from the risk of a safety accident.

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A Study on the Control System of Dynamic Vibration Absorber for Ship Superstructure (선박용 동흡진기 시스템에 관한 연구 - 중력진자식 및 원심진자식 동흡진기에 대한 -)

  • S.S. Kim;S.Y. Han;J.K. Eom;M.H. Hyun;J.H. Kim;M.H. Kim;D.K. Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.3
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    • pp.1-18
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    • 1995
  • This paper deals with the vibration absorbers of gravitational and centrifugal pendulum types for vibration controls of ship's substructures such as radarmasts, bridgewings and funnels. The mathematical model of such a vibrating system with an absorber is described as a 2 degree of freedom system and an efficient formulation for optimum design of the absorber is presented. For investigation applicability of the two types of the absorbers to a structure system, numerical calculations and experiments hove been performed with variation of mass ratios for each type. According to the results of investigations, the vibration absorber of gravitational type proved to be more useful and efficient than one of centrifugal pendulum type in a view point of mass ratio.

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Neuro-Fuzzy Modeling Approach for Hybrid Base Isolaton System (하이브리드 면진장치의 뉴로-퍼지 모형화)

  • Kim Hyun-Su;Roschke P. N.;Lee Dong-Guen
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.201-208
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    • 2005
  • Neuro-Fuzzy modeling approach is proposed to predict the dynamic behavior of a single-degree-of-freedom structure that is equipped with hybrid base isolation system. Hybrid base isolation system consists of friction pendulum systems (FPS) and a magnetorheological (MR) damper. Fuzzy model of the M damper is trained by ANFIS using various displacement, velocity, and voltage combinations that are obtained from a series of performance tests. Modelling of the FPS is carried out with a nonlinear analytical equation that is derived in this study and neuro-fuzzy training. Fuzzy logic controller is employed to control the command voltage that is sent to MR damper. The dynamic responses or experimental structure subjected to various earthquake excitations are compared with numerically simulated results using neuro-fuzzy modeling method. Numerical simulation using neuro-fuzzy models of the MR damper and FPS predict response of the hybrid base isolation system very well.

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On-line Detection of Cracks in Eggshell (계란 크랙의 온라인 검출)

  • 최완규;조한근;백진하;장영창;연광석;조성찬
    • Journal of Biosystems Engineering
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    • v.24 no.3
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    • pp.253-258
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    • 1999
  • This study was conducted to develop an automatic egg inspection system for detecting creaked eggs based on acoustic impulse response. This system includes a sound generator, a sound sensor with signal conditioner, and a computer. The sound generator that hit the sharp of the dull edges of an egg was constructed with a ceramic ball pendulum attached to a rotary type solenoid. The signal conditioner included a pre-amplifier and a digital signal processing (DSP) board. The parameters for distinguishing cracked and normal eggs were the area, the geometric centroid and the resonance frequency of power spectrum of the acoustic signal generated. An algorithm for on-line detection of the continuous transferring eggs was developed. The performance tests resulted with 91% success rate to separate cracked and normal eggs at the rate of 1 second per an egg.

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Response Control of Structure by Frictional Base Isolation System : Rigid-Mass Model (마찰지진격리장치와 구조물의 응답제어: 강체질량모델에서의 적용)

  • 김재관;이원주;김영중;김병현
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.426-431
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    • 2001
  • Seismic performance of base isolated rigid-mass model were studied through shaking table tests. Friction pendulum systems (FPS), pure-friction systems with laminated rubber bearing (LRB) were selected for the comparison of performance. Performance of specially designed isolation systems were tested statically using actuator and dynamically using shaking table. Numerical methods were developed to simulate the nonlinear behavior of the frictional base isolation systems. Two models were considered. one is modified Bouc-Wen model considering breakaway coefficient of friction and the other is classical Coulomb model. The results of numerical methods are found to be in very good agreement with test results.

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Position Control of Arago's Pendulum System by using Kalman Filter (칼만필터를 이용한 아라고 진자 시스템의 위치제어)

  • Park, Tae-Dong;Youn, Su-Jin;Park, Ki-Heon
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1765-1766
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    • 2008
  • 본 논문에서는, 전동기를 이용하는 위치제어 시스템을 이용하여, 이너루프 제어기 유무에 따라 시간 응답 특성 개선 효과에 대하여 실험을 통해 검증하고자 한다. 실험 플랜트로서, 전동기의 속도에 따라 진자의 위치를 제어하는 다중 안정도를 가지고 비선형 시스템인 아라고 진자 시스템을 이용한다. 이 시스템은 속도 정보를 알 수 있는 측정 장치가 없는데, 칼만필터로 전동기의 속도를 추정하고 속도 제어기를 설계하도록 한다. 또한, 선형 시스템을 고려하기 위하여 안정영역 동작점인 진자의 각도가 지면으로 부터 45$^{\circ}$인 선형화 모델을 이용한다.

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Modelling of IMU Error with Setteing Misalignment in Laboratory Test (실험실 시험 장착오차를 고려한 관성측정장치 오차 모델링)

  • Seong, Sang-Man;Lee, Dal-Ho;Lee, Jang-Gyu
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.4
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    • pp.428-433
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    • 1999
  • The errors of IMU(Inertial Measurement Unit) can be divided into deterministic and random errors. Since the required accuracy of the IMU is very high, the errors must be compensated by using an accurate error mode. In this paper, we present a method to get a more accurate error model in a laboratory test. This was done by considering the setting misalignment in the laboratory test in the IMU error model. We considered here the IMU which consits of DTG(dynamically tuned gyroscope) and pendulum type accelerometer. First, it was shown that the estimation result from the model which does not contain the setting misalignment gives considerable estimation error at the validation test. Second, a new model considering the setting misalignment was derived. Finally, by validation test using the estimation results from new model the validity of it was proved.

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A Study on Base Isolation Performance and Phenomenological Model of E-Shape Steel Hysteretic Damper (E-Shape 강재이력댐퍼의 수치모델과 기초격리구조물의 지진응답)

  • Hwang, Inho;Ju, Minkwan;Sim, Jongsung;Lee, Jong Seh
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5A
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    • pp.685-690
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    • 2008
  • Recently, as large structures become lighter and more flexible, the necessity of structural control for reducing excessive displacement and acceleration due to seismic excitation is increased. As a means to minimize seismic damages, various base isolation systems are adopted or considered for adoption. In this study, a base isolation system using hysteretic damper is shown to effectively protect structures against earthquakes. A mechanical model is determined that can effectively portray the behavior of a typical E-shape device. Comparison with experimental results for a hysteretic damper indicates that the model is accurate over a wide range of operating conditions and adequate for analysis. The seismic performance of hysteretic dampers are studied and compared with the conventional systems as a base isolation system. A five-story building is modeled and the seismic performance of the systems subjected to three different earthquake is compared. The results show that the hysteretic damper system can provide superior protection than the other systems for a wide range of ground motions.