DFT 기반의 시스템 모델링을 이용한 DC Motor의 위치제어

안현진(Hyun-Jin Ahn),심관식(Kwan-Shik Shim),임영철(Young-Cheol Lim),남해곤(Hae-Kon Nam),김광헌(Gwang-Heon Kim),김의선(Eui-Sun Kim) 대한전기학회 2012 전기학회논문지 Vol.61 No.4

This study presents a new method of system modeling by using the Discrete Fourier Transform for the position control system of DC Motor. And the proposed method is similar to the method of System Identification by analysis of correlation of the measured input-output data. The measured output signals are transformed to the frequency domain using DFT. The Fourier Spectrum of the transformed signals is used for knowing to the feature of having an important effect on the system. And transfer function of the second order system is estimated by the dominant parameter which is computed in the magnitude and the phase of Fourier spectrum of the transformed signals. In addition, the output signal includes the unique feature of system. So, although the basic parameter of the system is unknown for us, the proposed method has an advantage to system modeling. And the controller is easily designed by the estimated transfer function. Thus, in this paper, the proposed method is applied to the system modeling for the position control system of DC Motor and the PD-controller is designed by the estimated model. And the efficiency and the reliability of the proposed method are verified by the experimental result.

Aeroelastic modeling to investigate the wind-induced response of a multi-span transmission lines system

Ziad Azzi,Amal Elawady,Peter Irwin,Arindam Gan Chowdhury,Caesar Abi Shdid 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.2

Transmission lines systems are important components of the electrical power infrastructure. However, these systems are vulnerable to damage from high wind events such as hurricanes. This study presents the results from a 1:50 scale aeroelastic model of a multi-span transmission lines system subjected to simulated hurricane winds. The transmission lines system considered in this study consists of three lattice towers, four spans of conductors and two end-frames. The aeroelastic tests were conducted at the NSF NHERI Wall of Wind Experimental Facility (WOW EF) at the Florida International University (FIU). A horizontal distortion scaling technique was used in order to fit the entire model on the WOW turntable. The system was tested at various wind speeds ranging from 35 m/s to 78 m/s (equivalent full-scale speeds) for varying wind directions. A system identification (SID) technique was used to evaluate experimental-based along-wind aerodynamic damping coefficients and compare with their theoretical counterparts. Comparisons were done for two aeroelastic models: (i) a self-supported lattice tower, and (ii) a multi-span transmission lines system. A buffeting analysis was conducted to estimate the response of the conductors and compare it to measured experimental values. The responses of the single lattice tower and the multi-span transmission lines system were compared. The coupling effects seem to drastically change the aerodynamic damping of the system, compared to the single lattice tower case. The estimation of the drag forces on the conductors are in good agreement with their experimental counterparts. The incorporation of the change in turbulence intensity along the height of the towers appears to better estimate the response of the transmission tower, in comparison with previous methods which assumed constant turbulence intensity. Dynamic amplification factors and gust effect factors were computed, and comparisons were made with code specific values. The resonance contribution is shown to reach a maximum of 18% and 30% of the peak response of the stand-alone tower and entire system, respectively.

제진을 위한 3 자유도 정밀 스테이지의 설계와 모델링

문준희(Jun Hee Moon),김화수(Hwa Soo Kim),박희재(Heui Jae Pahk) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.3

Active vibration isolation systems need the following performance specifications which are different from those of existing positioning systems: usage of seismic sensors, strict suppression of phase lead/lag in signal processing for sensors and actuators, excellent control in low frequency range and so on. In consideration of such specifications, a 3-DOF precision stage for vibration isolation is designed and modeled based on the physical characteristics. Then the major parameters such as spring constants and damping coefficients are valued by the system identification method using empirical transfer function. Finite element analysis is used as a verification and simulation tool throughout this research. This paper lays the foundation for the future research on the control of the active vibration isolation system.

Electronic Power Distribution Systems Dynamic Interactions in Hybrid AC/DC

I. Cvetkovic,D. Boroyevich,D. Dong,P.Mattavelli,R. Burgos,M. Jaksic,G. Francis,Z. Shen,S. Ahmed,F. Wang 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

Hybrid electronic power distribution systems have majority of loads interfaced to energy sources through power electronics converters. Furthermore, all alternative, sustainable, and distributed energy sources can only be connected to electric grid through power electronics equipment. However, one of the main challenges in designing and developing of these hybrid ac/dc systems has been modeling and analysis of dynamic interactions between converters at the synchronous and higher frequencies. In order to address these problems, this paper employs terminal-behavioral modeling of power converters as possible methodology for analysis, system-level design, stability, and subsystem interactions study. Some simulation and experimental results are both shown for model verification and validation purposes.

Health monitoring of a bridge system using strong motion data

Mosalam, K.M.,Arici, Y. Techno-Press 2009 Smart Structures and Systems, An International Jou Vol.5 No.4

In this paper, the acceptability of system identification results for health monitoring of instrumented bridges is addressed. This is conducted by comparing the confidence intervals of identified modal parameters for a bridge in California, namely Truckee I80/Truckee river bridge, with the change of these parameters caused by several damage scenarios. A challenge to the accuracy of the identified modal parameters involves consequences regarding the damage detection and health monitoring, as some of the identified modal information is essentially not useable for acquiring a reliable damage diagnosis of the bridge system. Use of strong motion data has limitations that should not be ignored. The results and conclusions underline these limitations while presenting the opportunities offered by system identification using strong motion data for better understanding and monitoring the health of bridge systems.

Health monitoring of a bridge system using strong motion data

K. M. Mosalam,Y. Arici 국제구조공학회 2009 Smart Structures and Systems, An International Jou Vol.5 No.4

In this paper, the acceptability of system identification results for health monitoring of instrumented bridges is addressed. This is conducted by comparing the confidence intervals of identified modal parameters for a bridge in California, namely Truckee I80/Truckee river bridge, with the change of these parameters caused by several damage scenarios. A challenge to the accuracy of the identified modal parameters involves consequences regarding the damage detection and health monitoring, as some of the identified modal information is essentially not useable for acquiring a reliable damage diagnosis of the bridge system. Use of strong motion data has limitations that should not be ignored. The results and conclusions underline these limitations while presenting the opportunities offered by system identification using strong motion data for better understanding and monitoring the health of bridge systems.

고속 광 픽업 장치의 강인 서보 제어

임승철,정태영 한국소음진동공학회 1998 소음 진동 Vol.8 No.3

Recently, optical disk drives are increasingly demanded to have higher speed as well as high information density, especially for applications like CD ROM drives. To this end, improvement of their optical pickup structure and control is recognized the very challenging issue. In this paper, the pickup is first analytically modelled in a plane to describe its coupled auto-focusing and auto-tracking motions. Subsequently, the model is linearized and combined with actuator dynamics for the auto-focusing system. With its unmeasurable parameters being estimated based on experimental data, an approximate I-DOF linear model is obtained neglecting the coupling term. To design the high speed and robust positional servo controller realistic design specifications are addressed, and H control method is employed based on the approximate model. Finally, taking the pickup in a commerical high speed CD ROM drive as an example performance of the designed controller is verified through realtime experiments.

고배속 CD-ROM 광 픽업 장치의 H_∞ 강인 서보 제어

임승철,정태영 명지대학교 대학원 1998 대학원논문집 Vol.2 No.-

Recently, optical disk drives are increasingly demanded to have higher speed as well as high information density, especially for applications like CD ROM drives. To this end, improvement of their optical pickup structure and control is recognized the very challenging issue. In this paper, the pickup is first analytically modelled in a plane to describe its coupled auto-focusing and auto-tracking motions. Subsequently, the model is linearized and combined with actuator dynamics for the auto-focusing system. With its unmeasurable parameters being estimated based on experimental data, an approximate 1-DOF linear model is obtained neglecting the coupling term. To design the high speed and robust positional servo controller realistic design specifications are addressed, and H_∞ control method is employed based on the approximate model. Finally, taking the pickup in a commercial high speed CD ROM drive as an example performance of the designed controller is verified through realtime experiments.

현가부품 내구하중 추출을 위한 가상 내구 시험 기법 연구

손성효(Seong-Hyo Son),강대오(Dae-Oh Kang),허승진(Seung-Jin Heo),김동석(Dong-Seok Kim),강오성(Oh-Sung Kang) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

To reduce vehicle development cycles it is necessary to perform numerical durability analysis in an early development phase. This paper presents an alternative method 'VTL : Virtual Testing Lab' to predict the required loads for fatigue analysis. In VTL using Multi-Body Simulation (MBS), the loads prediction process can be performed for an constrained or unconstrained vehicle under several different conditions. Various VTL methods and related technologies showing different results are introduced and evaluated in this paper.

차량용 슬라이딩 도어 시스템 식별에 관한 연구

송문형(MoonHyung Song),정우현(WooHyun Jung),한인석(InSuck Han),신동호(Dongho Shin) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

This paper presents a identification method of sliding door system for passenger car called by IRSD(Invisible Rail Sliding Door) system, which gets over the limitations of the existing sliding door system in design stage. To design a door speed controller, it is essential to identify IRSD system with high accuracy. Two identification methods (Model based modeling and Black Box modeling) have been studied to find a mathematical model together with optimal values of unknown parameters. The results from two different methods show high similarity and it is validated through the comparison with sensor output that IRSD system identification shows good performance.