• Title/Summary/Keyword: Experimental verification

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Sensorless Estimation of Single-Phase Hybrid SRM using Back-EMF

  • Tang, Ying;He, Yingjie;Lee, Dong-Hee;Ahn, Jin-Woo
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.198-206
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    • 2017
  • This paper presents a novel scheme to estimate the rotor position of a single-phase hybrid switched reluctance motor (HSRM). The back-EMF generated by the permanent magnet (PM) field whose performance is motor parameter independent is adopted as an index to achieve the sensorless control. The differential value of back-EMF is calculated by hardware and processed by DSP to capture a fixed rotor position four times for every mechanical cycle. In addition, to accomplish the normal starting of HSRM, the determination method of the turn-off time position at the first electrical cycle is also proposed. In this way, a sensorless operation scheme with adjustable turn on/off angle can be achieved without substantial computation. The experimental verification using a prototype drive system is provided to demonstrate the viability of the proposed position estimation scheme.

Development of High Efficiency Boost DC/DC Converter For EV

  • Song, Sung-Geon;Lee, Sang-Hun;Song, Hyun-Jig;Park, Seong-Mi
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.4
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    • pp.415-421
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    • 2014
  • In this paper, reactorless high efficiency boost DC/DC converter for EV is proposed. In proposed converter, improves efficiency because decrease power loss when the switches are turned on/off using zero current switching (ZCS) at all switch of primary full bridge. By replacing reactance ingredients of L-C resonance circuit for ZCS with leakage inductance ingredients of high frequency transformer, it reduces system size and expense because of not add special reactor. For validity verification of proposed converter, in the paper implements simulation using PSIM and perform experiment by making 5KW DC/DC converter. In experimental results, efficiency of proposed converter conformed superiority.

Distinct Element Modelling of Stacked Stone Pagoda for Seismic Response Analysis (지진응답 해석을 위한 적층식 석탑의 개별요소 모델링)

  • Kim, Byeong Hwa;Lee, Do Hyung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.6
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    • pp.345-352
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    • 2018
  • It is inevitable to use the distinct element method in the analysis of structural dynamics for stacked stone pagoda system. However, the experimental verification of analytical results produced by the discrete element method is not sufficient yet, and the theory of distinct element method is not universal in Korea. This study introduces how to model the stacked stone pagoda system using the distinct element method, and draws some considerations in the seismic analysis procedures. First, the rocking mode and sliding mode are locally mixed in the seismic responses. Second, the vertical stiffness and the horizontal stiffness on the friction surface have the greatest influence on the seismic behavior. Third, the complete seismic analysis of stacked stone pagoda system requires a set of the horizontal, vertical, and rotational velocity time histories of the ground. However, earthquake data monitored in Korea are limited to acceleration and velocity signals in some areas.

Sensorless driving strategy of Single-Phase Hybrid SRM basing on Back-EMF detection (역기전력을 이용한 단상 하이브리드 SRM의 위치 추정 방법)

  • Tang, Ying;Lee, Donghee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.521-522
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    • 2016
  • This paper presents a novel scheme to estimate the rotor position of a single-phase hybrid switched reluctance motor (HSRM). The proposed method uses the differential of back-EMF within a position region to estimate rotor position. By detecting the crossing-zero signal of back-EMF differential value, the minimum position of back-EMF corresponding to an absolute rotor position can be captured and used for position estimation four times in every mechanical rotation. In this way, a sensorless operation with adjustable turn on/off angle can be achieved without substantial computation. For the starting, two current comparators are adopted. The experimental verification using a prototype drive system is provided to demonstrate the viability of the proposed sensorless scheme.

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Attitude Estimation of a Foot for Biped Robots Using Multiple Sensors (다중 센서 융합을 통한 이족 보행 로봇 발의 자세 추정)

  • Ryu, Je-Hun;You, Bun-Jae;Park, Min-Yong;Kim, Do-Yoon;Choi, Young-Jin;Oh, Sang-Rok
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.586-588
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    • 2004
  • Although stable control algorithm has been implemented to the biped robot, the stability is not guaranteed because of encoder errors and/or rigid body elastics. Hence precise body pose estimation is required for more natural and long term walk. Specially pelvis sloping by gravity or uneven ground on landing place are most critical reason for undulated motion. In order to overcome these difficulties an estimation system for foot position and orientation using PSD sensors and Gyro sensors is proposed along with calibration algorithm and experimental verification.

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Effects of Tensile Reinforcement of Steel Fibers in SFRC (강섬유보강콘크리트내 강섬유의 인장보강효과)

  • 김규선;이차돈;박제선;심종성;최기봉
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.10a
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    • pp.76-81
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    • 1992
  • Short, randomly disturbed steel fibers in concrete increase tensile strength and ductility of concrete under direct tension. These improvements are results form crack arrest mechanisms of steel fibers in concrete. These mechanisms are theoretically considered in this study and verification on the adequancy of different spacing for predicting tensile strength of SFRC are assessed. Results indicate that better correlation exists between experimental result and the spacing concept which take into account the effect of boundaries as well as vibration on reorientation of steel fibers inside concrete. Also considered is the modeling of stress-crack opening relationships in post-peak region of SFRC under tension which bass its deviation on micromechanics of fiber pull-out. Satisfactoring results are observed between tests results and the prediction of the model.

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Experimental Study on Secondary Moment of High-Strength RC Slender Columns under Eccentric Loads (편심을 받는 고강도콘크리트 장주의 2차모멘트에 관한 실험적 연구)

  • 박동규;배성용;이재훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.571-576
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    • 1998
  • This paper is a part of a research plan aimed at the verification of basic design rules of high-strength concrete columns. A total of 19 slender column specimens were tested to measure secondary moment and stiffness of eccentrically loaded reinforced concrete tied columns. Main variables included in this test program were concrete compressive strength, steel amount, eccentricity, and slenderness ratio. The concrete compressive strength varied from 356kg/$\textrm{cm}^2$ to 951kg/$\textrm{cm}^2$, the longitudinal steel ratios were between 1.13% and 5.51%, and slenderness ratios were 40 and 61. Calculated moment magnification factors and column stiffness based on design codes are higher than the test results for high axial load under small eccentricity, for higher slenderness ratio, for lower longitudinal steel ratio, and for high-strength concrete. The moment magnification method of the current design codes may provide a very conservative design for high-strength concrete slender column.

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Real Time Multiple Vehicle Detection Using Neural Network with Local Orientation Coding and PCA

  • Kang, Jeong-Gwan;Oh, Se-Young
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.636-639
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    • 2003
  • In this paper, we present a robust method for detecting other vehicles from n forward-looking CCD camera in a moving vehicle. This system uses edge and shape information to detect other vehicles. The algorithm consists of three steps: lane detection, ehicle candidate generation, and vehicle verification. First after detecting a lane from the template matching method, we divide the road into three parts: left lane, front lane, and right lane. Second, we set the region of interest (ROI) using the lane position information and extract a vehicle candidate from the ROI. Third, we use local orientation coding (LOC) edge image of the vehicle candidate as input to a pretrained neural network for vehicle recognition. Experimental results from highway scenes show the robustness and effectiveness of this method.

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Finite Element Modeling and Experimental Verification of the Structures with Bolted Joints (볼트결합부가 있는 구조물의 유한요소 모델링 및 실험적 검증)

  • Kim, Jin-Gon;Park, Seong-Su;Choe, Seok-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.6
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    • pp.1854-1861
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    • 1996
  • A reliable and practical finite element modeling technique to estimate the behavior of complex structures with bolted joints is important for engineeres in the industry. Accordingly, we have examined several simplified modeling techinques which do not require the use of special elements such as a gap eloement. The dynamic and static erxperiments have confirmed that the technique to model the bolted joints with eight-noded three dimensional elemnts which fill the bolt space gdives most satisfactory results.

Spectral Resolution Enhancement of Acousto-Optic Tunable Filter(AOTF) using Incident Angle Variation (음향광학변조필터의 입사각 변화를 이용한 분해능 향상 방법)

  • You, Jang-Woo;Ahn, Jeong-Ho;Kim, Dae-suk;Kwak, Yoon-Keun;Kim, Soo-Hyun;Lee, Yun-Woo;Whang, In-Duk
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.607-612
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    • 2004
  • Spectral resolution enhancement method of Acousto-Optic Tunable Filter (AOTF) using incident light angle variation is described. AOTF is a small, mechanically rigid, high speed and spectral resolution light tunable filter. The basic theory of AOTF and its experimental verification is described. AOTF can generate two opposite polarized light simultaneously which wavelength can be changed by incident angle variation. We focused on the common region of two filtered light at the specific incident angle. This region can be used to enhance the spectral resolution of AOTF.

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