• Title/Summary/Keyword: arc tracking

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Study on Development of High Speed Rotating Arc Sensor and Its Application (고속 회전 아크센서 개발 및 그 응용에 관한 연구)

  • Jeong, Sang-Kwun;Lee, Gun-You;Lee, Won-Ki;Kim, Sang-Bong
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.700-705
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    • 2001
  • The paper presents a seam tracking controller of high speed rotating arc sensor developed by microprocessor based system. The seam tracking algorithm is based on the average current value at each interval region of four phase points on one rotating cycle. To remove the noise effect for the measured current, the area during one rotating cycle is separated into four regions of front, rear, left and right. The average values at each region are calculated, using the regional current values and a low pass filter incorporating the moving average and exponential smoothing methods is adopted.

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Orbit Determination Using SLR Data for STSAT-2C: Short-arc Analysis

  • Kim, Young-Rok;Park, Eunseo;Kucharski, Daniel;Lim, Hyung-Chul
    • Journal of Astronomy and Space Sciences
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    • v.32 no.3
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    • pp.189-200
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    • 2015
  • In this study, we present the results of orbit determination (OD) using satellite laser ranging (SLR) data for the Science and Technology Satellite (STSAT)-2C by a short-arc analysis. For SLR data processing, the NASA/GSFC GEODYN II software with one year (2013/04 - 2014/04) of normal point observations is used. As there is only an extremely small quantity of SLR observations of STSAT-2C and they are sparsely distribution, the selection of the arc length and the estimation intervals for the atmospheric drag coefficients and the empirical acceleration parameters was made on an arc-to-arc basis. For orbit quality assessment, the post-fit residuals of each short-arc and orbit overlaps of arcs are investigated. The OD results show that the weighted root mean square post-fit residuals of short-arcs are less than 1 cm, and the average 1-day orbit overlaps are superior to 50/600/900 m for the radial/cross-track/along-track components. These results demonstrate that OD for STSAT-2C was successfully achieved with cm-level range precision. However its orbit quality did not reach the same level due to the availability of few and sparse measurement conditions. From a mission analysis viewpoint, obtaining the results of OD for STSAT-2C is significant for generating enhanced orbit predictions for more frequent tracking.

Separation Inverter Noise and Detection of DC Series Arc in PV System Based on Discrete Wavelet Transform and High Frequency Noise Component Analysis (DWT 및 고주파 노이즈 성분 분석을 이용한 PV 시스템 인버터 노이즈 구분 및 직렬 아크 검출)

  • Ahn, Jae-Beom;Jo, Hyun-Bin;Lee, Jin-Han;Cho, Chan-Gi;Lee, Ki-Duk;Lee, Jin;Lim, Seung-Beom;Ryo, Hong-Je
    • The Transactions of the Korean Institute of Power Electronics
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    • v.26 no.4
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    • pp.271-276
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    • 2021
  • Arc fault detector based on multilevel DWT with analysis of high-frequency noise components over 100 kHz is proposed in this study to improve the performance in detecting serial arcs and distinguishing them from inverter noise in PV systems. PV inverters generally operate at a frequency range of 20-50 kHz for switching operation and maximum power tracking control, and the effect of these frequency components on the signal for arc detection leads to negative arc detection. High-speed ADC and multilevel DWT are used in this study to analyze frequency components above 100 kHz. Such high frequency components are less influenced by inverter noise and utilized to detect as well as separate DC series arc from inverter noise. Arc detectors identify the input current of PV inverters using a Rogowski coil. The sensed signal is filtered, amplified, and used in 800kSPS ADC and DWT analysis and arc occurrence determination in DSP. An arc detection simulation facility in UL1699B was constructed and AFD tests the proposed detector were conducted to verify the performance of arc detection and performance of distinction of the negative arc. The satisfactory performance of the arc detector meets the standard of arc detection and extinguishing time of UL1699B with an arc detection time of approximately 0.11 seconds.

A Study on Adaptive Control to Fill Weld Groove by Using Multi-Torches in SAW (SAW 용접시 다중 토치를 이용한 용접부 적응제어에 관한 연구)

  • 문형순;정문영;배강열
    • Journal of Welding and Joining
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    • v.17 no.6
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    • pp.90-99
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    • 1999
  • Significant portion of the total manufacturing time for a pipe fabrication process is spent on the welding following primary machining and fit-up processes. To achieve a reliable weld bead appearance, automatic seam tracking and adaptive control to fill the groove are urgently needed. For the seam tracking in welding processes, the vision sensors have been successfully applied. However, the adaptive filling control of the multi-torches system for the appropriate welded area has not been implemented in the area of SAW(submerged arc welding) by now. The term adaptive control is often used to describe recent advances in welding process control by strictly this only applies to a system which is able to cope with dynamic changes in system performance. In welding applications, the term adaptive control may not imply the conventional control theory definition but may be used in the more descriptive sense to explain the need for the process to adapt to the changing welding conditions. This paper proposed various types of methodologies for obtaining a good bead appearance based on multi-torches welding system with the vision system in SAW. The methodologies for adaptive filling control used welding current/voltage, arc voltage/welding current/wire feed speed combination and welding speed by using vision sensor. It was shown that the algorithm for welding current/voltage combination and welding speed revealed sound weld bead appearance compared with that of voltage/current combination.

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