• Title/Summary/Keyword: measurement systems

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Stability Evaluation of In-Line Measurement System with Repeated Measurements (반복 측정이 가능한 인라인 측정시스템의 안정성 평가)

  • Joung, Sooho;Byun, Jai-Hyun
    • Journal of Korean Institute of Industrial Engineers
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    • v.30 no.1
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    • pp.36-43
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    • 2004
  • In-line measurement systems are preferred to those in analytical laboratories, since in-line systems provide rapid response to process upsets. If an in-line measurement system exhibits an unstable variation and if this instability in measurement variation goes undetected, it will make the process monitoring procedure invalid. This paper presents a stability evaluation procedure for the in-line measurement system using two independent readings from the in-line measurement system and one reading from the analytical laboratory, which requires less measurement cost and time.

Accuracy Improvement of Digital Measurement System by Modified Piecewise Measuring Functions (개선 구산 계측함수에 의한 디지털 계측시스템의 정밀도 향상)

  • Hong, Sung-Hun;Kang, Moon-Sung
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.2
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    • pp.138-145
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    • 2001
  • Measurement errors in a digital measurement systems are mainly due to the consisting elements accuracies and the circuit parameters changes following the environment variations such as temperature. Further, systems non-linearity makes the measurement accuracy worse, and accordingly a linearization method should be considered to avoid this worsening. In this study, a temperature error-correction method and linearization methods are proposed and a digital temperature measurement system utilizing these methods is realized. And the proposed measurement methods are observed to increase the measurement accuracy of the digital measurement system.

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A Case Study on the Compatibility Analysis of Measurement Systems in Automobile Body Assembly

  • Lee, Myung-Duk;Lim, Ik-Sung;Sung, Chun-Ja
    • International Journal of Reliability and Applications
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    • v.9 no.1
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    • pp.7-15
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    • 2008
  • The dimensional measurement equipment, such as Coordinate Measurement Machine (CMM), Optical Coordinate Measurement Machine (OCMM), and Checking Fixture (CF), take multiple dimensional measurements for each part in an automobile industry. Measurements are also recorded under different measurement systems to see if the responses differ significantly over these systems. Each measurement system (CMM, OCMM, and CF) will be considered as different treatments. This set-up provides massive amounts of process data which are multivariate in nature. Therefore, the multivariate statistical analysis is required to analyze data that are dependent on each other. This research provides step by step methodology for the evaluation procedure of the compatibility of measurement systems and clarify a systematic analyzation among the different measurement system's compatibility followed by number of case studies for each methodologies provided.

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Parameter Measurement of Induction Motors

  • Kim Kyung-Seo;Byun Sung-Hoon;Na Seung-Ho;Cho Byung-Guk;Kwon Bong-Hyun
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.751-755
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    • 2001
  • This paper presents the parameter measurement methods for high performance drive of induction motors. The proposed methods are selected by considering the factors that affect accuracy of measurement. Each method are refined to be adequate for measurement of each motor parameters. Proposed methods are easy to implement and only require inverter-motor system, which are important for practical application.

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The evaluation of measurement system for high power tests (대전력시험에 사용되는 측정시스템의 평가)

  • Lee, Dong-Jun;Jung, Heung-So;Kim, Won-Man;Kim, Sun-Koo;Ra, Dae-Ryeol;Kim, Chul-Hwan
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.286-288
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    • 2002
  • The rapid development of measurement systems for high power tests makes it possible to measure signals as well as analyze with the help of computer. Also, methods to evaluate such measurement systems are required recently. Uncertainty has been regarding as the most important factor in evaluating the measurement systems. Because of the character of the measurement systems for high power tests. the uncertainty shall be evaluated by each component. If the uncertainty evaluated by each component, it is convenient to evaluate total uncertainty of the measurement systems according to each component setting's combination. In this paper each component of high current measurement system of high power testing Dept. II in Korea Electrotechnology Research Institute is evaluated except sensors such as shunts and CTs. The total uncertainty of the measurement systems can be determined by that of each component including uncertainty of sensors.

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Auto-measurement of object by using image processor (영상처리기를 이용한 대상물체의 자동계측)

  • 백남칠;김영일;정영기;최호현
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.484-487
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    • 1987
  • In order to measure object larger than the optical field-of-view most video measurement systems utilize some sort of precision staging mechanism, and to utilize such a staging systems, Auto-Measurement System implemented in this paper has a precision of its own which affect the overall repeatability of the measuring instrument.

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Design and Analysis of a State Feedback Controller for a Chain of Integrators System under Measurement Noise (측정에러가 있는 적분기 시스템에서의 상태 궤환 제어기 설계 및 분석)

  • Youn, Jae-Seung;Choi, Ho-Lim
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.10
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    • pp.969-974
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    • 2010
  • In this paper, we propose a fault-tolerant controller for compensating measurement noise of feedback sensor. Because control systems operate via feedback sensor's signal, the measurement noise in sensor's signal results in performance degradation or even system failure. Therefore, control systems often demand on compensating measurement noise. Our controller is equipped with a compensator in order to reject or reduce the effect of measurement noise in feedback information. Our proposed method is verified via simulation and experiment for a Ball and Beam system.

Case Study on the Compatibility of Measurement Systems with Part-to-part Variations in Automobile Industry

  • Lee, Myung-Duk;Lim, Ik-Sung;Sung, Chun-Ja
    • International Journal of Reliability and Applications
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    • v.9 no.1
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    • pp.17-30
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    • 2008
  • Analysis of measurement systems is important to determine if the measurement process is adequate to measure the part-to-part variability in the process. Control chart techniques provide an effective, and easy-to-use method for performing this analysis. However, application with the real data for the evaluation procedure for multiple measurement systems have not been demonstrated. This research will provide a methodology for the evaluation of part-to-part variation and variation of different measurement systems step by step followed by number of case studies for each methodologies provided.

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Numerical Stability Improvement Technique for Indirect Feedback Kalman Filter in Delayed-Measurement Systems (시간지연을 고려한 간접 되먹임 구조 칼만필터의 수치안정성 향상 기법)

  • Nam, Seongho;Sung, Changky;Kim, Taewon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.1
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    • pp.25-32
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    • 2017
  • Most of weapon systems use aided navigation system which integrates inertial navigation and aiding sensors to compensate the INS errors increasing with the passage of time. Various aid sensors can be applied such as Global Navigation Satellite System (GNSS), radar, barometer, etc., but there might exist time delay caused by signal processing or transferring aid information. This time delay leads out-of-sequence measurements (OOSM) systems. Previously, optimal and suboptimal measurment update method for OOSM systems, where the time delay length are known, are proposed. However, previous algorithm does not guarantee the positive definite property of covariance matrix. In order to improve numerical stability for aided navigation using delayed-measurement, this paper proposes a new measurement covariance update algorithm be similar to Joseph-form in Kalman filter. Futhermore, we propose how to implement it in indirect feedback Kalman filter structure, which is commonly used in aided navigation systems, for time-delayed measurement systems. Simulation and vehicle test results show effectiveness of a proposed algorithm.

Measurement Accuracy of Oscillation-Based Test of Analog-to-Digital Converters

  • Mrak, Peter;Biasizzo, Anton;Novak, Franc
    • ETRI Journal
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    • v.32 no.1
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    • pp.154-156
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    • 2010
  • Oscillation-based testing of analog-to-digital converters represents a viable option for low-cost built-in self-testing in mixed-signal design. While numerous papers have addressed implementation issues, little attention has been paid to the measurement accuracy. In this letter, we highlight an inherent measurement uncertainty which has to be considered when deriving the parameters from the oscillation frequency.