• Title/Summary/Keyword: Gauge error

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Development of Displacement Measuring Sensor for Roll Eccentricity Contro1 at Hot Strip Mill (롤 편심제어를 위한 편심 측정장치 개발)

  • 전종학
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.167-167
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    • 2000
  • This study aims at the development of REC sensor causing the gauge error in the hot strip rolling process, and the improvement of the hydraulic AGC (Automatic Gauge Control) system. The gauge error outbreaks from the various reasons, however, mainly the roll eccentricity is considered to cause a such kind of error. In the study, the REC (Roll Eccentricity Control System) sensor is designed using sensor An On - line test of the system shows the comprehensive effects of controlling the gauge error of the hot strip. On - Line test shows the possibility of enhancing the accuracy for gauge.

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Research of Determining the Compressed Gauge Limit Compensating for Guage Error (계측기오차 보상을 위한 압축한계 설정에 관한 연구)

  • Lee, Jong-Seong;Ko, Sung-Ho
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.89-93
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    • 2002
  • When testing products before shipment to the customer, quality characteristics are measured to decide whether or not their values are between the specification limits. Unfortunately, this testing procedure can lead to incorrect decisions because of gauge error. That is, good products can erroneously be qualified as bad, and bad products as good, and this has consequences for producer's and consumer's risk. In cases of such as this, the compressed gauge limit can be used to achieve the desired product quality level dictated by the manufacturer or the customer. A compressed gauge limit is a limit set by the manufacturer on a test gauge that is tighter than the specification limit established by the customer. The compressed gauge limits should be set at levels to achieve the defect levels desired by the customer and simultaneously minimize the loss of good product that is rejected due to errors in the gauges. In this article, the models for determining the defect levels and the losses obtained by adding compressed gauge limits will be developed. A response surface model approach is utilized which allows an optimal operating condition to be generated relatively easily.

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A Study on Confidence Evaluation of the Observed Data According to the Rain Gauges Installation Conditions (우량계 설치조건에 따른 관측치 신뢰성 평가 연구)

  • Park, Ji-Chang;Kim, Nam;Kang, Myeong-Ju;Ryoo, Kyong-Sik
    • Journal of Environmental Science International
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    • v.18 no.10
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    • pp.1115-1121
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    • 2009
  • The purpose of this study is to estimate the impact of rainfall measurement according to the installation conditions of rain gauges: windbreak, grass mat, installation elevation or obstacle. Rain gauges were installed by the standards of Korea Meteorological Administration(KMA), and the rainfall measurement was conducted daily unit during two years(2007~2008). In conclusion, observed error of rain gauge did not affect whether windbreak was installed or not. If there is the obstacle around rain gauge, average error rate was increased about 3.3%: (2007year-2.49%, 2008year-4.10%). If rain gauge is located in a high place, average error rate was increased about 4.89%. Additionally, the observed error of rain gauge according to the wind speed has a positive correlation with obstacle and installation elevation and has a negative correlation with windbreak and has no affection with grass mat.

High Accurate Creep Compensation of the Loadcell using the Strain Gauge (스트레인 게이지식 로드셀의 고정밀 크립보상)

  • Seo, Hae-Jun;Jung, Haing-Sup;Ryu, Gi-Ju;Cho, Tae-Won
    • Journal of IKEEE
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    • v.16 no.1
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    • pp.34-44
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    • 2012
  • This paper proposes a practical compensation method by using digital signal processing over the creep error which is representative in strain gauge loadcell. The signal compensation method carry out the simulation by deciding compensation constant (time constant) and coefficient measuring the loadcell output response. Then, compensation constant and coefficient are stored on the microprocessor. By using calculated on microprocessor creep error compensation values, weighting value is showed as a digital signal by reducing error values measured through output signals of loadcell. In addition, we apply error compensation method in order to have a dedicated software for loadcell electronic scale. This technique is useful because it has great influence on error rate reduction that has been produced by conventional electronic scales (0.03%). As a result our technique gives better accuracy (0.01%~0.003%) as what is given by digital electronic scale, while it has less complex operation processing.

Computer integrated simulation of geometric features in 3 axis coordinate measuring machines

  • Pahk, Heui-Jae;Burdekin, M.;Peggs, G.
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1991.10a
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    • pp.379-401
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    • 1991
  • A comprehensive computer software has been implemented in conjunction with the software for volumetric error generator, to assess simulation on specific measurement tasks. The simulation algorithms have been developed for major measurement tasks, such as step gauge, ring gauge, sphere gauge, and cylinder gauge simulations etc. Verification and practical applications of the developed module have shown its efficiency and validity.

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OPTIMAL ERROR ESTIMATE FOR SEMI-DISCRETE GAUGE-UZAWA METHOD FOR THE NAVIER-STOKES EQUATIONS

  • Pyo, Jae-Hong
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.4
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    • pp.627-644
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    • 2009
  • The gauge-Uzawa method which has been constructed in [11] is a projection type method to solve the evolution Navier-Stokes equations. The method overcomes many shortcomings of projection methods and displays superior numerical performance [11, 12, 15, 16]. However, we have obtained only suboptimal accuracy via the energy estimate in [11]. In this paper, we study semi-discrete gauge-Uzawa method to prove optimal accuracy via energy estimate. The main key in this proof is to construct the intermediate equation which is formed to gauge-Uzawa algorithm. We will estimate velocity errors via comparing with the intermediate equation and then evaluate pressure errors via subtracting gauge-Uzawa algorithm from Navier-Stokes equations.

Gauge Capability Analysis and Designed Experiments (계측기 능력분석과 실험계획법)

  • Baik, Jaiwook;Jo, Jinnam
    • Journal of Korean Society for Quality Management
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    • v.24 no.3
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    • pp.145-159
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    • 1996
  • In today's organization, measurement plays a crucial role in helping improve process or quality. In this paper, we review the measurement error study, classical gauge repeatability and reproducibility study, and designed experiment suited for the determination of the measurement capability. Measurement error study is very simple to use but is rather crude. Hence, it should be used as a preliminary study to determine whether further study is necessary. Classical gauge repeatability and reproducibility (GR&R) study is the most common technique for evaluation of gauge capability. It calculates a percentage that relates the repeatability, reproducibility, and overall R&R to the specification range for the parameter measured. Hence, the individual repeatability and reproducibility statistics will indicate the area on which to concentrate. However, GR&R study only gives a point estimate of each component, which leaves a room for improvement. It is always good to integrate the use of control charts to ascertain the statistical stability of the measurement process. The tools of statistical experimental design are available for a comprehensive design and analysis of the measurement process. Hence, in this paper, we present gauge capability analysis as an experimental design problem and compare it with the classical GR&R study.

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Error Calibration of Initial Value of Weight Measuring Sensors with Different Feature of Forklift (특성이 다른 지게차 적재 중량 센서의 초기 값 오차 보정)

  • Han, Chi-moon;Yim, Choon-Sik;Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.23 no.2
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    • pp.214-220
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    • 2019
  • The calibration method of the initial value error obtained in the weight measurement through anchor bolt type strain gauge sensor is proposed. The strain gauge sensor is developed for preventing the overturning of forklift, which is the most frequent type of safety-accident in industry. It was confirmed that the initial value error is caused from the physical and mechanical error of anchor bolt, and the environmental problem. Since the elimination of these causes falls outside the realm of this research, we find out the calibrated values based on all the causes, and we adjust the initial values of analog-to-digital convertor (ADC) module consisted of strain gauge sensor block using the calibrated values. We use the linear interpolation method for our calibration. We confirm that four sensor modules have the different under 5% between the real weight and the measured value in the experiment applied with the calibration of initial values. The low correlation between the real weights and ADC values is also improved through the proposed calibration.

Estimation Model for Optimum Probabilistic Rainfall Intensity on Hydrological Area - With Special Reference to Chonnam, Buk and Kyoungnam, Buk Area - (수문지역별 최적확률강우강도추정모형의 재정립 -영.호남 지역을 중심으로 -)

  • 엄병헌;박종화;한국헌
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.38 no.2
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    • pp.108-122
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    • 1996
  • This study was to introduced estimation model for optimum probabilistic rainfall intensity on hydrological area. Originally, probabilistic rainfall intensity formula have been characterized different coefficient of formula and model following watersheds. But recently in korea rainfall intensity formula does not use unionize applyment standard between administration and district. And mingle use planning formula with not assumption model. Following the number of year hydrological duration adjust areal index. But, with adjusting formula applyment was without systematic conduct. This study perceive the point as following : 1) Use method of excess probability of Iwai to calculate survey rainfall intensity value. 2) And, use method of least squares to calculate areal coefficient for a unit of 157 rain gauge station. And, use areal coefficient was introduced new probabilistic rainfall intensity formula for each rain gauge station. 3) And, use new probabilistic rainfall intensity formula to adjust a unit of fourteen duration-a unit of fifteen year probabilistic rainfall intensity. 4) The above survey value compared with adjustment value. And use three theory of error(absolute mean error, squares mean error, relative error ratio) to choice optimum probabilistic rainfall intensity formula for a unit of 157 rain gauge station.

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Measurement of Mass Flow of Water in the Stem of Musk Melon by Sap Flow Gauge (열목지 경유센서에 의한 멜론 경유양의 측정)

  • 강곡명;양원모
    • Journal of Bio-Environment Control
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    • v.7 no.3
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    • pp.268-274
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    • 1998
  • The mass flow of water in the stem of melon measured by Sap Flow Gauge was compared with the actual flow calculated by the difference between supply and drainage nutrient water to investigate the possibility and accuracy of estimation of melon's transpiration in rockwool culture. The Sap Flow Gauge which was made with copper-constantan theromocouple and nichrome fiber by our research team, was attached to the 3rd node of melon. The outdoor temperature, room temperature, solar radiation and relative humidity were continually measured. The amount of supply and drainage nutrient water were simultaneously measured for calculation of practical consumption of nutrient water to compare with mass flow of sap. The measuring errors of Sap Flow Gauge were 0.3 to 31.8%, which were small at solar radiation of 20MJ.m$^{2}$.d$^{-1}$ . The mass flow of water was lower for the measured value by Sap Flow Gauge than the actual value at higher solar intensity, however it was higher at lower solar intensity The variation of error rate of each Sap Flow Gauge was 0.1 to 13.0%. The measuring error with Sap Flow Gauge was negatively related with solar intensity and temperature. Therefore, to measure more exactly the mass flow of sap for estimation of melon's transpiration, the compensation factor must be calculated.

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