• Title/Summary/Keyword: Inclination error

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A Study on the Automatic Level Measurement for Land Leveling (경지 균평 작업을 위한 자동 표고 측정에 관한 연구)

  • 김종안;김수현;곽윤근
    • Journal of Biosystems Engineering
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    • v.22 no.3
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    • pp.269-278
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    • 1997
  • An automatic level measurement system was developed to level the land fer direct seeding of rice. A laser transmitter/receiver set was used to measure land-level. The inclination error occurred in level measurement on irregular land surface could be compensated by attaching rotating mass. The level measuring experiments were performed on three kinds of different shapes(step, random, sine). This system could accurately measure step level of which amplitude was 40mm in 0.5s, random level change within $\pm$ 5mm maximum measurement error, and sine level change of which spatial frequency was 0.5m-1. To verify performance of the inclination error compensation system, frequency transfer function(acceleration input vs. inclination error) was computed by spectral analysis. The inclination error was decreased about 20㏈ by error compensation system.

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A Study on the Size Evaluation of Circular Flat Flaw with Indication by Straight Beam Inspection of Ultrasonic Wave (초음파(超音波)의 수직탐상법(垂直探傷法)에 의한 경사(傾斜)를 갖는 원형평면결함(圓形平面缺陷)의 크기 평가(評價)에 관한 연구(硏究))

  • Han, Eung-Kyo;Kim, Ki-Joong;Lee, Kook-Hwan
    • Journal of the Korean Society for Nondestructive Testing
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    • v.4 no.1
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    • pp.11-22
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    • 1984
  • In the straight beam inspection of ultrasonic wave, the method for evaluating flaw size by AVG diagram is useful as a method for the quantitative evaluation of results of ultrasonic flaw detection. This study was carried out the measure the size of circular flat flaw with the inclination by straight beam inspection and could be decreased the error of application due to the inclination of flaw by AVG diagram in consideration of correction coefficient. From the result of the experiment, the error by means of the application of experimental values to AVG diagram was increased as the inclination angle grows. Also, it n s increased the error of application as the detecting frequency and diameter of flaw grows in the same inclination angle. In case of diameter of flaw 6mm, AVG diagram could be applied to the inclination angle $3^{\circ}$ for 5 MHz, $7^{\circ}$ for 2.25 MHz, $15^{\circ}C$ for 1 MHz in the range of 20% error and the theory was concided with the experiment to $5^{\circ}C$ for 5 MHz, $10^{\circ}C$ for 2.25 MHz, $15^{\circ}C$ for 1 MHz in the range of 10% error by correction eq. (45) due to the inclination angle. Therefore, it is considered that the results obtained from this study will be somewhat helpful informations for the size evaluation of circular flat flaw with the inclination.

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Inclination and Non-horizontal Error Correction of Magnetic Compass by the Law of Gravity (중력 법칙을 이용한 전자나침반의 경사오차 및 비 수평오차 보정)

  • Park, Gye-Do;Lee, Jang-Myung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.3
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    • pp.606-611
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    • 2011
  • This paper proposes a correction method concerning the inclination error and non-horizontal error of magnetic compass when magnetic compass is vibrated. This system used the 2-axis variable resistance and pendulum. A pendulum hanging from the 2-axis variable resistance of this system is always maintain the horizontal because of gravity. but these data had some intrinsic error. So we used the low pass filter to solve this problem. So this system can get the accurate azimuth of magnetic compass. In conclusion, These results demonstrate convincingly by applied algorithm of experiment.

Characteristics of Roughness of Inclined Surface Fabricated by Various Rapid Prototyping Processes (여러 가지 쾌속조형 방식의 경사면 거칠기 특성)

  • Kim, Gi-Dae
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.5
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    • pp.48-54
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    • 2007
  • Surface of rapid prototype has inevitably stair-stepping error, which is attributed to the continuous building process of 2 dimensional area. In this study, rounded edge model was established to estimate the roughness of inclined surface which has stair-stepping error. To investigate the roughness of rapid prototypes, specimens that have various surface inclinations were manufactured by various types of RP machines. As the surface inclination increased, the roughness of the specimens manufactured by SL, FDM, or LOM process decreased, which coincides with the simulation results. However, surface roughness of 3DP specimen was almost independent of the inclination. Furthermore, as the angle of surface increased, roughness of poly-jet specimen also increased, which is attributed to the frictional behavior between writing head and scanned area.

Design & Analysis of an Error-reduced Precision Optical Triangulation Probes (오차 최소화된 정밀 광삼각법 프로브의 해석 및 설계)

  • Kim, Kyung-Chan;Oh, Se-Baek;Kim, Jong-Ahn;Kim, Soo-Hyun;Kwak, Yoon-Keun
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.411-414
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    • 2000
  • Optical Triangulation Probes (OTPs) are widely used for their simple structure. high resolution, and long operating range. However, errors originating from speckle, inclination of the object, source power fluctuation, ambient light, and noise of the detector limit their usability. In this paper, we propose new design criteria for an error-reduced OTP. The light source module for the system consists of an incoherent light source and a multimode optical fiber for eliminating speckle and shaping a Gaussian beam Intensity profile. A diffuse-reflective white copy paper, which is attached to the object, makes the light intensity distribution on the change-coupled device(CCD). Since the peak positions of the intensity distribution are not related to the various error sources, a sub-pixel resolution signal processing algorithm that can detect the peak position makes it possible to construct an error-reduced OTP system

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Development of accuracy for the statical inclinometer by error analysis (다축 수준기의 오차분석을 통한 측정 정밀도 향상)

  • Lee J.K.;Park J.J.;Cho N.G.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1797-1802
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    • 2005
  • In this study, we were developed an accuracy of the proposed two dimensional statical inclinometer what used a position sensitive detector(PSD) by an error analysis. The inclinometer consists of a laser source, a mass, an optic-fiber, and a PSD. The gravity direction on a base platform of the inclinometer is changed by an unknown inclination angle. And a laser spot is moved from the origin to another position of a PSD following a variation of an optical path by the gravity. These processes enable the inclinometer to estimate the inclination angle from distance information of the moving spot. A design methodology on the basis of a sensitivity analysis was applied to improve the measurement performance such as a full measuring range and a resolution. But it still has error factors, so we analyze the uncertainty of the inclinometer to evaluate the systematic errors from alignments, assembly error and so on. The experimental performance evaluation about the design objectives as a measuring range and a resolution was performed. And the validity and the feasibility of the design process were certified by an experimental process. Systematic errors eliminated to improve the accuracy of the inclinometer by the corrected measuring model from the calibration process between the inclination angle and the PSD position instead of the nominal measuring model. The ANOVA(analysis of variance) confirmed the effect of eliminating the systematic errors in the inclinometer. From these methodologies, the proposed inclinometer was able to measure with a high resolution(35.14sec) and a wide range(from $-15^{\circ}\;to\;15^{\circ}$

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Improvement of the Tapering Error in the Centerless Through-feed Ground Parts Using a Work-rest Blade (공작물 받침대를 이용한 무심관통이송 공작물의 테이퍼링 오차 개선)

  • Kim, Kang
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.7
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    • pp.70-77
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    • 2003
  • The centerless through-feed grinding is performed by passing the workpiece between the grinding wheel and the regulating wheel. So, the amount of removed material around the leading end, of the workpiece is always more than that around the trailing end until the leading end leaves the grinding wheel. Because of this, there are differences in diameters along the workpiece axis during grinding, and workpiece axis is not parallel to the grinding wheel axis and the contact lines between the workpiece and wheels. Thus the ground workpiece shows tapering error inherently. To eliminate this error, the workpiece axis must be kept to be parallel to the grinding wheel axis. And, the direction of the workpiece axis can be controlled by the work-rest blade. Therefore, the effects of work-rest blade inclination angle on the through-feed centerless ground part are investigated in this study. As a result, it is found that there is a positive inclination angle of the work-rest blade for minimizing the tapering error of a ground workpiece.

Tool Deflection and Geometric Accuracy to the Change of Inclination Position Angle during Machining Sculptured Surface (곡면가공시 경사위치각 변화에 따른 공구변형과 형상정밀도)

  • 왕덕현;박희철
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.4
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    • pp.55-64
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    • 2001
  • In this study, hemisphere and cylindrical shapes were machined for different tool paths and machining conditions with ball endmill cutters. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting is obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. Roundness values were found in least roundness error when down-milling in upward cutting. It is obtained the very little difference between 90。and 45。 of inclination position angle. The best surface roughness value was obtained in upward up-milling and showed different tendency with tool deflection and cutting force. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. Therefore, this phenomenon which is received over cutting resistance can be caused of chatter.

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Implementation and Design of Inertial Sensor using the estimation of error coefficient method for sensing rotation

  • Lee, Cheol
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.95-101
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    • 2020
  • We studied the Implementation and design of inertial sensor that enables to improve performance by reduce the noise of rotor which Angle of inclination. Analyze model equation including motion equation and error, signal processing filter algorithm on high frequency bandwidth with eliminates error using estimation of error coefficient method is was designed and the prototype inertial sensor showed the pick off noise up to 0.2 mV and bias error performance of about 0.06 deg/hr by the experiments. Accordingly, we confirmed that the design of inertial sensor was valid for high rotation.

A Study on magnetic sensor calibration for indoor smartphone position tracking (스마트폰 실내 위치 추적을 위한 지자기 센서 보정에 관한 연구)

  • Lee, Dongwook;Oh, Jongtaek
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.6
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    • pp.229-235
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    • 2018
  • Research on indoor location tracking technology using smart phone is actively being carried out. Especially, in order to display the movement path of the smartphone on the map, the azimuth angle should be estimated by using the geomagnetic sensor built in most smart phones. Due to the distortion of the magnetic field due to the surrounding steel structure and the inclination of the smartphone, the estimation error of azimuthal angle may be occurred. In this paper, we propose a correction method of the geomagnetic sensor at the stationary state and a correction method for the inclination of the smartphone. We also propose a method to correct the azimuth error due to the difference between the magnetic north and the grid north.