• 제목/요약/키워드: accuracy improvement

검색결과 2,415건 처리시간 0.031초

피복구성학적 인체계측방법에 관한 연구 - 평면사진계측방법을 중심으로 - (A Study on the Plan Photogrammetry for Clothing Design)

  • 박찬미;서미아
    • 복식문화연구
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    • 제5권1호
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    • pp.151-164
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    • 1997
  • This study pursues the problems of plan photogrammetry which is widely used in somatotyping at present, and find out a method which can improve accuracy of measurement on the basis of principles and mechanisms of photography-the basic foundation of the photographic analysis methods. As a result, this study proposes a new method which is based on the reference point method and perspective coordinate system. And the test measurement was operated to compare the measurement accuracy of the proposed method and the method based on reference grid screen method and perpendicular coordinate system which is commonly used at present. The result of this test measurement showed that the proposed method has higher accuracy. Two reasons can be pointed out for the improvement of measuring accuracy. The first reason is that the proposed perspective coordinate system reduces the perspective distortion of photography. And second reason is that measuring points can be closely placed to the scale and coordinate reference plan of measurement by the proposed reference point method which make possible to place measuring object (or person) at the center of scale and coordinate reference plan by utilizing reference points of measurement in the three dimensional space not on screen.

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위치 정밀도 향상을 위한 관절강성 파라미터 포함 로봇 캘리브레이션 (Robot Calibration with Joint Stiffness Parameters for the Enhanced Positioning Accuracy)

  • 강희준;신성원;노영식;서영수;임현규;김동혁
    • 제어로봇시스템학회논문지
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    • 제14권4호
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    • pp.406-410
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    • 2008
  • This paper presents a new robot calibration algorithm with joint stiffness parameters for the enhanced positioning accuracy of industrial robot manipulators. This work is towards on-going development of an industrial robot calibration software which is able to identify both the kinematic and non-kinematic robot parameters. In this paper, the conventional kinematic calibration and its important considerations are briefly described first. Then, a new robot calibration algorithm which simultaneously identifies both the kinematic and joint stiffness parameters is presented and explained through a computer simulation with a 2 DOF manipulator. Finally, the developed algorithm is implemented to Hyundai HX165 robot and its resulting improvement of the positioning accuracy is addressed.

High Lead Ball Screw를 사용한 고속이송계의 특성 (The Characteristics of High Speed Feed Drive System using High Lean Screw)

  • 고해주;박성호;정윤교
    • 한국공작기계학회논문집
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    • 제10권4호
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    • pp.97-103
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    • 2001
  • The study on the high-speed machine tool is very important for the improvement of productivity since it can shortens cutting and non-cutting time. Especially, high speed of feed drive system is the major research field. In the industries of the advanced countries, the feed drive systems at the speed of 60 m/min have been already developed based on the high lead ball screws. In this study, a high speed feed drive system at the speed of 60 m/ min has been developed, and its movements characteris-tics are investigated. As the movement characteristics, positioning accuracy, angular accuracy, straightness and micro step-response are measured. Thermal characteristics of the system is also discussed. For measuring the movement characteris-tics, a laser interferometer, a memory-based Hi-coder and a cooling device are used. The experimental results confirm that the movement characteristics and the thermal behavior of the system are satisfactory in the aspect of accuracy and stability.

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측벽 밀링에서 공구 변형 및 형상 정밀도 (Tool Deflection and Geometrical Accuracy in Side Wall Milling)

  • 류시형;주종남
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1811-1815
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    • 2003
  • Investigated is the relationship between tool deflection and geometrical accuracy in side wall machining. Form error is predicted directly from the tool deflection without surface generation. Developed model can predict the surface form error about three hundred times faster than the previous method. Cutting forces and tool deflection are calculated considering tool geometry, tool setting error, and machine tool stiffness. The characteristics and the difference of generated surface shape in up milling and down milling are discussed. The usefulness of the presented method is verified from a set of experiments under various cutting conditions generally used in die and mold manufacture. This study contributes to real time surface shape estimation and cutting process planning for the improvement of geometrical accuracy.

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열변형에 따른 가공 정밀도 개선에 관한 연구 (A Study of Improvement of Machining Accuracy Induced Thermal Deformation)

  • 홍성오
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1998년도 춘계학술대회 논문집
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    • pp.263-268
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    • 1998
  • Development of high speed feed drive system has been a major issue for the past few decades in machine tool industries. The reduction of the tool change time as well as rapid travel time can enhance the productivity. However, the high speed feed drive system generates more heat in nature, which leads thermal expansion that has adverse effects on the accuracy of machined parts. The detail of the model proposed is described in the paper together with the experimental methodologies using a proposed compact measurement system to examine the validity of the proposed approach. The results showed the machining accuracy could be maintained to better than $\pm$5${\mu}{\textrm}{m}$ while using this T-18 sensor

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고해상도 화상처리를 통한 자동 변형률 측정의 정확도와 편의성 개선 (Improvement of the Accuracy and Conveniency in Automated Strain Measurement through High-Resolution Image Processing)

  • 김형종;최선철
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 제5회 박판성형 SYMPOSIUM
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    • pp.34-39
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    • 2006
  • An automated surface-strain measurement system, named ASIAS, was developed by using the image processing and stereo vision techniques in the previous studies by the corresponding author and his coworkers. This system has been upgraded mainly to improve the accuracy through image enhancement, sub-pixel measurement, surface smoothing, etc., since the first version was released. The present study has still more improved the convenience of users as well as the accuracy of measurement by processing high resolution images 8 mega pixels or more which can be easily obtained from a portable digital steal camera. It is proved that high resolution image processing greatly decreases the measurement error and gives strain data without considerable deterioration of accuracy even when the deformed grids to be measured and the master grids for camera calibration are captured together in the same image, making the whole process of strain measurement much simpler.

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수치영상에 의한 인체형상의 3차원 정확도 분석 (The 3 Dimension Accuracy Analysis of Human Body Using the Digital Image)

  • 강준묵;배상호;주영은
    • 대한공간정보학회지
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    • 제5권2호
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    • pp.111-119
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    • 1997
  • 인체에 대한 정밀측정과 분석체계의 구축은 인체공학 연구에 중요한 의미를 지니고 있다 본 연구는 인체형상 모니터링을 위한 수치영상의 정확도 향상에 관한 연구로서 다양한 기하학적 조건에 따른 수치영상의 정확도를 분석하고 도출한 최적의 촬영조건을 인체형상에 적용하였다. 표준편차 1mm 이내의 3차원 수치자료를 획득하여 다양한 공간분석과 3차원 모니터링을 수행함으로써 인체공학 분야에 기초자료를 제공할 것으로 기대된다.

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쌍곡선항법시스템을 이용한 직각항법에 의한 측위정도 향상에 관한 연구 (A Study on the Position Accuracy Improvement Applying the Rectangular Navigation in the Hyperbolic Navigation System Area.)

  • 김우숙;김동일;정세모
    • 한국항해학회지
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    • 제13권1호
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    • pp.1-10
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    • 1989
  • Nowadays Hyperbolic Navigation System-LORAN, DECCA, OMEGA, OMEGA-is available on the ocean, and Spherical Navigation System, GPS (Global Positioning System) is operated partially. Hyperbolic Navigation System has the blind area near the base line extention because divergence rate of hyperbola is infinite theoretically. The Position Accuracy is differ from the cross angle of LOP although each LOP has the same error of quantity. GDOP(Geometric Dilution of Precisoin) is used to estimate the position accuracy according to the cross angle of LOP and LOP error. Hyperbola and ellipse are crossed at right angle everywhere. Hyperbola and ellipse are used to LOP in Rectangular Navigation System. The equation calculating the GDOP of rectangular Navigation System is induced and GDOP diagram is completed in this paper. A scheme that can improve the position accuracy in the blind area of Hyperboic Navigation System using the Rectangular Navigation System is proposed through the computer simulation.

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Automotive High Side Switch Driver IC for Current Sensing Accuracy Improvement with Reverse Battery Protection

  • Park, Jaehyun;Park, Shihong
    • Journal of Power Electronics
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    • 제17권5호
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    • pp.1372-1381
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    • 2017
  • This paper presents a high-side switch driver IC capable of improving the current sensing accuracy and providing reverse battery protection. Power semiconductor switches used to replace relay switches are encumbered by two disadvantages: they are prone to current sensing errors and they require additional external protection circuits for reverse battery protection. The proposed IC integrates a gate driver and current sensing blocks, thus compensating for these two disadvantages with a single IC. A p-sub-based 90-V $0.13-{\mu}m$ bipolar-CMOS-DMOS (BCD) process is used for the design and fabrication of the proposed IC. The current sensing accuracy (error ${\leq}{\pm}5%$ in the range of 0.1 A-6.5 A) and the reverse battery protection features of the proposed IC were experimentally tested and verified.

COAG 특징과 센서 데이터 형상 기반의 후보지 선정을 이용한 위치추정 정확도 향상 (Improvement of Localization Accuracy with COAG Features and Candidate Selection based on Shape of Sensor Data)

  • 김동일;송재복;최지훈
    • 로봇학회논문지
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    • 제9권2호
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    • pp.117-123
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    • 2014
  • Localization is one of the essential tasks necessary to achieve autonomous navigation of a mobile robot. One such localization technique, Monte Carlo Localization (MCL) is often applied to a digital surface model. However, there are differences between range data from laser rangefinders and the data predicted using a map. In this study, commonly observed from air and ground (COAG) features and candidate selection based on the shape of sensor data are incorporated to improve localization accuracy. COAG features are used to classify points consistent with both the range sensor data and the predicted data, and the sample candidates are classified according to their shape constructed from sensor data. Comparisons of local tracking and global localization accuracy show the improved accuracy of the proposed method over conventional methods.