• Title/Summary/Keyword: Accuracy control

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Calibration of gimballed inertial navigation systems using state estimation (상태변수 추정을 이용한 김발형 관성항법시스템의 교정기법에 대한 연구)

  • Kim, Gap-Jin;Song, Taek-Ryeol
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.1
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    • pp.62-67
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    • 1998
  • Gimballed Inertial Navigation Systems(GINS) are sophisticated autonomous electro-mechanical systems which supply the position, velocity and attitude of the vehicle on which they are mounted. In order to maintain accuracy of outputs, the GINS are required to regularly calibrate senior errors. However, existing calibration methods take up a long time due to multiposition alignments needed to increase accuracy. A particular system formulation for calibration of a GINS is proposed to enhance system observability and thus to expedite calibration procedure. Performance of the proposed calibration method is compared with existing methods such as Schuler test and muliposition alignment. Simulation studies show the proposed system formulation associated with a suggested suboptimal filter is accurate as well as efficient in error identification essential to GINS calibration.

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Acquisition of Large Scale Geographical Information by Remote Control of Non-Metric Camera (비측정용 카메라의 원격조종에 의한 대축척 지형정보 획득)

  • Kang, Joon-Mook;Yoon, Hee-Cheon;Bae, Yeon-Soung
    • Journal of Korean Society for Geospatial Information Science
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    • v.1 no.2 s.2
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    • pp.177-184
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    • 1993
  • To obtain large scale precise geographical information in local area we determined external orientation parameters of camn exactly and conducted aerial photography using remote control airship loaded 35mm non-metric camera that produced systematic error coefficients. Ground control Points were determined by differential GPS. Therefore we can try to improve accuracy and economical efficiency. Also, it is suggested that remote control airship photogrammetry can be applied to make large scale topographic map using analytical plotter as calibrated accuracy.

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A Study on The Visual Inspection of Fabric Defects (시각 장치를 이용한 직물 결함 검사에 관한 연구)

  • Kyung, Kye-Hyun;Ko, Myoung-Sam;Lee, Sang-Uk;Lee, Bum-Hee
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.959-962
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    • 1988
  • This paper describes an automatic visual inspection system for fabric defects based on pattern recognition techniques. The inspection for fabric defects can be separated into three sequences of operations which are the detection of fabric defects[1], the classification of figures of fabric defects, and the classification of fabric defects. Comparing projections of defect-detected images with the predefined complex, the classification accuracy of figures of fabric defects was found to be 95.3 percent. Employing the Bayes classifier using cluster shade in SGLDM and variance in decorrelation method as features, the classification accuracy of regional figure defects was found to be 82.4 percent. Finally, some experimental results for line and dispersed figures of fabric defects are included.

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Review and Suggestions of Models for Measurement System Analysis (측정 시스템 분석 모형의 고찰 및 새로운 모형의 제안)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.10 no.1
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    • pp.191-195
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    • 2008
  • The present study contributes reviewing and suggesting various models for measurement system analysis (MSA). Measurement errors consist of accuracy, linearity, stability, part precision, repeatability and reproducibility (R&R). First, the major content presents split-plot design, and the combination method of crossed and nested design for obtaining gage R&R. Second, we propose $\bar{x}-s$ variable control chart for calculating the gage R&R and number of distinct category. Lastly, investigating the determination of gage performance curve which establishes the control specification propagating calibration uncertainties and measurement errors is described.

Study on Analyzing and Correction of Dynamic Battery Alignment Error in Naval Gun Fire Control System by using Image of Boresight Telescope (포배열카메라 영상을 활용한 함포 사격통제시스템의 동적배열오차 분석 및 보정방법)

  • Kim, Eui-Jin;Suh, Tae Il
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.6
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    • pp.745-751
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    • 2013
  • In naval gun firing, firing accuracy comes from the combination of each component's accuracy in CFCS (Command and Fire Control System) like tracking sensors and gun. Generally, battery alignment is done to correct the error between gun and tracking sensor by using boresight telescope on harbor and sea. But normally, the battery alignment can compensate only the static alignment error and ignore dynamic alignment error which is caused by own ship movement. There was no research on this dynamic alignment error until now. We propose a new way to analyze dynamic arrangement error by using image of boresight telescope. In case of the dynamic alignment error was due to time delay of own ship attitude information, we propose the way to compensate it.

Relationship between motion speed and working accuracy of industrial articulated robot arms

  • Goto, Satoru;Nakamura, Masatoshi;Kyura, Nobuhiro
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.230-233
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    • 1993
  • This paper described a relationship between motion speed and working accuracy of industrial articulated robot arms. Working accuracy of the robot arm deteriorates at high speed operation caused by a nonlinear transformation of the kinematics and the time delay of the robot arm dynamic. The deterioration of the following trajectory was expressed as a linear function of the squares of the robot arm motion speed, depending upon a posture of the robot arm and division interval of the objective trajectory.

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Multi-view Rate Control based on HEVC for 3D Video Services

  • Lim, Woong;Lee, Sooyoun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.245-249
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    • 2013
  • In this paper, we propose two rate control algorithms for multi-view extension of HEVC with two rate control algorithms adopted in HEVC and analyze the multi-view rate control performance. The proposed multi-view rate controls are designed on HEVC-based multi-view video coding (MV-HEVC) platform with consideration of high-level syntax, inter-view prediction, etc. not only for the base view but also for the extended views using the rate control algorithms based on URQ (Unified Rate-Quantization) and R-lambda model adopted in HEVC. The proposed multi-view rate controls also contain view-wise target bit allocation for providing the compatibility to the base view. By allocating the target bitrates for each view, the proposed multi-view rate control based on URQ model achieved about 1.83% of average bitrate accuracy and 1.73dB of average PSNR degradation. In addition, about 2.97% of average bitrate accuracy and 0.31dB of average PSNR degradation are achieved with the proposed multi-view rate control based on R-lambda model.

The Design, Fabrication, and Characteristic Experiment for Control Rod Position Indicator Using Reed Switch in System-Integrated Modular Advanced Reactor (리드스위치를 이용한 일체형원자로용 제어봉 위치지시기 설계 제작 및 특성해석)

  • Hur, Hyung;Kim, Jong-In;Kim, Kern-Jung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.8
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    • pp.452-461
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    • 2003
  • The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indicator system and its actual implementation in the existing nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The arrangement of permanent magnet and reed switches is the most important procedure in the design of control rod position indicator. The hysteresis of reed switches is one of the important factors in a repeat accuracy of control rod position indicator as well. This paper investigates efficiency of the magnetic flux concentrator and the hysteresis using FEM and verified differences in physicals characteristics by comparing the results of FEM and those of the experiment. As a result, it is shown that the characteristics of prototype control rod position indicator have a good agreement with the results of FEM.

Kinematic Iidentification for Improving Robot Accuracy (로보트 accuracy향상을 위한 kinematic identification)

  • 조선휘;김문상;김귀식;장현상
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.131-137
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    • 1989
  • The effect of kinematic model choice on robot calibration is examined. This paper presents a complete formulation to identify the actual robot kinematic parameters directly from position data. The method presented in this paper applies to any serial link manipulator with arbitrary order and combination of revolute and prismatic joint.

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Improvement of Robot Motion Accuracy Through Link Parameter Calibrationa (연자보정 방법을 이용한 로보트 운동 정밀도 개선)

  • 이상조;조의정
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.21-26
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    • 1988
  • The application of robot to industry is increasing and as a result the study on robot is widely being carried out. In this study, to improve the accuracy of robot motion the method which calibrates initially assumed link parameters is considered. This method calibrates 4N link parameters for N D.O.F. robot with rigid links.

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