• Title/Summary/Keyword: Precision Evaluation

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A Study on the Measurement Method and Uncertainty Factors for Precision Inspection to Feed Unit of High Precision Machine Tool (고정밀 공작기계 이송장치의 정밀도 측정방법 및 불확도 요인에 관한 연구)

  • Kim, Sang-Hwa;Kim, Byung-Ha;Choi, Woo-Gak
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.4
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    • pp.55-61
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    • 2012
  • Very important content in performance evaluation of machine tool is positioning accuracy and repeatability precision measurements of feed mechanism. A study analyses the measurement method and uncertainty factors by ISO-based test method. Reliable results can't be derived without the notion of measurement uncertainty. The reason is that the measured value includes a lot of uncertain factors. Finding the factor that affects the measurement of parameter is important for estimation of measurement precision. In this paper, the evaluation of uncertainty analysis about positioning accuracy and repeatability precision measurements of high precision feed mechanism is presented to evaluate the important factors of uncertainty.

Prediction and Evaluation Method of Energy Consumption in Machine Tools (공작기계의 에너지 소비량 평가기법 및 예측기술)

  • Lee, Chan-Hong;Hwang, Jooho
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.5
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    • pp.461-466
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    • 2013
  • In this paper, main mechanism and measurement method of energy consumption for machine tools are investigated by experiment and simulation. To evaluate total energy consumption of the machine tools, standard test workpiece and measuring method and test procedures are suggested. And, improvement of energy consumption evaluation by the motion kinematics theory is used. In addition, to estimate energy consumption of machine tools in design process, mass distribution of the structure and 5 axis motions are investigated and simulated by numerical analysis.

Precision Evaluation Method for the Positioning Error of Three-DOF Parallel Mechanism using Coordinate Measuring Machine (CMM) (CMM을 이용한 3자유도 병렬기구 위치 오차의 정밀 평가 기법)

  • 권기환;박재준;이일규;조남규;양현익
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.11
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    • pp.99-109
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    • 2004
  • This paper proposes precision evaluation method for the positioning error of three-DOF translational parallel mechanism. The proposed method uses conventional CMM as metrology equipment to measure the position of end-effector. In order to obtain accurate measurement data from CMM, the transform relationship between the coordinate system of the parallel mechanism and the CMM coordinate system must be identified. For this purpose, a new coordinate referencing (or coordinate system identification) technique is presented. By using this technique accurate coordinate transformation relationships are efficiently established. According to these coordinate transformation relationships, an equation to calculate error components at any arbitrary position of the end-effector is derived. In addition, mathematical fitting models to represent the position error components in the two-dimensional workspace of the parallel mechanism are also constructed based on response surface methodology. The proposed error evaluation method proves its effectiveness through the experimental results and its application to real three-DOF parallel mechanism.

Construction of High-Precision Ultrasonics Distance Amplitude Characteristics Curve for Integrity Evaluation of Rail Weld Zone (레일용접부의 건전성평가를 위한 고정밀 초음파 거리진폭특성곡선의 구축)

  • 윤인식
    • Journal of the Korean Society of Safety
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    • v.18 no.1
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    • pp.8-13
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    • 2003
  • This study proposes integrity evaluation method of weld zone in rails using high precision distance amplitude characteristics curve(DACC) and ultrasonic signals. For these purposes, the ultrasonic signals for defects(porosity and crack) of weld zone in rails are acquired in the type of time series data and echo strength. 6 lines in the DACC indicated damage evaluation standard of weld zone in rails. The aquired ultrasonic signals agree fairly well with the mesured results of reference block and sensitivity block(defect location, beam propagation distance, echo strength, etc). The proposed high precision DACC in this study can be used for integrity evaluation of weld zone in rails.