• Title/Summary/Keyword: On-machine Measurement

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The Development and Evaluation of OMM(On the Machine Measuring) System Using Scanning Probe (Scanning Probe를 이용한 OMM(On the Machine Measuring) 시스템 개발 및 평가)

  • Kim, S.H.;Kim, I.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.10
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    • pp.71-77
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    • 1996
  • This paper describes the development of on the machine measuring(OMM) system which can directlry measure the three dimensional machined dimensilnal accuracy using scanning probe in milling machine. Two algolithms, continuous path(CP) measurement using UC program and CAD data assisted point to point(PTP) measurement, were developed regarding specification of scanning probe. The OMM system was contructed to verify the developed system suing the proposed algorithm, and actually measured three kinds of machined TV shadow mask molds. The developed system was evaluated it's repeatability and compared with the current measurement system of CMM(Coording Measuring Machine) in terms of relative accuracy and time reduction and productivity increase.

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Measurement Error Modeling for On-Machine Measurement of Sculptured Surfaces

  • Cho, Myeong-Woo;Lee, Se-Hee;Seo, Tae-Il
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.2
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    • pp.73-80
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    • 2001
  • The objective of this research is to develop a measurement error model for sculptured surface in On-Machine Measurement(OMM) process based on a closed-loop configuration. The geometric error model of each axis of a vertical CNC machining center is derived using a 4$\times$4 homogeneous transformation matrix. The ideal locations of a touch-type probe for the sculptured surface measurement are calculated from the parametric surface representation and X-, Y- directional geometric errors of the machine. Also the actual coordinates of the probe are calculated by considering the pre-travel variation of a probe and Z-directional geometric errors. Then, the step-by-sep measurement error analysis method is suggested based on a closed-loop configuration of the machining center including workpiece and probe errors. The simulation study shows the simplicity and effectiveness of the proposed error modeling strategy.

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On-Machine Measurement System Development of Hole Accuracy using Machine Vision (머신비젼을 이용한 구멍 정밀도의 기상측정시스템 개발)

  • Kim, Min-Ho;Kim, Tae-Yeong
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.5
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    • pp.7-13
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    • 2010
  • The integrity and accuracy of the drilling hole are decided by positional error, diameter error, the roundness, the straightness, the cylindericity, size of the burr, the surface roundness and others. Among these parameters, positional error and diameter error have the most important parameters. The diameter error has been widely studied, but there has been little research done about the positional error due to the difficulty of measuring it. The measurement of hole location and diameter would be performed by CMM(Coordinate Measurement Machine). However, the usage of CMM requires much time and cost. In order to overcome the difficulties, we have developed a hole location and diameter error measuring device using machine vision. The developed measurement device attached to a CNC machine can determine hole quality quickly and easily.

Development of On-the-Machine Measurement(OMM) System (기상측정(機上測定) 시스템 개발)

  • Lee, Seung-Woo;Kim, Sun-Ho
    • IE interfaces
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    • v.11 no.1
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    • pp.199-205
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    • 1998
  • This paper describes the development of on-the-machine measuring(OMM) system which can directly measure the two and three dimensional machined accuracy using a scanning probe in milling machine. Two algorithms, NC program based continuous path(CP) measurement and CAD data assisted point to point(PTP) measurement, are developed for three dimensional measurements, with consideration of the characteristics of the scanning probe. The algorithms are used to develop an auto measuring system. The delveloped system is compared with the CMM (Coordinate Measuring Machine) in terms of accuracy and repeatability. The OMM system is expected to realize measurement time reduction and hence result in high productivity.

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A Study on the out-diameter measuring machine by the LVDT sensors (LVDT 센서를 이용한 외경 측정 방안에 대한 연구)

  • Hwang J.H.;Roh J.H.;Park Ki-Hong
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.291-292
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    • 2006
  • Currently A demand of high precision workpiece is increasing in industry. At present, roundness measuring machine using Air bearing, coordinate measuring machine that are used from measurement station. but these machines will not be able to apply to In-line process. because of like these machine's price are very expensive and measurement time is long. also, the complexity of conventional roundness measurement method based on fourier transform, it makes difficult to development analysis program. This work present new architecture of a Out-diameter measuring system fur analysis of roundness of product. In this system, the influence of table motion errors is minimize by using two LVDT sensor and knife edge contact tip. We are produce a test machine and make an experimenter on Out-diameter of test bearing. The measurement result compared with roundness measuring machine.

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Measurement of Tool Wear using Machine Vision in Flat End-mill (머신비젼을 이용한 평 엔드밀 공구의 마모측정)

  • Kim, Tae-Young;Kim, Eung-Nam;Kim, Min-Ho
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.1
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    • pp.53-59
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    • 2011
  • End milling is available for machining the various shape of products and has been widely applied in many manufacturing industries. The quality of products depends on a machine tool performance and machining conditions. Recognition characteristics of the cutting condition is becoming a critical requirement for improving the utilization and flexibility of present-day CNC machine tools. The measurement of tool wear would be performed by coordinate-measuring machine(CMM). However, the usage of CMM requires much time and cost. In order to overcome the difficulties, on-line measurement(OLM) system was applied for a tool wear measurement. This study shows a reliable technique for the reduction of machining error components by developing a system using a CCD camera and machine vision to be able to precisely measure the size of tool wear in flat end milling for CNC machining. The CCD camera and machine vision attached to a CNC machine can determine tool wear quickly and easily.

A Study on Error Detection Algorithm of COD Measurement Machine

  • Choi, Hyun-Seok;Song, Gyu-Moon;Kim, Tae-Yoon
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.4
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    • pp.847-857
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    • 2007
  • This paper provides a statistical algorithm which detects COD (chemical oxygen demand) measurement machine error on real-time. For this we propose to use regression model fitting and check its validity against the current observations. The main idea is that the normal regression relation between COD measurement and other parameters inside the machine will be violated when the machine is out of order.

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A Study on the Thermal Effects Measurement and Uncertainty Estimation for High Precision Machine Tools (고정밀 공작기계의 열적효과 측정 및 불확도 추정에 관한 연구)

  • Son, Deok-Soo;Kim, Sang-Hwa;Park, Il-Hwan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.2
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    • pp.107-113
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    • 2013
  • When the main spindle of high precision machine tools are run many hours, heat is generated in bearing parts of the inside of the spindle. Also, headstock is appeared distortion by inside and outside temperature difference of a machine. This paper studies method to measure behavior of machine tool about these thermal effects. In addition, it estimates measurement uncertainty factors which can be appeared in thermal effects measurement. Finding the factor of thermal affect measurement is important for estimation of measurement uncertainty. This paper measures thermal effects of high precision machine tools and evaluates the important factors of uncertainty.

Development of An Optical Surface Roughness Sensor for On-the-Machine Measurement (기상 측정을 위한 광학적 표면 거칠기 측정 센서 개발)

  • Kim, Hyun-Soo;Hong, Seong-Wook
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.168-178
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    • 1994
  • This paper presents an optical surface roughness sensor developed for intermediate- process measurement on the machine. The light scattering method is adopted for the sensor, which is designed conpact and flexible enough to apply to 'on the machine' measurement of surface roughness. The developed sensor has special features such that it makes use, as the measurement parameter, of the ratio between fluxes of the incident light, and the specularly and partly diffusely reflected light, and that it can adjust the incident light angle. The experimental investigation reveals not only the sensor has good performance as a surface roughness sensor but the sensor is very robust so as to be useful in in-process measurement.

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A Study on Measurement Uncertainty of CMM used for Inspection of Precision Machined parts. (정밀가공 부품 검사에 사용되는 삼차원측정기의 측정불확도 연구)

  • 이갑조;오상록;김종관
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.3-9
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    • 2004
  • The machining parts must be produced within the specification of drawing and those will be able to meet function and efficiency. At that time. it is necessary not only precision machine or machining technique but also the measurement technique is very important. So. the improvement of precise measurement technique is to be joined together at once with improvement of product technique. Finally. he quality and value of the parts are decided by precision measurement. This paper aims to study on he measurement uncertainty when the machined parts are inspected with 3-dimensional coordinate measuring machine. The objectives are to remove an error of measurement and to improve quality and productivity of the mass products.

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