摘  要：以坐標(biāo)測(cè)量機(jī)測(cè)量孔徑為例，闡述測(cè)量過(guò)程中影響測(cè)量結(jié)果的不確定度來(lái)源，根據(jù)測(cè)量模型建立孔徑測(cè)量的GUM法不確定度評(píng)定模型；利用對(duì)坐標(biāo)測(cè)量機(jī)的測(cè)量系統(tǒng)量值特性指標(biāo)分析的方法，給出基于量值特性分析法的各標(biāo)準(zhǔn)不確定度分量的評(píng)定模型。通過(guò)對(duì)汽車空調(diào)壓縮機(jī)后缸體的孔徑測(cè)量，比較兩種方法評(píng)定的擴(kuò)展不確定度。實(shí)例分析可以看出：對(duì)于坐標(biāo)測(cè)量機(jī)復(fù)雜的非線性測(cè)量模型，GUM法在計(jì)算靈敏系數(shù)時(shí)，運(yùn)算量較大且獲得的是近似結(jié)果，因此其可操作性不強(qiáng)；量值特性分析法通過(guò)對(duì)測(cè)量系統(tǒng)整體的分析，基于大量的實(shí)驗(yàn)數(shù)據(jù)對(duì)測(cè)量結(jié)果進(jìn)行測(cè)量不確定度評(píng)定，其流程和操作性更為便捷、有效。
關(guān)鍵詞：計(jì)量學(xué)；不確定度評(píng)定；孔徑測(cè)量；坐標(biāo)測(cè)量機(jī)
文獻(xiàn)標(biāo)志碼：A       文章編號(hào)：1674-5124（2016）01-0026-05
Uncertainty evaluation model for aperture measurement of
coordinate measuring machines
XU Lei， CHEN Xiaohuai， CHENG Yinbao， JIANG Rui， WANG Hanbin， CHENG Zhenying
（School of Instrument Science and Opto-electronics Engineering，Hefei University of Technology，
Hefei 230009，China）
Abstract: The factors which may influence the measurement uncertainty of aperture measurement by coordinate measuring machine （CMM） were analyzed. Two uncertainty models were established based on guide to the expression of uncertainty in measurement （GUM） and measurement system analysis（MSA）. Measurement uncertainty for aperture of workpiece were evaluated by the two methods. Moreover， seen from the evaluation example， the results of uncertainty evaluation obtained from GUM and MSA were compared， the comparison result indicates that GUM method needs large amounts of computation and can only get the approximate results in the calculation of sensitivity coefficient but MSA method analyses the whole measurement system and evaluates uncertainty through a large number of experimental data，which is more convenient and more effective than GUM method.
Keywords: metrology； uncertainty evaluation； aperture measurement； CMM