涡旋盘的三坐标滤波粗差测量策略研究

Research on CMM measuring strategy of scroll compressor parts

三坐标测量机是用于机加工零件三维尺寸检测的一种精密仪器,三坐标测量中需要对测量元素的滤波和粗差进行合理设置,滤波能从表面粗糙度的影响中分离出集合元素的波纹度(形状误差),在大多数的测量任务中只有形状误差是重要的,通过研究滤波的类型、方式和设置,获取各种元素的滤波设置并得到最佳测量策略。粗大误差,简称粗差,指明显超出规定条件下预期的误差,因而其也为明显歪曲测量结果的误差,所以在处理数据时应将其剔除,否则将对标准差、平均差产生严重的影响。三坐标可以通过设置异常因子,改变异常值消除的界限,合理的设置粗差可以减少测量误差,提高测量精确度,通过研究发现在三坐标扫描元素时选择清除粗大误差,系数取决于标准偏差,推荐值2~3为合理的设置。

CMM is a precision instrument,used for measure machining parts of three dimensional size detection,CMM measurement need to make reasonable setting on measuring element with filter and Outlier.Filtering can separate the ripple from the effect of roughness ripples.In most measurement task only shape error is important,through the study of types of filtering,way and Settings,get all sorts of elements of the filter Settings and get the best measurement strategy.Gross error.It refers to the error that obviously exceeds the expectation under the specified conditions,so it is also the error that obviously distorts the measurement results.Therefore,it should be eliminated when processing the data,otherwise it will have a serious impact on the standard deviation and average difference.The limit of the elimination of outliers can be changed by setting anomaly factors in the CMM.A reasonable setting of gross error can reduce measurement errors and improve measurement accuracy.Through the study,it is found that the coarse error is selected to be cleared when the elements are scanned at CMM,and the coefficient depends on the standard deviation.The recommended value is 2-3,which is the good setting.