基于坐标测量机的自由曲面检测采样策略  

Sampling strategy for free-form surface inspection by using coordinate measuring machines

作　　者：温秀兰[1] 王东霞[1] 朱晓春[1] 赵艺兵[1] 

机构地区：[1]南京工程学院自动化学院,江苏南京211167

出　　处：《光学精密工程》2014年第10期2725-2732,共8页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.51075198);江苏省自然科学基金资助项目(No.BK2010479);江苏省"333人才工程"和"六大人才高峰"项目

摘　　要：为了实现自由曲面快速精确的检测和评定,研究了检测过程涉及的采样策略.提出采用随机Hamersley采样、简单随机采样和列系统采样3种方法设置自由曲面上的测量点.采用拟粒子群算法优化变换参数,实现被测曲面与设计曲面之间的定位,采用曲面细分法搜索设计模型上与被测点距离最近点以计算自由曲面轮廓度误差.为了对基于坐标测量机（CMM）在不同采样策略下的检测结果进行比较,采用非均匀有理B样条生成零件设计模型,选择相同的加工工艺在不同的加工中心加工多个零件得到粗糙度不同的自由曲面.最后,使用CMM在所设计的采样策略下实测零件,用提出的方法计算零件的轮廓度误差,并与CMM内置软件的计算结果进行比较.实验结果显示：选择随机Hammersley采样法和中等采样点数的采样策略检测效果最佳,不仅测量精度高,而且耗时少、成本低.应用提出的方法计算自由曲面轮廓度误差时,其精度比由CMM内置软件计算结果高10％～22％,表明提出的方法适用于自由曲面零件轮廓度误差的快速精确检测与评定.To inspect and evaluate free-form surface（FFS） parts rapidly and precisely, the sampling strategies involved in inspecting processing were researched. Three kinds of sampling methods , ran-domized Hamersley sampling, simple random sampling and aligned systematic sampling were proposed to specify a set of measuring points and a quasi particle swarm optimization searching was used to opti- mize the transformation parameters to implement the localization between measured FFS and designedFFS. Then , the surface subdivision method was taken to find the closest points on the design model corresponding to measured points to calculate the profile errors of the FFS. In order to compare the results of different sampling strategies, design models for parts were generated by non-uniform ration-al basis spline and some parts were manufactured on different machining centers to obtain the surfaces of different roughnesses based on the same processing technology. Finally,these parts were measuredon a Coordinate Measuring Machine（CMM） by setting different sampling strategies and the profile er- rors were calculated by the proposed method and CMMs software, respectively. The experiments re-sults verify that the best sampling strategy for FFS inspection is the randomized Hamersley sampling method and a medium size. It has the merits of higher precision, lower cost and less time. Moreover, the evaluation precision of FFS profile error computed by the proposed method is higher 10%--22 %than that by CMM software. These results show that the proposed method is suitable for the profile error inspection of FFS parts rapidly and precisely.

关 键 词：自由曲面检测 采样策略 随机Hamersley采样 采样大小 坐标测量机 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] TH72[自动化与计算机技术—计算机科学与技术]