基于NURBS曲面敏感点的曲面检测测点优化  

Measuring points optimization in machining error inspection based on reconstruction of NURBS control points driven by sensitive points

作　　者：赖金涛 傅建中[1] 沈洪垚[1] 甘文峰[1] 

机构地区：[1]浙江大学机械工程学院,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2015年第7期1201-1207,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51175461);高等学校博士学科点专项科研基金资助项目(20120101110055)

摘　　要：基于NURBS曲面控制点重构的加工误差在机测量方法,提出测点优化选择方法.通过对NURBS曲面进行分析,将曲面上控制点影响最强点和曲面极值点定义为曲面的敏感点,利用曲面敏感点的在机测量数据对NURBS曲面控制点进行重构,得到拟合加工曲面.比较加工曲面和设计曲面可以得到曲面的加工误差,对曲面的加工精度进行评估,指导曲面的误差补偿.实验过程对一自由曲面进行实际加工,通过在机测量和三坐标测量得到曲面的加工误差,分别利用均布法、等参数法和敏感点法对测点进行选择,得到相应的拟合加工曲面.分析结果表明,采用提出的测点优化选择方法获得的加工曲面具有更好的拟合精度.A new method to optimize the sampling points of free-form surface was proposed in the surface error inspection based on reconstruction of NURBS control points.The NURBS surface was analyzed,and the points mostly affected by the control points and the extreme points were defined as the sensitive points of the surface.The machined surface was obtained by reconstruction of NURBS control points using the measurement data at the sensitive points.The machining error of the surface can be achieved by calculating the difference between the machined surface and designed surface.Then the accuracy of the surface can be further evaluated and compensated.The experiment was conducted on a NURBS surface and the machining error of the part was achieved both through the on-machine method and the coordinate measurement method.The uniformly distribution method,the equi-parameter method and the proposed method for measuring points selecting were applied to the NURBS surface.Results showed that the machined surface with the sensitive point method had a better fitting accuracy.

关 键 词：NURBS曲面 控制点重构 测点优化 在机测量 

分 类 号：TH161[机械工程—机械制造及自动化]