B样条滤波器建立表面轮廓中线的方法

根据离散B样条函数的Z域表达式，B样条空间中对信号的拟合和分解可以表示成FIR滤波器和IIR滤波器的滤波过程，再结合变分原则，构建了表面粗糙度测量中用于确定中线的B样条滤波器。将零相移滤波技术应用到B样条滤波器的实现中，得到了相应的差分方程。对一实际工件表面轮廓进行了实验，验证了该方法的可行性，该滤波器同样具有零相移的特性，与其它方法相比，其具有计算效率高的优点。

An approach for determining the mean line in surface metrology applying B-Spline filter

According to Z-transform representations of discrete B-Spline functions, the fitting and decomposing of the signal in B-Spline space can be implemented by FIR filters and IIR filters. Based on that and variational calculus, the B-Spline filter constructed to determine the mean line in surface roughness measurement comes into being. The difference equations for B-Spline filter is deduced by the technique of zero phase shift filtering. The experiment in the surface profile of a workpiece validate this method. The B-Spline filter also bears the characteristic of zero phase shift and has more computing efficiency than other methods.