Research about Separation of the Surface Geometry Error for Large-scale Holes Based on Wavelet Transform

摘要

In order to meet high accurate measuring of geometry error for large-scale holes, an non-contact measuring method used laser probe is presented. According to the characteristics of holes's actual surface composited by multiple frequency component. In order to accurately extract the various types of error signal, in the analysis of the traditional digital filter algorithm and wavelet transform through the experimental analysis of the steps of wavelet filter decomposition, and extracte integratedly the surface form error, surface waviness and surface roughness, to meet the measurement requirements of large-scale holes. The measuring system has the characteristics of simple, practical, reliable, and anti-interference. In the industrial scene, the measuring of size and geometrical error for hole workpiece usually adopts the method that using dial- gauge or micrometer as tool to measure the hole diameter directly, these methods are applicable to measure low accuracy and small-size, for such as diesel engine of large power so large-scale hole diameter and high accuracy, this method has some defect. And the measure result can't match international standard's definition for shape geometrical error, it just can be measured approximately. In order to meet high accurate measuring of geometry error for large-scale holes, an non-contact measuring method used laser probe is researched.