超精加工表面形貌任意频率的提取及重构
2018-10-19
作者：况良杰，庞启龙，徐幼林
单位：南京林业大学
摘要：采用功率谱密度（PSD）和连续小波方法（CWT）相结合的方法分析磷酸二氢钾（KDP）晶体超精加工表面形貌中的频率特征。采用PSD提取取样长度和周期范围内表面形貌上的所有频率特征，针对PSD得到的三个显著实际频率特征进行频率的提取，同时获得CWT的尺度因子a；用Mexican Hat小波函数实现连续小波变换还原实际频率形貌。结果表明：在采样域内，实际频率为0.0138μm-1的表面形貌与原始表面极为接近，是KDP晶体超精加工表面形貌及影响表面粗造度的主要频率特征。
关键词：频率；表面形貌；超精加工；PSD；CWT
中图分类号：TG356.28；TH164文献标志码：A
Extraction and Reconstruction of Arbitrary Frequency
Topography on Ultra Precision Surface
Kuang Liangjie，Pang Qilong，Xu Youlin
Abstract:To reconstruct the actual morphologies of the frequency characteristics on ultraprecision surface，and the relationship with machining process is analyzed.In the paper，Power Spectral Density method (PSD) and Continuous Wavelet Transform (CWT) are used to analyze the frequency characteristics of KDP crystal surface in ultraprecision machining.All the frequency characteristics of the sampling length and the surface morphology within the periodic range can be obtained by PSD.According to frequency analysis results obtained by PSD，the actual frequency characteristics can be extracted and also achieve the scale of CWT.Realization of continuous wavelet transform with Mexican Hat wavelet function，final reduction of actual frequency morphology.The result shows that the surface morphology of the value is 0.0138μm-1 which is closest to the sample surface，and the main frequency characteristics of the affected roughness and KDP crystal surface in ultraprecision machining is considered.
Keywords:frequency；surface topography；ultraprecision machining；PSD；CWT