平面铣削粗糙表面微观形貌仿真方法研究

Research on simulation method of micro topography of rough surface in plane milling

为了更加准确地实现平面铣削粗糙表面的仿真,基于小波分层理论与小波能量分析提出一种新的微观表面形貌仿真方法。首先基于db9小波基函数对实测平面铣削表面形貌信号进行多尺度分解,结合分层信号的小波能量分析实现复杂形貌信号中主体成分的剥离,将平面铣削表面形貌信号划分为高频频段、理论频段与低频频段3个频段。并将高频频段、低频频段信息重构出数字组合模型,然后结合铣刀参数与加工参数所得到的理论形貌,最终实现对平面铣削粗糙表面的形貌仿真。最后将实测粗糙表面与仿真表面就相关粗糙度参数进行了对比分析。对比结果显示,算术平均偏差Sa、均方根偏差Sq、偏态Ssk及峰态Sku相对误差的最大值分别为2.568%、2.786%、4.785%与-2.431%。总体来讲,实测表面与仿真表面的粗糙度参数相对误差不超过5%。该方法为更加准确地实现平面铣削粗糙表面的仿真提供了一种新的途径。

In order to realize the simulation of rough surface milling more accurate,a new micro surface topography simulation method based on wavelet hierarchical theory and wavelet energy analysis is proposed.Firstly,based on db9 wavelet basis function,the multi-scale decomposition of the measured surface topography signal of plane milling is carried out,and the main components of complex surface signal are stripped by wavelet energy analysis of layered signal.The surface topography signal of plane milling is divided into three frequency bands,namely high frequency band,theoretical frequency band and low frequency band.The high-frequency band and low-frequency band information are reconstructed into a digital combination model,and then combined with the theoretical topography obtained by milling cutter parameters and processing parameters,the topography simulation of plane milling rough surface is finally realized.Finally,the measured rough surface and the simulated surface are compared and analyzed.The results show that the maximum relative errors of arithmetic mean deviation Sa,root mean square deviation Sq,skew Ssk and kurtosis Sku are 2.568%,2.786%,4.785%and-2.431%,respectively.Generally speaking,the relative error between the measured surface and the simulated surface is less than 5%.This method provides a new way to realize the simulation of plane milling rough surface more accurately.