基于多尺度高度场修正的零件表面形貌建模及应用

摘要

针对目前产品设计阶段建立的零件表面模型局限于单一尺度,难以研究零件原始轮廓下的表面形貌对产品质量与性能影响的问题,提出一种基于多尺度高度场修正的零件表面形貌建模方法.首先提出包含加工参数的归一化分数维特征函数来模拟零件表面微观结构,再通过小波分析将零件表面高度场分解到不同的尺度下,并分别进行多尺度基准面评定和结构参数评定.然后提出基于多尺度参数驱动的零件表面形貌修正与合成方法,生成满足粗糙度、波纹度和等效平面度技术要求并叠加了形状的零件表面形貌模型.最后给出了在机床导轨设计分析中的应用实例,验证了文中方法的可行性和实用性.%Since most part surface models are established at single scale in product design stage and it is hard to study the influence of part surface topography of practical profile on the product fitting accuracy, a modeling method of part surface topography based on the revised multi-scale altitude field is proposed. Firstly, the micro-topography of a part surface is simulated by normalized fractal characteristic function with processing parameters, and the part surface altitude field is decomposed into varied scales by wavelet analysis, and the multi-scale evaluation of datum planes and texture parameters is carried out. Then the revise and synthesis methods of part surface topography based on multi-scale parameter driving are proposed, so the model of part surface topography is generated, which expresses the part form and meets the multi-scale specifications of roughness, waviness and equivalent flatness. Finally, the efficiency and feasibility of the proposed method is validated by design and analysis of the guide rail of the machine tool.