面向复杂曲面类零件加工知识重用的多态工艺模板生成与空间映射机制

Complex curved surface parts are widely used in the field of aviation, but the mismatch between the low efficiency and long cycle of NC programming of such parts and the increasing performance of machining equipment greatly limits the improvement of the overall manufacturing level of aviation products. This project focuses on the intelligent programming of NC machining of complex curved surface parts, and successively studies the generation and mapping mechanism of process templates for the reuse of machining knowledge, as well as its modification method. Firstly, the multistate process models for NC machining of complex curved surface parts are constructed, and the NC machining knowledge of each contact point on the multistate process model is represented by means of multivariate vector space, and then the multistate process templates for process reuse are generated. Secondly, aiming at the problem of process reuse of complex curved surface similar parts, a mapping mechanism of multistate process knowledge template for multi-axis machining process based on space transformation mapping was proposed to realize the reuse of processing knowledge among complex curved surface similar parts. Then, aiming at the problem of knowledge correction after process reuse, the constraint relation between the process knowledge and the geometric boundary of similar parts is established, and the constraint unified processing method based on distance monitoring is adopted to adjust the process knowledge adaptively, so as to improve the accuracy of process reuse. The research results of this project can further enrich and improve the NC machining technology theory of complex curved surface parts, and provide technical support for the intelligent programming of such parts.

复杂曲面类零件在航空领域应用广泛，但这类零件数控编程效率低、周期长与加工设备性能不断攀升之间的不匹配问题极大地限制了航空产品整体制造水平的提升。本项目围绕复杂曲面类零件数控加工的智能编程问题，依次开展面向加工知识重用的工艺知识模板生成与映射机制以及修正方法的研究。通过构建复杂曲面零件数控加工过程的多态工序模型，采用多元向量空间表征多态工序模型上各切触点处的加工知识，生成面向加工过程工艺重用的多态工艺知识模板；针对复杂曲面相似零件的工艺重用问题，提出基于空间变换的多轴加工工艺模板映射机制，实现加工知识在复杂曲面相似零件之间的重用；针对工艺重用后加工知识修正问题，分析加工知识与相似零件几何边界的约束关系并建立约束模型，采用基于距离监视的约束统一处理方法自适应调整加工知识，从而提高工艺重用精确度。本项目的研究成果可进一步丰富和完善复杂曲面类零件数控加工工艺理论，为该类零件的智能编程提供技术支持。

本项目围绕复杂曲面类零件数控加工的智能编程问题，首先通过构建复杂曲面零件数控加工过程的多态工序模型，建立了曲面实体由参数域-物理域的变形映射模型，采用多元向量空间表征了多态工序模型上各切触点处的几何信息加工知识，生成了复杂曲面类零件面向加工过程工艺重用的多态工艺知识模板；其次，针对复杂曲面相似零件的工艺重用问题，提出了基于空间变换的多轴加工工艺模板映射机制，通过改进现有配准算法对相似复杂曲面类零件进行点云配准从而求解相似曲面间的空间变换关系。仿真实验结果表明，本项目提出的改进算法能有效完成相似复杂曲面类零件间的配准，求解相似复杂曲面类零件间较为精确的空间变换关系。在此基础上，结合曲面实体变形映射模型由参数域-物理域的一一对应关系以及参数域中参数的比例不变性，利用相似零件之间的空间变换关系，建立了多态工艺知识模板在复杂曲面相似零件之间的空间变换映射机制，将参数域中表征的复杂曲面零件多态工艺知识模板通过空间变换关系一一映射到物理域以获得相似零件的工艺知识，从而实现加工知识在复杂曲面相似零件之间的重用；针对工艺重用后加工知识修正问题，分析了加工知识与相似零件几何边界的约束关系并建立约束模型，采用距离监视的约束统一处理方法自适应调整加工知识。本项目的研究成果在一定程度上丰富和完善了复杂曲面类零件数控加工工艺理论，为该类零件的智能化编程提供技术支持。