【作者】 黄伟军；

【导师】 胡于进； 蔡力钢；

【作者基本信息】 华中科技大学 ， 机械设计及理论， 2012， 博士

【摘要】 工艺过程规划与优化是合理安排产品的制造工艺、缩短开发周期、降低成本、提高产品质量的一种重要手段,同时也是数字化设计与制造以及定量化CAPP中一尚未得到很好解决的难题。论文以现有CAPP领域研究成果和工艺优化研究工作为基础,对复杂零件工艺方案优化中的一些基础性和共性问题展开了深入地探讨；建立了工艺过程规划优化各个阶段的数学模型,从加工方案选择、装夹与定位基准决策、工艺路线安排、制造资源分配等多个层面对复杂零件的工艺过程方案进行优化。首先,对零件特征加工方案决策过程及方法进行了研究,分析归纳了影响特征加工方案选择的几个主要的因素；建立了特征加工方案决策的模糊综合评判数学模型,通过对模糊关系的合成运算来实现决策过程；提出了特征的加工资源预配置问题并对其实现方法进行了探讨。其次,对零件特征的装夹与定位基准选择方法展开了深入研究。针对传统研究中定位基准决策方法效率偏低的问题,论文提出了一种考虑特征公差关系的基于模糊综合评判的定位基准辅助决策方法：首先,建立了加工特征的TAD以及公差关系信息模型,按照保证公差要求的原则将零件的加工特征分类成若干组装夹特征集合,然后遵循相关的工艺知识以及推理流程来为每一组特征集合选择定位基准；构造了多定位基准优化选择的模糊评判数学模型以及推理过程模型,详细讨论了该过程的实现及操作方法。然后,在以上工作的基础上,对零件工艺路线的规划与优化问题进行了深入地分析,建立了该问题求解的数学模型,构造了GA-SA混合算法来进行问题的求解。针对传统研究中对约束处理能力不足而惩罚函数策略又并非凑效的问题,同时根据问题本身求解的需要建立了工艺约束的有向图模型并且将图论中相关的图搜索技术嵌入到混合算法的主框架内,藉此提出了一种基于有向图理论结合GA-SA混合算法的复杂零件工艺路线规划与优化问题求解新方法；基于有向图约束模型,针对工艺路线优化问题所设计的图拓扑排序与染色体串的约束调整算法使得初始化和进化过程中所有解都被限定在可行域内,缩小了问题的搜索空间,提高了算法的收敛速度。对传统基于静态资源的工艺规划与优化问题模型进行了扩展,论文优化方法策略兼顾考虑车间层的动态资源状况,能够根据加工车间资源实时变化情况来对优化过程进行调整,同时所设计的优化方法机制可以保证计算得到多个最优的工艺路线方案。建立了制造资源的层次结构模型,利用面向对象技术和实体-联系方法对车间层的各种资源的属性关系和联系进行了一致性的描述和分类,以规范化方式建立了制造资源、工艺信息之间的联系模型,以此为基础得到了制造资源的数据库逻辑模型,开发了相应的制造资源信息管理子系统。结合以上所做工作与所取得的理论研究成果,以实际的加工车间为工艺优化理论与方法的应用环境,设计和开发了工艺优化原型系统。该系统是一个基于产品三维模型的集成系统,可直接利用产品的三维设计模型来进行工艺过程设计与管理。最后对全文进行了总结,展望了进一步的研究方向。更多还原

【Abstract】 Process planning optimization is the significant means of reasonable arrangement for the manufacturing process of the products, shortening product development cycles, reducing costs and improving product quality. Process planning optimization is a problem which has not yet been well solved in digital design and manufacturing as well as in quantitative CAPP. The paper is based on the existing CAPP research and process planning optimization study, some in-depth discussion in some of the basic and common problems on the process planning optimization of complex parts have been launched. Mathematical model for optimization at all stages of the process planning, from machining operation selection, set-up planning and datumn decision-making, process routing, manufacturing resource allocation, is established for the process planning optimization of the complex parts.First of all, the research on the methodology of the selection for the feature machining operation has been done, the main factors and basic principles which affect the decision-making of the machining operation selection have been analyzed, and the subjection degree function of fuzzy mapping between feature properties factors and the alternative processing collection has been defined; So a fuzzy reasoning mathematical model for machining operation election for a feature is put forward.The decision-making process is implemented through the synthesis of fuzzy relationships, the issues of resource pre-configuration for each machining feature and the corresponding realization have been discussed.Secondly, the research on the methodology of set-up and location datum selection for the part features has been done thoroughly, then the location datum selection based on fuzzy comprehensive evaluation method is proposed considering the characteristics of tolerance relations. In order to improve the efficiency of the decision-making, firstly, based on the the TAD and tolerance relations of the features, the processing features of a part are classified into a number of set-ups in accordance with the principle of ensuring the tolerance requirements, and then the location datum for each group feature set is determined following the corresponding process principles and reasoning process; The fuzzy comprehensive evaluation mathematical model and the related reasoning process of the location datum selection optimization are established, the implementation of the process is discussed in detail.Then, the problem of the process route optimization is analyzed on the basis of the above work, and the corresponding mathematical model is put forward; A hybrid GA-SA algorithm has been developed to solve the process route optimization problem.A process constraint directed graph model is established to solve the problem and a corresponding graph search technology in graph theory is embedded into the main frame of the hybrid algorithm,then a effective methodology of process planning optimization for the complicated part is proposed based on the graph theory and GA-SA hybrid algorithm.The optimization can adjust dynamically according to the actual manufacturing resource conditions in the plant, and the mechanisms can guarantee producing multiple optimal process routes.A hierarchical model of the manufacturing resources is put forward, the consistency description and classification of the properties relationships and linkages among resources on the shop floor by using object-oriented technology and E-R approach is developed, the link between the manufacturing resources and processing information is established by the standardize way, then the database logical model of manufacturing resources is obtained and a manufacturing resource information management subsystem is developed.Combined with the previously research work and achievements, the actual processing plant is treated as the application environment, a prototype system for process planning and optimization is designed and developed. The prototype system is integrated with3D CAD commercial software and based on the three-dimensional model, the3D design models of the product can be used directly to carry out the process planning design.Finally, the researehes in the dissertation are summarized and some future research direction has been presented.更多还原