【作者】 曹瑞军；

【导师】 刘长安；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 客户对企业产品的要求主要体现在产品质量、成本和交货期上。随着科技的发展进步，企业生产出高质量的产品已非难事，但在保证质量的前提下，在规定的交货时间内为客户提供低价格的产品的难度越来越高。根据这一情况，并结合企业现状，本文系统、深入的研究了面向复杂技术产品的快速设计相关理论和关键技术，分析了BP神经网络在成本估算方面的应用，最后开发了相应的软件系统。本文采用功能结构映射理论和基于实例的推理技术来实现产品的快速设计。研究了基于功能论的设计方法。通过对功能进行分析和分解，建立产品的功能模型，然后通过功能结构映射为每个末位功能元寻求对应的子结构解，并依次利用功能元与其所属功能元的隶属关系得到整个产品的整体结构解集，最后通过形态学综合法进行筛选、评价和决策得到最优解。复杂技术产品的变型设计就是有效利用企业现有的成熟产品资源，对企业产品设计的调查分析得知有70％以上的实际工作属于变型设计，同时变型设计面临的主要问题是产品的设计表达和设计检索问题。针对这一状况，本文详细介绍了CBR技术的原理、流程以及发展状况，结合基于事物特性的产品建模方法和面向对象的产品建模方法的优点提出了多视图多层次的产品模型，既便于产品结构和功能的复用，又能表达产品设计的过程性和层次性。由于产品实例的属性类型多种多样，本文详细讨论了不同数据类型的属性相似度计算公式，并在此基础上计算产品实例库中的实例与新问题实例的相似度，从而完成实例检索，最后通过修正得到新问题的解，然后，对新解进行特征分析和信息提取，按照该层次的模版将其存入实例库，完成实例库的自学习功能，即在完成产品快速设计的同时，又扩充了实例库。从产品的方案设计到最后的详细设计，产品结构信息是逐渐明晰的，如果我们能在每个阶段都能估算出成本，不仅能够指导和评价设计师的设计工作，还可为产品最后报价及领导决策提供依据。本文在第四章分析总结了按产品结构树辅以BP神经网络进行成本估算的相关理论及其在成本估算方面的应用。综合利用上述研究理论和技术，作者开发了产品快速设计及成本估算软件系统，并应用于清理机的快速设计及成本估算，取得了满意的效果。更多还原

【Abstract】 The main requirements of the customer in product can be summarized as quality, cost and delivery term. With the development of science and technology, it is not hard for enterprises to produce the products of high quality. However, on the premise of guaranteeing the quality, it is becoming more and more difficult to provide for customer the product of low price within the given time. In the light of this case, the relevant theories and key technologies directing at complex machinery product is systematically, deeply studied based on the actual situation of enterprise. The application of BP neural network in the cost estimating is analyzed. Finally the relevant software platform is developed.The mapping between function and structure and the technology of Case-Based Reasoning are adopted to realize the product rapid design. The design method based on function is studied. The function model of product is established through analyzing and decomposing the function. Then corresponding solution of the structure is searched through the mapping from function to structure for every end function cell. Successively, the holistic solution of the structure is obtained using the relationship of subordination between the function cell and that belonging to it. Finally, the optimal solution is accomplished after screening, evaluation and decision through the synthesized method of morphology.Variant design of complex technical product means the effective usage of the existing resource of the enterprise. The investigation on design activity of the enterprise shows that up to 70% of the actual activity belongs to variant design. At the same time, the main problem facing variant design is how to effectively express and retrieve the product. In view of this condition, the principle, the procedure and the state of the art are briefly introduced. Combining the advantages of two product modeling methods, one is based on tabular layout of article characteristics, the other is object-oriented, the product model of multi-view multi-layer model is proposed, which is convenient for the reusage of product structures and function and can express procedure and layer of the product as well. The computing formula for different kinds of attribute similarity is briefly discussed, due to variety of attribute type of product case. Based on this, the similarity between the historical cases in database and the current design requirements is calculated, thus, the case retrieval is completed, the optimal solution is obtained. Finally, the feature analyzing and information extraction are carried on, the new case is saved into case base. While the rapid design is completed, it also enriches the case base.The information of the product is gradually clear during the process, from scheme design to detail design. If we can estimate the cost in every phase, it not only conducts and evaluates the designer’s task, but also can provide the basis for the quotation of prices and decision of the leaders. The relevant theories and the application in the aspect of cost estimate according to the structure tree assisted by BP artificial neural network are analyzed.According to the theories and technique above, the software platform for product rapid design and cost estimating is developed. The design tool is applied to shot blasting machine design, which proved to be efficient.更多还原