专家系统在产品可制造性分析中的应用研究

【作者】 杨蓓；

【导师】 陈国勋；

【作者基本信息】 郑州大学 ， 计算机软件与理论， 2004， 硕士

【摘要】 近年来，专家系统技术已广泛应用到工业、农业、军事、医学以及国民经济和社会生活的各个方面。将专家系统的研究应用于产品的可制造性分析中，利用它指导产品设计，对于提高产品质量，缩短产品的开发周期，降低产品的制造成本具有显著的应用效果。 本文细致研究和分析了专家系统技术在产品可制造性分析中的应用。论述了专家系统的一般结构和特点，以及相关的知识表示方法和推理技术，讨论了可制造性分析的策略、度量尺度和分析方法。依据产品可制造性分析的功能要求和特点，采用基于特征的可制造性分析方法，建立产品可制造性分析系统原型，并对其系统结构、知识表示、推理机制等方面做了一些有意义的研究工作。 知识的表示与组织是专家系统的关键技术之一。以机加工零件为例，研究了产品的可制造性分析知识的组成、分类和特点，结合零件的特征表示和知识的一般表达方法，本着提高推理效率的思想，提出了一种混合的产品可制造性分析知识表达方法，并提出产品可制造性分析知识库的组织策略，采用关系型数据库建立了产品可制造性分析知识库。在推理机制的研究方面，在对系统推理机的功能和性能要求进行分析的基础上，研究了零件可制造性分析系统的推理策略，采用正向分类的推理方法建立产品可制造性分析推理机。推理机直接从零件模型信息文件中提取事实，避免了要求用户根据产品模型输入大量事实或回答大量问题，大大简化了系统的操作。推理过程中采用关键词对知识库进行分类，以提高系统效率。 基于上述研究和分析，开发了基于特征和知识的产品可制造性分析系统原型，用于对产品的设计模型进行分析和评价，以指导和加快产品设计过程。更多还原

【Abstract】 In recent years, the technology of expert system is already broadly used in industry, agriculture, military, medical science and national economies with each aspect of society life.It is applied to product manufacturability analysis in manufacturing industry and guiding the product designs, and it will have remarkable effect on improving product quality, reducing lead-time and cost of product.The technology of expert system applied to product manufacturability analysis is researched in this paper. The general construction and the characteristics of the expert system, some knowledge representation methods and inference technique are discussed. The paper introduces the strategy, the dimensions and the methods of product manufacturability analysis. This dissertation gives a product manufacturability analysis prototype system with feature-based method, it also puts forward some new methods concerned on system construction, knowledge representation and inference engine.Knowledge representation and organization is one of the key technique of expert system in the buildup. With the mechanical parts for a characteristic, a kind of mixed knowledge representation method which can represent product manufacturability analysis is developed after studying the composing, the classification and the characteristics of product manufacturability knowledge, joining together parts feature representation with the representation method of knowledge to improve the efficiency of inference engine. Based on relational data base technique,the knowledgy base is organized. In the aspects of inference research, the inference engine is designed adopting to forward-reasoning and classf ication method. The inference engine can obtain the information from product molding file instead of inputting much of data or answering many questions so as to simplify the operation of the user very much. During the process of inference, the knowledge base is classified by the keywords to improve the system efficiency.Base on the above researches, a feature and knowledge-based prototype system of product manufacturability analysis is developed, used for proceeding the analysis to the design model of the product and guiding and quickening product design process.更多还原