【作者】 尹作重；

【导师】 王涛； 黎晓东；

【作者基本信息】 机械科学研究总院 ， 计算机应用， 2009， 硕士

【摘要】 模糊Petri网有很好的知识表达、逻辑推理功能和动态描述因果关系的能力,不但适于表示模糊产生式规则知识,而且进行故障诊断时可以通过矩阵运算,具备良好的并行处理和较强的容错性。模糊Petri网在模糊知识表示和推理方面获得了广泛的应用,而专家系统中关键的问题之一是知识的表示和推理方法,将模糊Petri网作为知识表达和推理工具与专家系统结合的研究目前尚处于初步阶段。本文是将模糊Petri网引进专家系统作为知识表示和推理工具的一次尝试。本文在模糊Petri网理论的基础上,详细阐述了模糊规则产生式和模糊Petri网的映射关系,并给出了两者之间的通用转换算法,文中还对模糊Petri网的主要推理算法进行了研究,采用矩阵运算形式化推理作为专家系统的推理算法。本文对模糊专家系统理论和方法进行了研究,着重分析了本课题专家系统的模糊知识表示、推理机制和隶属函数确定问题。文中将面向对象的思想应用到本系统的分析、设计和实现中,阐述了系统的框架组成以及各组成模块之间的交互协作的运行机制。另外本文详细阐述了本系统网格可视化技术的原理,描述了网格框架模型工作流程和FPN模型图元对象与网格框架对象的映射算法,并将设计模式思想引入到本系统可视化模块的设计实现中,降低了各模块的耦合性,保证了系统的可维护性和可重用性。最后本文以轮胎式装载机变速箱故障诊断为例,对该专家系统进行了验证和实验,并通过一个故障诊断实例证实了模糊Petri网方法与专家系统结合进行故障诊断是可行的,具有较好的理论研究意义和应用前景。更多还原

【Abstract】 Fuzzy Petri net has a good knowledge representation, logical reasoning and dynamic description of the functional capacity of a causal relationship, with its parallel processing matrix computation and strong fault tolerance. Fuzzy Petri net is widely used in the fuzzy knowledge representation and reasoning aspects recently,one of the key issues in Expert system is knowledge representation and reasoning, and the research about Fuzzy Petri nets combined with expert system is still at an initial stage.In this paper, the research about the Fuzzy Petri net introduced into expert system as a tool for knowledge representation and reasoning is attempted. Based on the theory of fuzzy Petri net, the detailed production of fuzzy rules and fuzzy Petri net mapping relations and the conversion common algorithms are given. the main reasoning algorithm on the fuzzy Petri net is discussed, and the matrix operations as a formal reasoning algorithm for expert system reasoning is used.In this paper, as topics of the fuzzy expert system theory and methods, the knowledge representation, reasoning mechanisms and the determination of membership function are discussed, Object-oriented thinking has been applied to the system analysis , design and implementation, The system framework of the composition and the collaboration operating mechanism in the interactive module are discribed, This paper discussed the problems in the fuzzy Petri net automatic modeling and simulating visualization , and proposed solutions and the specific methods based on grid visualization technology. Design Pattern is introduced into the design visualization module implementation.Finally, through the tire loader gearbox fault diagnosis example, the expert system based on Fuzzy Petri Net is verified, and has a good meaning and application of theoretical research prospects.更多还原