基于粗糙集理论的装载机故障诊断的研究.doc

摘  要  工程机械是国民经济中的重要设备。发展工程机械的故障诊断技术，对于加快工 程进度、提高工作效率有着十分重要的现实意义。但在故障诊断技术研究中，知识获 取问题成为制约故障诊断技术发展的“瓶颈”。本文以工程机械中的典型设备—装载机 的故障诊断为研究对象，将粗糙集理论引入到故障诊断技术的研究中，针对故障诊断 知识获取、在信息不完备情况下的故障诊断及容错性等问题展开了深入细致地研究。 本文综合分析了故障诊断理论和技术的研究现状，对粗糙集的理论及其发展状况 进行了总结，阐明了在故障诊断中应用粗糙集理论的重要性。 介绍了粗糙集理论用于诊断知识获取的理论基础，阐述了基于粗糙集理论的故障 诊断知识自动获取的方法和技术。给出了诊断问题的决策表模型；提出了采用基于粗 糙集理论与二值逻辑运算相结合的属性约简算法以及改进的值约简算法来实施知识获 取的约简，然后结合具体的故障诊断实例说明了该算法的实用性。 提出了故障知识的分层获取的概念，并将其应用于装载机的故障知识获取的过程 中；分析了装载机的诊断知识，提出使用产生式规则来表示知识，并将规则分为一级 规则、二级规则，分层获取；设计了诊断推理策略和流程。 分析了装载机故障诊断的特点，提出了装载机故障诊断的体系结构，讨论了软件 的实现方法；给出了基于粗糙集理论的装载机故障诊断系统的运行实例。 最后，对全文进行了总结，并对以后的研究重点和方向进行了展望。  关键词：故障诊断  知识获取  粗糙集  决策表  约简  I Abstract Construction machinery is the main equipment in the national economy. Therefore it is very important to develop the fault diagnosis technology of construction machinery, which can quicken the rate of project’s progress, and improve its efficiency. In the research of fault diagnosis the problem related to knowledge acquisition has become a bottleneck of the development of fault diagnosis technology. In this dissertation, the rough set theory has been applied to the fault diagnosis of the loader—a typical construction machinery, in order to solve the problems such as knowledge acquisition, fault diagnosis when the datum about working condition is imprecise, inconsistent, and incomplete, fault-tolerance performance of fault diagnosis system. The research statue of fault diagnosis theory and technique are analyzed comprehensively. Then the rough set theory and its current research are discussed generally and the necessity of the application of rough set theory in fault diagnosis field is also stated in this dissertation. On the basis of introducing the rough set theory, the method and technique of fault diagnostic knowledge acquisition based on rough set is discussed. This dissertation put forward the model of fault diagnosis using decision table. By taking the rough set and duality Boolean calculation as the basis, the algorith