机械设备诊断的理论、技术与方法

The Theory,Technique and Method for Mechanical Device Diagnosis

本文对设备诊断学的几个基本理论问题进行了深入的探讨。进一步深化和发展了诊断问题的概念体系;深入论述了设备诊断学的目的、任务及过程;对诊断方法进行了较为全面而系统的划分。文中的基本论点是对文献[1]—[4]的进一步发展与完善。

This paper discusses some fundamental theory problems of the device diagnostics.The conceptual sys-tem for derice diagnostic problem is built up in definitive form.The fundamental conceptions about the sys- tem and its outputs,functions,restrictive conditions,characteristic signals,symptoms,fault and abnormalstates are defined and discussed.The paper analyzes the common and different respects between fault andabnormal state,as well as the ultimate causes which cause the system fault and the system abnormal state.Based on the above discussion,the mechanism about the happening and propagation of the fault is discussedand the basic properties of the fault are given.The four basic properties of the fault are the hierarchicalproperty.the time delay property,the interrelative property and the uncertain property.The formal defini-tion with universal significance about the diagnostic problem and its solution is provided,and the probablysimplified forms about this formal definition are discussed,thus the mathematic description about the diag-nostic problem and its solution is built.The paper discusses the purpose,content and the process of the device diagnosis,and emphaticallyanalyses the three important stages of the diagnostic process,which are the extraction of the characteristicsignals,the abstraction of the symptoms and the state recongnition.In accordance with above three stages,the paper discusses the main types of characteristic signals and its extractive methods,and the differenttypes of symptoms and its abstractive methods,and the different methods for state recongnition.Accordingto the different stages of the diagnostic process,the device diagnostic methods are classified and the maincharacteristics of different diagnostic methods are discussed.In accordance with the difference of state re-congnitive methods,the paper emphatically classifies the intelligent diagnostic methods according to differ-ent diagnostic model used,and analyzes the main method of intelligent diagnostic technique and its charac-teristics,thus a kind of classification method about the diagnostic technique is built in this paper.