Analysis And Modeling Method Of Hierarchical Propagation Characteristics Of Electronic Equipment Faults

Electronic equipment generally possesses complex structures and numerous components which are highly correlated and coupled in function and formation.Therefore,A fault that occurs somewhere in the electronic equipment will spread through all levels of the electronic equipment(such as device level,functional circuit level,etc.)and finally shut down the electronic equipment.However,the fault propagation properties at different levels of electronic equipment are not apparent at present,making it difficult to analyze the spreading and locating of the faults in those electronic equipment levels.As a result,fault diagnosis of hierarchical electronic equipment has become a significant challenge.This thesis mainly focuses on the analysis and modeling method of hierarchical fault propagation of electronic equipment with the support of the key and basic research project.The main research contents of this thesis are as follows:(1)Analysis of fault propagation characteristics of electronic equipmentBased on the complexity and diversity of the hierarchical fault propagation,the characteristics of the hierarchical fault propagation of electronic equipment are analyzed from four aspects: the propagation medium,the propagation process(form),the propagation path,and the propagation uncertainty.Results show that the hierarchical fault propagations endow the properties of multi-media,multi-path mode,and intense uncertainty,which lays a foundation for the subsequent propagation modeling of electronic equipment fault.(2)Modeling and analysis of hierarchical fault propagation of electronic equipmentBased on the characteristics of hierarchical fault propagation of electronic equipment,the causal topology network model and hierarchical modeling idea are introduced to abstract the electronic equipment as a causal hierarchical topology network according to the functional structure relationship.The network nodes are defined as the fault modes of the multilevel electronic equipment.Then,the fault propagation model based on the causal hierarchical topology network is formed through the correlation and fusion of propagation parameters.On this basis,the definition and resolution method of CHTNM related parameters are proposed.Finally,based on the constructed CHTNM,a fault hierarchical propagation reasoning method of electronic equipment on the global hierarchical topology network is proposed,which can realize the quantitative reasoning of fault hierarchical propagation path and the highest risk path in electronic equipment.(3)Application and verification of typical electronic equipmentAs a millimeter-wave radar is chosen to be a typical object,the vertical hierarchy division and node selection are firstly carried out.The CHTNM of a millimeter-wave radar is constructed based on the data and relevant information of FMEA.Then,the model parameters of the millimeter-wave radar are demonstrated according to the model parameter solution method proposed in this paper.As a result,the hierarchical propagation path law of the typical fault mode(intermittent open-circuit fault of the primary power supply)of the millimeter-wave radar under different fault intensities is obtained through reasoning and analysis.Finally,the experiment of "the intermittent fault injection propagation" shows that the proposed CHTNM can infer and analyze electronic equipment’s hierarchical propagation fault path.