Behavior Analysis Of Fault Propagation In Machining Center

As one of the important carriers of intelligent manufacturing,it is very important to ensure the healthy and reliable operation of machining centers.Machining center is a complex system composed of multiple components,and there is a high coupling relationship between the components of the system.The existence of this coupling relationship makes the fault propagation of machining center possible,but also brings great difficulties to fault diagnosis.In actual production,the cost and time spent on locating the fault source should not be ignored.Therefore,it is of great significance to study the determination of critical fault propagation path in machining center.Firstly,based on the fault information of machining center collected on the spot,the module is divided according to the working process and principle of machining center,and related fault identification are carried out.Considering the transmission of machining center fault,combined with directed graph theory and design structure matrix(DSM),the fault propagation hierarchy model of machining center is constructed,which can clarify the mechanism of complex fault propagation.Secondly,considering the influence of multiple random truncation,the Johnson method is applied to correct the sequence of system component failures,and the rate of occurrence of failures model of component based on time correlation is established.According to the fault propagation hierarchy model of machining center,the criticality importance degree of the system component node is calculated,and the coupling degree function is used to calculate the fault influence degree between the nodes of the system components.On this basis,the fault propagation probability of each node is calculated by combining the fault probability model of the system component,and the fault propagation intensity model is constructed to evaluate the fault propagation ability by combining with the edge-betweenness which reflects the structural characteristics of the model.Finally,taking a machining center as an example,combining the hierarchical structure model of fault propagation and based on the fault propagation intensity,the critical fault propagation path of machining center is analyzed by reverse reasoning,and the critical fault source is located.The simulation and analysis software of fault propagation in machining center is designed and compiled in order to realize the computerization of the analysis.The method is compared with the method of determining the critical fault propagation path of machining center based on comprehensive failure rate to verify the rationality and validity of the analysis method.The analysis and verification of diagnostic theory show that considering the fault propagation behavior from multiple perspectives,the proposed method can correct the deviation caused by the traditional description of fault propagation behavior based on a single index,and make the identification of critical fault propagation path and the location of fault source more accurate,which is in line with engineering practice.