Key fault propagation path identification of CNC machine tools based on maximum occurrence probability

In order to revise the deviation caused by ignoring the dynamic character of fault propagation in traditional fault propagation path identification methods, a method based on the maximum occurrence probability is proposed to identify the key fault propagation path. Occurrence probability of fault propagation path is defined by dynamic importance, dynamic fault propagation probability and fault rate. Taking the fault information of CNC machine tools which subject to Weibull distribution as an example, this method has been proven to be reasonable through comparative analysis. Result shows that the key fault propagation path of CNC machine tools is not unique, but changes with time. Before 1000 hours, key fault propagation path is electrical component (E) to mechanical component (M); after 1000 hours, key fault propagation path is auxiliary component (A) to mechanical component (M). This change should be taken into account when developing maintenance strategies and conducting reliability analysis.

Automated summary

To overcome the deviation caused by neglecting the dynamic nature of fault propagation in traditional methods, a new approach is proposed based on the maximum occurrence probability to identify the key fault propagation path. The occurrence probability is defined by dynamic importance, dynamic fault propagation probability, and fault rate. By analyzing the fault information of CNC machine tools that follow Weibull distribution, it is proven that the method is reasonable. The results show that the key fault propagation path of CNC machine tools changes with time, from electrical component (E) to mechanical component (M) before 1000 hours, and from auxiliary component (A) to mechanical component (M) after 1000 hours. This change should be considered in maintenance strategies and reliability analysis.