Analysis of Life-cycle Reliability and Component Importance of Propeller Pitch Control System using Bayesian Network

Propeller pitch control systems have complex structures with various components that participate in different task stages. In this study, a fault tree analysis model and multistage Bayesian network are used to qualitatively and quantitatively analyze the importance of these components and calculate the changes in system reliability. First, the fault tree analysis model of each stage is established according to system components. On this basis, the importance of each component is qualitatively analyzed. Next, the fault tree model is transformed into a Bayesian network model for reliability analysis and the quantitative analysis of importance. The changes in the reliability and importance of each unit during the operation of the pitch control system are obtained. The system reliability after 400 h of operation is 0.982. The components with high importance in the system are the motor, carbon brushes, and circuit connections. Protective measures are proposed to provide technical support for the safe operation of the propeller pitch control system.