Reliability evaluation of phased mission system under multiple correlated failure modes

Phased Mission System (PMS) is widely used in large complex equipment such as spacecraft and satellites. Due to sophisticated structure and complex missions, the components and systems of the large complex equipment have multiple failure modes which are correlated. On the one hand, taking multiple correlated failure modes in to consideration can describe the multi-state characteristics of the system more accurately and decouple the correlation between different phases of the system more clearly. On the other hand, its complexity makes the reliability evaluation of PMS more difficult. To solve this problem, this paper discusses the modeling method of multiple failure modes and their correlation, and proposes an improved combination method of Multiple Failure Mode Tree (MFMT) and Multi-state and Multi-valued Decision Diagram (MMDD) model, completes the reliability evaluation of PMS in cross-level (failure mode-component-system) and cross-scale (single phase-multiple phase). Finally, the MFMT-MMDD model of the satellite attitude orbit control system (AOCS) is established and Monte Carlo simulation is used to verify the feasibility and accuracy of this modeling method.