Reliability analysis for redundant system with multiple FOGs based on fault tree analysis method

Reliability analysis for redundant system of multiple fiber optical gyroscopes(FOGs) is a key issue in health management of inertial measurement system.In traditional reliability analysis of inertial measurement system,the common cause failure(CCF) is not considered,or is difficult to derive the analytical solutions even the CCF is considered.Therefore,in this paper,the multiple beta factor(MBF) model is applied to model the CCF of the inertial measurement system,and the fault tree analysis(FTA) method is used to analyze the system reliability.The numerical example shows that the results without considering the CCF or by the simplified CCF model are relatively optimistic,therefore the risk of failure is increased;by contrast,when the MBF model is utilized,the analytical solution is easily obtained by the FTA method,and the results are satisfctory.