Abstract: The aero-engine is a pivotal component of an airplane. The operating reliability assessment of the aero-engine is greatly meaningful in guaranteeing the flight safety. In practice, operating conditions of the aero-engines vary. It leads to that degradation degrees and failure times for different aero-engines are with great degrees of discreteness. Aiming at solving the problem that reliability assessment methods based on probability statistical analysis are inappropriate to assess the reliability of the individual aero-engine, a novel method using the condition monitoring information is proposed. The condition subspace of the aero-engine is constructed by utilizing the Kernel principal component analysis(KPCA) to describe the performance change of the aero-engine. The principal angles between the subspaces from the normal state and the damage state are calculated. The principal angles are transformed into operating reliability index by a proper mapping function. The proposed method is validated by using both the aero-engine run-to-failure data shared by National Aeronautics and Space Administration and the practical test data from a repair factory of aero-plane. The results illustrate the proposed method can assess the operating reliability of the aero-plane reasonably. It also offers valid approach for the operating reliability assessment of the aero-plane whose failure model subjects to small sample characteristics.

Key words: Aero-engine, Condition monitoring information, Operating reliability, Principle angles, Subspace