In view of actual conditions of aero engine's rub-fault

the application limitations of variant diagnosis methods were analyzed.Aboundary extension method was presented for restraining the ending effect of the reconstructive signals;and an improved method was adapted to process both short time series and long time series based on singularity value decomposition and the boundary extension method.The selective method of singularity values for reconstruction was also discussed.Then the vibrating signals of certain aero engine were analyzed

showing good detection results of fault signals of a certain Aero-engine.