Construction method of multi-stage degradation threshold for shipborne helicopter based on flight parameters

Abstract

Safety is an important indicator to measure the performance of ship-borne helicopters, and the state monitoring of shipborne helicopters is the main way to ensure the safety of shipborne helicopters. As the flight time of the shipborne helicopter increases, many components will gradually degrade, and corresponding threshold need to be set to ensure the normal operation the shipborne helicopter. The commonly used fixed threshold method will cause false alarms due to different flight states, so it is necessary to dynamically construct the state thresholds under different flight states. Firstly, the empirical mode decomposition is used to denoise the signal, and then the extracted monitoring features of the shipborne helicopter are classified according to the stability in multiple flight states. A fixed threshold is setted by statistical characteristics for stable features. The dynamic feature selects flight parameters that are highly correlated with feature changes as indicators, and uses principal component analysis to fuse them to construct a dynamic threshold index.The proposed method is verified by actual flight data, and the result shows that the dynamic threshold index can effectively reduce the false alarm rate.