A method for identifying rotating blade asynchronous vibration by all-phase FFT

The technology of rotating blade vibration measurement based on bladetip-timing(BTT) is badly sub-Nyquist-sampled method.In order to identify rotating blade asynchronous vibration,the asynchronous vibration signal model based on BTT is analyzed.A method for identifying asynchronous vibration by multi-probes traversing used all-phase FFT technology is designed.The arithmetic of all-phase FFT and multi-probes traversing are deduced in theory,and also are validated in simulation by computer.The method is applied to vibration measurement experiment for a certain model of aerial equipment.The experimental results indicate that the identified results of blade asynchronous vibration are in accord with the designed results of the blade in theory.The problem of identifying blade asynchronous vibration in sub-Nyquist-sampling is solved,and the BTT system is ameliorated greatly.