Phase Difference Estimation of Helicopter Fault Signal Based on Bi-Spectrum

At helicopter fault diagnosis, the phase difference estimation of fault signal is often used. Due to the impact of the actual working environment, the fault signals collected for analysis are greatly affected by noise, and the signal-to-noise ratio is high, which is not conducive to the phase difference estimation. In this paper, considering the property that bi-spectrum can effectively suppress Gaussian noise, the phase difference of fault signal is obtained by signal reconstruction, bi-spectrum solution and initial phase estimation based on bi-spectrum theory. The simulation results show its effectiveness.