Feed pump bearing fault diagnosis method based on second-order group delay operator time-frequency filtering

The invention belongs to the field of mechanical equipment diagnosis, and relates to a feed pump bearing fault diagnosis method based on second-order group delay operator time-frequency filtering. The fault characteristic period of a target bearing is obtained by executing the following steps, and then the fault of the target bearing is diagnosed, and the method comprises the steps that S1, vibration signals of the target bearing in service are collected through a piezoelectric acceleration sensor installed on a bearing seat; s2, converting the vibration signal into a time-frequency domain through S conversion to obtain transient characteristic information of the vibration signal; s3, deriving a first-order group delay operator based on the ideal impact signal model, and further obtaining a second-order group delay operator based on the first-order group delay operator; and S4, diagnosing the fault of the target bearing by identifying the transient impact occurrence time of the vibration signal in the time-fr