Rotor dynamic and static rub impact fault diagnosis method based on instantaneous frequency shaft centerline orbit

The invention discloses a rotor dynamic and static rub impact fault diagnosis method based on an instantaneous frequency shaft centerline orbit. The method comprises the following steps: mounting two displacement sensors of which the included angle is 90 degrees on a vibration testing section; acquiring displacement vibration signals x(t) and y(t); performing EEMD (Ensemble Empirical Mode Decomposition) on the displacement vibration signals x(t) and y(t) respectively; performing spectral analysis on obtained mode components; respectively selecting IMF signal components IMFx(t) and IMFy(t) which are mainly power frequency components; calculating by using a direct orthogonal method to obtain instantaneous frequencies IFx(t) and IFy(t); subsequently decomposing single-component signals IMFx(t) and IMFy(t) into amplitude modulation signals and frequency modulation signals by means of normalization; synthesizing a shaft centerline orbit by using the calculated instantaneous frequencies IFx(t) and IFy(t) of one-time rotation frequency components in directions X and Y; identifying the running state of a rotor by using the shape of the shaft centerline orbit; extracting instantaneous fluctuation information of the rotating speed of the rotor by a bending vibration signal; synthesizing the instantaneous frequency shaft centerline orbit to realize effective diagnosis on rotor rub impact faults. The method disclosed by the invention has the advantages of improving the accuracy of the diagnosis on faults such as dynamic and static rub impact of the rotor and increasing the utilization rate of a bending vibration monitoring signal of the rotor.