The invention discloses a non-intrusive permanent
magnet synchronous
servo motor bearing fault on-line diagnosis method and
system, and the method comprises the steps: injecting a
chirp current
signal in a tuning stage, calculating a
frequency response function through combining with a rotating speed feedback
signal, and determining a resonant frequency according to the
frequency response function; calculating a theoretical characteristic order according to the motor bearing
size parameter; in a motor operation stage, collecting a motor rotating speed
signal and determining a theoretical characteristic frequency according to the theoretical characteristic order; determining an optimal
resonance demodulation frequency band according to the
resonance frequency and the theoretical characteristic frequency, and performing band-pass filtering on the motor rotating speed signal according to the optimal
resonance demodulation frequency band; an envelope signal of the filtered signal is calculated online through an orthogonal
demodulation algorithm, the
frequency spectrum of the envelope signal is obtained through FFT analysis, threshold comparison is conducted on the
frequency spectrum of the envelope signal and the amplitude corresponding to the theoretical characteristic frequency, and fault diagnosis result judgment is completed. According to the invention, on-line diagnosis of the bearing fault of the permanent
magnet synchronous
servo motor under the condition of low-performance
chip resources is realized.