Adaptive stochastic resonance in bistable system driven by noisy NLFM signal: phenomenon and application

The stochastic resonance (SR) in a bistable system driven by nonlinear frequency modulation (NLFM) signal and strong noise is studied. Combined with empirical mode decomposition (EMD) piecewise idea, an adaptive re-scaled SR method based on the optimal intrinsic function (IMF), proposed to enhance weak NLFM signal. At first, considering advantages of EMD for dealing non-stationary signals, segmented processed EMD. Meanwhile, cross-correlation coefficient used as measure select IMF that contains feature. Then, spectral amplification gain indicator realize each sub-segment reconstruct enhanced Finally, effectiveness highlighted analysis short-time Fourier transform spectrum simulation results. As application example, verified adaptability bearing fault diagnosis under speed-varying condition represents typical complicated mechanical engineering. research provides new way enhancement signals. This article part theme issue ‘Vibrational systems (part 1)’.