| CPC G01M 99/005 (2013.01) | 10 Claims |

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1. A method for diagnosing rotor rub-impact in a rotating machinery based on vibration signal deconstruction and frequency modulation characteristic anti-noise enhancement comprising the following steps:
step 1: collecting, by a vibration acceleration sensor, a signal sequence from a rotating machinery device;
step 2: converting, based on two-stage integration transformation and high-pass filtering, a collected vibratory acceleration signal into a vibratory displacement signal;
step 3: performing targeted extraction on a rotating frequency component in the vibratory displacement signal based on an improved variational mode decomposition method;
step 4: calculating and estimating instantaneous fluctuation characteristics of a fundamental frequency of the extracted rotating frequency component using a quadrature-derivative-based normalized Hilbert transform to obtain an instantaneous frequency;
step 5: inputting a calculated instantaneous frequency sequence into an optimum stochastic resonance system for anti-noise enhancement of intrawave frequency modulation characteristics, wherein potential energy parameters of a stochastic resonance system and a step length of a Runge-Kutta calculation process are optimized by a particle swarm optimization algorithm to obtain the optimum stochastic resonance system; and
step 6: processing fast Fourier transform on the instantaneous frequency of the intrawave frequency modulation characteristics after anti-noise enhancement, diagnosing and identifying a rotor rub-impact fault of the rotating machinery based on a distribution characteristic of harmonic amplitudes related to a rotor rotating frequency, issuing, by a main control unit, a warning to an operator, and promptly conducting, by the operator, a shutdown inspection and a maintenance of the target rotating machinery, to obtain the rotating machinery without the rotor rub-impact fault.
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