Zhejiang University

Zhejiang Lab

Dazhuan Wu

Bin Huang

Peng Wu

Shuai Yang

Tian Xiang

Yaochun Hou

Pengcheng Du

Yuxuan Wang

Kexin Pu

Pengzhong Wang

Lu Wang

A gear fault diagnosis method based on joint weighted envelope noise-resistant correlation of sub-signals, comprising: converting an original vibration signal sequence into an envelope signal through a signal sequence element-wise squaring-low-pass filtering-square root computation process, reconstructing the envelope signal according to different time intervals to obtain a series of sub-signals, calculating a fault information representation measure of each sub-signal based on an L-moment theoretical index, assigning a weight to each sub-signal with Sigmoid transformation, calculating a joint weighted envelope noise-resistant correlation function of the envelope signal sequence and the reconstructed sub-signals based on the envelope signal, the reconstructed sub-signals and the corresponding weights thereof, and determining a characteristic frequency according to a reciprocal of a time interval value corresponding to the characteristic peak in a plot of the joint weighted envelope noise-resistant correlation function with the time interval to eventually identifying a gear fault.

Gear fault diagnosis method based on joint weighted envelope noise-resistant correlation of sub-signals

A method for diagnosing rotor rub-impact in a rotating machinery based on vibration signal deconstruction and frequency modulation characteristic anti-noise enhancement, including: converting, based on two-stage integration transformation and high-pass filtering, vibratory acceleration signals from a rotating machinery device into vibratory displacement signals; performing targeted extraction on a rotating frequency component therein based on an improved variational mode decomposition method; 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; inputting a calculated instantaneous frequency sequence into an optimum stochastic resonance system for anti-noise enhancement of intrawave frequency modulation characteristics; and processing FFT on an instantaneous frequency of intrawave frequency modulation characteristics after anti-noise enhancement, and 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.

Method for diagnosing rotor rub-impact in rotating machinery based on vibration signal deconstruction and frequency modulation characteristic anti-noise enhancement

The present disclosure discloses a horizontal-axis ocean current power generation device for an underwater vehicle. The power generation device is disposed in a groove of a rotary body of the underwater vehicle, and includes an undercarriage unit, a yawing unit, and a power generation unit. The undercarriage unit can realize elevation and descent of the entire power generation device, and the power generation unit is capable of realizing arbitrary rotation within 360&#xb0; in a horizontal plane through the yawing unit. The power generation device can actively yaw based on change of an ocean current direction to perform an incident flowing function. The power generation unit respectively drives an outer shaft and an inner shaft to rotate through a front blade and a rear blade that rotate in opposite directions, so as to drive inner and outer rotors of a motor, thereby cutting magnetic induction to generate electric power.

Horizontal-axis ocean current power generation device for underwater vehicle

Growing community of inventors

Hangzhou, China

Dazhuan Wu