Multipoint Optimal Minimum Entropy Deconvolution and Convolution Fix: Application to vibration fault detection

Incipient Fault Diagnosis of Rolling Bearings Based on Impulse-Step Impact Dictionary and Re-Weighted Minimizing Nonconvex Penalty Lq Regular Technique

“…In order to generate an impulse-step impact signal representative of that obtained from the double impact of the rolling element with the anterior and lagging fault edge, the time-domain waveforms of impulse-step impact atom, step-impulse impact atom, impulse-step impact atom, and the impulse-step impact signal without/with noise generated using Equation (6) are shown in Figure 2, where the simulated bearing type was NACHI 2206GK whose detailed parameters are listed in Table 1. The parameters of the impulse-step impact equation were set as follows: the system damping constant τ is 0.001, peak value ratio a is 0.3, the system natural frequency f n = 10,000 Hz, the impulse-like response happened u is 0.005, the rotor speed rotation frequency f r is 800 rpm.…”

“…Therefore, the major concern in bearing fault feature extraction is to determine which signal processing tools and algorithms to use to distinguish and diagnose early stage fault characteristics. Up to now, various fault diagnosis techniques have been proposed attempting to address the above challenges, such as wavelet/wavelet-packet transform [4], local mean decomposition (LMD) and its extension [5], minimum entropy deconvolution (MED) and its extension [6,7] and artificial intelligence (AI) algorithms such as artificial neural network (ANN) and fuzzy algorithm [8][9][10], Hilbert envelope spectrum [11], energy and entropy methods [12][13][14], higher order statistical techniques [15][16][17][18], to mention just a few. Unfortunately, some potential drawbacks and severe shortcomings related to the common techniques still remained unresolved.…”

Vibration diagnostics of planetary gearbox of engineering and transport machines based on spatial model application

“…The vertical line on Fig.2a schematically reflects Fig. 2, b illustrates the example of initial three teeth mesh according to equations (4)(5)(6). The blue dotted circle shows allocation of ring-gear mesh points, the red one -points of sun-gear meshes.…”

“…Different vibration analysis techniques developed over the last decades provide breakthrough in planetary gearboxes diagnostics. However, their wide application met some limitations.Many works consider diagnostic indicators of gear problems in frequency domain using spectral analysis [1], spectral characteristics of vibration signal [2], energy ratio based on difference spectra [3] and so called non-iterative deconvolution approach [4]. The Harmonic Index feature in [5] is defined as the amplitude sum of all apparent sidebands of a specific gear meshing harmonic of the raw data.To separate modulations in a planetary gearbox, a modulation signal bi-spectrum based sideband estimator was developed and used to achieve a sparse representation for the complicated signal contents, which allows effective enhancement of various sidebands for accurate diagnostic information [6].…”

Diagnosis of Localized Faults in Multistage Gearboxes: A Vibrational Approach by Means of Automatic EMD-Based Algorithm

“…The success of the fault identification strongly depends on the employed signal processing techniques, the system typology under investigation, and the working condition. In fact, the state of the art about the identification of localized gear faults covers a wide range of different approaches such as the following: the cyclostationary theory [2][3][4], which takes advantage of the hidden periods embodied in the vibration signals; the Kurtogram [5] for the selection of the frequency band associated with the maximum Spectral Kurtosis; time-frequency signal representations like Continuous Wavelet Transform [6]; the blind deconvolution algorithms [7,8], which estimate the excitation source due to the presence of the fault from the noisy observation; condition indicators based on the Time Synchronous Average [9].…”