Novel Cyclo-Nonstationary Indicators for Monitoring of Rotating Machinery Operating Under Speed and Load Varying Conditions

Abstract Condition monitoring arises as a valuable industrial process in order to assess the health of rotating machinery, providing early and accurate warning potential failures allowing for planning effective realization preventative maintenance actions. Nowadays, machinery (gas turbines, wind etc.) manufacturers adopt new business models, not only equipment itself but also additionally taking on responsibilities condition monitoring, by embedding sensors systems within each unit prompting actions when necessary. Among others, rolling element bearings are one most critical components machinery. In complex machines, failure indications an bearing damage weak compared other sources excitations (e.g., gears, shafts, rotors). Vibration analysis is widely used various methods have been proposed, including time frequency domain. number applications, changes operating conditions (speed/load) influence vibration change amplitude characteristics vibroacoustic signature, making them nonstationary. Under changing environments, where speed load vary, assumption quasi-stationary appropriate result, time-frequency time-order representations introduced, such Short Time Fourier Transform Wavelets. Recently, emerging interest has focused modeling signals cyclostationary, which particular class nonstationary stochastic processes. The classical cyclostationary tools, Cyclic Spectral Correlation Density (CSCD) Modulation Spectrum (CMS), can be extract interesting information about cyclic behavior signals, under that constant or nearly constant. Global diagnostic indicators proposed measure cyclostationarity steady conditions. overcome this limitation, generalization both SCD CMS functions displaying Order versus Frequency well cyclo-nonstationarity cover speed-varying scope paper propose novel approach cyclo-nonstationary based simultaneous independently varying effectiveness evaluated simulated real captured dedicated test rig.