Rolling bearing defect severity evaluation using recurrence plot entropy

This paper presents a new approach to evaluate rolling bearing defect severity based on Recurrence Plot (RP) entropy. As a quantitative measure, the RP entropy is calculated from the probability distribution of the diagonal line length in the recurrence plot, where such plot graphically depicts a system's dynamics and provides a global picture of the autocorrelation in a time series over all available time-scales, in the reconstructed phase space, to characterize changing dynamics of the system. The experimental results have indicated that, as the working condition of the bearing deteriorates due to the initiation and/or progression of the structural damages, the frequency information contained in the vibration signal becomes increasingly complex, leading to the increase of the RP entropy. Therefore, the RP entropy can serve as an effective parameter for defect severity evaluation of rolling bearings.