An alternative demodulation method using envelope-derivative operator for bearing fault diagnosis of the vibrating screen

Abstract

The Teager–Kaiser energy operator (TKEO) and Hilbert transform (HT) are widely used as conventional demodulation methods in the signal processing field; however, it is well known that they are sensitive to vibration interference and noise, and these limitations hamper their applications, especially in the presence of strong noise. A vibrating screen is a kind of screening equipment in the field of vibrating machinery, which differs greatly from the rotating machinery in terms of structural characteristics and operational principles. The vibration signal extracted from the vibrating screen is not only comprised of multiple constituents but also a great deal of background noise. Thus, TKEO and HT have a large limitation on bearing fault diagnosis of the vibrating screen. To overcome these shortcomings, an alternative energy operator method named the envelope-derivative operator (EDO) is proposed. The results of simulation and bearing fault diagnosis of the vibrating screen indicate that EDO can effectively extract fault characteristic frequency, certifying its feasibility and superiority in comparison with TKEO and EDO.