A more refined fault detection and diagnosis of gear system based on higher order cumulants (HOCs)

Aim: Ref. 8 by Lai et al on HOC fault detection and diagnosis of a gear system needs, in our opinion, to be refined. In the full paper, We explain our refinements in some detail; in this abstract, we just add some pertinent remarks to listing the two topics of explanation. The first topic is: HOCs and HOC spectrum. In this topic, we mention that HOC spectrum gives such information as phase, amplitude value, double-cycle and symmetry. The second topic is: HOC fault detection of a gear transmission system. In this topic, we did experiments on the vibration response detection of normal gears, gears with cracks at tooth roots, gears with cracks at pitch-circle and gears with tooth face abrasion at different rotating speeds of a running decelerator. Then we analyzed their bispectrum, bicoherence spectrum and 1.5 spectrum with HOCs. The experimental results and their analysis, shown in Figs. 2 through 21 in the full paper, indicate preliminarily that the fault detection and diagnosis of the gears with HOCs are effective and more refined than those achievable by Ref. 8's method.