A Novel QPC Detector for the Health Monitoring of Rotating Machines

Higher-order spectra such as the bispectrum/bicoherence are widely used for the analysis of various nonlinear phenomena. However, the traditional bicoherence definition fails when its 'phase randomization' assumption is not satisfied, and this assumption is often not appropriate for continuous health monitoring of rotating machines. Therefore, we propose a novel quadratic phase coupling detector based on the bicoherence. Through theoretical and experimental comparison, it is shown that our approach is superior to previously proposed methods at high SNRs, and can also address partially coupled cases which previous approaches completely failed to deal with.