SECE-based piezoelectric energy sensor for the diagnostics of timing belt

The article presents a novel idea for the fault diagnostics of the timing belt based on developing a piezoelectric energy sensor attached to the synchronized electric charge extraction (SECE) interface. The device is composed of a piezoelectric cantilever beam with a tip magnet impulsively excited by another small magnet attached on the surface of a moving timing belt. As a result, energy is harvested by frequency up-conversion mechanism operated under magnetic plucking. It is observed that the extent to which power harvested from the failing belt is higher than that from the healthy belt, giving rise to the basis for condition monitoring of the timing belt by detecting the output power. In addition, the analysis shows that the power sensitivity to the magnetic distance can be enhanced to 145% by the SECE interface circuit in comparison with the standard (STD) interface circuit. The consequence of it is that the SECE case exhibits a more accurate decision boundary determined by the logistic regression to classify the healthy and flawed states, as confirmed by the experiment.