The application of Hilbert-Huang transform energy spectrum in brushless direct current motor vibration signals monitoring of unmanned aerial vehicle

Abstract

Due to the characteristics of structure, brushless direct current motor has a long lifetime, which makes it more difficult to obtain failure data. Accordingly, valid degeneration characteristics are required in life prediction. In this article, a novel method of condition monitoring and comparing is presented, which contributes to life prediction. Experiments were conducted for hundreds of hours to get degradation data of brushless direct current motor used in rotor of unmanned aerial vehicle. Furthermore, the vibration characteristics were analyzed by Hilbert-Huang transform to get energy spectrum. And, the differences in energy spectrum between two groups of sample collected were quantified by Euclidean distance. According to the scan under microscope, the oxidation was observed on surface of the used bearing, which leads to the changes in energy spectrum. The experimental results demonstrate that Hilbert-Huang transform energy spectrum can be effectively applied to monitor and evaluate the status of brushless direct current motor.