Integration Approach for Local Damage Detection of Vibration Signal from Gearbox Based on KPSS Test

Abstract

In this paper we discuss a problem of local damage detection based on the vibration signal analysis. One of the classical approach is to extract features of the analyzed signal that differ for damaged and healthy case. We propose to test the integration property in order to check if given signal corresponds to healthy or damaged machine. The integration issue is known from the econometric analysis. However actually this methodology is used in various fields including operational condition monitoring and fault detection. We say the signal is integrated with order d if after differentiation d times it becomes stationary. In the proposed procedure we extract the appropriate subsignals from the original raw signal and use the Kwiatkowski–Phillips–Schmidt–Shin (KPSS) statistics in order to test if they are integrated. We expect that for the healthy case the subsignals are integrated, therefore the KPSS test does not reject the H0 hypothesis of integration. For the damaged case the subsignals containing the impulses related to damage are not integrated therefore the H0 hypothesis is rejected. This approach is a continuation of the authors’ previous works and allows to detect the local damage by the inspection of the KPSS statistics. We apply the methodology to the real vibration signals from gearbox.