Multiple oscillations detection in control loops by using the DFT and Raleigh distribution

This work introduces an oscillation detection method by analyzing the magnitude of signal after the discrete Fourier transform (DFT). Properties of Raleigh distribution are used to calculate a threshold in order to detect multiple oscillations simultaneously. The proposed algorithm is able to detect oscillations in presence of colored noise based on a statistical test. Two simulation examples are provided to verify the effectiveness of the method.