Accuracy Issues of Discrete Hilbert Transform in Identification of Instantaneous Parameters of Vibration Signals

M. Meissner Institute of Fundamental Technological Research of the Polish Academy of Sciences, A. Pawińskiego 5B, 02-106 Warsaw, Poland

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In the paper, an accuracy of the discrete Hilbert transform: method in a detection of amplitude and frequency of vibration signals has been examined. This issue was studied for sinusoidal damped vibrations often encountered in practical applications. It has been shown that an inexactness of the Hilbert transform generates fictitious oscillations of amplitude and frequency. For small damping of vibrations these oscillations were significant only at both ends of a discrete signal. An error induced by a numerical algorithm was especially severe for strongly damped vibrations because it manifested itself by a large overestimation of amplitude and erroneous jumps of frequency. To reduce the error generated by the Hilbert transform method, the appropriate modification of discrete signal was proposed.

DOI: 10.12693/APhysPolA.121.A-164 PACS numbers: 02.30.Uu, 46.40.Ff, 43.20.Ks