Application of evolution of singular values in multisymptom diagnostics of machines

The paper presents a possibility of observation of singular values evolving in time as quantities carrying diagnostic information. To prove the usefulness of singular values for this purpose many numerical simulations have been conducted. It has been proved that when observing changes of singular values obtained from SVD during the lifetime of a machine, the appearance of reversal points must be taken into account. The appearance of such points may prove that the symptom values change abruptly (e.g. structure cracking). The appearance of such an abrupt change can easily be overlooked because of variable working parameters of the machine, which influence the values of measured symptoms and generalized symptoms after SVD. Singular values are almost insensitive to changes of working parameters, so it is easier to pick out such changes in their evolution than directly in symptoms. The paper also presents an example of application of the proposed method for real diagnostic data obtained from ball bearings.