Reduction of Trendless Sequences of Data by Universal Parameters

This chapter demonstrates how to obtain a quantitative description of noise samplings or, more precisely, of trendless sequences containing clearly expressed fluctuations only. Besides the mean value, standard deviation and range, it is shown that it is possible to find up to ten more parameters useful for a quantitative reading of a wide class of trendless sequences. The analysis carried on in this chapter considers real data from acoustic noise signals produced by frictionless vehicle bearings (in normal regimes) and by bearings with different types of defects. The method is defined by a “struggle” principle between positive and negative fluctuations and enables the detection of any deliberately created defect in the bearings and its quantitative description in terms of nine parameters. As with the methods introduced in previous chapters, a suitable application of the proposed method for the quantitative reading of a wide class of trendless noise containing different types of fluctuations requires an optimisation phase. To synthesise, the aim of this chapter is to convince the reader that not only signals but also fluctuations contain deterministic information, useful for a deeper analysis and quantitative reading.