A method for the correlation dimension estimation for on-line condition monitoring of large rotating machinery

In this paper, we introduce a robust method for the correlation dimension estimation in an automatic way for its implementation in on-line condition monitoring of large rotating machinery. The method is called Automatic-Attractor Dimension-Quantitative Estimation (A-AD-QE). It is based on a systemic analysis of the second derivative of the correlation integral obtained by the Grassberger and Procaccia algorithm. The A-AD-QE method concentrates its attention on the scaling region definition and it also has the possibility to analyse the geometrical structure of the obtained multidimensional second derivative of the correlation integral and its relation with the pseudo-phase portrait. The effectiveness of the introduced method was verified by means of the calculation of well-known analytic models as Lorenz attractor, van der Pol oscillator and Henon Map. Furthermore, the A-AD-QE method was applied to process real vibration signals of large rotating machines. As a typical example we analysed four measurements, recorded at different points. The obtained results demonstrate the applicability of the method in real vibration signal processing for this kind of machines.