Study on Fractal Box Dimension and Its Application to Fault Diagnosis of Hydraulic Pump

Abstract

Fractal box dimension is a new method to represent self-similarity and complexity of non-stationary mechanical fault signal. In this paper, we first present the basic conception of fractal and box dimension. Then we propose the algorithm to calculate the box dimension of discrete signal. On the basis of wavelet packet decomposition, we quantitatively analyze the vibration signal under different conditions with fault characteristic by way of box dimension. Experimental results show that the box dimensions are different in evidence because of the difference of fault mechanism. As a successful application, fractal box dimension can be used to recognize the fault pattern of hydraulic pump effectively.