Application of mathematical-morphology-based generalized fractal dimensions in engine fault diagnosis
Shuang-shan Mi · Zhendong yu chongji · 2011
The vibration signals generated by engine can be regarded as a typical nonlinear signal.The fractal geometrical theory provides an efficient tool to characterize the nonlinearity of such a signal.Multifractal contains more information compared to single fractal and can characterize geometrical features and local scale behavior more appropriately.In order to overcome the deficiency of the traditional calculation method of the generalized fractal dimensions,a mathematical-morphology-based generalized fractal estimation technique was proposed here.Signals acquired from different types of engine condition,such as,normal condition,misfire fault and intake valve clearance fault were employed to evaluate this new method.Results revealed that the generalized fractal dimensions calculated based on mathematical morphology are very stable and have a superior capacity to distinguish different engine operating states.Furthermore,mathematical morphology operation contained only simple addition,subtraction,maximum and minimum operations,it dramatically reduced the computational complexity compared to other techniques.Thus,it was verified that the proposed method is a fast and effective technique for accurate fault diagnosis of engine.