Technical Method of Fault Diagnoses Based on Fractal Theory

Four different fault signals are simulated and collected which are oil whip fault signal, rub-impact fault signal, rub-oil whip coupling fault signal and rub - oil whip - loose coupling fault signal In the experimental stage. Using fractal theory, fractal dimension of vibration signal of X direction and the Y direction are separately calculated and resultant dimension of these two directions is obtained. Then, resultant dimension and its dimension energy spectrum are used as characteristic quantity to achieve the feature extraction and recognition. Because resultant dimension is synthesis of the fractal dimension of two directions vibrates signal, it combines the vibration information of two directions. Therefore, it can reflect comprehensively and really mechanical system´s vibration characteristic, the reliability of failure diagnosis is greatly improved.