Application Of Fractal Method On The Condition Measurement And Fault Diagnosis Of Reciprocating Compressor

Fractal is a new subject and it is especially fit for researching nonlinear system. Recently signal processing methods based on fractal have been applied to mechanical system fault diagnosis. The objective of the proposed research is to develop a method based on fractal theory for analyzing the nonlinear signals of mechanical system. This method will provide further useful information about the underlying .dynamics. It is possible to implement mechanical system fault diagnosis by using this method combined with other signals analysis methods.The research objective of this article is 2D12 reciprocating compressor, make a experiment based on the application of fractal, including the obtaining and collecting of data ,pick-up of character parameter, the fault diagnosis method and so on. during the course of pick-up of character parameter apply correlation and lyapunov exponent to be the character parameter, have important attachment to discuss the choice of the calculating method of correlation dimension and calculating parameter, aim at unstable characteristic of vibration signal of reciprocating compressor to analyse, apply wavelet to de-noise ,guarantee to get the fractal dimension exactly, combine several typical dynamic system, use the procedure to calculate the known signal, and discuss the influence of parameter and noise to the result, propose several methods to ensure parameter and value range influencing correlation dimension, and analyse to boxing dimension.On the part of fault fractal analysis and diagnosis instance of 2D12 reciprocating compressor ,with correlation dimension to analyse to the reciprocating compressor acceleration signal of different working (fault) condition and different parts, the result shows that correlation is very sensitive to fault of equipment and can reflect dynamic characteristic of complex mechanical system, combined with lyapunov exponent to judge whether all the fault conditions of compressor situate in chaos condition, in the end aim at characteristic of vibration signal of reciprocating machinery. Develop fault diagnosis software.