Quantitative Identification of Crack Faults in Aviation Hydraulic Pipeline Based on Multifractal Theory

The vibration mechanism of aviation hydraulic pipeline is complex, and the fault signal interference coupling. Moreover, the fault characterization is not obvious, and the identification rate of early crack fault and propagation is not high. In order to address the above problems, a fault diagnosis method based on multifractal and local linear identification was proposed in this paper to carry out fractal analysis on vibration signal with the generalized dimension. It was analyzed from the general dimension correlation coefficient spectrum diagram and the general dimension correlation coefficient change law that, the general dimension correlation coefficient can identify the early fault of crack and the crack propagation. The model space sample database was established by means of multifractal diagnosis method to identify the pending signals of any crack fault, and the local linear identification method was used to perform simulation analysis on the pending vibration signals. The results showed that the fractal theory can be used to quantitatively identify the crack fault length in aviation hydraulic pipe.