Diagnosing weak fault of rolling bearing using duffing system

Abstract

Bearing's early fault signal always contains cyclical impulses and strong noise, so it is difficult to extract the feature of weak fault. It can be found if weak periodic signal was input Duffing system, then the variance of the system output value X appears maxima . This phenomenon can be occurred only under the condition of Duffing system parameter p is equal to the angular frequency of input periodic signal. By using classical fault diagnosis method, the frequency range of fault signal has been obtained. Then Duffing system parameter p would be adjusted in accordance with this frequency range. In the process of adjusting parameter p, the largest variance of Duffing system output X would be appeared. With this method, fault feature frequencies can be extracted and fault type can be judged. Simulated and real weak rolling bearing fault signals have been analyzed in this paper, the result showed the validity of the proposed method.