Nonlinear fault diagnosis based on Volterra series & its application in rotor systems

The Volterra series theory is a general description of nonlinear systems. As its full consideration of nonlinear factors, Volterra series can show the essential characteristics of nonlinear systems. The basic theory of Volterra series is briefly introduced in this paper first. Then, generalized impulse response function (GIRF) is identified by using genetic algorithm (GA). Satisfactory identification result is achieved. Finally, this method is employed in the area of fault diagnosis for rotor-bearing systems. We investigate the changes of GIRF of rotor signals under different conditions during run-up stages. The effectiveness of the method is verified by experimental. This research of the paper provides a new way of fault diagnosis for mechanical systems.