The research of unknown weak fault signal detection on the duffing oscillator with Hu moment invariants

The chaotic system is sensitive to the initial value, and this property can be applied in the weak signal detection. There are periodic, critical and chaotic states in a chaotic system. When the system is in the critical state, a small perturbation of system parameter may lead to a qualitative change of the systems state. This paper introduces a method to detect the unknown weak signals by using Hu moment invariant to identify the chaotic nature automatically. The authors choose the Duffing equation, using MATLAB to carry on the simulation, to study the changes of the Hu moment invariant when the phase transmit the chaotic state to periodic state. By means of observing the phase locus chart and time domain chart, the weak signal will be detected.