Abstract:

We adopt an equation group of 16 equations to measure the weak sine signal with unknown phase place.The threshold values of the 16 equations are already confirmed.When the weak signal joins the system,we verify 16 equations one by one to see whether the phase portrait changes from chaos to big yardstick cycles in the systematic output.If so,this equation can be used to measure the signal.If not,the experiment is continued.We can find one or many equations that are suited finally.In this paper,we consider the mean of those equations with phase portrait changes as the amplitude of the weak signal.

Key words: weak signal detection;Duffing oscillator;chaos