Weak signal detecting of gas concentration based on Duffing chaotic oscillator

The novel method of detecting weak coal gas concentration signal is proposed based on Duffing chaotic oscillator theory in the paper. The chaotic feature of Duffing oscillator is introduced, the basic principle of periodic signal detection with Duffing chaotic oscillator is described, and the chaotic threshold of Duffing oscillator is discussed and determined by the Melnikov function. The autocorrelation theory and chaotic signal amplitude detection method are combined to decrease the detecting errors for weak coal gas concentration signals. Theory analysis and simulation results show that the higher sensitivity and good anti-noise performance are obtained by using of the Duffing chaotic oscillator due to its sensitivity to the initial measurement condition while the tested signal with periodic perturbation is used as the driving force of Duffing equation.