Aiming at the weak signal detection problem under strong noise background

the weak signal detection principle based on Duffing oscillator is analyzed. Combining the complementary ensemble empirical mode decomposition (CEEMD) method with the variable-scale Duffing oscillator

a new weak signal detection method is proposed. The complex noisy signal is decomposed into different intrinsic mode functions (IMF) by using CEEMD. Through the Duffing system bifurcation diagram and its changes

the critical threshold of the phase trajectory change is found

and the information detection of the noisy signal is realized. The results show that the joint detection method can not only immune noise well

but also effectively detect multi-frequency periodic signals with signal-to-noise ratio as low as -73dB.