A new algorithm for the detection and parameters estimation of linear frequency modulation (LFM) signal was proposed．Firstly,the influence of LFM signal on the phase diagram of the Duffing chaotic oscillator was analyzed,and then the demodulation frequency processing was implemented to transform the LFM signal into periodic signal．At last,Duffing oscillators filter array was constructed to realize the detection and parameters estimation of LFM signal and Lyapunov exponent was exploited to judge the state of the system.The numerical simulation showed that this algorithm operated easily and could effectively detect the weak LFM signal.Moreover,better parameter estimation precision was obtained in the case of low signal-noise-ratio (SNR).
