The research of weak signal frequency detection based on chaos system and PD control

The amplitude and frequency of weak signal is usually detected in strong noise. And the detection method of frequency is less to be researched. In this paper we use Rossler chaotic oscillator and proportional differential control to detect the frequency of the weak signal. At first we control Rossler system to critical state from periodic state to chaotic state. Then the unknown signal is put to the Rossler system. The Rossler system becomes chaotic state right now. Lastly we use proportional differential control to regulate the system to periodic state and the method of spectrum analysis to detect the unknown frequency. The advantages of the presented method are that the detection precision is higher and the detection means is simpler than Duffing equation which needs many chaotic oscillators. Through numerical simulation it is verified that the presented method is feasible.