The Study Of Weak Signal Detection Based On Chaotic Oscillator And Wavelet Theory

The weak signal detection is a new subject, which studies the principle and the method of detecting the weak signal under the strong noise background, and the weak signal detection technology has been the hot topic in the signal detecting area. Chaotic oscillator detection for weak signal belongs to an important application of chaos theory, because chaos oscillator is sensitive to weak signals and immune to noise, so chaos oscillator has good prospects and has made a great progress in signal detection technique now. Wavelet analysis possesses excellent characteristic of time-frequency localization and is suitable for analyzing the transient or time-varying signals.The paper has analyzed the dynamic characteristics of chaos oscillator, and provided the concrete method of weak signal detection, which is dependent on the property of the system from chaotic state to periodic state. By the MATLAB simulation, it has been proved that it is possible and feasible to detect the weak signal from the strong noise background through the chaos oscillator system. A detection system united by the chaotic oscillator detection method and wavelet ideas is proposed. Signals are pretreated according to wavelet multi-resolution analysis, and then are detected through the chaos oscillator system. This paper emphatically analyzes weak signal detection method for unknown frequency under the strong noise background. After a large number of simulation experiments, the united detection system could obtain the ideal effect for signal recognition and improve the signal detection capacity. In addition, the detection system is applied to rolling bearing's fault diagnosis for the ball and outer raceway. Through experiment analyzing, the detection system depending on chaos oscillator and wavelet analysis is well positioned to detect the fault of bearing, which has a high practical value in the actual project application.