Weak Signal Detection Based On Chaos And Wavelet

It has been long time since people are subject to noise signal interference which makes the research of weak signal detection integrated technology and cutting-edge field in measurement techniques field.Weak signal is the signal that is submerged in noise,the purpose of weak signal detection is to improve the rate of signal to noise.The only way to extract useful signal is to enlarge the amplitude of weak signal in condition of effectively control noise.In order to extract useful signal,it need to study the origin and nature of the noise,analyzing the cause and law of the noise and the transmission route of the noise.Taking effective ways to control noise,studying the statistical characteristics and differences and find out theory and methods of detecting useful signal from noise background.The paper introduces the application of weak signal detection based on wavelet,using fine time-frequency characteristic to handle the signal and get fault feature signal.Analyzing chaos movement of Duffing oscillator, detecting weak signal as the phase of oscillator being sensitive to period signal and immune to noise,detecting signal of different frequency with reference signal of different frequency,it makes oscillator general to signal detection of different,frequency by adjusting system parameters.Providing the theory,method and experience of fault diagnosis in strong noise based on chaos theory and wavelet theory.Studying outstanding zoom performance of wavelet in time-frequency localization,the ability of frequency division of orthogonal wavelet,maximum module transmission in wavelet transform of the singular point of signal and random noise and giving the ways of eliminating noise.Using orthogonal wavelet multi-resolution to decompose,eliminate and reconstruction the signal in order to improve signal-to noise ratio.Locating time-domain of fault feature signal and extracting fault feature frequency.Using intermittent chaos theory of Duffing oscillator to study fault diagnosis of weak signal in strong noise background.Making period interfere signal sensor as internal drive signal disturbance and getting it into chaos detection,observing time history chart of state variables of chaotic oscillator,it discovers chaos detection system is in a state of intermittent chaos and proves the feasibility of detecting weak period signal by using Duffing chaotic oscillator.