Weak Periodic Signal Detection Based On A Deformable Lorenz Chaotic System

Chaotic oscillator detection for weak periodic signal belongs to an importantapplication of Chaotic theory in information science, chaotic system is sensitive to weaksignals and immune to noise,which make chaos have good prospects and a great grogressin signal detection technique. In the paper,Based on Lorenz chaotic system, a deformableLorenz chaotic system is constructed by added cycle motive power signals.The followinggives the main work of this paper in detail.The validity of Melnikov's method in the generalized Hamilton proves thatdeformable Lorenz system has a deformation transformation in the sense of Smale chaos.The deformable Lorenz system is further proved that it has dynamical behavior,such aspower spectrum, Poincare mapping Lyapunov exponents pectrum.The maximum Lyapunov exponent will be used to distinguish chaos state from classperiod state as the quantification basis.It can automatically identify the critical state ofchaotic systems and can more accurately determine the presence of weak signals.Thechaos detection combines with the cross-correlation detection method to achieve weakperiodic signals amplitude detection in strong noise.The method can effectively detectweak periodic signals in strong noise.Approximate periodic solutions of the deformable Lorenz systems is deduced fromthe average method.Deformable Lorenz system and State feedback control are usedtogether to detect the frequency of weak signal.Deformable Lorenz system is controlled tocritical state from class periodic state to chaotic state.The method of spectrum analysis isused to measure the frequency of the detected signal.Simulation results show this methodhas higher detection precision.Finally,we detect the frequencies to different frequencyweak sine signals and non-sine periodic signals.Its results show that the chaotic system isfeasible and effective.Based on the known the frequency of weak sine signals,the deformable Lorenzsystem and the presetting phase approximation method are used together to detect thephase of weak sine signals. The deformable Lorenz chaotic system is applied to power system interharmonicsdetection.It can detect amplitude, frequency and phase of weak interharmonics in noise.