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Applications Of Chaos In Weak Signal Measuring And Parameters Estimation

Posted on:2005-11-19Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z ChenFull Text:PDF
GTID:1118360122470959Subject:Measurement technology and equipment
Abstract/Summary:PDF Full Text Request
This paper is based on the theory of chaos and symbolic dynamics. The property than output of a chaotic system is highly sensitive to its parameters is used in weak signal detection and system parameters estimation. In order to do this, a chaotic system is designed, in which, one of the unknown parameters is the measured value or parameter being estimated. Between the parameter and the symbolic series corresponding to chaotic orbits of the system output, there should be a homologous relationship. Since the symbolic series are digital values themselves, it is very convenient to be acquired by logic judgment and processed by computer.In the part of weak signal detection, a new method of signal detection based on all parameters sensitivity of chaotic systems is proposed. Completely different from traditional measurement methods, all of the sensitive parameters are considered in the process of measuring. The method is used in temperature measurement firstly, in which, all working electronic elements involved are put in the environment of temperature being measured. The experiment results show that it is effectiveness in improving the accuracy and sensitivity,A new type of single voltage source driven chaotic circuit is designed, its characters are analyzed in detail. The circuit is used in high resolution resistance measuring. The coupled chaotic circuit array composed of this circuit is researched by computer simulation and circuit experiment. Results show that, it is feasible to improve the stability of orders of chaotic systems and reduce noise in measuring by coupling.For a class of linear systems or the systems containing a nonlinear recovering force, it is discussed how to make them become chaotic systems by adding a nonlinear feedback unit, and the parameters estimation method of the system is introduced. The systems of 1 order, 2 order and 3 order, which keep one or two unknown parameters are researched by computer simulation, and the experiment results indicate that this method has extremely high sensitivity and resolution. At the same time, the applicable limits of the systems are also given.
Keywords/Search Tags:Chaos, Chaotic circuit, Signal detection, Temperature measurement, Resistance measurement, Parameters estimation
PDF Full Text Request
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