Identification of Continuous Time Systems with Direct and Feedback Nonlinearities
نویسندگان
چکیده
This paper presents a procedure for the identification of two types of a continuous-time linear system interconnected by direct and feedback memoryless nonlinearities. The first case is the continuous time Hammesrstein system and the second is a specific case of the continuous time Wiener system. The direct and feedback nonlinear elements, described by bounded unknown functions, are expressed as a linear combination of some base functions. Both the parameters of the linear system and of the nonlinear elements representation are identified. To improve the representation of the nonlinear functions, the set of basis functions is iteratively refined. It is possible to identify the dominant nonlinearities, applying the singular value decomposition to the input matrix. In our approach, the linear dynamic subsystem is described by a transfer function of a given order and the distribution based identification method is applied. The DCHI (Distribution based Continuous time Hammerstein system Identification equations (DCHI) and the DCNFI (Distribution based of Continuous time Nonlinear Feedback Identification) equation are obtained. The consistency of the identification is analyzed and experimental results are presented. Key-Words: Identification, Nonlinear systems, Distributions.
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