Global estimation of modal parameters for dynamic Systems using fraction orthogonal polynomials possesses higher precision than the general rational fraction orthogonal polynomials algorithm. The object of this paper is to introduce a new technique to derive the global piecewise fitting method for modal parameter identification of dynamic Systems. Based on the global fraction orthogonal polynomials algorithm, a global piecewise fitting method for eliminating affections of modes outside of fitting bands is proposed. Both lower and higher modes outside of the fitting band are analyzed and processed. The frequency response data are revised by means of modes in two frequency bands close to the fitting band, and a curve fitting model is derived. The proposed method is compared with that of the traditional estimation without regard to the affections of modes outside of the fitting band. For this comparative study, simulated data are used. Simulation research indicates that the processed approach is effective.
Parameter Identification in Dynamic Systems Using the Homotopy Optimization Approach
