\(H_\infty\) robust identification with frequency data sampled unequally (Q2785112)

The present paper is devoted to the study of robust identification of some single-input single-output discrete unknown systems which are sampled randomly on the unit circle of the complex plane. The convergence of the robust identification procedure and the bound on the worst explicit error refer to \textit{A. J. Helmicki}, \textit{C. A. Jacobson} and \textit{C. N. Nett} [IEEE Trans. Autom. Control 36, 1163-1176 (1991; Zbl 0758.93020)]. NEWLINENEWLINENEWLINEBy applying some results given in the above-mentioned paper of Helmicki and some properties derived herein for trigonometric series and interpolation polynomials, a sufficient condition for the convergence of the robust identification procedure of the discrete systems considered is established and the identification error bound is also estimated.NEWLINENEWLINENEWLINEThe authors claim that the results obtained improve the known treatment of robust identification given by \textit{J. R. Partington} [Int. J. Control 58, 21-31 (1993; Zbl 0773.93015)].