Approximating delay elements by feedback

A procedure for obtaining a proper rational approximant of the transfer function of a delayer is suggested. In particular, the step response of the unity-feedback system with the delayer in the direct path is first approximated by truncating the Fourier series expansion of its periodic component, and then the corresponding direct-path rational transfer function is derived, thus arriving at a stable Blaschke product.

[1]  James Lam,et al.  Balanced realization of Pade approximants of e/sup -sT/ , 1991 .

[2]  Lawrence T. Pileggi,et al.  Asymptotic waveform evaluation for timing analysis , 1990, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[3]  Umberto Viaro,et al.  Model reduction for control systems with restricted complexity controllers , 1985 .

[4]  P. Mäkilä,et al.  Approximation of delay systems—a case study , 1991 .

[5]  Derek P. Atherton,et al.  An optimal model reduction method for closed-loop systems , 1991, [1991] Proceedings of the 30th IEEE Conference on Decision and Control.

[6]  J. Lam,et al.  Balanced realisation and Hankel-norm approximation of systems involving delays , 1986, 1986 25th IEEE Conference on Decision and Control.