Discrete system analysis using continuous Padé approximations. (1983)
Type of ContentElectronic Thesis or Dissertation
Thesis DisciplineElectrical Engineering
Degree NameDoctor of Philosophy
PublisherUniversity of Canterbury
AuthorsHamilton-Jenkins, M. A.show all
Continuous systems are often emulated by discrete systems. This thesis analyses such emulations by substituting ans-domain Padé approximant for the time delay operator. The result is a "quasi-continuous" model of the discrete system which is effectively a distorted case of the continuous system being emulated. Thus the size of the distortions is a measure of emulation accuracy. The best quasi-continuous models have a one to one correspondence with the continuous system.
SISO transfer functions have been studied using low order approximants leading to simple expressions for distortion, and simple methods of compensating the discrete system by pre-warping its parameters. Higher order approximants result in complex models which are simplified by Padé reduction techniques giving a more accurate distortion measure.
In addition MIMO matrix formulations have been developed for cases when the system structure is both constrained and unconstrained. The constrained case leads to more difficult formulations.
Overall the method gives useful results for comparing and improving discrete systems.