Control Design for Stable Systems with Both Input-Output and Internal Delays by Algebraic Means

L. Pekař and R. Prokop (Czech Republic)


Algebraic control design, time-delay systems, Nyquist plot, gain margin.


The goal of this contribution consists in algebraic design of controllers for stable processes with time delay not only in input-output relation but also with internal delays. In contrast to many other methods, the proposed method is not based on the time delay approximation. A control structure combining standard 1DOF and 2DOF control structures is considered. The control design is performed in the RMS ring of retarded quasipolynomial (RQ) meromorphic functions; an algebraic method based on the solution of the Bézout equation with Youla-Kučera parameterization is presented. Final controllers are of so called anisochronic type and ensure feedback loop stability, tracking of the step reference and load disturbance attenuation. As tuning method, prescribed gain margin based on the Nyquist plot is chosen for this contribution.

Important Links:

Go Back