Relations Between Control Signal Properties and Robustness Measures

In English In this paper we consider control signal properties, such as maximum magnitude and activity, as well as system robustness measures. We derive an ideal controller and control signal for exponential disturbance rejection for a first order process with time delay. For the resulting closed-loop system, it is shown analytically that there are strong interconnections between robustness measures and control signal properties regarding load disturbance attenuation. The results imply that popular controller design methods implicitly take control signal properties into consideration.