A strongly stable implementation of state derivative feedback in system vibration suppression

Abstract

The effect of small delays in the state derivative feedback control loop is studied. Such an unusual feedback has proved useful in system vibration suppression, which is used here as a case study example. It is shown that even very small delays at the system inputs can destroy stability of the closed loop system. To prevent such fragility with respect to the delays, the strong stability concept developed for the neutral time delay systems is adopted. It is demonstrated that only such feedback gains can practically be used for which the closed loop system is strongly stable.