Design guidelines concerning the destabilizing high-frequency mode of an integral force feedback-based active damping unit

Adding active damping in a collocated fashion to a badly damped mechanical plant guarantees the stability of the closed-loop system. However, collocation is lost beyond a certain frequency due to restrictions imposed by practical implementation. In this paper, the effect of the first non-collocated mode in the active damping loop is analyzed on the basis of its most relevant parameters. The results are summarized in two figures that provide guidelines for both designing an active damper unit and tuning its controller.