Tolerance of Delayed Feedback Control for Maintaining Periodic Rotation

In this paper, we experimentally investigate a window of periodic rotation in the bifurcation diagram with respect to delay under a delayed feedback control. A control scheme with delay is proposed for establishing periodic rotation inherent in a parametric pendulum. The experiments elucidate the existence range of periodic rotation in the domain of delay. This possibly represents the tolerance of the proposed control with mistuned delay. It is confirmed that frequency synchronization governs the existence and width of the range.