Fig. 6

Bifurcation plots for different preset angle. (a) \(\alpha _{pre}(^\circ )\) = \(0^\circ\) , (b) \(\alpha _{pre}(^\circ )\) = \(5^\circ\), (c) \(\alpha _{pre}(^\circ )\) = \(10^\circ\), (d)  \(\alpha _{pre}(^\circ )\) = \(15^\circ\), (e) \(\alpha _{pre}(^\circ )\) = \(20^\circ\), and \(\overline{\omega }\) = 0.67, \(f_{y}\) = 2.25 Hz, \(f_{\alpha }\)= 3.35 Hz, Regime (i) stable fixed point (FP) attractor, Regime (ii) coexisting stable FP and stable LCO attractors, and Regime (iii) stable LCO attractor, showing the subcritical Hopf bifurcation.