ON THE FEASIBILITY OF STABILIZING PARAMETRIC ROLL WITH ACTIVE BIFURCATION CONTROL

When parametric resonance occurs on a ship, large roll motion develops rapidly and severe damage on cargo is likely. Some vessels have even capsized in moderate seas for reasons believed to be parametric resonance. This paper revisits the analysis of parametric resonance and assess the possibility to dynamically modify the instability region where parametric roll can occur. It is shown how a control strategy for roll stabilization could be modified to change a bifurcation in roll motion and stabilize the motion, even after parametric resonance has started. The paper addresses issues of achievable performance and demonstrates the approach on a yaw-sway-roll-surge model of a containership.