Ensuring Safe Roll Dynamics in Marine Vessels Based on a Safety-Enhanced Control Framework

This paper presents a safety-enhanced control framework for ensuring safe roll dynamics in monohull marine vessels equipped with canting keels. Motivated by the regulatory shift introduced through the IMO's Second Generation Intact Stability Criteria (SGISC), dynamic stability limits associated with parametric rolling and excessive lateral acceleration are recast as enforceable constraints within a unified quadratic program (QP). The canting keel mechanism introduces additional challenges due to actuator saturation, electromechanical limits, and significant rotational inertia. A control architecture combining Control Lyapunov Functions (CLFs) and Control Barrier Functions (CBFs) is formulated to guarantee stability and forward invariance of the roll-angle safe set associated with parametric rolling. The excessive-acceleration criterion, being algebraically dependent on the control input, is incorporated into the set of admissible inputs as a state-dependent affine constraint. Numerical simulations under stochastic wave excitation demonstrate that the framework truncates resonance cycles during parametric rolling and actively bounds lateral accelerations under synchronous rolling conditions, while preserving baseline roll stabilization performance.