Experimental Model-Free Trim Control of a Planing Hull With Interceptor

Abstract

This study presents the design, development, and real-sea validation of an automatically controlled interceptor system for dynamic trim control in planing hulls. The interceptor mechanism is integrated with an ultra-local-model-based, real-time model-free control strategy, enabling trim-angle regulation without an explicit hydrodynamic plant model. By continuously compensating for nonlinearities and modeling uncertainties through online estimation, the proposed approach is well suited to practical marine operation. First, the system was installed on a planing boat to investigate the influence of interceptor plate height on trim dynamics; then, the control system was evaluated under Beaufort 0 and Beaufort 1 conditions for trim-angle regulation. The experimental control results demonstrate effective trim setpoint regulation across interceptor plate heights, while maintaining mean trim behavior around the desired reference despite wave-induced disturbances. Performance improvements were observed in cruise operation relative to a baseline case with interceptor control disabled, including attainable cruising speed when operating near-favorable trim settings. A comparative study with a conventional proportional–integral controller is also reported, along with additional trials using different model-free controller parameters, to highlight differences in tracking behavior and parameter sensitivity. The presented results support the feasibility of model-free interceptor-based trim regulation in real-sea experiments.