波浪中 Resonance-Free SWATH 運動の水中翼による非線形制御

抄録

A Resonance-Free SWATH (RFS), which has negative restoring forces, is introduced to minimize the motion responses in waves because the strict time-punctuality and the high value of the cargo require the superior seaworthiness such as no speed reduction and no slamming. Accordingly, the attitude of RFS should be adjusted by small underwater control fins. The latent ability of RFS for seaworthiness is not completely made use in the case of PD control because P gain in PD control acts as the large restoring force. In this study, a nonlinear sliding mode control has been applied to make up for deficiencies in PD control. The simulation using the time domain simulator for the sliding mode control and the experiments using the model have been carried out. As a result, the effectiveness of the sliding mode control has been confirmed. The pitch motion response of RFS under the sliding mode control is decreased by half compared with PD control.