Journal of the Society of Naval Architects of Japan · 1981 · 149 citations · 2 references
EngineeringMarine EngineeringOcean EngineeringNaval ArchitectureShip ManeuveringShip StabilityAutopilot SystemsManeuveringRoll DynamicsShip DynamicsSteering DynamicsYaw DynamicsCaptive Model TestingCoupled Motion AnalysisCoupled Yaw MotionDirectional StabilityPerturbation AnalysisRoll Motion DynamicsShip Maneuvering DynamicsTurning Performance
A smaller metacenteric height improves turning but worsens course‑keeping, and yaw‑sway‑roll‑rudder coupling can cause anomalous rolling during high‑speed automatic steering. The study focuses on yaw‑sway‑roll‑rudder coupling and introduces a perturbation stability analysis to investigate it. Digital simulation of maneuvering motions and numerical calculation of directional stability indices based on captive model tests, combined with a perturbation stability analysis, were used. The analysis reveals the possibility of unstable yaw‑roll behavior due to roll‑induced yaw moment, small GM, and inadequate autopilot steering control parameters.
Digital simulation of maneuvering motions and numerical calculation of directional stability indices are carried out on the basis of captive model test of a typical container ship. An emphasis is laid upon yaw-sway-roll-rudder coupled motion. The smaller metacenteric height proved to introduce the better turning performance and the poorer course-keeping characteristics.The yaw-sway-roll-rudder coupling can be a cause of anomalous rolling which is frequently observed at automatically steered, high speed operations in seaways. We introduce a perturbation stability analysis on the problem. It reveals the possibility of an unstable yaw-roll behavior due to roll-induced yaw moment, small GM and inadequate control parameters of autopilot steering system.
2