Dynamic modeling and analysis of shipborne stable platforms in non-inertial system

Here, to deal with large amplitude and multi-dimensional irregular sway motion of ships under harsh sea conditions, a 6-DOF parallel platform scheme to isolate ship motion was proposed, and dynamic characteristics of this scheme were deeply studied. Firsdy, based on vector relations, velocity, Jar: obi matrix, and energy equations of platform components in inertial coordinates were derived, and their explicit dynamic equations in non-inertial system were deduced using Lagrange equation and virtual work principle. Secondly, the virtual sealed model of the platform was built using the software Adams, and sway motion of ship under complex sea conditions was simulated using P-M wave spectrum and the software RAO. Joint simulation of the software MATLAB and the software Adams was realized based on the software SIMULINK. Finally, ship motion examples under level 5 sea conditions were calculated and analyzed. It was shown that the driving force error between theoretical results and simulation results is within 0. 11% to verify the correctness of the dynamic model derived here; the platform can compensate ship's roll, pitch and yaw motions by 95.7%, 97.7% and 87. 9%, respectively to verily the effectiveness of the proposed scheme; the study results have guiding significance for dynamic control of shipborne stable platforms in non-inertial system. © 2024 Chinese Vibration Engineering Society. All rights reserved.