A method for the kinematic analysis of a novel wave compensation bed for ships based on the 8PSS-UP parallel platform

Abstract

In addressing the need to reduce internal vessel vibrations and alleviate crew motion sickness during maritime voyages, this paper introduces a novel wave compensation resting bed and presents a kinematic analysis method tailored for marine environments. Diverging from conventional designs, this shipboard bed features a fixed platform hosting the drive unit, controlling the upper platform's movement via a slider's displacement, and incorporating a bottom Anti-Torsion (UP) frame. Employing the closed-loop vector method, the paper initially undertakes inverse kinematics of the shipboard bed, yielding solutions for slider displacement, velocity, and acceleration. Subsequently, the forward kinematics are resolved using the Newton-Gauss iterative method, with validation through ADAMS and MATLAB simulations. The velocity matrix analysis is then utilized to assess platform singularity, gauging the shipboard bed design's viability. Lastly, a wave model and a vessel heave-surge model in random waves are established to explore shipboard bed motion in unpredictable sea conditions. This study provides insights for the innovative design of shipboard resting beds and establishes a theoretical foundation for future wave compensation control in similar structures.