Ocean Wave Active Compensation Analysis of Hybrid Boarding System Based on Multitask Motion Planning

As the hybrid system consists of 3-DOFs series mechanism and the 6-DOFs parallel mechanism has been widely used to transport the personnel maintenance or materials into the offshore wind turbine platform and offshore oil platform, it is important to maintain the stability of gangway in the presence of ocean wave to ensure the safety of maintenance personnel. In this paper, to compensate the ocean wave disturbance, the task priority method is presented. Moreover, the kinematic redundancy and motion constraints of the hybrid mechanism are taken into consideration. Firstly, we establish the kinematics equation based on the designed model of the hybrid mechanism. And the Jacobian matrix and its pseudo inverse of hybrid mechanism in the task space is derived. The multi-task priority hybrid organization planning is established in the form of pseudo-inverse solution. Moreover, the framework based on the mechanism end motion, joint limit and avoiding singular tasks, designed a system coordinated motion planning algorithm to reasonably solves the redundance while maximizing the space allocation problem. Finally, the simulation experiment is carried out and the results demonstrate the effectiveness of the proposed method.