Screw Theory Kinematics Modeling and Workspace Analysis Base on Offshore Gangway

This paper carries out research on the offshore gangway, and introduces the spinor theory method which is simpler to calculate and more comprehensive to describe than the D-H parameter method. Referring to the modeling method of the series manipulator, the exponential product formula is applied to the kinematic analysis of the offshore gangway and the forward kinematic equation is established. The work space of the bridge was obtained by Monte Carlo method, and the 3D point cloud map of the gangway work space was drawn by MATLAB. The whole process shows the superiority and simplicity of spinor theory compared with D-H parameter method in inverse kinematics analysis and provides a new idea for similar kinematics and even dynamics analysis. Taking the RRP structure of telescopic gangway of offshore gangway as an example, the kinematics model based on screw exponential product equation is explained by Lie group knowledge and screw theory, the forward kinematics problem is analyzed, and a complete identification method with geometric significance is provided.