Abstract: Accurately determining the spatial pose of segment erectors and motion targets for each joint in automated segment assembly is challenging. To address this drawback, a kinematic calculation model has been developed for a six-degree-of-freedom assembly erector, featuring a large translation function. A high-precision forward and inverse kinematics analysis method, incorporating critical factors such as differential extension and retraction of lifting hydro-cylinders, asymmetric design of lifting beams, and quantitative extension of a small suction cup′s hydro-cylinder, is proposed. A forward kinematic solution-based calculation method is introduced to quantify the impact of joint motion errors on the positioning accuracy of the erector′s end-effector. Key findings are as follows: (1) The position accuracy of the segment erector′s end is less than 0.2 mm after cross checking between the forward kinematics and three-dimensional design model results. (2) Deflection, pitch, and rotation motions of the suction cup exhibit mutual interference. Nevertheless, the simplified inverse kinematic solution achieves a target motion accuracy of less than 0.5 mm, satisfying the requirements for automatic assembly. (3) If the execution error of the erector′s rotation angle exceeds 0.1°, then the resulting end position deviation exceeds 7 mm, highlighting the need for further optimization of the rotation mechanism′s design.

Key words: shield segment, segment erector, forward and inverse solutions, error analysis