Forward-kinematics-based approaches for pose accuracy of docking mechanism with joint clearance

Joint clearance, as an important stochastic factor, can significantly deteriorate positioning and repeatability accuracies and lower assembly quality of a 6-DOF docking mechanism. Considering pose accuracy with traditional error model that possesses inherent imprecision, both probabilistic and deterministic approaches based on forward kinematics are presented to analyze comprehensive pose error (CPE) in simulation. Results indicate an identical trend emerges for each CPE with both approaches, and both CPEs perform opposite variations as the moving platform upgrades. The findings provide theoretical reference for refinement of assembly quality evaluation of this mechanism.