Design and analysis of a redundant actuated humanoid wrist joint parallel mechanism

With the widespread application of humanoid robots and industrial robotic arms in production and daily life, their limited flexibility and weak load-bearing performance have become inadequate to meet practical demands. This study employs biomimetic design principles to analyze the biomechanical and structural properties of the human wrist joint. Based on this analysis, we propose a novel redundantly driven two-degree-of-freedom (2-DOF) parallel mechanism. Firstly, kinematic analysis is conducted from perspectives including degrees of freedom, inverse kinematics, and Jacobian matrix, with its performance validated through numerical models and simulation analysis. Subsequently, the mechanism's performances are evaluated through workspace analysis, singularity investigation, and dexterity assessment, demonstrating its singularity-free workspace and high operational dexterity. Based on these analyses, an experimental platform was established, physical prototypes were fabricated, and a control system was designed. The experimental results validate both the feasibility of the humanoid wrist joint design and its potential for practical applications. This structure demonstrates broad applicability across multiple fields, such as humanoid robot wrist joints, wrist rehabilitation equipment, industrial robotic arms, and special robots.