A Novel Reconfigurable Dexterous Hand Based on Triple-Symmetric Bricard Parallel Mechanism

Abstract

This paper introduces a novel design for a robotic hand based on parallel mechanisms. The proposed hand uses a triple-symmetric Bricard linkage as its reconfigurable palm, enhancing adaptability to objects of varying shapes and sizes. Through topological and dimensional synthesis, the mechanism achieves a well-balanced degree of freedom and link configuration suitable for reconfigurable palm motion, balancing dexterity, stability, and load capacity. Furthermore, kinematic analysis is performed using screw theory and closed-loop constraints, and performance is evaluated based on workspace, stiffness, and motion/force transmission efficiency. Finally, a prototype is developed and tested through a series of grasping experiments, demonstrating the ability to perform stable and efficient manipulation across a wide range of objects. The results validate the effectiveness of the design in improving grasping versatility and operational precision, offering a promising solution for advanced robotic manipulation tasks.

Figures (14)

• Figure 1: Topological graphs and connection arrays.
• Figure 2: Transformation and Decomposition of the Graph.
• Figure 3: Symmetrical six-bar mechanisms
• Figure 4: Structural design of the triple-symmetric Bricard mechanism
• Figure 5: (a) Triple-symmetric Bricard mechanism, where $\beta$ and $\gamma$ denote the rotation angles of adjacent revolute joints as defined in the local link frames; (b) corresponding curves of $\beta$ and $\gamma$ with $\omega = 2\pi/3$.