A Coupled Tendon-Driven Modular Robotic Hand for Dexterous Manipulation

Abstract

This letter presents a modular coupled tendon-driven robotichand that employs a 2 motor 2 degrees-of-freedom (2M2D) coupled tendon driven joint module, in which two motors operate in a coordinated manner to actively drive flexion/extension and abduction/adduction of each finger through four tendons fixed to the fingertip. This coupled mechanism significantly enhances output torque while maintaining a simplified layout, each finger and corresponding actuator is implemented as an independent, detachable module, enhancing system flexibility and maintainability. Experimental results demonstrated that the coupled tendon-driven mechanism enhanced fingertip, lateral swing forces and load-bearing capacity by approximately 70% compared to decoupled tendon-driven mechanism. In terms of dexterity, the proposed hand achieved the highest score in the Kapandji test, fully reaching all ten reference positions, successfully completed all 33 grasp types defined in the GRASP taxonomy, and demonstrated effective in-hand manipulation capabilities. These results highlight the system’s strong potential for applications in dexterous robotic hands, prosthetic devices, and service robots.