Design of a Robotic Gripper Based on Mechanism Doublet for Multifunctional Operations

Abstract

Robotic grippers with multiple grasp modes are essential for compound manipulation tasks requiring both object acquisition and task execution. However, existing multimodal grippers typically rely on additional actuators, reconfiguration mechanisms, or passive adaptation, and rarely extend beyond grasping operations. This letter presents a novel robotic gripper based on two symmetrically arranged mechanism doublets (MDs) coupled through a scissor mechanism, where pinching, enveloping, and cutting are intrinsically generated within a single-DoF rigid kinematic chain. The proposed architecture enables deterministic transition among multiple functional modes without dedicated switching actuators or tool exchange. Experiments validated the grasping and cutting capabilities and achieved a maximum pinching force of 24.2 N and an enveloping pull-off force of 72.5 N. Compound-task demonstrations in power equipment maintenance and precision fruit harvesting further verified the effectiveness of the integrated multifunctional operation.