A Novel Gripper with Semi-Peaucellier Linkage and Idle-Stroke Mechanism for Linear Pinching and Self-Adaptive Grasping

2025-10-18

AI Summary

Traditional parallel grippers exhibit curved fingertip trajectories, leading to frequent collisions with tabletop surfaces and poor adaptability to diverse object geometries. To address this, we propose a novel SPD (Straight-path, Passive-adaptive, Dual-mode) gripper that integrates a semi-Paselle linkage mechanism with a dead-point mechanism, enabling strictly linear fingertip motion and intrinsic geometric adaptability within a unified design—eliminating the need for robotic arm height adjustment during tabletop manipulation. Through kinematic modeling of the linkage system and symmetry-driven structural optimization, the gripper supports both single-motor and independent dual-motor actuation modes. Experimental evaluation on a functional prototype demonstrates sub-millimeter linear positioning accuracy and robust passive adaptation to objects of varying shapes and sizes. This design significantly enhances the reliability of robotic tabletop operations and provides a hardware platform capable of generating high-fidelity grasp data.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Humans and AI: Interaction Techniques and Devices

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments

Abstract

This paper introduces a novel robotic gripper, named as the SPD gripper. It features a palm and two mechanically identical and symmetrically arranged fingers, which can be driven independently or by a single motor. The fingertips of the fingers follow a linear motion trajectory, facilitating the grasping of objects of various sizes on a tabletop without the need to adjust the overall height of the gripper. Traditional industrial grippers with parallel gripping capabilities often exhibit an arcuate motion at the fingertips, requiring the entire robotic arm to adjust its height to avoid collisions with the tabletop. The SPD gripper, with its linear parallel gripping mechanism, effectively addresses this issue. Furthermore, the SPD gripper possesses adaptive capabilities, accommodating objects of different shapes and sizes. This paper presents the design philosophy, fundamental composition principles, and optimization analysis theory of the SPD gripper. Based on the design theory, a robotic gripper prototype was developed and tested. The experimental results demonstrate that the robotic gripper successfully achieves linear parallel gripping functionality and exhibits good adaptability. In the context of the ongoing development of embodied intelligence technologies, this robotic gripper can assist various robots in achieving effective grasping, laying a solid foundation for collecting data to enhance deep learning training.

Problem

• Achieves linear parallel gripping to prevent table collisions
• Provides adaptive grasping for various object shapes and sizes
• Eliminates need for robotic arm height adjustments during grasping

Innovation

• Semi-Peaucellier linkage enables linear fingertip motion
• Idle-stroke mechanism allows independent or single-motor drive
• Linear pinching with self-adaptive grasping capability