Design, Analysis, and Optimization of a Grasping-Based Robotic Screwing Tool

This paper presents a grasping-based robotic screwing tool. Unlike traditional tools that rely on mechanical fitting for torque transmission, we propose using parallel gripping to secure objects onto the screwing tool, enabling robotic screwing for non-standard objects. We give the analysis and design of a two-finger parallel gripping mechanism. The mechanism’s dimensions are optimized to enhance transmission smoothness, reduce resistance, and account for the envelope radius during rotation, followed by the modeling of its kinematics and gripping force. Then, the gripping mechanism is integrated with an open gear set to create a grasping-based robotic screwing tool. Additionally, customizable and replaceable fingertips of the screwing tool are developed to enhance the flexibility of the tool. Experiments show that the tool can stably grasp various non-standard objects and complete screwing assembly. It has particular advantages over existing two-finger grippers when handling long objects. The tool’s fingertips can be autonomously replaced by the robot, allowing it to adapt to different assembly tasks.