Using A Rotary Spring-Driven Gripper to Manipulate Objects of Diverse Sizes and Shapes

Abstract

This paper introduces a new gripper mechanism that is capable of grasping objects of various sizes and shapes without the need for a closed-loop control system. Industries such as the food and beverage industry are seeking innovative soft grippers with a simplified control system. The proposed design utilizes a rotary mechanism with springs to achieve both force-closure and form-closure grasping. The design sets itself apart from most soft grippers with its ability to offer grasping forces in all lateral directions. The gripper is designed in a cylindrical shape and is actuated by a stepper motor with a gearbox to enhance the torque. Three stacked curvilinear and linear rails convert the motor’s rotational motion into linear motion. The grasping component consists of three curved parts, each incorporating numerous compression springs. Currently, the gripper can effectively grasp objects ranging from five to nine centimeters in diameter, with a maximum height of ten centimeters. However, the design is scalable based on specific application requirements. A comprehensive CAD model of the mechanism was developed, and multiple analyses were conducted, including motion, topology, and stress analyses. Finally, a functional prototype of the gripper was constructed and successfully tested for grasping fruits and vegetables of different sizes and shapes. This research can be further expanded to explore the application of the gripper in space exploration with its novel and completely electro-mechanical foundation.