Strong Compliant Grasps Using a Cable-Driven Soft Gripper

Gregory Xie, Lillian Chin, Byungchul Kim, Rachel M. Holladay, Daniela Rus

Abstract: The natural flexibility of soft robotic grippers allows for versatile and compliant grasping. However, this same flexibility can restrict the gripper’s strength. Striking a balance between compliance and strength is essential for effective soft grippers. In this work, we present Flexible Robust Observant Gripper (FROG), a soft gripper that is both compliant and strong. We describe the mechanical design of the gripper, characterize the soft flexures used in the design, and analyze the grasp forces generated by the gripper. Utilizing the structure of the gripper, we develop feedforward grasp controllers and a classifier to distinguish between grasp types. Grasping experiments show that FROG can effectively grasp a variety of objects, including very soft or delicate items. Holding force tests show that our gripper can conform to the grasped object and exert large grasp forces.