Design and Control of a Monolithically Integrated Robotic Arm and Gripper Using Spatially Varying Hybrid Braided Structures

Abstract

This letter presents a soft robotic arm–gripper system based on a deployable braided structure, where the arm and gripper are monolithically integrated through spatially varying braiding parameters without rigid connectors. The arm segment adopts a hybrid dual-layer architecture, whose outer constraining layer decouples bending from radial expansion and prevents buckling under high actuation loads through interfacial contact pressure. Conversely, the distal gripper utilizes a high braiding angle to enhance its deployability for adaptive object enveloping with a self-forcing effect. To compensate for the hysteresis inherent in fibrous structures, a coarse-to-fine visual servoing strategy is further developed for accurate positioning and grasping. Experiments show that the system maintains profile stability under cable actuation, with a demonstrated payload of 180 g and a structural weight of only 7.2 g. The system’s efficacy is further confirmed through “macro-mini” collaborative manipulation with a serial robot and precise grasping in confined spaces. The proposed approach offers a scalable manufacturing paradigm for functionally graded soft robots.