A universal modular reconfigurable end-effector based on a self-locking articulated continuum robot for fabric manipulation in flat sewing

Abstract In the context of small-lot and diversified garment production (GP), the lack of versatility in traditional fabric manipulation methods for flat sewing makes it difficult to efficiently handle fabrics of various materials, shapes, and sizes, which restricts the process of intelligent GP. This paper proposes a universal modular reconfigurable end-effector consisting of an articulated continuum robot (ACR), a multi-parallelogram mechanism (MPM), flexible press components (FPCs), and a drive unit. The ACR is composed of a plurality of stabilized self-locking joints (SLJs) connected in series. The SLJ is mechanically restrained by a shape memory alloy coil triggered to maintain a self-locking or releasing state with zero energy consumption. During the motion process, the ACR can realize various modes of movement and multiple morphology changes under one set of the drive unit, and the morphology of the ACR is mapped 1:1 on the FPCs through the MPM to realize the isospaced reconfiguration of the end-effector. Repeated tests on the SLJ prototype 1000 times were successful. Meanwhile, this paper analyzes the workspace of the end-effector prototype and verifies its motion performance with an average error of 1.1 mm. The self-locking stiffness was determined to be 78.685 g mm −1 without motor drive through stiffness experiments, showing good structural self-locking characteristics. In addition, fabric manipulation experiments on a flat sewing table—including pressing, moving, and separating tasks—demonstrated high success rates and no damage to the fabric. Particularly, after improving the friction characteristics with rubber contact surfaces, a 100% success rate was achieved. The experimental results show that the end-effector possesses reconfigurability and maintains the reconfigured form without energy consumption. It can also manipulate various fabrics with different materials, shapes, and sizes, showing good adaptability and versatility.