A robotic end-effector with rolling up mechanism for pick-and-release of a cotton sheet

Abstract

In this paper we introduce a novel robotic end-effector for pick-and-release of a sheet of cotton cloth. One of the main operations in a factory for sewing cloth products is to pick up cloth parts, provide them to a sewing machine, and sew them together. Fabric products are assembled by performing this work in various processes. Each work starts with a lot of cloth parts stacked near a sewing machine. In the case of underwear, thin cotton cloth is the target of manipulation, but such cloth parts tend to stick to each other, and a certain skill or technical acuity is required for picking up. Therefore, this work is basically done manually in the present. The purpose of this study is to automate such manipulation, so we devise an end-effector that picks up only the top one of stacked cotton sheets. The proposed end-effector has a mechanism that is a cylindrical brush attached with a remover cloth on its surface. The cylindrical brush is grounded on a cotton sheet, and then is rotated to roll up only the cotton sheet. This mechanism makes it possible to release the sheet by rotating the brush in the reverse. We constructed hardware with this function and attached it to the tip of a robotic manipulator. In addition, we performed system integration so that the initial position of rolling up a cotton sheet could be automatically determined from images taken by a camera. We also conducted evaluation experiments.