adfa, p. 1, 2011. © Springer-Verlag Berlin Heidelberg 2011 Human robot collaboration for folding fabrics based on force/RGB-D feedback. Panagiotis N. Koustoumpardis, Konstantinos I. Chatzilygeroudis, Aris I. Synodinos, Nikos A. Aspragathos Mechanical Engineering & Aeronautics Dept., University of Patras, Rio Patras, Greece. koust@mech.upatras.gr Abstract. In this paper, the collaboration of a human and a robot for executing complicated handling tasks of non-rigid objects is investigated. A hierarchical control system is developed for the co-manipulation task of folding sheets like fabrics/cloths. The system is based on force and RGB-D feedback in both higher and lower control levels of the process. In the higher level, the perception of the human’s intention is used for deciding the robot’s action, then in the lower level the robot reacts to the force/RGB-D feedback to follow the human guidance. The proposed approach is tested in the folding of a rectangular piece of fabric. The experiments showed that the robotic system is capable to track the human’s move- ment in order to help her/him to accomplish the folding co-manipulation task. Keywords: human robot collaboration, folding, cloths, force/RGB-D control, human intention, co-manipulation. 1 Introduction. In the industrial and craft sectors as well as in domestic and agricultural domains there are various tasks where two humans are needed to manipulate a non-rigid object. In cloth/carpet/upholstery/awning industries such tasks are transportation, handling and folding of long fabric sheets [1]. Moreover, similar tasks are found in automotive as- sembly such as: upholstery of seats, carpets and long cables or in robotic space appli- cations such as blanket manipulation for satellites. Other cases can be found in the han- dling of sheets for laying-up the plies of a composite material. Also, the folding of fabrics from people with disabilities and especially in cases where only the one hand is functional, is a substantial problem. Despite the wide challenges for great research op- portunities into this scientific field, the automation of such tasks is still rudimentary. The robotized manipulation of non-rigid and highly flexible sheet like objects is a very complicated problem due to their very low bending resistance, their large defor- mations and their materials’ non-linearity [2]. This kind of objects can change their shape by twisting, buckling, folding and wrinkling due to gravity. It is often said that they have “infinite” degrees of freedom since it is very hard to define how many are needed to define their configuration.