Various garments will be presented in a random pile on an arbitrary background and novel ways of manipulating them (sorting, folding, etc.) will be learned on demand in a real-life dynamic environment.
In short, the sequence of tasks to be performed by the robotic system is the following:
Picking - one arm grasps a piece of garment and extracts it from the pile.
Recognition - the garment is presented to the camera and turned until the system recognises the type of clothing (e.g. trousers, skirt, T-shirt, etc.).
Folding - the garment is prepared for folding by flattening it on a rigid working surface. Then, a sequence of gestures for folding that specic piece of garment is carried out.
The gripper plays a central role during the picking phase. It must be capable of performing a reliable precision grasp of the garment at the point specied by the vision system. Since the heap of clothes is highly unstructured and the types of textiles are various, the ideal grasp is similar to an index-thumb pinch, with high precision and high gripping force.
The recognition of garment type is executed from two different points of view. First of all, computer vision algorithms are used to identify the shape of the hanging object. In the second place, the visual information is accompanied by the information delivered by state-of-the-art tactile sensors placed on the gripper's ngertips.
The third step is the automated folding of the garment. The piece is first spread on a working surface, and then a sequence of precision grasps and arms motions completes the required folding. In order to spread the garment, the gripper has to be equipped with a smooth surface functionally similar to the human palm. While the other arm holds it fixed to the table, this surface slides on the garment unfolding it.
Secondly, during the folding phase the piece lying on the surface often has to be picked from the edges. After such sliding motion, the upper nger is closed, resulting in a pinch grasp. Besides, the contact of the lower finger with the surface must be as soft as possible in order to avoid any harm. Accordingly, the mechanism is designed to provide a compliant behaviour.
The gripper is a simple and efficient design leading to a commercially viable device. In order to meet the demands of a wide range of garment-handling tasks, a gripper should be robust and resistant and at the same time simple and low-cost. Industrial grippers have the advantages to be robust, very cost-eective, and easy to mount on any industrial arm.
Project official site: http://www.clopema.eu/