Generative design of 3D printed grippers for robot/human collaborative environments

Abstract

This paper aims to design a gripper for disassembling the refrigerator door gasket with a collaborative robot. The design concept is based on a fixed and robust finger used for guiding, whereas the second finger moves to pinch the gasket. The gripper's working conditions have been characterised by a universal testing machine. Results have shown that the vertical force for extracting the gasket is lower than the collaborative robot's nominal force. Extraction force increases with increasing speed and gasket-length. The second input for the generative design based on topology optimisation is the design space, with an asymmetrical distribution for the moving and static finger. The resulting optimised material distribution has been reinterpreted, taking into consideration the design for additive manufacturing principles. Finally, the gripper has been 3D printed with a short carbon fibre reinforced polyamide in a filament extrusion machine. The resulting gripper is 50% lighter than the monolithic solutions designed and manufactured by conventional technologies.