An energy-efficient approach for 3D printing with a Linear Delta Robot equipped with optimal springs

In this paper a novel approach for sustainable 3D printing with a Linear Delta Robot equipped with elastic elements is presented and experimentally validated. Energy saving is achieved thanks to the introduction and optimization of linear springs that are mounted on the robot with different configurations: in parallel to the prismatic joints, or directly connecting the end-effector to the fixed frame. The elastic elements allow for a conversion between potential and kinetic energy during a cyclic motion, as for instance the printing of a material layer in additive manufacturing, resulting in actuators energy saving. To reduce the energy consumption, the spring parameters are optimized for the different scenarios by considering the kinematic, dynamic and electro-mechanical models of the parallel robot performing a 3D printing trajectory. The proposed approach is experimentally validated, showing an energy reduction up to almost 50% with respect to the nominal case without springs. The method is general and can be applied for energy efficiency and sustainability in several fields of robotics and computer-integrated manufacturing