Impedance control architecture for robotic-assisted micro-drilling tasks

Abstract

Abstract This paper discusses a computed-torque impedance control architecture for robotic-assisted micro-drilling tasks. The micro-drilling process used in molds for the glass industry is analyzed, including motion and contact interaction strategies. A Cartesian impedance controller referred to the end-effector with posture optimization is proposed to tackle this delicate drilling problem. In free space, during the alignment phase, the controller includes integral actions for both spatial orientation and positioning, guaranteeing an accurate posture before insertion. A seven degrees of freedom (dof) collaborative robot from Franka Emika and real molds from industry are used in the experiments to validate our approach. To capture the appropriate strategy for micro-drilling an expert operator from industry demonstrated the task, enabling to record position and force data based on human skills. Several autonomous robotic experiments are reported with different drills (of diameter 0.6, 0.5 and 0.4\u202fmm) and in various molds, validating the proposed methodology.