Depth-based localization for robotic peg-in-tube assembly

Peg-in-tube assembly stands ahead of a more common benchmark task for industrial assembly, i.e., `pegin-hole´. The robot can easily be deceived to detect the actual hole while performing a `peg-in-tube´ task as the tube has a surrounding pocket that cannot support the peg. The paper presents a thorough geometrical analysis of the `peg-in-tube´ assembly process, and proposes a novel algorithm based on depth measurements of peg center to perform `peg-in-tube´ task. The results are demonstrated on a KUKA KR5 Arc industrial robot with a chamferless cylindrical peg and a tube having a minimum clearance of 0.10 mm.