Autonomous robotic de-manufacturing requires precise spatial localization of fasteners for successful unscrewing, as even small deviations can result in tool misalignment or failure. This study quantifies screw localization accuracy in hard disk drives across the chain from localization to realized tool position in a gantry robot system. Validation was performed in three stages: first realized coordinates from a gantry robot were compared with coordinate measurement machine (CMM) measurements, second predicted screw coordinates from computed tomography data were compared with CMM data, and third the predicted screw coordinates were compared against manually annotated locations. In all cases, deviations were separated into axial and radial components, with angular components reported where possible. Radial deviations were typically in the sub-millimeter range, with offsets between 0.4 and 0.61 mm across stages, but remain above the tolerances required for robotic tool engagement. While manual annotations provided additional geometric information, including screw orientation, it did not resolve this gap. The study introduces a consistent procedure for evaluating localization accuracy along the full chain from estimation to robotic execution.
Griffioen et al. (Thu,) studied this question.