Residual error correction for reducing the uncertainty of a sample-tracking robotic 3D measurement system

Abstract

This paper presents a method for post-correction of disturbing relative motion between a robotic 3D measurement system and a sample under test. The active sample-tracking measurement platform carries a high-precision scanning confocal chromatic sensor acts as an end-effector of a robot, targeted for operation in a vibration-prone environment. The proposed method does not require any additional hardware and enables a point-by-point correction of the sequentially acquired 3D point cloud by the measured residual sample-tracking error. For experimental measurements at the maximum frame rate of 1fps in a workshop-like environment, which induces a resonant 47 Hz relative motion, the axial measurement error and uncertainty is reduced by 20% to 0.19µm and 0.25 µm, respectively.