Assessment of Laser Galvanometer Scanning System Accuracy Using Ball-Bar Standard

Abstract

The laser projector based on the laser galvanometer scanning system enables the projection of CAD-based laser images onto geometrical objects. Furthermore, the system can perform a scan of components in order to control proper positioning (e.g., welded structures). We decided to conduct research aimed at determining the suitability of such systems for length measurements and assess their accuracy. These systems are commonly calibrated with the use of flat calibration boards, although their capability of projecting and scanning 3D objects. For this reason, a new method based on ISO 10360 has been proposed. Analysis of the system’s ability to perform length measurements, selection of a reference standard, and the tested device accuracy were the main objectives of the study. A ball-bar with a nominal length of 3000 mm was chosen as a reference standard. Positions of the reference element in the workspace were determined, and three series of five measured deviations were performed in each setting. The obtained values of measurement errors prove that it is possible to use ball-bar standards to assess the accuracy of the described systems, which is defined by the equation MPE(E0) = ±0.5 mm. The proposed method could be adapted to perform more complex analyzes in this area.