Novel alignment method for optical 3D gear metrology of spur gears with a plain borehole
In 3D optical metrology, novel approaches to characterise the geometrical quality of gears require a custom gear alignment process to produce reliable results. This study proposes a novel scan alignment method known as subsequent gear alignment (SGA). It emphasises on the proper alignment of the gear hole and follows the alignment of gears in real-world applications. Therefore, the SGA method increases the usability of the previously developed and published methods. The scanned data were first processed with both the commercial global alignment and SGA methods and then evaluated to obtain standard geometrical parameters. These were compared with those obtained by the tactile method, and the SGA method offered improved results over the global alignment method.
Steps to reproduce
The folder Measurement data - STL contains the measurement (scanned) data used in the study. The folder reference data includes the mesh and the point cloud of the reference data. The script alignment_script performs the first three steps performed in the SGA alignment. The last step is described in the paper and uses the library https://trimsh.org/. The evaluation of the aligned data to obtain standard geometrical parameters is done with a script explained in detail in the paper: https://doi.org/10.1016/j.measurement.2020.108584