High-Speed on-Machine Metrology: the Impact of Operational Parameters and Workpiece Geometry on Contact Scanning Accuracy

Contact coordinate measuring systems determine the dimensions and forms of complex geometries. In the context of Industry 4.0, measurement integration into the manufacturing process, such as a machine tool, is sought. On-machine measurement (OMM) may enhance productivity and reduce costs, but it also presents challenges, including the presence of coolant and contaminants, as well as dynamic errors that impact measurement. The influence of scanning speed and sense, as well as the size and type of the measured ring gauges, on measurement is experimentally investigated based on bidirectional scans of five reference ring gauges at three speeds between 2116 mm/min and 15240 mm/min. The actual measurement deviations from the nominal value were isolated by subtracting the first harmonic from the raw machine and probe readings. The peak-to-peak values and root mean square (RMS) values of probe readings were used to assess the results. The peak-to-peak and RMS values increase as the speed and diameter of the ring increase. In the case of high scanning speed, for example, the RMS value is 0.126 mm, and for low scanning speed, the RMS value is 0.062 mm. The non-parametric Kruskal-Wallis test shows a significant impact of scanning speed (p = 7.75e-9) and ring size (p = 9.31e-4) on the magnitude of error.