Accuracy and process performance in the inspection of complex geometry as a function of scanning parameters

This study examines the effects of scanning mesh resolution on the measurement accuracy and duration for parts with double curvature. The research employed a standard aircraft component, referred to as a hatch base. This component features a double curvature that conforms to the external contours of an airplane. Measurements were carried out using a portable Scantech KSCAN Magic scanner, which captures part geometry without a fixed datum using positional markers. This scanner has a linear accuracy of 0.020 mm, repeatability of 0.010 mm, volumetric accuracy of 0.015 mm + 0.030 mm/m, and resolution of 0.010 mm. Geometric inspection was performed on the external and internal surfaces of the part. The analysis involved a curve constructed along the part surface and specific datum features, namely, hole centers. For both the reference model and scanned data, the intersection points of each hole axis with the part surface were determined to construct these curves. The results demonstrate that an increase in resolution from 0.1 mm to 0.025 mm significantly extends the scanning time, thereby reducing the geometric inspection throughput by nearly a factor of four, without a corresponding improvement in accuracy. To enhance the measurement accuracy of critical features, such as holes or complex geometry zones, it is recommended to apply a combined inspection method involving scanning with locally increased resolution on concave and critical surfaces. The study established that a mesh resolution of 0.1 mm represents the most rational choice for real-world production environments, as it provides acceptable accuracy with minimal time investment. The implementation of such optimized scanning strategies can reduce the duration of quality control operations while maintaining the required quality standards for the manufactured parts.

milling, scanning, double-curvature surface, mesh resolution, accuracy, geometry inspection