Precision measurement and three-dimensional visualization of high aspect ratio helical deep-hole profiles

Abstract Precision measurement research is commonly faced with a significant challenge in accurately inspecting internal contours of components with high aspect ratios and helical deep-hole features, such as screw drill stators and gun barrels. However, a study targeting full-metal screw-drill stators has established a measurement system capable of achieving remarkable results. The system integrates a mechanical automatic centering device, a laser displacement sensor, an angular displacement sensor, and a data acquisition system, ensuring accurate measurements of the internal contours of full-metal screw-drill stators with inner diameters ranging from 98 mm to 180 mm. The results demonstrate a repeatability accuracy of ±0.005 mm and an uncertainty of ±0.02 mm ( k = 2) for measuring the diameter of the internal contour sections. The findings also reveal a three-dimensional error model of the internal contours, reconstructed via a point cloud rotation registration algorithm, which allows for the visualization of internal contour errors in the screw drill stator. With this innovative measurement system, the accurate inspection of internal contours of components with high aspect ratios and helical deep-hole features is no longer an insurmountable challenge.