To address the issue of shape deformation of aircraft skin during the forming

clamping

and machining processes

which compromises CNC milling accuracy

a method for in-process measurement of aircraft skin surfaces based on machining features is proposed. This method ensures the machining accuracy of the skin by acquiring the contour of the surface to be machined. First

a surface fitting method suitable for machining features is introduced

based on the curvature distribution characteristics of aircraft skin. A curvature-driven surface fitting error calculation method is proposed to quantify the fitting errors. Second

for the measurement point planning of machining features

a mesh division method based on boundary equal division is presented. Then

an optimization strategy for adaptive measurement point density adjustment is proposed based on surface fitting errors. Finally

the proposed method is applied to measurement planning and machining verification for the machining features of a large aircraft cabin skin. Experimental results show that the proposed method can reasonably distribute the measurement points on the machining feature surface

accurately acquire the feature surface contour

and ensure that the machining accuracy of the skin meets the tolerance design requirements.