Aircraft Surface Measurement And Data Processing For Shield's Inner Surface Repair

It is of great significance to improve the assembly quality of aircraft's heat shields for the safety of aircraft.In assembly,aircraft surface is the reference part and the heat shields are the moving part.Theoretically,these two parts should be fully fit.Since the aircraft is an assembly unit of large size,it's inevitable that part of its surface is beyond the manufacture tolerance,which reduces the precision of assembly.The traditional way to solve this problem is by manually repairing or adding filler,which depends on the experience of operation,and easily affect the gap and the step between the heat shields.In order to improve heat shields' assembly precision on aircraft surface's poor precision areas,a solving method based on digital measurement was proposed.First,aircraft surface's poor precision areas would be found by its' measure points.Second,the poor precision areas' heat shields' inner surface would be reconstructed.Finally,heat shield's actual inner surface would be machined according to its' reconstructed surface.The main contents of this paper are as follows:(1)A research into aircraft surface's digital measurement scheme.Aircraft surface's measurement requirements were analyzed,and then the digital measurement system of it was designed based on the existing measurement equipment.Aircraft surface's measurement process was designed.(2)A research into laser radar's measurement planning.A method for generating laser radar's measurement guide points was put forward.Laser radar's measurement stations were determined by an interactive way.Laser radar's measurement path was planned based on MST tree.(3)A research into distinguishing aircraft surface's poor precision areas.Noise points in measurement data was removed according to the continuous distribution of grid.Poor precision areas' measurement points and heat shields' design mode were put together to find heat shields that need to be repaired.(4)A research into the reconstruction method of heat shield's inner surface.Measurement point cloud was segmented by heat shield's contour.Point cloud section division technology was forward.A section curve extraction method which can both ensure G1 continuous point's extracting precision and curvature smoothing was proposed.Heat shield's inner surface was reconstructed by skinning.