Research On Reconstruction Method Of Solid Rocket Motor Inner Profile

Thermal protective layer is an important part of solid rocket motor.The research on the reconstruction method of engine inner profile and the accurate measurement of thermal protective layer thickness have important guiding effect on ensuring the quality of final product.In this paper,an inner profile measurement method based on laser scanning is designed,and the simplified method of point cloud data is improved to realize the reconstruction of engine inner profile and the measurement of thermal protective layer thickness.The main work is as follows:(1)The internal profile detection device of solid rocket engine based on laser displacement sensor was designed,and the internal profile scanning of the engine was realized.The displacement value was converted into three-dimensional coordinate point cloud by D-H model.The point cloud noise is divided into large noise and small noise,and the noise reduction methods of octree and bilateral filtering are used to eliminate the noise of point cloud data.(2)The ICP(Iterated Nearest Point)algorithm is used to realize the data Mosaic of the coordinate point cloud.Combining curvature reduction and raster reduction algorithms,an adaptive point cloud data reduction algorithm was studied,which eliminated the redundancy of point cloud data while ensuring the features of inner surface.(3)By comparing different reconstruction methods,the Poisson reconstruction method is selected to complete the 3D reconstruction of the solid rocket engine inner profile.A method of measuring the thickness of thermal protective layer based on the projection of normal vector is studied,and the thickness rendering method based on radius is adopted,which provides a basis for the further repair of thermal protective layer.(4)Based on the three-dimensional reconstruction of the inner profile,the measurement results of different sections of the actual engine show that the maximum error between the thickness of the thermal protective layer and the actual thickness is within 0.1mm,which realizes the high-precision measurement of the thickness of the thermal protective layer of solid rocket engine.