Efficient free-form surface layering method based on grid intersection and application thereof

Abstract

The invention belongs to the related technical field of additive manufacturing, and discloses an efficient free-form surface layering method based on grid intersection and application thereof, and the method comprises the following steps: (1) screening out triangular patches of an STL model and a curved surface slice layer in a common collision space; (2) voxelization is carried out on the public collision space, all voxels through which the triangular patches pass are determined, and then ID numbers of the triangular patches are stored in the voxels; (3) solving an intersection line section; (4) connecting the intersecting line sections into an intersecting line ring; (5) carrying out triangulation on the polygonal regions segmented by the intersecting line rings of the intersecting triangular patches, and screening out new subdivided triangular patches in the STL model; meanwhile, triangular patch vertexes located in the STL model are obtained, searching is carried out according to the obtained triangular patch vertexes to obtain triangular patches which contain the triangular patch vertexes and do not belong to intersecting triangular patches, and then layering is completed. According to the invention, the efficiency and precision are obviously improved.

Description

technical field [0001] The invention belongs to the technical field related to additive manufacturing, and more particularly, relates to an efficient free-form surface layering method based on grid intersection and its application. Background technique [0002] The traditional additive manufacturing process is based on the plane layered method. Using the plane layered method to manufacture parts has many limitations and shortcomings, such as the need to add support materials, there is a step effect, which causes the surface distortion of the model, and it is difficult to form on a curved substrate. . The surface layering method can improve these limitations and deficiencies well, and has obvious improvements in achieving conformal manufacturing, reducing the loss of model surface features, and improving the surface accuracy of parts. With the continuous development of multi-degree-of-freedom additive manufacturing technology, CLFD (Curved Layer Fused Deposition) has been ex...

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Problems solved by technology

[0003] In the field of additive manufacturing surface processing, there are currently many surface layering algorithms, such as Chinese invention patent CN110750870 A and Chinese invention patent CN 111951399 A, which propose a method based on voxel surface distance field for surface layering and path planning, based on voxel The layered method of curved surface, its algorithm time complexity and space complexity are both cubic complexity, after voxelization, the amount of data is large, the calculation time is very long, and there are precision errors, which cannot handle large-scale models and complex lattices Structure and other models

Another example is the Chinese invention patent CN 110126279 A, ​​which proposes surface layering based on triangular mesh subdivision and reverse offset along the normal direction of the patch. This method needs to continuously traverse all the triangle patches of the model, and each layering requires Triangular mesh reconstruction of offset point cloud data is relatively inefficient

In the existing triangular patch-based gridded surface layering method, when using the surface slice layer to intersect the model, it is necessary to traverse all the triangular patches of the model and the triangular patches of the surface slice layer, and the time complexity of the algorithm is Quadratic complexity, unable to handle large-scale complex models

[0004] To sum up, the existing surface layering methods have problems such as low efficiency and inability to deal with large-scale models. At present, some surface layering algorithms can only deal with simple surface models and have problems such as accuracy errors. They are widely used in the field of surface processing. restricted

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