Laser Metal Deposition Trajectories on Offset Mesh Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating trajectories in laser metal deposition processes fail to accurately handle multi-layer coating on complex surfaces, leading to issues like loss of equidistance between trajectories, self-intersections, and computational complexity, particularly in convex and concave regions.
Innovation Solution
A mesh-based method is implemented to compute the offset of a surface for each layer, using a Marching Cubes algorithm to generate an isosurface free from self-intersections, which allows for the calculation of accurate and efficient multi-layer trajectories by projecting the boundary of the workpiece onto the offset mesh and determining the deposition paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the same trajectories are repeated for each layer with increased distance from the surface, then the deposition process is simplified, but the equidistance between trajectories is lost causing microgrooves in convex regions and heaps in concave regions
Solution Approach 1:
The patent applies preliminary action by computing the offset surface (FACE) for each layer before generating trajectories. This ensures that the trajectory generation is based on the actual deformed surface geometry from previous layers, allowing equidistant trajectories to be maintained throughout the multi-layer deposition process. The offset surface computation is performed in advance for each layer, preventing the accumulation of geometric errors.
2Ease of operation
If the same trajectories are repeated for each layer with increased distance from the surface, then the process is straightforward, but laser trajectories may intersect each other in subsequent layers
Solution Approach 1:
The patent performs preliminary computation of the offset surface for each layer before trajectory generation. This ensures that trajectories are generated on the correct deformed geometry, preventing self-intersections and ensuring trajectory validity throughout the multi-layer process.
3Measurement precision
If direct computation of valid offset FACEs in parametric space is performed, then exact offset surfaces are obtained, but the computational complexity becomes very high due to simultaneous polynomial set solutions
Solution Approach 1:
The patent uses a mesh-based representation for the offset surface instead of exact parametric surfaces. The mesh is a computationally inexpensive approximation that can be easily generated and modified for each layer. This disposable mesh approach avoids the high computational cost of solving polynomial sets while providing sufficient accuracy for trajectory generation.
4Device complexity
If indirect methods are applied on discrete surface representations, then computational complexity is reduced, but the precision and quality of the coated surface deteriorates
Solution Approach 1:
The patent uses a mesh-based discrete representation that is computationally efficient while maintaining sufficient precision for the application. The mesh can be refined if needed, and the approach balances computational cost with coating quality by using the mesh solely for offset computation and trajectory generation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the generation of accurate multi-layer trajectories for laser metal deposition on free form surfaces, avoiding self-intersections and computational complexity, and effectively handles both convex and concave regions, improving the precision and quality of the coated surface.
Implementation Method 1
Heated by a laser beam, the material melts and solidifies on the surface
Implementation Method 2
the material melts and solidifies on the surface
Implementation Method 3
using a Marching Cubes algorithm to generate an isosurface free from self-intersections
Implementation Method 4
by projecting the boundary of the workpiece onto the offset mesh and determining the deposition paths
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
A computer implemented method and system for obtaining trajectories for laser metal deposition. The method comprises providing, to a controller, a mesh (M) representing a surface of a workpiece on which the laser metal deposition is to be carried out, the surface of the workpiece being delimited with a boundary (∂M). Then, the controller generates an isosurface of the surface from the mesh (M), the isosurface being an offset mesh (Moffset) that represents the surface of the piece, being unbounded and having a predefined offset (d) relative to the surface of the piece. After that, the controller traces the boundary (∂M) of the surface of the workpiece onto the isosurface to bound the isosurface and calculates the trajectories for laser metal deposition onto the bounded isosurface.