Additive Manufacturing Bead Geometry for Low-Complexity Path Planning
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Solution Overview
Problem
Existing additive manufacturing methods require complex arithmetic operations for trajectory planning when approximating bead shapes as circles or ellipses, leading to complications in geometric calculations and joint cross-section representation.
Innovation Solution
The method involves dividing three-dimensional shape data into trapezoidal and parallelogram bead models for bead formation, where trapezoidal models are used for non-adjacent beads and parallelogram models for adjacent beads, simplifying the arithmetic operations and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a bead shape is approximated by a circle or an ellipse in the setting of the welding pass and the trajectory plan, then the geometric calculation such as the extraction of the position of the intersection point between the curved surfaces becomes complicated
Solution Approach 1:
The bead formation process is segmented into two distinct cases: non-adjacent beads modeled as trapezoids and adjacent beads modeled as parallelograms. This segmentation simplifies the geometric calculations by avoiding complex curved surface intersections while maintaining sufficient accuracy for manufacturing purposes.
Solution Approach 2:
The patent uses simplified geometric models (trapezoids and parallelograms) instead of precise circular or elliptical bead models. These simplified models are computationally inexpensive and sufficient for trajectory planning, sacrificing minimal accuracy for significant gains in calculation efficiency.
2Manufacturing precision
If an appropriate curvature is set to express the joint cross section calculated from the welding conditions, then the trajectory plan of the bead formation becomes complicated
Solution Approach 1:
The joint cross-section representation is segmented into trapezoidal and parallelogram shapes based on bead adjacency. This segmentation eliminates the need for complex curvature calculations while accurately representing the joint geometry for trajectory planning purposes.
Solution Approach 2:
The patent changes the geometric parameters from curved dimensions (radii, arc lengths) to linear dimensions (base lengths, heights) of polygons. This parameter transformation simplifies the mathematical operations required for trajectory planning while maintaining the ability to express joint cross-sections accurately.
3Productivity
If a circle or ellipse is used to approximate bead shape, then the geometric calculation becomes complicated, but using simpler shapes may reduce manufacturing precision
Solution Approach 1:
The bead model is segmented into context-dependent shapes: trapezoids for non-adjacent beads and parallelograms for adjacent beads. This segmentation achieves a balance between computational efficiency and manufacturing precision by using the simplest adequate geometry for each case.
Solution Approach 2:
The patent applies asymmetric geometric models (trapezoids with non-parallel sides) rather than symmetric shapes like circles or ellipses. This asymmetry better represents actual weld bead geometry and simplifies calculations by avoiding curved surface intersections.
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 allows for the creation of a trajectory plan for bead formation without complex arithmetic, resulting in accurately and efficiently manufactured additively-manufactured objects with reduced design errors.
Implementation Method 1
depositing a bead formed by melting and solidifying a filler metal on a base
Implementation Method 2
depositing a bead formed by melting and solidifying a filler metal on a base
Data Source
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AI summary
In the present invention, when manufacturing a shaped object by stacking beads, a process for separation into a plurality of bead models applies a trapezoid bead model with a trapezoidal cross-section to a position for the formation of a bead in an area which is not adjacent to an existing bead. This process applies a parallelogram bead model with a parallelogram cross-section, the opposing sides in a bead lamination direction of which are parallel to each other and the opposing sides in a bead arrangement direction of which are parallel to lateral sides of other adjacent bead models, to a position for formation adjacent to an already formed bead.