Systems, media, and methods for pre-processing and post-processing in additive manufacturing

Patent metadata

Field	Value
Publication number	US-10395372-B2
Application number	US-201715635485-A
Country	US
Kind code	B2
Filing date	Jun 28, 2017
Priority date	Jun 28, 2016
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

Systems, methods, and media for pre-processing and post-processing in additive manufacturing are provided. A method includes receiving object geometry data. The method may further include generating a sectional snapshot and a bounding box. The method may also include performing a boundary tracing operation on the sectional snapshots. Further still, the method may include executing a contour mapping algorithm. The method may additionally include outputting slice contour points with respect to the object to be fabricated.

First claim

The invention claimed is:

1. A system for image processing of a computer-modeled object to be fabricated, comprising:
memory; and
a processor coupled to the memory, the processor being configured to:
receive object geometry data and support geometry data;
create sectional snapshots and generate a bounding box;
perform a boundary tracing operation on the sectional snapshots;
execute a contour mapping algorithm;
perform color-based segmentation of sectional snapshots and pixel segregation;
perform pixel dimension calculations utilizing a section bounding box;
perform pixel counting to calculate a sintering area and an associated time value; and
output slice contour points with respect to the object to be fabricated and the calculated sintering area and the associated time value.

2. A computer-implemented method for image processing of a computer-modeled object to be fabricated, comprising:
receiving object geometry data and support geometry data;
creating sectional snapshots and generating a bounding box;
performing a boundary tracing operation on the sectional snapshots;
executing a contour mapping algorithm;
performing color-based segmentation of sectional snapshots and pixel segregation;
performing pixel dimension calculations utilizing a section bounding box;
performing pixel counting to calculate a sintering area and an associated time value; and
outputting slice contour points with respect to the object to be fabricated and the calculated sintering area and the associated time value.

3. A computer-implemented method for image processing of a computer-modeled object to be fabricated, comprising:
receiving object geometry data and support geometry data;
generating a sectional snapshot and a bounding box;
performing color-based segmentation of sectional snapshots and pixel segregation;
performing a boundary tracing operation on the sectional snapshots;
executing a contour mapping algorithm;
utilizing a removability calculation for pixel traversal; and
outputting slice contour points with respect to the object to be fabricated and a support removability score.

4. The computer-implemented method of claim 3 further comprising a mapping algorithm for fabrication of the object that comprises, for a plurality of slices of the object:
receiving bounding box data, sectional snapshots, sectional bounding box data, and a defined slice thickness value;
opening a slice snapshot file for a current slice and performing thresholding to generate a binary image of the current slice;
applying boundary tracing on the binary image to obtain boundary pixels of the current slice;
identifying extreme pixels from boundary pixels of the current slice to calculate length and width of the current slice;
translating an origin of the boundary pixels to a global origin;
performing a non-uniform scaling operation on at least some of the boundary pixels to obtain three dimensional object contour points; and
translating the object contour points from the global origin to an actual origin of contour of the object.

5. The computer-implemented method of claim 3 , further comprising a support removability calculator, for fabrication of the object, comprising:
designating portions of the object as part and support portions based upon imported part and support geometry;
generating a three-dimensional matrix based upon resolution and a quantity of sectional snapshots of the object;
categorizing pixels of a subject snapshot of the snapshots into part pixels, support pixels, and void pixels;
identifying, utilizing pixel traversal, accessible support pixels in a plurality of orthogonal directions and a plurality of diagonal directions with respect to the subject snapshot;
designating accessible pixels with respect to the subject snapshot and updating the three-dimensional matrix;
updating support pixels for accessibility in a plurality of orthogonal directions, lateral diagonal directions, and longitudinal diagonal directions; and
determining a removability percentage based upon the support pixels and the accessible support pixels.

6. The computer-implemented method of claim 3 , further comprising a sintering parameters calculator for fabrication of the object, comprising:
receiving part and support portions of the object;
receiving machine parameters comprising slice thickness, scanning velocity, and recoating time;
identifying bounding box dimensions for combined part and support geometry;
for a subject slice of a plurality of slices:
generating a subject sectional snapshot and a sectional bounding box;
performing boundary tracing on the subject sectional snapshot and identifying extreme pixels across length and width;
cropping an excess portion of the subject sectional snapshot and retaining the subject sectional snapshot only within the extreme pixels;
performing segmentation on the subject sectional snapshot to:
map the sectional bounding box to the subject sectional snapshot and find a dimension of each pixel;
calculate an area of the sectional bounding box;
calculate a quantity of total pixels comprising part pixels, support pixels, and void pixels in the subject sectional snapshot; and
calculate a part pixel fraction and a support pixel fractions within the total pixels in the subject sectional snapshot;

determining a sintering part area based on multiplication of the calculated part pixel fraction by the area of the sectional bounding box;
determining a sintering support area based on multiplication of the calculated support pixel fraction by the area of the sectional bounding box; and
calculating sintering time based upon pixel traversal length divided by the received scanning velocity machine parameter.

7. The computer-implemented method of claim 3 , further comprising a sharp corner detector for fabrication of the object, comprising:
capturing a sectional snapshot of the object based upon a received layer thickness value;
converted the captured sectional snapshot to a binary image using a binary thresholding operation;
identifying boundary pixels from the binary image and identifying corner pixels in the binary image; and
superimposing the boundary pixels and the corner pixels to generate vectors formed at one of the corner pixels.

8. The computer-implemented method of claim 3 , further comprising a modified topology optimization algorithm regarding manufacturing constraints for thin features, comprising:
receiving a density value for a finite element;
utilizing finite element analysis to:
determine physical density based upon a density filter applied to the element density value;
applying a manufacturing constraint to the physical density to determine a modified physical density, wherein the modified physical density comprises a relation between physical density and mapped density;
applying solid isotropic material with penalization to the modified physical density to determine an elastic modulus, a plurality of nodal deformations, and a compliance value, wherein the elastic modulus comprises a ratio of force exerted to a resultant deformation;

utilizing optimization to minimize a compliance value to:
based upon the compliance value, utilize compliance as an objective function for optimization;
update design densities with a value of net compliance lower than the compliance value; and
provide the value of net compliance as an updated element density value in the finite element analysis.

9. The computer-implemented method of claim 3 , further comprising a modified topology optimization algorithm regarding manufacturing constraints for support structure volume, comprising:
receiving a density value for a finite element;
utilizing finite element analysis

Assignees

• Univ Cincinnati

Inventors

• Anand Sundararaman
• Vaidya Rohit
• Chowdhury Sushmit
• Mhapsekar Kunal
• Mcconaha Matthew

Classifications

• G06F2111/10

  Numerical modelling · CPC title

• G06F2111/06

  Multi-objective optimisation, e.g. Pareto optimisation using simulated annealing [SA], ant colony algorithms or genetic algorithms [GA] · CPC title

• G06F30/20

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• G06T2219/008

  Cut plane or projection plane definition · CPC title

• G06T2210/12

  Bounding box · CPC title