AUTOMATED METROLOGY AND MODEL CORRECTION FOR THREE DIMENSIONAL (3D) PRINTABILITY

• US 20150269282A1
• Filed: 03/18/2014
• Published: 09/24/2015
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Nelaturi, Saigopal, Kim, Walter, Rangarajan, Arvind, Kurtoglu, Tolga
• Granted Patent: US 10,061,870 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: G06F 2113/10 Additive manufacturing, e.g. 3D printing
• CPC Class Codes: G06F 2119/18 Manufacturability analysis or optimisation for manufacturability
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: G06F 30/17 Mechanical parametric or variational design
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics
• CPC Class Codes: G06T 2219/008 Cut plane or projection plane definition
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A system and a method automate metrology, measurement, and model correction of a three dimensional (3D) model for 3D printability. Slices of the 3D model are received or generated. The slices represent 2D solids of the 3D model to be printed in corresponding print layers. Medial axis transforms of the slices are calculated. The medial axis transforms represent the slices in terms of corresponding medial axes. A local feature size at any point along a boundary of the slices is determined as the shortest distance from the point to a corresponding medial axis.

Claims

1. A system for automated metrology, measurement, and model correction of a three dimensional (3D) model for 3D printability, said system comprising:

at least one processor configured to;

receive or generate slices of the 3D model, the slices representing two dimensional (2D) solids of the 3D model to be printed in corresponding print layers;

calculate medial axis transforms of the slices, the medial axis transforms representing the slices in terms of corresponding medial axes; and

determine a local feature size at any point along a boundary of the slices as the shortest distance from the point to a corresponding medial axis.

2. The system according to claim 1, wherein the at least one processor is further configured to:

generate one of the slices by intersecting a 2D plane parallel to a build orientation of the 3D model at a height of the corresponding print layer.

3. The system according to claim 1, wherein the at least one processor is further configured to:

compare the local feature size to a threshold feature size to determine a deviation; and

display the deviation to a user by a display device.

4. The system according to claim 3, wherein the threshold feature size is one of a minimum printable feature size, a minimum recommended feature size for a print material selected by a user, and a feature size specified by the user.

5. The system according to claim 1, wherein the at least one processor is further configured to:

simulate printing of the slices to identify corresponding printability maps, each printability map partitioning a slice into at least two disjoint sets of regions, the at least two disjoint sets including a first set of regions formed of features sized smaller than a threshold feature size and a second set of regions formed of features sized larger than the threshold feature.

6. The system according to claim 5, wherein the threshold feature size is one of a minimum printable feature size, a minimum recommended feature size for a print material selected by a user, and a feature size specified by the user.

7. The system according to claim 5, wherein the at least one processor is further configured to:

quantify deviations between designed and manufactured geometries by determining the difference between the threshold feature size and a local feature size at any point along a boundary of the first set that overlaps with a boundary of the slice, the local feature size being the shortest distance from the point to a corresponding medial axis of the slice.

8. The system according to claim 5, wherein the at least one processor is further configured to:

identify regions of the 3D model requiring modification for 3D printability from the printability maps;

automatically or manually determine corrections to the 3D model; and

display the determined correction to a user by a display device.

9. The system according to claim 5, wherein the at least one processor is further configured to:

identify a largest local feature size of the second set for each of the slices;

determine a padding value for each slice of the 3D model or for the entire 3D model from the largest local feature sizes of the slices; and

thicken each of the slices by the corresponding padding value.

10. The system according to claim 1, wherein the at least one processor is further configured to:

identify segments of the medial axes where thickening the slices does not change topology and continuity of the slices; and

thicken the slices along the identified segments.

11. The system according to claim 1, wherein the at least one processor includes a plurality of processors, and wherein the plurality of processors are configured to simultaneously calculate medial axis transforms of a plurality of the slices in parallel.

12. A method for automated metrology, measurement, and model correction of a three dimensional (3D) model for 3D printability, said method comprising:

receiving or generating by at least one processor slices of the 3D model, the slices representing two dimensional (2D) solids of the 3D model to be printed in corresponding print layers;

calculating by the at least one processor medial axis transforms of the slices, the medial axis transforms representing the slices in terms of corresponding medial axes; and

determining by the at least one processor a local feature size at any point along a boundary of the slices as the shortest distance from the point to a corresponding medial axis.

13. The method according to claim 12, further including:

generating one of the slices by intersecting a 2D plane parallel to a build orientation of the 3D model at a height of the corresponding print layer.

14. The method according to claim 12, further including:

comparing the local feature size to a threshold feature size to determine a deviation, the threshold feature size being one of a minimum printable feature size, a minimum recommended feature size for a print material selected by a user, and a feature size specified by the user; and

displaying the deviation to a user by a display device.

15. The method according to claim 12, further including:

simulating printing of the slices to identify corresponding printability maps, each printability map partitioning a slice into at least two disjoint sets of regions, the at least two disjoint sets including a first set of regions formed of features sized smaller than a threshold feature size and a second set of regions formed of features sized larger than the threshold feature.

16. The method according to claim 15, wherein the threshold feature size is one of a minimum printable feature size, a minimum recommended feature size for a print material selected by a user, and a feature size specified by the user.

17. The method according to claim 15, further including:

quantifying deviations between designed and manufactured geometries by determining the difference between the threshold feature size and a local feature size at any point along a boundary of the first set that overlaps with a boundary of the slice, the local feature size being the shortest distance from the point to a corresponding medial axis of the slice.

18. The method according to claim 15, further including:

identifying regions of the 3D model requiring modification for 3D printability from the printability maps;

automatically or manually determine corrections to the 3D model; and

display the determined correction to a user by a display device.

19. The method according to claim 15, further including:

identifying a largest local feature size of the second set for each of the slices;

determining a padding value for each slice of the 3D model or for the entire 3D model from the largest local feature sizes of the slices; and

thickening each of the slices by a corresponding padding value.

20. The method according to claim 12, wherein the at least one processor is further configured to:

identify segments of the medial axes where thickening the slices does not change topology and continuity of the slices; and

thicken the slices along the identified segments.

21. A system for automated metrology, measurement, and model correction of a three dimensional (3D) model for 3D printability, said system comprising:

at least one processor configured to;

receive or generate slices of the 3D model, the slices representing two dimensional (2D) solids of the 3D model to be printed in corresponding print layers;

calculate medial axis transforms of the slices, the medial axis transforms representing the slices in terms of corresponding medial axes;

identify segments of the medial axes where thickening the slices does not change topology and continuity of the slices; and

thicken the slices up to a threshold feature size along the identified segments.