Tool path planning process for component by layered manufacture

• US 6,823,230 B1
• Filed: 09/07/2000
• Issued: 11/23/2004
• Est. Priority Date: 09/07/2000
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Chard, Jeffrey A., Jamalabad, Vikram R., Gasdaska, Charles J.
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): Rao, Sheela S
• Application Number:
  US09/657,134
• Time in Patent Office: 1,538 Days
• Field of Search: 700/119, 700/182, 700/120
• US Class Current: 700/119
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/49035 Reconstruct boundary volume from stack of layer contours, sections
• CPC Class Codes: Y02P 80/40 Minimising material used in manufacturing processes
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Methods for improving the manufacture of objects made by layered manufacturing techniques through improved tool path generation. A vertex improvement aspect improves tool paths used to form vertices. Outer perimeter vertices can be improved by automatically creating an outer boundary reflecting the design intent to have material extending to the perimeter vertex. The outer boundary can be used as a contour tool path or as a limit to travel by raster tool paths. Boundary vertices within parts can be improved by extending more internal boundary vertices outward toward enclosing vertices, thereby eliminating some internal voids. Contour boundaries near outer perimeter corners can be better defined by extending outward a contour tool path toward the corners. Narrow regions between combinations of outer and/or inner perimeters can be filled through improved tool paths. Layer regions near inner voids can receive consistent filling through an improved raster tool path method. Sub-perimeter voids between raster bead pair turn-arounds and contour beads can be eliminated by automatically adjusting the raster tool path vertices toward the adjacent raster bead pair and/or contour bead.

Claims

1. A method for generating additive tool paths to form a convex layer portion by layered manufacturing, wherein said convex layer portion has a outer perimeter defined by a perimeter first leg portion coupled to a perimeter vertex portion coupled to a perimeter second leg portion, wherein said perimeter vertex portion has a perimeter vertex tip portion, wherein said tool path has an associated tool path width, the method comprising the steps of:

generating said tool path within said convex layer portion, such that said tool path has a tool path first leg portion disposed at about said offset distance from said perimeter first leg portion and coupled to a tool path vertex portion, said vertex tool path portion having a tool path vertex tip portion disposed at about said offset distance from said perimeter vertex tip portion and coupled to a tool path second leg portion, said tool path second leg portion being disposed at about said offset distance from said perimeter second leg portion.

2. A method for generating additive tool paths as in claim 1, wherein said tool path generating step includes forming a curved tool path vertex portion.

3. A method for generating additive tool paths as in claim 1, wherein said tool path generating step includes generating an initial tool path vertex portion having an initial tool path vertex tip portion disposed at a distance greater then said offset distance from said perimeter vertex tip portion, wherein said tool path generating step includes moving said initial tool path vertex tip portion closer to said perimeter vertex tip portion to form said tool path vertex tip portion.

4. A method for generating additive tool paths as in claim 3, wherein said moving step includes moving said initial tool path vertex tip portion to a distance of about said tool path width from said perimeter vertex tip portion.

5. A method for generating additive tool paths as in claim 4, wherein said tool path generating step includes generating a tool path vertex portion first leg disposed between said tool path first leg and said tool path vertex tip portion, wherein said tool path generating step includes generating a tool path vertex portion second leg disposed between said tool path second leg and said tool path vertex tip portion, wherein said tool path generating step includes generating said first and second tool path vertex legs at a closest distance of about one tool path width from said perimeter vertex portion.

6. A method for layered manufacturing performed by forming material having a bead width along a tool path, the method comprising:

automatically adjusting a tool path vertex to be close to an outer perimeter vertex by automatically disposing the tool path vertex a distance at about half the bead width from the perimeter vertex, including bringing regions on either side of the tool path vertex closer than about half the bead width to corresponding perimeter vertex regions.

7. A part having a convex portion made by a layered manufacturing process comprising forming at least two nested material beads, each bead having a vertex, such that said bead vertices have no voids therebetween.

8. A part made by a process as in claim 7, wherein said bead vertices are formed at a center-to-center distance therebetween of about one bead width.

9. A part made by a process as in claim 7, wherein said convex portion forms an interior angle of less than about seventy degrees (70°

).

10. A part made by a process as in claim 7, wherein said convex portion forms an interior angle of less than about forty degrees (40°

).

11. A method for generating at least one tool path within a layer region for layered manufacturing, wherein said layer region includes a material region disposed within an outer perimeter, wherein said tool path has an associated offset distance, the method comprising the steps of:

offsetting said outer perimeter inward toward said material region by about said tool path offset to form a first outer boundary;

identifying at least one outer perimeter vertex;

identifying a first outer boundary vertex on said first outer boundary derived from said outer perimeter vertex;

relocating said first outer boundary vertex from an original position to a relocated position disposed closer to said outer perimeter vertex than said original position, such that said first outer boundary is modified by being moved closer to said outer perimeter vertex; and

generating at least one tool path within said relocated first outer boundary.

12. A method for generating at least one tool path as in claim 11, wherein said tool path generated is a raster tool path generated within said relocated first outer boundary.

13. A method for generating at least one tool path as in claim 11, wherein said tool path generated is a contour tool path generated along said relocated first outer boundary.

14. A method for generating at least one tool path as in claim 11, wherein said first outer boundary vertex identifying step includes identifying a first outer boundary vertex tip point and selecting at least one outer boundary base point on either side of said first outer boundary vertex tip point, wherein said identifying outer perimeter step includes identifying an outer perimeter vertex tip point, further comprising relocating said outer boundary vertex tip point toward said outer perimeter vertex tip point, and relocating said outer boundary vertex to extend between said first outer boundary vertex base points and said relocated first outer boundary vertex tip point.

15. A method for generating at least one tool path as in claim 14, wherein said identified outer perimeter vertex tip point is a virtual point formed from an average of at least two outer perimeter points.

16. A method for generating at least one tool path as in claim 11, further comprising

offsetting said relocated first outer boundary inward toward said material region by about said tool path offset to form a second outer boundary including a second outer boundary vertex having an original position;

identifying at least one second outer boundary vertex;

identifying a second outer boundary vertex on said second outer boundary derived from said first outer boundary vertex;

relocating said second outer boundary vertex from said original position to a relocated position disposed closer to said first outer boundary vertex than said original position, such that said second outer boundary is modified by being moved closer to said first outer boundary vertex; and

generating at least one inner tool path within said relocated second outer boundary.

17. A method for generating at least one tool path as in claim 16, wherein said inner tool path generated is an inner raster tool path generated within said relocated second outer boundary.

18. A method for generating at least one tool path as in claim 16, wherein said inner tool path generated is an inner contour tool path generated along said relocated second outer boundary.

19. A method for generating at least one tool path as in claim 11, wherein said first outer boundary vertex is moved to about one offset distance from said outer perimeter vertex.

20. A method for generating at least one tool path portion within a layer region for layered manufacturing, wherein the layer region has at least a first outer perimeter portion and a second outer perimeter portion meeting at an angle of less than 180 degrees to each other at an outer perimeter vertex, wherein said layer region has a material portion between said first and second perimeter portions, wherein said tool path has an associated offset corresponding to about half of an associated tool path bead width, wherein said tool path offset and first perimeter define a first outer boundary first leg substantially parallel to said first perimeter and disposed in said material portion, wherein said tool path offset and said second perimeter define a first outer boundary second leg substantially parallel to said second perimeter and disposed in said material portion, wherein said first outer boundary first leg and first outer boundary second leg intersect at a first outer boundary vertex, wherein the method comprises the steps of:

generating a modified first outer boundary vertex point which lies between said perimeter vertex point and said first outer boundary vertex point;

generating a first leg tool path portion along a portion of said first outer boundary first leg;

generating a second leg tool path portion along a portion of said first outer boundary second leg;

generating a third tool path portion extending from said first leg tool path portion to said modified first outer boundary vertex point; and

generating a fourth tool path portion extending from said modified first outer boundary vertex point and extending to said second leg tool path portion, such that said tool path extends nearer said perimeter vertex at said modified first outer boundary vertex point than at said first outer boundary vertex point.

21. A method as in claim 20, wherein said third and fourth tool path generation steps include generating arcuate tool paths.

22. A method as in claim 20, wherein said third and fourth tool path generation steps include generating substantially straight tool paths.

23. A method as in claim 20, wherein said first and second tool path generation steps include generating tool paths no closer than about one offset distance from said perimeter at distances of more than about four offset distances from said perimeter vertex.

24. A method for generating at least one tool path within a layer region for layered manufacturing, wherein said layer region has at least a first contour tool path first leg and a first contour tool path second leg, wherein said first contour tool path first and second legs, when extended, meet at an internal angle of less than 180 degrees at a first contour tool path vertex, wherein said layer has a material portion between said first contour tool path first and second legs, wherein said tool path has an associated offset corresponding to about half of an associated tool path bead width, wherein said tool path offset and first contour tool path first leg define a first contour boundary first leg parallel to said first contour tool path first leg and disposed in said material portion, wherein said tool path and said first contour tool path second leg define a first contour boundary second leg parallel to said first contour tool path second leg and disposed in said material portion, wherein said first contour boundary first and second legs intersect at a first internal boundary vertex, wherein the method comprises the steps of:

generating a modified internal vertex point which lies between said contour tool path vertex point and said first boundary vertex point;

generating a first tool path leg portion along a portion of said first contour boundary first leg;

generating a second tool path leg portion along a portion of said first contour boundary second leg;

generating a third tool path portion extending from said first tool path leg portion to said modified internal vertex point; and

generating a fourth tool path portion extending from said modified internal vertex point and extending to said second tool path leg portion,

such that said tool path extends nearer said contour vertex point than said first boundary vertex point.

25. A method as in claim 24, wherein said third and fourth tool path generation steps include generating arcuate tool paths.

26. A method as in claim 24, wherein said third and fourth tool path generation steps include generating substantially straight tool paths.

27. A method as in claim 24, wherein said first and second tool path generation steps include generating tool paths no closer than about 2 offsets distance from said contour intersection point.

28. A method for generating an additive tool path to form a perimeter vertex by layered manufacturing, wherein the tool path has an associated tool path offset, the method comprising the steps of:

obtaining a first data representation of said perimeter vertex;

obtaining a second data representation of a first tool path offset inward from said perimeter vertex;

identifying at least one perimeter point on a tip of said perimeter vertex;

selecting a first tool path point from said second data representation that was offset inward from said perimeter vertex tip point; and

moving said first tool path point toward said perimeter vertex point, such that said first tool path point is located closer to said perimeter vertex point.

29. A method for generating an additive tool path as in claim 28, wherein said moving step includes moving said first tool path point to a distance of about one offset from said perimeter vertex point.

30. A part made according to a part design by a layered manufacturing technique, the part design having at least one layer having an outer perimeter vertex portion disposed between a perimeter first leg and a perimeter second leg, said outer perimeter vertex portion having an interior angle of less than about 150 degrees, the outer perimeter defining a material portion and a non-material portion, the process for forming said layer comprising the step of:

forming a first material bead offset into said material portion from said perimeter first leg, perimeter vertex portion, and perimeter second leg, wherein said first bead has a first leg offset inward by about an offset distance from said perimeter first leg, wherein said first bead has a second leg offset inward by about said offset distance from said perimeter second leg, wherein said perimeter vertex portion has a perimeter vertex tip, wherein said first bead has a first bead vertex tip, said first bead vertex tip being disposed at about said offset distance inward from said outer perimeter vertex tip.

31. A part made according to a design as in claim 30, wherein said first bead is formed along a first outer boundary, wherein said bead has a bead width, wherein said offset distance from said design outer perimeter and said first outer boundary is about equal to half of said bead width.

32. A part made according to a design as in claim 30, wherein said first bead is formed along a first outer boundary, wherein said bead has a bead width, wherein said offset distance from said design outer perimeter and said first outer boundary is less than about half of said bead width.

33. A part made according to a design as in claim 30, wherein said first bead is formed along a first outer boundary, further comprising the step of forming a second bead along a second outer boundary, said second outer boundary being offset at a second offset distance inward from said first outer boundary.

34. A part made according to a design as in claim 33, wherein said second offset distance from said design outer perimeter is about equal to twice said bead width.

35. A part made according to a design as in claim 30, wherein said first bead is formed along a first outer boundary, further comprising the step of forming a filling said layer between said bead first and second legs, wherein said filling is performed within a second outer boundary, said second outer boundary being offset at a second offset distance inward from said first outer boundary.

36. A part made according to a design as in claim 35, wherein said filling is performed with a second bead formed at acute angles to said first bead, said second bead formed along a second bead center line, wherein said second bead center line does not comes closer than said second outer boundary to said first bead, wherein said second offset distance is about equal to said bead width.

37. A method for generating at least one tool path within a layer region for layered manufacturing, wherein said layer region has at least a first perimeter and a second perimeter, wherein said layer region has a material portion between said first and second perimeters, wherein said tool path has an associated offset corresponding to about half of an associated tool path bead width, wherein said two perimeters define a narrow region therebetween, wherein said two perimeters are separated at a distance of less than about double said tool path offset, the method comprising the steps of:

obtaining a relative preservation weighting for preserving each of said two perimeters in said narrow region; and

generating a tool path between said perimeters in said narrow region as a function of said relative preservation weightings.

38. A method for generating at least one tool path as in claim 37, wherein said obtaining step includes obtaining a substantially equal preservation weighting for said first and second perimeters, and said tool path generating step includes generating a tool path through said narrow region about equidistant from said first and second perimeters.

39. A method for generating at least one tool path as in claim 37, wherein said generating tool path step includes performing a medial axis transformation.

40. A method for generating at least one tool path as in claim 37, wherein said obtaining step includes obtaining a substantially greater preservation weighting for said first perimeter relative to said second perimeter, and said tool path generating step includes generating a tool path through said narrow region disposed further from said first perimeter than from said second perimeter.

41. A method for generating at least one tool path as in claim 37, wherein said obtaining step includes obtaining a substantially greater preservation weighting for said first perimeter relative to said second perimeter, and said tool path generating step includes generating a tool path through said narrow region disposed further from said first perimeter than from said second perimeter.

42. A method for generating at least one tool path as in claim 37, wherein said obtaining step includes obtaining a substantially one hundred percent (100%) preservation weighting for said first perimeter and substantially zero percent (0%) preservation weighting for said second perimeter, and said tool path generating step includes generating a tool path through said narrow region at closest about one offset distance from said first perimeter.

43. A method for generating at least one tool path as in claim 37, wherein said first and second perimeters are both inner perimeters corresponding to inner voids, wherein said obtaining step includes obtaining a substantially equal preservation weighting for said first and second perimeters, and said tool path generating step includes generating a tool path through said narrow region about equidistant from said inner voids.

44. A method for generating at least one tool path as in claim 37, wherein said first and second perimeters are both inner perimeters corresponding to inner voids, wherein said obtaining step includes obtaining a substantially equal preservation weighting for said first and second perimeters, and said tool path generating step includes generating a tool path through said narrow region including performing a medial axis transformation.

45. A method for generating at least one tool path as in claim 37, wherein said first and second perimeters are both outer perimeters corresponding to outer surfaces, wherein said obtaining step includes obtaining a substantially equal preservation weighting for said first and second perimeters, and said tool path generating step includes generating a tool path through said narrow region about equidistant from said outer surfaces.

46. A method for generating at least one tool path as in claim 37, wherein said first and second perimeters are both outer perimeters corresponding to outer surfaces, wherein said obtaining step includes obtaining a substantially equal preservation weighting for said first and second perimeters, and said tool path generating step includes generating a tool path through said narrow region including performing a medial axis transformation.

47. A method for generating at least one tool path as in claim 37, wherein said first perimeter is an inner perimeter corresponding to an inner void, wherein said second perimeter is an outer perimeter corresponding to an outer surface, wherein said obtaining step includes obtaining a substantially greater preservation weighting for said first perimeter relative to said second perimeter, and said tool path generating step includes generating a tool path through said narrow region further from said first perimeter and closer to said second perimeter, such that said inner void is preserved more than said outer surface near said inner void.

48. A method for generating at least one tool path as in claim 37, wherein said first perimeter is an inner perimeter corresponding to an inner void, wherein said second perimeter is an outer perimeter corresponding to an outer surface, wherein said obtaining step includes obtaining a substantially greater preservation weighting for said second perimeter relative to said first perimeter, and said tool path generating step includes generating a tool path through said narrow region further from said second perimeter and closer to said first perimeter, such that said outer surface is preserved more than said void near said outer surface.

49. A method for generating at least one tool path within a design layer region for layered manufacturing, wherein said design layer region has an inner void, wherein said design layer region has an outer perimeter and at least one inner perimeter associated with said inner void, wherein said design layer region has a material region between said outer perimeter and said inner perimeter, wherein said tool path has an associated offset corresponding to about half of an associated tool path bead width, wherein said tool path has an origin, the method comprising the steps

(a) establishing an inner perimeter boundary disposed at about said offset distance from said inner void perimeter toward said material region, such that a first margin is established about said inner void within said material region;

(b) generating said tool path along a line until said line intersects said inner perimeter boundary at an intersection point;

(c) if said intersection point is the first intersection of said tool path with said inner perimeter boundary, executing step (d), otherwise executing step (e);

(d) continuing said tool path in a direction following said inner perimeter boundary in a direction such that said tool path initially proceeds most toward said tool path origin; and

(e) continuing said tool path in a direction following said inner perimeter boundary in a direction such that said tool path initially proceeds most away from said tool path origin.

50. A method for generating at least one tool path within a design layer region for layered manufacturing, wherein said design layer region has an inner void, wherein said design layer region has an outer perimeter and at least one inner perimeter associated with said inner void, wherein said design layer region has a material region between said outer perimeter and said inner perimeter, wherein said tool path has an associated offset corresponding to about half of an associated tool path bead width, wherein said tool path has an origin, the method comprising generating said tool path along a plurality of line segments which do not approach said void inner perimeter closer than about said offset distance, and which follow said inner perimeter at about said offset on opposite sides of said inner void perimeter.

51. A method for generating at least one tool path within a design layer region for layered manufacturing, wherein said design layer region has an inner void, wherein said design layer region has an outer perimeter and at least one inner perimeter associated with said inner void, wherein said design layer region has a material portion between said outer perimeter and said inner perimeter, wherein said tool path has an associated offset corresponding to about half of an associated tool path bead width, wherein said tool path has an origin, the method comprising the steps of:

(a) establishing a first axis in said design layer relative to said outer perimeter, thereby establishing a second axis orthogonal to said first axis;

(b) generating an outer perimeter boundary into said material region, having a distance from said outer perimeter of about said offset distance;

(c) generating an inner perimeter boundary into said material region, having a distance from said inner perimeter of about said offset distance;

(d) generating a plurality of parallel guides parallel to said first axis;

(e) establishing a tool path origin point, and initializing said tool path generation at said origin point parallel to said first axis;

(f) continuing generating said tool path line until said tool path intersects a line selected from the group of outer perimeter boundaries, inner perimeter boundaries, and guide lines;

then, executing step (g);

(g) if said step (f) tool path intersection is an outer perimeter boundary intersection, then generating said tool path to follow said outer perimeter boundary in a direction initially most away from said origin, then executing step (f);

(h) if said step (f) tool path intersection is an inner perimeter boundary intersection, and if said step (f) intersection is the first intersection with said inner perimeter boundary, then generating said tool path to follow said inner perimeter boundary in a direction initially most toward said origin, then executing step (f);

(i) if said tool path intersection is an inner perimeter boundary intersection, and if said intersection is not the first intersection with said inner perimeter boundary, then generating said tool path to follow said inner perimeter boundary in a direction initially most away from said origin, then executing step (f);

(j) if said step (f) tool path intersection is a guide line intersection, then generating said tool path along said guide line in a direction most initially toward said origin, then executing step (f); and

(k) repeating steps (f) through (j) until no more contiguous travel of unvisited guide lines is possible.

52. A method for generating at least one tool path as in claim 51, wherein said design layer region has a vertex, wherein said establishing tool path origin step includes establishing said tool path origin to a point near said vertex.

53. A method for generating at least one tool path as in claim 51, wherein said establishing tool path origin step includes initializing said tool path origin to a point near a vertex defined by:

selecting two outer perimeter lines, offsetting each outer perimeter line inward to define an outer perimeter boundary line, and determining a point location where said two outer perimeter boundary lines intersect in said material region, and setting said origin to about said point location.

54. A method for generating at least one tool path as in claim 51, wherein said outer perimeter includes a vertex defined by two outer perimeter lines meeting at an angle, wherein said establishing tool path origin step includes determining a point location bisecting said angle at a distance of about one offset from said vertex, and setting said origin to about said point location.

55. A method for generating at least one tool path as in claim 51, wherein said design layer has at least one outer contour tool path, and said outer perimeter is established at an offset distance inward from said outer contour tool path.

56. A method for generating at least one tool path as in claim 51, wherein said guide lines are virtual guide lines.

57. A method for generating tool paths for a layer for layered manufacturing comprising the steps of:

obtaining an outer boundary for said layer;

forming a plurality of substantially parallel raster tool path pairs, said pairs having a first segment coupled at a first raster vertex to a second segment, said second segment coupled at a second vertex to a third segment, wherein said second segment is substantially parallel to said outer boundary, wherein said first and second segments are substantially parallel to each other and to said raster tool path pairs;

wherein said raster tool path pairs are separated by inter-pair lines disposed between a first segment of a first raster pair and a third segment of a second, adjacent raster pair;

wherein an inter-pair intersection point is formed by a projection extension of said inter-pair line to said outer boundary; and

positioning first and second raster vertices disposed on either side of said intra-pair line at about one half of said raster tool path bead width from said inter-pair intersection point.

58. A method for generating tool paths as in claim 57, further comprising projecting said first and third raster segments to form first and second raster intersection points with said outer boundary, further comprising determining if said outer boundary has any first vertices in between said first raster intersection point and inter-pair intersection point, and using said any first vertices in said positioning first raster vertices, further comprising determining if said outer boundary have any second vertices in between said second raster intersection point and inter-pair intersection point, and using said any second vertices in said positioning second raster vertex.

59. A method for generating tool paths as in claim 58, wherein said any first vertices are averaged with said first raster intersection point to form a first average point used to position said first raster vertex, wherein said any second vertices are averaged with said second raster intersection point to form a second average point used to position said second raster vertex.

60. A method for generating tool paths as in claim 57, wherein said outer boundary is an inward offset perimeter of said layer having a contour bead.

61. A part made by a layered manufacturing process comprising forming an outer contour bead and inner raster beads disposed at an angle to said contour bead such that no voids exist between said raster beads and said contour beads.

62. An automatic method for making a part by a layered manufacturing process comprising forming material raster beads at an angle to an outer contour bead such that no voids exist between said raster beads and said contour beads.

63. An automatic method as in claim 62, wherein said forming step includes forming raster bead turnaround portions having vertices, wherein said raster bead turnaround vertices are located as a function at least in part of said angle.