Model generation system having closed-loop extrusion nozzle positioning

• US 5,402,351 A
• Filed: 01/18/1994
• Issued: 03/28/1995
• Est. Priority Date: 01/03/1991
• Status: Expired due to Term

• Current Assignee: Stratasys Incorporated
• Original Assignee: International Business Machines Corporation
• Inventors: Mackay, John D., Koppelman, George M., Goodman, Douglas S., Jackson, Robert R., Gracer, Franklin, Batchelder, John S., Curtis, Huntington W.
• Primary Examiner(s): Envall, Jr., Roy N.
• Assistant Examiner(s): Garland, Steven R.
• Application Number:
  US08/183,512
• Time in Patent Office: 434 Days
• Field of Search: 364/468, 364/474.24, 395/118-120, 264/22, 264/40.1, 425/135, 156/59, 156/350
• US Class Current: 700/119
• CPC Class Codes: B29C 41/36 Feeding the material on to the mould, core or other substrate
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/266 Means for allowing relative movements between the apparatus parts, e.g. for twisting the extruded article or for moving the die along a surface to be coated
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/37572 Camera, tv, vision
• CPC Class Codes: G05B 2219/49015 Wire, strang laying, deposit fluid, welding, adhesive, hardening, solidification, fuse
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Disclosed are methods and apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object that is stored within a memory. A method includes the steps of (a) evaluating the stored definition of the object to locate any un-supported features of the object; in response to locating an un-supported feature, (b) defining a support structure for the un-supported feature; (c) generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and (d) translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures. The step of translating includes the steps of, generating a feedback signal that is indicative of at least one characteristic of a most recently fabricated portion of the object; and monitoring the feedback signal to detect a deviation of at least a location of the most recently fabricated portion of the object from a corresponding location as expressed in the associated portion of the fabrication tool movement list. Also disclosed are methods and apparatus for anti-aliasing aliased surface features of the object, representing the object definition in a vector format, generating a bit-mapped representation of the object, and an analysis of the definition of the object to identify and subsequently compensate for a region of the object that has a potential to retain heat during fabrication.

Claims

1. A method for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising the steps of:

evaluating the stored definition of the object to locate any un-supported features of the object;

in response to locating an un-supported feature,

defining a support structure for the un-supported feature;

generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the step of translating includes the steps of,

generating a feedback signal that is indicative of at least one characteristic of a most recently fabricated portion of the object; and

monitoring the feedback signal to detect a deviation of at least a location of the most recently fabricated portion of the object from a corresponding location as expressed in the associated portion of the fabrication tool movement list.

2. A method as set forth in claim 1 wherein the step of evaluating includes a step of slicing the definition of the object into a plurality of vertically stacked planes.

3. A method for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising the steps of:

evaluating the stored definition of the object to locate any un-supported features of the object;

in response to locating an un-supported feature,

defining a support structure for the un-supported feature;

generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the definition is stored as a plurality of vectors representing the object.

4. A method as set forth in claim 3 wherein at least the steps of evaluating and defining are performed using the stored plurality of vectors.

5. A method as set forth in claim 4 wherein the step of generating the fabrication tool movement list includes an initial step of converting the plurality of stored vectors to a bit-mapped representation of the object.

6. A method for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising the steps of:

evaluating the stored definition of the object to locate any un-supported features of the object;

in response to locating an un-supported feature,

defining a support structure for the un-supported feature;

generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the step of generating the fabrication tool movement list includes an initial step of analyzing the definition of the object to identify alias features associated with a periphery of the object.

7. A method as set forth in claim 6 wherein the step of analyzing includes a step of adding additional features to the definition of the object to reduce a magnitude of identified alias features.

8. A method for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising the steps of:

evaluating the stored definition of the object to locate any un-supported features of the object;

in response to locating an un-supported feature,

defining a support structure for the un-supported feature;

generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the step of generating the movement list includes a step of analyzing the definition of the object to identify regions of the object having a potential to retain heat during the step of translating.

9. A method as set forth in claim 8 wherein the step of analyzing includes a step of modifying the fabrication tool movement list to compensate for a retention of heat by the identified regions.

10. A method for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising the steps of:

evaluating the stored definition of the object to locate any un-supported features of the object;

in response to locating an un-supported feature,

defining a support structure for the un-supported feature;

generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the step of translating includes the steps of;

generating a feedback signal that is indicative of at least one characteristic of a most recently fabricated portion of the object;

monitoring the feedback signal to detect a deviation of at least a location of the most recently fabricated portion of the object from the corresponding location as expressed in an associated portion of the fabrication tool movement list; and

modifying a subsequent portion of the fabrication tool movement list to compensate for a detected deviation.

11. Apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising:

means for evaluating the stored definition of the object to locate any un-supported features of the object;

means, responsive to the evaluating means locating an un-supported feature, for defining a support structure for the un-supported feature;

means for generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

means for translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the translating means comprises,

means for generating a feedback signal that is indicative of at least one characteristic of a most recently fabricated portion of the object;

means for monitoring the feedback signal to detect a deviation of at least a location of the most recently fabricated portion of the object from the corresponding location as expressed in an associated portion of the fabrication tool movement list; and

means for modifying a subsequent portion of the fabrication tool movement list to compensate for a detected deviation.

12. Apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising:

means for evaluating the stored definition of the object to locate any un-supported features of the object;

means, responsive to the evaluating means locating an un-supported feature, for defining a support structure for the un-supported feature;

means for generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

means for translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the definition is stored as a plurality of vectors representing the object and wherein the generating means includes means for converting the plurality of vectors to a plurality of horizontally disposed layers each of which is expressed in a bit mapped representation.

13. Apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising:

means for evaluating the stored definition of the object to locate any un-supported features of the object;

means, responsive to the evaluating means locating an un-supported feature, for defining a support structure for the un-supported feature;

means for generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

means for translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures;

wherein the generating means includes means for analyzing the definition of the object to identify alias features associated with a surface of the object; and

further includes means for adding surface features to the definition of the object for substantially anti-aliasing the surface.

14. Apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object stored within a memory means, comprising:

means for evaluating the stored definition of the object to locate any un-supported features of the object;

means, responsive to the evaluating means locating an un-supported feature, for defining a support structure for the un-supported feature;

means for generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and

means for translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures; and

further comprising;

means for generating a feedback signal that is indicative of at least one characteristic of a most recently fabricated portion of the object; and

means for monitoring the feedback signal to detect a deviation of at least a location of the most recently fabricated portion of the object from a corresponding location as expressed in the associated portion of the fabrication tool movement list.

15. Apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object, comprising:

means for evaluating the definition of the object to locate an aliased surface feature;

means, responsive to the evaluating means locating an aliased surface feature, for defining a compensating anti-aliasing surface feature;

means for generating a fabrication tool movement list expressive of movements required by the fabrication tool to fabricate the object and the anti-aliasing surface feature;

means for translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and the anti-aliasing surface feature;

means for generating a feedback signal that is indicative of at least one characteristic of a most recently fabricated portion of the object; and

means for monitoring the feedback signal to detect a deviation of at least a location of the most recently fabricated portion of the object from a corresponding location as expressed in the associated portion of the fabrication tool movement list.