Methods and Apparatus for Handheld Tool

• US 20130231771A1
• Filed: 03/04/2013
• Published: 09/05/2013
• Est. Priority Date: 03/02/2012
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Paradiso, Joseph, Zoran, Amit, Shilkrot, Roy
• Granted Patent: US 9,342,632 B2
• Time in Patent Office: Days
• US Class Current: 700/182
• CPC Class Codes: B44B 3/009 using a computer control means
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/35134 3-D cad-cam
• CPC Class Codes: G05B 2219/49023 3-D printing, layer of powder, add drops of binder in layer, new powder
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y02T 10/82 Elements for improving aerodynamics

Abstract

In exemplary implementations of this invention, a computer-assisted, handheld machining tool allows even an inexperienced user to carve a complex 3D object, while maintaining artistic freedom to modify the sculpture from an initial CAD design. The tool prevents the user from unintentionally removing material from a volume defined by the CAD design. It does so by slowing or halting spindle rotation as the bit approaches or penetrates the protected volume. The user can override this protective feature. The tool may operate in at least three interaction modes: (i) a static mode in which a static CAD model is used, where the computer assists by preventing the user from damaging the static model; (ii) a dynamic mode where the computer dynamically modifies the CAD model during the sculpting process; and (iii) an autonomous mode where the computer can operate independently of the user, for tasks such as semi-automatic texture rendering.

Claims

1. Apparatus comprising a machining tool, wherein the machining tool:

(a) is configured to be handheld by a human user while effecting removal of material from an object;

(b) includes a bit;

(c) is configured to be able to perform a function, the function comprising slowing or halting the removal of material depending on position of the bit relative to a physical region defined by a CAD model;

(d) is configured to enable or disable the function, in response to input from the user, and

(e) is configured to accept in real time or to compute in real time modifications to the CAD model, which modifications to the CAD model are determined, at least in part, by at least some movements of the bit relative to the object during the removal of material.

2. The apparatus of claim 1, wherein the modifications to the CAD model comprise deformation of a surface of the CAD model, which deformation minimizes either (i) penetration of the bit into the physical region defined by the CAD model, (ii) amount of material removed from the physical region defined by the CAD model, or (iii) another value that depends at least in part on the penetration or the amount of material removed.

3. The apparatus of claim 1, wherein the modifications alter the CAD model to maximize percentage, by volume, of the object that is occupied by the physical region defined by the CAD model.

4. The apparatus of claim 1, wherein the modifications are computed, at least in part, by selecting, out of a set of multiple CAD models, a selected CAD model that maximizes percentage, by volume, of the object that is occupied by the physical region defined by the selected CAD model.

5. The apparatus of claim 1, wherein the apparatus is further configured to actuate the bit to move in paths relative to the object that are not determined by the user.

6. The apparatus of claim 1, wherein the apparatus includes at least one sensor for detecting data indicative of position of the machining tool relative to the object.

7. The apparatus of claim 1, wherein the apparatus includes at least one sensor for detecting data indicative of pressure exerted by the machining tool on the object.

8. The apparatus of claim 1, wherein the apparatus includes one or more transducers for providing feedback to the user regarding at least one of a group consisting of:

(i) position of the machining tool relative to the object, or (ii) pressure exerted by the machining tool on the object.

9. The apparatus of claim 1, wherein the modifications to the CAD model are computed, at least in part, by one or more computers that are external to the machining tool.

10. The apparatus of claim 9, wherein the apparatus further comprises the one or more computers.

11. The apparatus of claim 1, wherein different CAD models are used for different portions of the object, in accordance with selections inputted by the user.

12. The apparatus of claim 11, wherein the function protects a hybrid physical region, which region does not correspond to any single CAD model.

13. A method comprising using a machining tool, wherein the machining tool:

(a) is configured to be handheld by a human user while effecting removal of material from an object;

(b) includes a bit;

(c) is configured to be able to perform a function, the function comprising slowing or halting the removal of material depending on position of the bit relative to a physical region defined by a CAD model;

(d) is configured to enable or disable the function, in response to input from the user, and

(e) is configured to accept in real time or to compute in real time modifications to the CAD model, which modifications to the CAD model are determined, at least in part, by at least some movements of the bit relative to the object during the removal of material.

14. The method of claim 13, wherein the modifications to the CAD model comprise deformation of a surface of the CAD model, which deformation minimizes either (i) penetration of the bit into the physical region defined by the CAD model, (ii) amount of material removed from the physical region defined by the CAD model, or (iii) another value that depends at least in part on the penetration or the amount of material removed.

15. The method of claim 13, wherein the modifications alter the CAD model to maximize percentage, by volume, of the object that is occupied by the physical region defined by the CAD model.

16. The method of claim 13, wherein the modifications are computed, at least in part, by selecting, out of a set of multiple CAD models, a selected CAD model that maximizes percentage, by volume, of the object that is occupied by the physical region defined by the selected CAD model.

17. The method of claim 13, wherein the apparatus is further configured to actuate the bit to move in paths relative to the object that are not determined by the user.

18. The method of claim 13, wherein different CAD models are used for different portions of the object, in accordance with selections inputted by the user.

19. Apparatus comprising a machining tool, wherein the machining tool:

(a) is configured to effect removal of material from an object, the removal of material having an operative rate and occurring within an operative zone;

(b) is configured to be handheld by a human user during the removal of material;

(c) is configured to be able to perform a function, the function comprising slowing or halting the operative rate depending on position of the operative zone relative to a physical region defined by a CAD model;

(d) is configured to enable or disable the function, in response to input from the user, and

(e) is configured to accept in real time or to compute in real time modifications to the CAD model, which modifications to the CAD model are determined, at least in part, by at least some movements of the operative zone relative to the object during the removal of material.

20. Apparatus comprising a tool for subtractive fabrication or additive fabrication, wherein the tool:

(a) is configured to effect removal of material from or deposition of material to an object;

which removal or deposition has an operative rate and occurs within an operative zone;

(b) is configured to be handheld by a human user during the removal or deposition;

(c) is configured to be able to perform a function, the function comprising altering the operative rate depending on position of the operative zone relative to a physical region defined by a CAD model;

(d) is configured to enable or disable the function, in response to input from the user, and

(e) is configured to accept in real time or to compute in real time modifications to the CAD model, which modifications to the CAD model are determined, at least in part, by at least some movements of the operative zone relative to the object during the removal or deposition of material.