Contact patch simulation

Patent metadata

Field	Value
Publication number	US-9971339-B2
Application number	US-201213628007-A
Country	US
Kind code	B2
Filing date	Sep 26, 2012
Priority date	Sep 26, 2012
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A method and an apparatus for smart automation of robotic surface finishing of a three-dimensional surface of a workpiece is described. A finite element analysis simulation is conducted providing data for generation of a three-dimensional path along the surface of the workpiece. The finite element can include properties of the workpiece, finishing tool, and the robot configured to maneuver the finishing tool. The surface of the workpiece is finished using one or more surface finishing tools along the three-dimensional path. The surface of the workpiece includes at least a flat region and a curved region.

First claim

What is claimed is:

1. A method for machining and polishing a workpiece to form a target workpiece, the method comprising, at a controller unit in communication with a single material removal tool:
generating (i) a simulated material removal path for modifying dimensions of the workpiece according to desired dimensions of the target workpiece, and (ii) a simulated surface finishing path for polishing the workpiece according to a desired surface finish of the target workpiece;
generating an intermediate three-dimensional path along the workpiece that is based on a difference between at least one characteristic of the workpiece and at least one corresponding desired characteristic of the target workpiece, wherein the intermediate three-dimensional path includes a first weighted amount of the simulated material removal path and a second weighted amount of the simulated surface finishing path;
receiving, from the controller unit, a signal associated with the intermediate three-dimensional path at the single material removal tool; and
causing, in response to receiving the signal, the single material removal tool to remove an amount of material from the workpiece in accordance with the intermediate three-dimensional path.

2. The method of claim 1 , wherein, subsequent to the removal of the amount of material from the workpiece, the method further comprises:
comparing the at least one characteristic to the at least one corresponding desired characteristic of the target workpiece; and
when there is a discrepancy between the at least one corresponding desired characteristic and the at least one characteristic:
adjusting each of the first and second weighted amounts to reduce the discrepancy.

3. The method of claim 1 , wherein the method further comprises:
determining an amount of finishing force to be applied to the workpiece in conjunction with removing the amount of material.

4. The method of claim 1 , wherein the method further comprises:
receiving an amount of force feedback while removing the amount of material from the workpiece; and
adjusting each of the first and second weighted amounts based on the amount of force feedback.

5. The method of claim 2 , further comprising:
generating a subsequent intermediate three-dimensional path along the workpiece that is based on the first and second adjusted weighted amounts.

6. The method of claim 1 , wherein the single material removal tool is coupled to a robotic handler having 6-degrees of freedom of movement.

7. The method of claim 1 , wherein the at least one characteristic includes a material composition.

8. The method of claim 1 , wherein the intermediate three-dimensional path is further based on one or more properties of the single material removal tool.

9. A material processing system for machining and polishing a workpiece to form a target workpiece, the material processing system comprising:
a controller unit capable of:
generating (i) a simulated material removal path for modifying dimensions of the workpiece according to desired dimensions of the target workpiece, and (ii) a simulated surface finishing path for polishing the workpiece according to a desired surface finish of the target workpiece, and
generating an intermediate three-dimensional path along the workpiece that is based a difference between at least one characteristic of the workpiece and at least one corresponding desired characteristic of the target workpiece, wherein the intermediate three-dimensional path includes a first weighted amount of the simulated material removal path and a second weighted amount of the simulated surface finishing path; and

a material removal tool in communication with the controller unit and capable of removing an amount of material from the workpiece in accordance with the intermediate three-dimensional path.

10. The material processing system of claim 9 , wherein the material processing system further comprises:
an analysis module in communication with the controller unit, the analysis module configured to:
obtain the at least one characteristic of the workpiece subsequent to removing the amount of material,
compare the at least one characteristic to the at least one corresponding desired characteristic of the target workpiece, and
when there is a discrepancy between the at least one characteristic and the at least one corresponding desired characteristic:
cause the controller unit to adjust each of the first and second weighted amounts in order to reduce the discrepancy.

11. The material processing system of claim 9 , further comprising a force feedback sensor coupled to the material removal tool.

12. The material processing system of claim 10 , wherein the at least one characteristic of the workpiece is provided by a three-dimensional scanner that is in communication with the controller unit.

13. The material processing system of claim 10 , wherein the at least one corresponding desired characteristic corresponds to a surface finish or a material composition of the target workpiece.

14. The material processing system of claim 10 , wherein the at least one corresponding desired characteristic includes:
an amount of force applied by the material removal tool to a surface of the workpiece;
a surface speed of the material removal tool;
an amount of contact time between the material removal tool and the surface of the workpiece; or
an angle of the material removal tool relative to the surface of the workpiece.

15. The material processing system of claim 10 , wherein the analysis module is further configured to:
determine a difference between the amount of material removed from the workpiece and a targeted amount of material to be removed from the workpiece;
when the difference between the amount of material removed and the targeted amount of material to be removed exceeds a tolerance value:
cause the controller unit to reduce the difference.

16. A non-transitory computer readable medium storing instructions that, when executed by one or more processors of a material processing system, cause the material processing system to:
generate (i) a simulated material removal path for modifying dimensions of a workpiece according to desired dimensions of a target workpiece, and (ii) a simulated surface finishing path for polishing the workpiece according to a desired surface finish of the target workpiece;
generate a control signal associated with an intermediate three-dimensional path;
provide the control signal to a single material removal tool that causes the single material removal tool to remove an amount of material from the workpiece according to the intermediate three-dimensional path, wherein the amount of material removed corresponds to a first weighted amount of the simulated material removal path and a second weighted amount of the simulated surface finishing path;
obtain a characteristic of the workpiece subsequent to removing the amount of material;
compare the characteristic to a target characteristic of a target workpiece; and
when the characteristic does not correspond to the target characteristic:
adjust the first and second weighted amounts to remove an updated amount of material from the workpiece.

17. The non-transitory computer readable medium of claim 16 , wherein the characteristic of the workpiece is provided by a scanner that is in communication with the material processing system.

18. The non-transitory computer readable medium of claim 16 , wherein comparing the characteristic to the target characteristic includes:
determine a difference betwee

Assignees

• Maloney Max A
• Bujtor Howard E
• Miehm Brian K
• Apple Inc

Inventors

• Maloney Max A
• Bujtor Howard E
• Miehm Brian K

Classifications

• G05B2219/35009

  Dynamic simulation · CPC title

• G05B2219/35168

  Automatic selection of machining conditions, optimum cutting conditions · CPC title

• Y02P90/265

  Cross-Sectional Technologies · mapped topic

• G05B19/4099 Primary

  Surface or curve machining, making three-dimensional [3D] objects, e.g. desktop manufacturing · CPC title

• G05B2219/45062

  Surface finishing robot · CPC title