Systems and methods for high accuracy fixtureless assembly

Patent metadata

Field	Value
Publication number	US-12325138-B2
Application number	US-202217814441-A
Country	US
Kind code	B2
Filing date	Jul 22, 2022
Priority date	Dec 17, 2018
Publication date	Jun 10, 2025
Grant date	Jun 10, 2025

Abstract

An approach to positioning one or more robotic arms in an assembly system may be described herein. For example, a system for robotic assembly may include a first robot, a second robot, and a control unit. The control unit may be configured to receive a first target location proximal to a second target location. The locations may indicate where the robots are to position the features. The control unit may be configured to calculate a first calculated location of the first feature of the first subcomponent, measure a first measured location of the first feature of the first subcomponent, determine a first transformation matrix between the first calculated location and the first measured location, reposition the first feature of the first subcomponent to the first target location using the first robot, the repositioning based on the first transformation matrix.

First claim

What is claimed is:

1. A method of robotic assembly, comprising:
measuring a first feature of a first subcomponent;
fitting the first feature to a corresponding feature of a computer-aided design (CAD) model of the first subcomponent;
determining a fixture location of the first subcomponent based on the fitting;
receiving a first target location indicating where a first robot is to position the fixture location of the first subcomponent, the first target location proximal to a second target location indicating where a second robot is to position a second feature of a second subcomponent such that the first subcomponent and the second subcomponent form a component when coupled together with the fixture location of the first subcomponent in the first target location and the second feature of the second subcomponent in the second target location;
calculating a first calculated location of the fixture location;
measuring a first measured location of the fixture location;
determining a first transformation matrix between the first calculated location and the first measured location; and
repositioning the fixture location to the first target location using the first robot, the repositioning based on the first transformation matrix.

2. The method of claim 1 , further comprising:
receiving a second target location indicating where the second robot is to position the second feature of the second subcomponent;
calculating a second calculated location of the second feature of the second subcomponent;
measuring a second measured location of the second feature of the second subcomponent;
determining a second transformation matrix between the second calculated location and the second measured location; and
repositioning the second feature of the second subcomponent to the second target location using the second robot, the repositioning based on the second transformation matrix.

3. The method of claim 2 , wherein measuring the first measured location of the fixture location of the first subcomponent and measuring the second measured location of the second feature of the second subcomponent use a same metrology unit.

4. The method of claim 2 , wherein at least repositioning the fixture location of the first subcomponent or repositioning the second feature of the second subcomponent is further based on a relative comparison of the first calculated location and the second calculated location.

5. The method of claim 1 , wherein at least the first subcomponent or the second subcomponent comprise a plurality of components.

6. The method of claim 5 , wherein the plurality of components comprises a chassis for a transport structure.

7. The method of claim 1 , wherein the first target location comprises a tool center point (TCP).

8. The method of claim 1 , wherein the first target location comprises a location offset from a tool center point (TCP).

9. The method of claim 8 , wherein the measuring of the first feature including scanning the first subcomponent to determine a relative location of the fixture location of the first subcomponent relative to the TCP, the first robot configured to pick up the first subcomponent based on the scanning.

10. The method of claim 1 , wherein the first calculated location comprises a dynamic nominal location indicating a calculated location of a moving fixture location at a specific time, the specific time coinciding with the measuring of a first location of the fixture location.

11. The method of claim 1 , further comprising repeating the calculating, the measuring, the determining, and the repositioning.

12. The method of claim 1 , further comprising adjusting at least accuracy boundaries or gain based on repeating of at least the calculating, the measuring, the determining, or the repositioning.

13. The method of claim 1 , wherein measuring the first measured location of the fixture location of the first subcomponent comprises measuring by a processor.

14. The method of claim 1 , wherein repositioning the fixture location of the first subcomponent to the first target location using the first robot based on the first transformation matrix comprises sending the first transformation matrix to a control unit in the first robot.

15. The method of claim 1 , further comprising:
measuring at least two locations on the first subcomponent, the at least two locations including the first target location,
wherein the fitting including determining a fit for the at least two locations, and
wherein repositioning the fixture location of the first subcomponent to the first target location using the first robot, the repositioning based on the first transformation matrix is further based on the fit for the at least two locations.

16. The method of claim 1 , wherein measuring the first measured location of the fixture location of the first subcomponent comprises scanning a shape of a part.

17. The method of claim 1 , wherein measuring the first measured location of the fixture location of the first subcomponent comprises measuring a fixture point on the first subcomponent.

18. The method of claim 1 , further comprising attaching the first subcomponent to the second subcomponent.

19. The method of claim 18 , wherein attaching the first subcomponent to the second subcomponent includes attaching the first subcomponent to the second subcomponent using a ultra-violet (UV) adhesive.

20. The method of claim 1 , wherein the first feature includes the fixture location.

21. The method of claim 1 , wherein the first feature includes a geometry of the first subcomponent.

22. The method of claim 21 , wherein the geometry includes at least a surface of the first subcomponent.

23. The method of claim 1 , wherein the first feature includes a joint.

24. The method of claim 1 , wherein the fitting of the first feature including performing a best fit to data.

25. The method of claim 24 , wherein the performing of the best fit including performing a calculation based on a first geometry of the first feature relative to a tool center point (TCP) frame.

26. The method of claim 25 , wherein the first feature including a second feature, and
wherein the performing of the calculation is based on a second geometry of the second feature relative to the TCP frame.

27. The method of claim 1 , wherein the determining of the fixture location including performing a calculation of an offset relative to a tool center point (TCP) frame.

28. The method of claim 27 , wherein the performing of the calculation is based on a best fit calculation.

29. The method of claim 27 , wherein the TCP frame is defined on the first subcomponent.

30. A system for robotic assembly, comprising:
a first subcomponent comprising a first feature;
a first robot;
a second robot; and
a control unit coupled to the first robot and the second robot, wherein the control unit includes a processor configured to:
measure the first feature,
fit the first feature to a corresponding feature of a computer-aided design (CAD) model of the first subcomponent,
determine a fixture location of the first subcomponent based on the fit of the first feature to the corresponding feature,
receive a first target location indicating where the first robot is to position the fixture location of the first subcomponent, the first target location proximal to a second target location

Assignees

• Divergent Tech Inc

Inventors

• Czinger Lukas Philip
• Rawas Oussama
• Bowden Jr Thomas Samuel
• Smith Roy

Classifications

• B22F10/31

  Calibration of process steps or apparatus settings, e.g. before or during manufacturing · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F10/25

  Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS] · CPC title

• B25J9/1628

  characterised by the control loop · CPC title