Automated assembly and welding of structures

• US 8,322,591 B2
• Filed: 02/27/2012
• Issued: 12/04/2012
• Est. Priority Date: 04/03/2008
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Diez, Fernando Martinez, Herman, Keith Alan, Wang, Huijun, Ludewig, Howard W., Robinson, Mathew Mark
• Primary Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US13/405,606
• Publication Number:
  US 20120152911A1
• Time in Patent Office: 281 Days
• Field of Search: None
• US Class Current: 228/102
• CPC Class Codes: B23K 11/11 Spot welding
• CPC Class Codes: B23K 2101/006 Vehicles
• CPC Class Codes: B23K 37/0211 travelling on a guide member, e.g. rail, track
• CPC Class Codes: B23K 37/0461 Welding tables
• CPC Class Codes: B23K 37/047 moving work to adjust its position between soldering, welding or cutting steps B23K37/053 takes precedence
• CPC Class Codes: B23P 2700/50 Other automobile vehicle parts, i.e. manufactured in assembly lines
• CPC Class Codes: B25J 15/0608 with magnetic holding means
• CPC Class Codes: B25J 9/0084 comprising a plurality of manipulators
• CPC Class Codes: B25J 9/0096 co-operating with a working support, e.g. work-table
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 29/53961 with work-holder for assembly

Abstract

A system for automated assembly and welding is disclosed. The system includes a pallet for receiving incoming workpieces; a workpiece holder having a plurality of electromagnets; a handling robot configured to transport incoming workpieces from the pallet to the workpiece holder; and a controller in communication with the workpiece holder and the handling robot. The controller is configured to determine an orientation of a workpiece positioned on the workpiece holder, and to selectively adjust an activation state of one or more electromagnets of the workpiece holder based upon the orientation of the workpiece. A method of assembling and welding workpieces is also disclosed.

Claims

1. A method of assembling workpieces, the method comprising:

positioning a first workpiece on a work holding system having a plurality of electromagnets;

positioning a second workpiece on the work holding system;

selectively activating the electromagnets to hold the first and second workpieces to the work holding system;

welding the first and second workpieces together; and

inspecting the first and second workpieces once they are welded together;

wherein the electromagnets are selectively adjusted based upon positions of the first and second workpieces and based upon positions of a welding tool used to weld the first and second workpieces together.

2. The method of claim 1, further comprising the step of:

configuring hard stops on the work holding system before positioning the first workpiece on the work holding system;

wherein the step of welding the first and second workpieces together comprises;

tack welding the first and second workpieces together;

inspecting the first and second workpieces once they are tack welded together; and

welding the first and second workpieces together if the inspected tack welding surpasses a predetermined quality threshold.

3. The method of claim 2, wherein the step of inspecting the first and second workpieces once they are tack welded together comprises:

manipulating the first and second workpieces using a handling robot; and

viewing the first and second workpieces using a CCD camera manipulated by a working robot.

4. The method of claim 1, further comprising:

positioning a third workpiece adjacent to one of the first and second workpieces;

tack welding the third workpiece to one of the first and second workpieces;

inspecting the first, second, and third workpieces once they are tack welded together; and

welding the third workpiece to one of the first and second workpieces if the inspected tack welding surpasses a predetermined quality threshold.

5. The method of claim 4, wherein the step of inspecting the first, second, and third workpieces once they are tack welded together comprises:

manipulating the first, second, and third workpieces using a handling robot; and

viewing the first, second, and third workpieces using a CCD camera manipulated by a working robot.

6. The method of claim 1, further comprising:

applying adhesive to a third workpiece; and

pressing the third workpiece against one of the first and second workpieces so as to adhere the third workpiece to one of the first and second workpieces.

7. A method of assembling workpieces, the method comprising:

positioning a plurality of workpieces on a work holding system having a plurality of electromagnets;

selectively activating the electromagnets to hold the workpieces to the work holding system;

retrieving a camera to inspect the workpieces held to the work holding system;

retrieving a welding torch to weld the workpieces together; and

retrieving a camera to inspect the workpieces once they are welded together;

wherein the electromagnets are selectively adjusted based upon positions of the workpieces and based upon positions of the welding torch as it welds the workpieces together.

8. The method of claim 7, wherein positioning of the workpieces is performed by a handling robot;

and retrieving of the camera and welding torch is performed by a working robot.

9. The method of claim 8, wherein the selective adjustment of the electromagnets is based upon commands sent by a controller to at least one of the handling robot, working robot, and work holding system.

10. The method of claim 9, wherein the selective adjustment of the electromagnets is based upon a predetermined adjustment sequence stored in a memory of the controller.

11. The method of claim 7, further comprising the step of:

configuring hard stops on the work holding system before positioning the first workpiece on the work holding system;

wherein the step of retrieving a welding torch to weld the workpieces together comprises tack welding the first and second workpieces together;

inspecting the first and second workpieces once they are tack welded together; and

welding the first and second workpieces together if the inspected tack welding surpasses a predetermined quality threshold.

12. The method of claim 7, further comprising:

positioning a third workpiece adjacent to one of the first and second workpieces;

tack welding the third workpiece to one of the first and second workpieces;

inspecting the first, second, and third workpieces once they are tack welded together; and

welding the third workpiece to one of the first and second workpieces if the inspected tack welding surpasses a predetermined quality threshold.

13. The method of claim 12, wherein the step of inspecting the first, second, and third workpieces once they are tack welded together comprises:

manipulating the first, second, and third workpieces using a handling robot; and

viewing the first, second, and third workpieces using a CCD camera manipulated by a working robot.

14. The method of claim 7, further comprising:

applying adhesive to a third workpiece; and

pressing the third workpiece against one of the first and second workpieces so as to adhere the third workpiece to one of the first and second workpieces.

15. A method of assembling workpieces, the method comprising:

positioning a first workpiece on a work holding system having a plurality of electromagnets;

positioning a second workpiece on the work holding system;

selectively activating the electromagnets to hold the first and second workpieces to the work holding system; and

welding the first and second workpieces together;

wherein the electromagnets are selectively adjusted based upon positions of the first and second workpieces and based upon positions of a welding tool used to weld the first and second workpieces together.

16. The method of claim 15, further comprising the step of:

configuring hard stops on the work holding system before positioning the first workpiece on the work holding system;

wherein the step of welding the first and second workpieces together comprises;

tack welding the first and second workpieces together;

inspecting the first and second workpieces once they are tack welded together; and

welding the first and second workpieces together if the inspected tack welding surpasses a predetermined quality threshold.

17. The method of claim 16, wherein the step of inspecting the first and second workpieces once they are tack welded together comprises:

manipulating the first and second workpieces using a handling robot; and

viewing the first and second workpieces using a CCD camera manipulated by a working robot.

18. The method of claim 15, further comprising:

positioning a third workpiece adjacent to one of the first and second workpieces;

tack welding the third workpiece to one of the first and second workpieces;

inspecting the first, second, and third workpieces once they are tack welded together; and

welding the third workpiece to one of the first and second workpieces if the inspected tack welding surpasses a predetermined quality threshold.

19. The method of claim 18, wherein the step of inspecting the first, second, and third workpieces once they are tack welded together comprises:

manipulating the first, second, and third workpieces using a handling robot; and

viewing the first, second, and third workpieces using a CCD camera manipulated by a working robot.

20. The method of claim 15, further comprising:

applying adhesive to a third workpiece; and

pressing the third workpiece against one of the first and second workpieces so as to adhere the third workpiece to one of the first and second workpieces.