Automated assembly and welding of structures

• US 20090249606A1
• Filed: 12/05/2008
• Published: 10/08/2009
• Est. Priority Date: 04/03/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Wang, Huijun, Robinson, Mathew Mark, Ludewig, Howard W., Diez, Fernando Martinez, Herman, Keith Alan
• Granted Patent: US 8,157,155 B2
• Time in Patent Office: Days
• US Class Current: 29/428
• 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 system for assembling workpieces, the system comprising:

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;

wherein 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.

2. The system of claim 1, further comprising a working robot configured to operate relative to workpieces positioned on the workpiece holder;

wherein the controller is in further communication with the working robot.

3. The system of claim 2, wherein the working robot is configured to perform one or more of inspecting, measuring, photographing, welding, drilling, and machining of workpieces positioned on the workpiece holder.

4. The system of claim 2, further including a tool changing station having a camera and a welding torch;

wherein the working robot is configured to selectively retrieve the camera or welding torch for operating relative to workpieces positioned on the workpiece holder.

5. The system of claim 1, wherein the electromagnets are connected to a support structure and configured to fix a workpiece to the support structure, and the support structure includes hard stops configured to orient a workpiece fixed to the support structure.

6. The system of claim 5, wherein the support structure includes a fixed table or a movable robotic arm.

7. The system of claim 1, further comprising a detection unit configured to collect data about incoming workpieces received on the pallet.

8. The system of claim 7, wherein the detection unit is a camera.

9. The system of claim 7, wherein the controller is further configured to determine an identity of the workpiece and to operate the workpiece holder and the handling robot based upon the identity of the workpiece.

10. The system of claim 2, further comprising a welding wire feeder in communication with the controller;

wherein the controller is configured to operate the welding wire feeder in cooperation with the working robot when the working robot is manipulating a welding torch.

11. 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.

12. The method of claim 11, 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.

13. The method of claim 12, 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.

14. The method of claim 11, 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.

15. The method of claim 14, 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.

16. The method of claim 11, 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.

17. 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.

18. The method of claim 17, 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.

19. The method of claim 18, 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.

20. The method of claim 19, wherein the selective adjustment of the electromagnets is based upon a predetermined adjustment sequence stored in a memory of the controller.