Device for avoiding interference

• US 20020169522A1
• Filed: 05/09/2002
• Published: 11/14/2002
• Est. Priority Date: 05/09/2001
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Kanno, Ichiro
• Granted Patent: US 6,597,971 B2
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: B25J 9/1666 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 19/4061 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 2219/40087 Align hand on workpiece to pick up workpiece, peg and hole
• CPC Class Codes: G05B 2219/40317 For collision avoidance and detection
• CPC Class Codes: G05B 2219/40476 Collision, planning for collision free path
• CPC Class Codes: G05B 2219/40497 Collision monitor controls planner in real time to replan if collision
• CPC Class Codes: G05B 2219/40559 Collision between hand and workpiece, operator

Abstract

An interference avoiding device capable of determining occurrence of an interference in a robot operation in advance and automatically avoiding the interference, to be suitably applied to an automatic picking-up operation of randomly stored workpieces. A position/orientation of a workpiece and a position/orientation of a tool for getting hold of the workpiece in a teaching operation, and shapes/dimensions of the tool and the storage box are determined and stored in a storage device. A command position/orientation Ta of the tool for getting hold of an objective workpiece is determined based on a detected position/orientation Wa of the workpiece and it is determined whether or not an interference between the tool an the storage box will occur based on the position/orientation Ta and the stored information. If it is determined that an interference will occur, a rotational phase or an inclination angle of the tool with respect to the workpiece is changed within an allowable range of the position/orientation of the tool with respect to the workpiece, to obtain a new position/orientation of the tool. If it is determined that an interference will not occur under the new condition of the position/orientation of the tool, the new position/orientation is adopted. If an interference is still determined to occur, an alarm is issued and the operation of the robot is stopped.

Claims

1. An interference avoiding device for avoiding an interference between an operational device attached to a robot and a peripheral object, comprising:

storing means for storing information on shape/dimensions of the operational device, and shape/dimensions and position/orientation of the peripheral object;

interference determining means for determining an interference between the operational device and the peripheral object based on the information stored in said storing means and a commanded position/orientation of the operational device;

position/orientation setting means for setting a new position/orientation of the operational device for avoiding the interference between the operational device and the peripheral object in place of the commanded position/orientation of the tool, when it is determined that an interference will occur by said interference determining means.

2. An interference avoiding device according to claim 1, wherein said position/orientation setting means automatically determines the new position/orientation of the operational device for avoiding the interference.

3. An interference avoiding device according to claim 1, wherein said position/orientation setting means determines the new position/orientation of the operational device by selecting one of a plurality of predetermined positions/orientations.

4. An interference avoiding device according to claim 1, wherein said position/orientation setting means sets position/orientation of the operational device for avoiding the interference as a new taught position/orientation.

5. An interference avoiding device according to claim 1, further comprising means for continuously operating the robot in accordance with the new position/orientation of the operational device.

6. An interference avoiding device according to claim 1, wherein said position/orientation setting means stops an operation of the robot when it is determined that an interference will occur by said interference determining means.

7. An interference avoiding device according to claim 1, further comprising determining means for determining an interference between the operational device and the peripheral object on condition of the new position/orientation of the operational device, and display means for displaying a message when it is determined that an interference will occur by said determining means.

8. An interference avoiding device according to claim 1, further comprising determining means for determining an interference between the operational device and the peripheral object on condition of the new position/orientation of the operational device, and control means for suspending an operation of the robot when it is determined that an interference will occur by said determining means and then resuming the operation of the robot.

9. An interference avoiding device according to claim 1, wherein said position/orientation setting means rewrites an operation program of the robot by replacing the commanded position/orientation of the tool with the new position/orientation for avoiding the interference.

10. An interference avoiding device according to claim 1, wherein said interference determining means determines an interference between the operational device and the peripheral object in operation of the robot.

11. An interference avoiding device according to claim 1, wherein said interference avoiding device is incorporated into a robot controller or an information processing device connected to the robot.

12. An interference avoiding device according to claim 11, wherein said information processing device includes an operation simulation device of the robot.

13. An interference avoiding device according to claim 1, wherein the new position/orientation of the operational device is used for obtaining information by means a sensor attached to the robot.

14. An interference avoiding device according to claim 1, wherein the commanded position/orientation of the operational device is determined based on information obtained by a sensor attached to the robot.

15. An interference avoiding device according to claim 14, wherein said storing means stores information on position/orientation of a workpiece in a teaching operation and position/orientation of a tool as the operational device for holding the workpiece in the teaching operation, and the commanded position/orientation of the tool is determined based on the determined position/orientation of the workpiece and the stored information on the positions/orientations of the workpiece and the tool in the teaching operation.

16. An interference avoiding device according to claim 14, wherein said storing means stores information on position/orientation of a tool as the operational device for holding a workpiece with respect to position/orientation of the workpiece in a teaching operation based on CAD information in an off-line teaching device, and the commanded position/orientation of the tool is determined based on the determined position/orientation of the workpiece and the stored information on the position/orientation of the tool with respect to the position/orientation of the workpiece.

17. An interference avoiding device according to claim 14, wherein said sensor comprises a two-dimensional sensor or a three-dimensional sensor.

18. An interference avoiding device according to claim 14, wherein the operation to be performed by the robot is a picking operation of picking up a workpiece by the operational device, and the peripheral object is a storage box storing workpieces.

19. An interference avoiding device according to claim 14, wherein the operation to be performed by the robot is one of spot welding, arc welding and sealing.

20. An interference avoiding device according to claim 14, wherein the robot is directly or indirectly fixed to a structure fixed on a floor, a wall or a ceiling.

21. An interference avoiding device according to claim 14, wherein the robot is arranged to be movable along one or two axes.

22. An interference avoiding device for avoiding an interference between a robot and a peripheral object, comprising:

storing means for storing information on shape/dimensions of the robot, and shape/dimensions and position/orientation of the peripheral object;

interference determining means for determining an interference between the robot and the peripheral object based on the information stored in said storing means and a commanded position/orientation of the robot;

position/orientation setting means for setting a new position/orientation of the robot for avoiding the interference between the robot and the peripheral object in place of the commanded position/orientation of the robot, when it is determined that an interference will occur by said interference determining means.

23. An interference avoiding device according to claim 22, wherein said position/orientation setting means automatically determines the new position/orientation of the robot for avoiding the interference.

24. An interference avoiding device according to claim 23, wherein said position/orientation setting means determines the new position/orientation of the robot by selecting one of a plurality of predetermined positions/orientation of the robot.

25. An interference avoiding device according to claim 22, wherein said position/orientation setting means sets position/orientation of the robot for avoiding the interference as a new taught position/orientation.

26. An interference avoiding device according to claim 22, further comprising means for continuously operating the robot in accordance with the new position/orientation of the robot.

27. An interference avoiding device according to claim 22, wherein said position/orientation setting means stops an operation of the robot when it is determined that an interference will occur by said interference determining means.

28. An interference avoiding device according to claim 22, further comprising determining means for determining an interference between the robot and the peripheral object on condition of the new position/orientation of the robot, and display means for displaying a message when it is determined that an interference will occur by said determining means.

29. An interference avoiding device according to claim 22, further comprising determining means for determining an interference between the operational device and the peripheral object on condition of the new position/orientation of the operational device, and control means for suspending an operation of the robot when it is determined that an interference will occur by said determining means and resuming the operation of the robot.

30. An interference avoiding device according to claim 22, wherein said controller rewrites an operation program of the robot by replacing the commanded position/orientation of the robot with the new position/orientation for avoiding the interference.

31. An interference avoiding device according to claim 22, wherein said interference determining means determines an interference between the robot and the peripheral object in operation of the robot.

32. An interference avoiding device according to claim 22, wherein said interference avoiding device is incorporated into a robot controller or an information processing device connected to the robot.

33. An interference avoiding device according to claim 32, wherein said information processing device includes an operation simulation device of the robot.

34. An interference avoiding device according to claim 22, wherein the new position/orientation of the robot is used for obtaining information by means a sensor attached to the robot.

35. An interference avoiding device according to claim 22, wherein the commanded position/orientation of the robot is determined based on information obtained by a sensor attached to the robot.

36. An interference avoiding device according to claim 35, wherein said storing means stores information on position/orientation of a workpiece in a teaching operation and position/orientation of the robot for performing an operation on the workpiece in the teaching operation, and the commanded position/orientation of the robot is determined based on the position/orientation of the workpiece obtained by said sensor, and the stored information on the positions/orientations of the workpiece and the robot in the teaching operation.

37. An interference avoiding device according to claim 35, wherein said storing means stores information on position/orientation of the robot with respect to position/orientation of the workpiece in a teaching operation based on CAD information in an off-line teaching device, and the commanded position/orientation of the robot is determined based on the position/orientation of the workpiece obtained by said sensor and the stored information on the position/orientation of the robot with respect to the position/orientation of the workpiece.

38. An interference avoiding device according to claim 35, wherein said sensor comprises a two-dimensional sensor or a three-dimensional sensor.

39. An interference avoiding device according to claim 35, wherein the operation to be performed by the robot is a picking-up operation of picking up a workpiece, and the peripheral object is a storage box storing workpieces.

40. An interference avoiding device according to claim 35, wherein the operation to be performed by the robot is spot welding, arc welding or sealing.

41. An interference avoiding device according to claim 35, wherein the robot is directly or indirectly fixed to a structure fixed on a floor, a wall or a ceiling.

42. An interference avoiding device according to claim 35, wherein the robot is arranged to be movable along one or two axes.