Manufacturing method and manufacturing device for manufacturing a joined piece

• US 9,904,271 B2
• Filed: 11/16/2012
• Issued: 02/27/2018
• Est. Priority Date: 11/16/2011
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hayata, Junji, Takizawa, Satoru
• Primary Examiner(s): Anya, Charles E
• Application Number:
  US14/357,907
• Publication Number:
  US 20140309762A1
• Time in Patent Office: 1,929 Days
• Field of Search: None
• CPC Class Codes: B25J 9/1682 Dual arm manipulator; Coordination of several manipulators
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 19/402 characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/39131 Each of the manipulators holds one of the pieces to be welded together
• CPC Class Codes: G05B 2219/39132 Robot welds, operates on moving workpiece, moved by other robot
• CPC Class Codes: G05B 2219/39393 Camera detects projected image, compare with reference image, position end effector
• CPC Class Codes: G05B 2219/39397 Map image error directly to robot movement, position with relation to world, base not needed, image based visual servoing
• CPC Class Codes: G05B 2219/40611 Camera to monitor endpoint, end effector position
• CPC Class Codes: Y10S 901/42 Welding
• CPC Class Codes: Y10S 901/47 Optical

Abstract

A manufacturing method for joining first and second members to create a joined piece using a robot with pre-inputted instruction data. The method includes operating the robot to hold the second member for joining to the first member and photographing the second member to obtain an image of the second member at the holding position; comparing the image to a reference image of a joining position of a reference second member joined to a reference first member; determining a deviation amount by which the holding position of the second member deviates from the joining position in the reference image; determining a correction amount for correcting the holding position of the second member is to be corrected in order to reduce the deviation amount of the holding position of the second member; correcting the holding position of the second member according to the correction amount, and then subsequently joining the first and second members.

Claims

1. A manufacturing method for manufacturing a joined piece involving operating a robot according to pre-inputted instruction data to join a first member to a second member to create the joined piece, the method comprising:

operating the robot so as to hold the second member at a holding position and photographing the second member using a camera to obtain a first positioning image of the second member at the holding position;

comparing the first positioning image to a reference image taken by a camera of a joining position of a reference second member joined to a reference first member;

determining a deviation amount by which the holding position of the second member deviates from the joining position in the reference image based on comparison results thereof;

determining, based on the deviation amount, a correction amount by which the holding position of the second member is to be corrected in order to reduce the deviation amount of the holding position of the second member; and

correcting the holding position of the second member according to the correction amount, and then subsequently joining the second member to the first member to form the joined piece;

photographing the second member after the joining of the second member to the first member to obtain a joined image of the second member, comparing the joined image obtained thereby to the reference image, and confirming weather the second member joined to the first member is within a predetermined permissible range;

correcting the instruction data for the robot to the position of the second member yielded by the correction amount for the holding position of the second member that was determined when the joining position of the first member and the second member is confirmed to be within the permissible range and

in response to correcting the instruction data to within the permissible range, welding the first member and the second member together.

2. The manufacturing method according to claim 1, wherein

the photographing of the second member to obtain the first positioning image is performed from the same position as for the photographing of the joining position of the reference first member and the reference second member.

3. The manufacturing method according to claim 2, further comprising

photographing and saving the second member joined to the first member as a manufacturing reference image, after the correcting of the instruction data when the second member joined to the first member has been confirmed as being within the permissible range;

and

photographing an additional first member and an additional second member are that are to be joined to obtain an additional imaged, and comparing the additional second member joined to the additional first member in the additional image obtained thereby with the second member joined to the first member in the manufacturing reference image to determine whether a position of the additional second member is acceptable or not.

4. The manufacturing method according to claim 2, wherein

upon correcting the holding position of the second member, the instruction data that designates the joining position for the robot to join the first member and the second member is corrected along with the holding position of the second member.

5. The manufacturing method according to claim 1, further comprising:

photographing and saying the second member joined to the first member as a manufacturing reference image, after the correcting of the instruction data when the second member joined to the first member has been confirmed as being within the permissible range; and

photographing an additional first member and an additional second member are that are to be joined to obtain an additional imaged, and comparing additional second member joined to the additional first member in the additional image obtained thereby with the second member joined to the first member in the manufacturing reference image to determine whether a position of the additional second member is acceptable or not.

6. The manufacturing method according to claim 5, further comprising

photographing and saving the second member joined to the first member as a manufacturing reference image, after the correcting of the instruction data when the second member joined to the first member has been confirmed as being within the permissible range;

and

photographing an additional first member and an additional second member are that are to be joined to obtain an additional imaged, and comparing the additional second member joined to the additional first member in the additional image obtained thereby with the second member joined to the first member in the manufacturing reference image to determine whether a position of the additional second member is acceptable or not.

7. The manufacturing method according to claim 5, wherein

upon correcting the holding position of the second member, the instruction data that designates the joining position for the robot to join the first member and the second member is corrected along with the holding position of the second member.

8. The manufacturing method according to claim 1, wherein

upon correcting the holding position of the second member, the instruction data that designates the joining position for the robot to join the first member and the second member is corrected along with the holding position of the second member.

9. The manufacturing method according to claim 1, wherein

the first member is an elongated steering member basepiece, and the second member is a part being joined to the steering member basepiece.

10. The manufacturing method according to claim 1, wherein the photographing of the second member to obtain the first positioning image is performed from the same position as for the photographing of the joining position of the reference first member and the reference second member.

11. The manufacturing method according to claim 1, wherein upon correcting the holding position of the second member, the instruction data that designates the joining position for the robot to join the first member and the second member is corrected along with the holding position of the second member.

12. The manufacturing method according to claim 1, wherein the first member is an elongated steering member basepiece, and the second member is a part being joined to the steering member basepiece.

13. A manufacturing device comprising:

a first robot configured to hold a first member;

a second robot configured to hold a second member at a predetermined position on the first member;

a third robot configured to hold the second member being held by the second robot to the first member at a holding position;

a camera arranged to obtain an image of the second member being held to the first member or the second member joined to the first member; and

a controller programmed to compare a first positioning image taken by the camera to a reference image taken by the camera and to correct the holding position at which the second member is being held by the second robot based on comparison of the first positioning image to the reference image, the first positioning image being an image of the second member being held at the holding position by the second robot being operated according to pre-inputted instruction data, and the reference image being an image of a second reference member joined to a first reference member,

the camera photographing the second member after the joining of the second member to the first member to obtain a joined image of the second member,

the controller comparing the joined image obtained thereby to the reference image, and confirming whether the second member joined to the first member is within a predetermined permissible range,

the controller correcting the instruction data for the robot to the position of the second member yielded by the correction amount for the holding position of the second member that was determined when the joining position of the first member and the second member is confirmed to be within the permissible range and

a welding device, in response to correcting the instruction data to within the permissible range, welding the first member and the second member together.

14. The manufacturing device according to claim 13, wherein

the first robot is configured to hold an elongated steering member as the first member, and

the second robot is configured to hold the second member as a part that is being joined to the steering member.