Vision target based assembly

• US 6,317,953 B1
• Filed: 04/29/1992
• Issued: 11/20/2001
• Est. Priority Date: 05/11/1981
• Status: Expired due to Term

• Current Assignee: Laser Measurement International Inc.
• Original Assignee: Lmi-Diffracto
• Inventors: Pryor, Timothy R.
• Primary Examiner(s): Bryant, David P.
• Application Number:
  US07/875,282
• Time in Patent Office: 3,492 Days
• Field of Search: 294/070.1, 294/070.4, 297/20, 297/21, 297/01, 700/95, 700/114, 700/219, 700/220, 700/221, 700/222, 700/253, 700/259
• US Class Current: 29/407.04
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: B23P 19/10 Aligning parts to be fitted together
• CPC Class Codes: B25J 13/088 with position, velocity or acceleration sensors
• CPC Class Codes: B25J 18/002 comprising beam bending compensation means
• CPC Class Codes: B25J 19/021 Optical sensing devices
• CPC Class Codes: B25J 19/022 using lasers
• CPC Class Codes: B25J 19/023 including video camera means
• CPC Class Codes: B25J 9/1684 Tracking a line or surface by means of sensors
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G05B 19/39 using a combination of the means covered by at least two of the preceding groups G05B19/21, G05B19/27 and G05B19/33
• CPC Class Codes: G05B 19/401 characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/34033 Control processor and signal processor cooperate
• CPC Class Codes: G05B 2219/36417 Programmed coarse position, fine position by alignment, follow line, path adaptive
• CPC Class Codes: G05B 2219/36439 Guide arm in path by slaving arm to projected path, beam riding
• CPC Class Codes: G05B 2219/37572 Camera, tv, vision
• CPC Class Codes: G05B 2219/39057 Hand eye calibration, eye, camera on hand, end effector
• CPC Class Codes: G05B 2219/39393 : Camera detects projected image, compare with reference image, position end effector
• CPC Class Codes: G05B 2219/45064 : Assembly robot
• CPC Class Codes: G05B 2219/45083 : Manipulators, robot
• CPC Class Codes: Y10T 29/49764 : with testing or indicating
• CPC Class Codes: Y10T 29/49769 : Using optical instrument [excludes mere human eyeballing]
• CPC Class Codes: Y10T 29/4978 : Assisting assembly or disassembly
• CPC Class Codes: Y10T 29/53004 : with means to regulate operation by use of templet, tape, card or other replaceable information supply
• CPC Class Codes: Y10T 29/53009 : with comparator
• CPC Class Codes: Y10T 29/53087 : with signal, scale, illuminator, or optical viewer
• CPC Class Codes: Y10T 29/53091 : for work-holder for assembly or disassembly

Abstract

Methods for assembling, handling, and fabricating are disclosed in which targets are used on objects. The targets can be specifically applied to the object, or can be an otherwise normal feature of the object. Conveniently, the targets are removable from the object or covered by another object during an assembling process. One or more robots and imaging devices for the targets are used. The robots can be used to handle or assemble a part, or a fixture may be used in conjunction with the robots. Conveniently, the CAD design system is used in designing the targets as well as for the assembly process using the targets. A plurality of targets can also be used to monitor and inspect a forming process such as on a sheet panel.

Claims

1. An assembly arrangement wherein a work piece is to be connected to a structure, comprising:

means for determining a position in which said work piece should be connected relative to said structure using pre-recorded data which relates to the design of said structure;

means for supporting and moving said work piece into its determined position relative to said structure;

means for determining a correct position for each of a plurality of reference points defined on said work piece using said pre-recorded structure design data;

means for determining the deviation between the actual position and the correct position for each of said reference points while said work piece is supported in situ, memory bank means containing said pre-recorded data;

means for controlling said work support means, said control means utilizing said pre-recorded data to position said work piece such that deviations are within predetermined tolerances; and

means for fixing said work piece to said structure when the deviations between the correct and actual positions of said reference points are within said predetermined tolerances.

2. An assembly arrangement as claimed in claim 1, wherein said means for determining an actual position includes an electro-optical device.

3. An assembly arrangement as claimed in claim 1, wherein said means for determining an actual position includes a TV camera.

4. An assembly arrangement as claimed in claim 1, wherein the actual position determined by said means for determining an actual position is made in at least two degrees of freedom.

5. An assembly arrangement as claimed in claim 1, wherein the actual position determined by said means for determining an actual position is made in three dimensions.

6. In a method of assembling a structure wherein a work piece is connected to a structure, the steps of:

determining a position in which said work piece should be disposed relative to said structure using pre-recorded data which relates to the design of said structure;

using work support means to support and move said work piece into the determined position relative to said structure;

determining a correct position for each of a plurality of reference points defined on said work pieces, using said pre-recorded data;

determining an actual position for each of said plurality of reference points;

determining the deviation between each of the actual positions and the correct positions of each of said reference points after said work piece has been moved into said determined position;

using said pre-recorded data to position said work piece such that deviations are within predetermined tolerances; and

fixing said work piece to said structure when the deviations between the correct and actual reference points are within said predetermined tolerances.

7. In a method of assembling as claimed in claim 6, wherein said determining of an actual position step is performed electro-optically.

8. In a method of assembling as claimed in claim 6, wherein said determining an actual position step is performed with a TV camera.

9. In a method of assembling as claimed in claim 6, wherein said determining an actual position step determines actual position in at least two degrees of freedom.

10. In a method of assembling as claimed in claim 6, wherein said determining an actual position step determines actual position in three dimensions.

11. An assembly system comprising:

a work support robot for supporting a work piece, said work support robot including a gripper which can be changed to assume the configuration of a portion of said work piece, said portion being intended to be gripped by said gripper, said work piece support robot being arranged to move said work piece into a predetermined position relative to a body to which the work piece is to be connected;

a securing robot for securing the work piece to the body;

measuring means for determining the disposition of said work piece on said body and for producing data from which the disposition can be determined;

control means responsive to said work piece position data means for controlling the operation of said work piece supporting robot, said control means including;

a memory in which design and assembly data is stored,

processing means for using said design and assembly data for interpreting the data from said measuring means and for producing control signals to control said work piece support and securing robots and said measuring means, said control means being arranged to;

move said work support robot to a position wherein the work piece is supported in said predetermined position,

induce the measuring means to determine the position of a predetermined reference point on the work piece,

compare the actual position of the reference point with that derived from the design data and determine if there is a deviation between the two positions,

produce correction values which are used to adjust said work piece support robot in a manner which tends to eliminate any deviation, and

induce the securing robot to secure the work piece to said body.

12. An assembly system as claimed in claim 11, wherein said measuring means includes an electro-optical device.

13. An assembly system as claimed in claim 11, wherein said measuring means includes a TV camera.

14. An assembly system as claimed in claim 11, wherein said measuring means determines disposition in at least two degrees of freedom.

15. An assembly system as claimed in claim 11, wherein said measuring means determines disposition in three dimensions.

16. A method of assembly comprising:

supporting a work piece on a support robot, said work piece support robot having a gripper which can be changed to assume the configuration of a portion of said work piece, said portion to be gripped by said gripper;

moving said work piece into a predetermined position relative to a body to which the work piece is to be connected;

using measuring means, determining the position of said work piece while the work piece is supported by said support robot and producing data by which said position can be determined;

providing control means responsive to said work piece position data for controlling the operation of said work piece supporting robot, said control means including a memory in which said design and assembly data is stored, and processing means for using said design and assembly data for interpreting the data from said measuring means and for producing control signals to control said work piece support robot and said securing robot and said measuring means, said control means being arranged to;

move said supporting robot to a position wherein the work piece is supported in said predetermined position;

induce the measuring means to determine the position of a predetermined reference point on the work piece;

compare the actual position of the reference point with that derived from the design data and to determine if there is a deviation between the two positions;

produce correction values which are used to adjust said work piece support robot in a manner which tends to eliminate said deviation; and

induce the securing robot to secure the work piece to said body.

17. A method of assembly as claimed in claim 16, wherein the measuring means used in said determining the position step is an electro-optical device.

18. A method of assembly as claimed in claim 16, wherein the measuring means used in said determining the position step is a TV camera.

19. A method of assembly as claimed in claim 16, wherein said determining the position step determines actual position in at least two degrees of freedom.

20. A method of assembly as claimed in claim 16, wherein said determining the position step determines actual position in three dimensions.

21. A method for flexibly assembling components to form an assembly of components at an assembly station, wherein (a) each of the components has at least one critical positioning feature, (b) the assembly station includes a plurality of spaced programmable locators, and (c) each of the programmable locators is controlled by a control device having a control program, said method comprising the steps of:

supporting at least one of the components by at least one of the plurality of spaced programmable locators;

independently moving the programmable locator or locators under program control of the control device to adjust the support location of at least one of the plurality of components;

joining the components to obtain an assembly of the components, and

determining the location of at least one point on the components or the assembly of components.

22. A method for assembling components as claimed in claim 21, wherein said determining step is performed after said joining step.

23. A method for assembling components as claimed in claim 21, wherein said determination step is performed before said joining step.

24. A method for assembling components as claimed in claim 21, wherein said determination step is performed during said joining step.

25. A method for assembling components as claimed in claim 21, wherein said moving step moves the components to be substantially in contact with each other prior to said joining step.

26. A method for assembling components as claimed in claim 21, including the further step of correcting the position of at least one of the programmable locating robots using the determined location.

27. A method for assembling components as claimed in claim 21, wherein said moving step includes the step of using design data of at least one of said components in positioning one or more of said programmable locators.

28. A method for assembling components as claimed in claim 21, wherein said moving step includes the step of using design data of the assembly in positioning one or more of said programmable locators.

29. A method for assembling components as claimed in claim 21, further including the step of clamping at least one of said components.

30. An apparatus for flexibly assembling components to form an assembly of components at an assembly station, wherein each of the components has at least one critical positioning feature, said apparatus comprising:

a plurality of spaced programmable locators provided at the assembly station;

a control device having a control program which controls each of the programmable locators;

a supporting means for supporting at least one of the components by at least one of the plurality of spaced programmable locators;

a moving means for independently moving the programmable locator or locators under program control of the control device to adjust the support location of at least one of the plurality of components;

a joining means for joining the components to obtain an assembly of the components, and

a determining means for determining the location of at least one point on the components or the assembly of components.

31. An apparatus for assembling components as claimed in claim 30, wherein said control device causes said determining means to be actuated after said joining step.

32. An apparatus for assembling components as claimed in claim 30, wherein said control device causes said determining means to be actuated before said joining step.

33. An apparatus for assembling components as claimed in claim 30, wherein said control device causes said determining means to be actuated during said joining step.

34. An apparatus for assembling components as claimed in claim 30, wherein said moving means moves the components to be substantially in contact with each other prior to actuation of said joining means.

35. An apparatus for assembling components as claimed in claim 30, further including a correcting means for correcting the position of at least one of the programmable locating robots using the determined location.

36. An apparatus for assembling components as claimed in claim 30, wherein said moving means includes a using means for using design data of at least one of said components in positioning one or more of said programmable locators.

37. An apparatus for assembling components as claimed in claim 30, wherein said moving means includes a using means for using design data of the assembly in positioning one or more of said programmable locators.

38. An apparatus for assembling components as claimed in claim 30, further including a clamping means for clamping at least one of said components.