Robotic work object cell calibration method

Abstract

The robotic work object cell calibration method includes a work object or emitter. Initially, placing the work object is placed in a selected position on a fixture or work piece on the shop floor. The work object emits a pair of beam-projecting lasers which intersect at a tool contact point and act as a crosshair. The robot tool is manipulated into the tool contact point. The work object emits four plane-projecting lasers which are used to adjust the roll, yaw, and pitch of the robot tool relative to the tool contact point. The robotic work object cell calibration method of the present invention increases the accuracy of the off-line programming and decreases robot teaching time.

Claims

1. A method for calibrating a robot work path for a robot tool, said method comprising: a. placing a work object relative to a selected position on a fixture on an automotive shop floor, said fixture being positioned on said automotive shop floor, said work object including first and second lasers, said first laser emitting a first laser beam, said second laser emitting a second laser beam, said first and second laser beams intersecting at a laser intersection point; b. manipulating said robot tool into alignment with said laser intersection point of said work object so as to enable calibration of said robot work path for said robot tool relative to said laser intersection point when said work object is mounted onto said fixture; and c. downloading an offline program relative to said work object, said work object being placed onto said robot tool in a position defined by CAD simulation software on said automotive shop floor; whereby said offline program enables said robot work path to be calibrated relative to a known point in space when said work object is mounted on said fixture on said automotive shop floor.

2. The method of claim 1, further comprising said work object including a plane-projecting laser, said plane-projecting laser being capable of projecting a laser plane.

3. The method of claim 1, further comprising said work object including first and second plane-projecting lasers, said first and second plane-projecting lasers being capable of projecting first and second laser planes.

4. The method of claim 1, wherein said fixture comprises a NAAMS hole pattern mount disposed on said work object.

5. The method of claim 1, wherein said fixture comprises a NAAMS hole pattern mount disposed on said work object, said work object being mountable upon said fixture on said automotive shop floor.

6. The method of claim 1, wherein said CAD simulation software is compatible with robotic simulation packages.

7. A method for calibrating a robot work path, said method comprising: a. providing a work object being mountable onto a fixture on an automotive shop floor relative to said robot tool, said work object including a first and second laser, said work object being positionable on said automotive shop floor; b. providing first and second lasers positioned on said work object, said first laser being capable of emitting a first laser beam, said second laser being capable of emitting a second laser beam, said first and second laser beams intersecting at a laser intersection point; c. enabling a manipulation of said robot tool into alignment with said laser intersection point of said work object for calibration of said robot work path, an offline program being downloadable relative to said work object when said work object is placed onto said robot tool in a position defined by CAD simulation software on said automotive shop floor, that allows for calibration of said robot work path for said robot tool relative to said laser intersection point when said work object is mounted onto said fixture on said automotive shop floor.

8. The method of claim 7, further comprising said work object including a plane-projecting laser, said plane-projecting laser being capable of projecting a laser plane.

9. The method of claim 7, further comprising said work object including first and second plane-projecting lasers, said first and second plane-projecting lasers being capable of projecting first and second laser planes.

10. The method of claim 7, wherein said fixed mounting position comprises a NAAMS hole pattern mount disposed on said work object.

11. The method of claim 7, wherein said fixed mounting position comprises a NAAMS hole pattern mount disposed on said work object, said work object being mountable upon said fixture on said automotive shop floor.

12. The method of claim 7, wherein said CAD simulation software is compatible with robotic simulation packages.

13. A system for calibrating a robot work path, said system comprising: a. a robot having a robot tool disposed thereon; and b. a work object being mountable onto a fixture, said fixture being disposed on an automotive shop floor relative to said robot tool, said work object including first and second lasers, said first laser emitting a first laser beam and said second laser emitting a second laser beam, said first and second lasers being positioned on said work object, said first and second laser beams intersecting at a laser intersection point, said work object being positionable relative to said robot tool and being cooperatively engageable with CAD simulation software, an offline program being downloadable relative to said work object using said CAD simulation software, said offline program enabling said robot work path to be calibrated relative to a known point in space with said work object mounted on said fixture on said automotive shop floor, said known point in space being defined in three dimensions (X,Y, and Z) and relative to three rotational axes (Rx, Ry, and Rz).

14. The system of claim 13, further comprising said work object including a plane-projecting laser, said plane-projecting laser being capable of projecting a laser plane.

15. The system of claim 13, further comprising said work object including first and second plane-projecting lasers, said first and second plane-projecting lasers being capable of projecting first and second laser planes.

16. The system of claim 15, wherein said fixture is a NAAMS hole pattern mount disposed on said work object.

17. The system of claim 15, wherein said fixture comprises a NAAMS hole pattern mount disposed on said work object, said work object being mountable upon said fixture on said automotive shop floor.

18. The system of claim 15, wherein said CAD simulation software is compatible with robotic simulation packages.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts the first preferred embodiment of the work object for use in the robotic work object calibration method of the present invention, the two beam-projecting lasers being used for aligning the tool contact point with the work object.

(2) FIG. 2 depicts the first preferred embodiment of the work object for use in the robotic work object calibration method of FIG. 1, the four plane-projecting lasers being emitted from the work object.

(3) FIG. 3 depicts an exploded view of the first preferred embodiment of the work object for use in the robotic work object calibration method of FIG. 1, further depicting the weld gun with the tool contact point of the weld gun aligned to the horizontal and vertical alignment lasers.

(4) FIG. 4 depicts the exploded view of the first preferred embodiment of the work object for use in the robotic work object calibration method of FIG. 3, further depicting the addition of two pairs of plane-projecting lasers for adjusting the roll, yaw, and pitch of the tool head of the weld gun.

(5) FIG. 5 depicts an assembly view of the first preferred embodiment of the work object for use in the robotic work object calibration method of FIG. 1, further depicting the work object being mounted onto a fixture with the robot tool head aligned to the two beam-projecting lasers using the tool contact point.

(6) FIG. 6 depicts the assembly view of the work object for use in the robotic work object calibration method of FIG. 5, further depicting the four plane-projecting lasers being used for adjusting the roll, yaw, and pitch of the tool head of the robot.

(7) FIG. 7 depicts another exploded view of the first preferred embodiment of the work object for use in the robotic work object calibration method of FIG. 6, further depicting the work object being mounted to the fixture with the robot tool aligned to the tool contact point alignment lasers and the roll, yaw, and pitch alignment lasers.

(8) FIG. 8 depicts an assembly view of a second preferred embodiment of the work object of the work object for use in the robotic work object calibration method of the present invention, two plane-projecting lasers being emitted along the horizontal axis of the work object, a pair of beam-projecting lasers intersecting at a tool contact point, the robot tool being aligned to the tool contact point and to this pair of plane-projecting lasers.

(9) FIG. 9 depicts an assembly view of a third preferred embodiment of the work object of the work object for use in the robotic work object calibration method of the present invention, two plane-projecting lasers being emitted along the vertical axis of the work object, a pair of beam-projecting lasers intersecting at a tool contact point, the robot tool being aligned to the tool contact point and to this pair of plane-projecting lasers.

(10) FIG. 10 depicts a fourth preferred embodiment of the work object of the work object for use in the robotic work object calibration method of the present invention, one plane-projecting laser being emitted along the vertical axis of the work object, and a beam-projecting laser intersecting one of the vertical plane-projecting lasers at a tool contact point.

(11) FIG. 11A depicts a robot and a fixture for use on a shop floor in a prior art embodiment without the work object of FIG. 1, and FIGS. 11 B and 11 C depict a similar robot, fixture with the work object used in the present invention, showing how in a simplified manner the work object is used to obtain a new zero location and calibrate the path between the fixture and the robot.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) Referring now to the drawings, FIGS. 1 and 2 disclose a first preferred embodiment of a work object or emitter [10] for use in the robotic work object calibration method of the present invention. The work object [10] is used to calibrate the work path of a robot tool based on a tool contact point (point in space) [60]. The known point in space

(13) is defined in three dimensions (X, Y, and Z) and relative to their rotational axes R.sub.x (pitch), R.sub.y (yaw), and R.sub.z (roll).

(14) The work object [10] includes a horizontal frame member [22] that includes a pair of opposing frame ends [32A and 32B], and a vertical frame member [24] that includes a pair of opposing frame ends [32C and 32D]. A plane-projecting laser [41, 42, 43, and 44] is preferably disposed at each frame end [32A, 32B, 32C, and 32D], respectively, and a projected laser plane [51, 52, 53, and 54] is emitted from each of the plane-projecting lasers [41, 42, 43, and 44], respectively.

(15) Extending along the horizontal frame member [22] are three arms parallel which combine to form the general shape of the letter E of an E-shaped structure [25] which is horizontally aligned and generally centrally disposed relative to horizontal frame member [22]. The center arm (not numbered) of the E-shaped structure [25] is shorter than the two end arms [26A and 26B].

(16) A first beam-projecting laser [58] is emitted from the center arm of the E disposed at the proximate center of the work object [10]. A second beam-projecting laser [56] is emitted from one of the arms [26A] of an E-shaped structure [25] and is directed into the opposing arm [26B].

(17) The first beam-projecting laser [58] intersects and is essentially perpendicular and coplanar with the second beam-projecting laser [56] at a known point in space [60], defined in three dimensions in terms of X, Y, and Z coordinates.

(18) The first beam-projecting laser [58] is essentially coplanar with the two projected laser planes [51 and 52] emitted from the plane-projecting lasers [41 and 42] emitted from frame ends [32A and 32B]. Also, the first beam-projecting laser [58] is essentially coplanar with the two projected laser planes [53 and 54] emitted from the plane-projecting lasers [43 and 44] emitted from frame ends [32C and 32D]. The work object

(19) is mountable onto a fixture [90] and enables a robot work path to be calibrated relative to the known point in space [60].

(20) The plane-projecting lasers [41, 42, 43, and 44] project the four projected laser planes [51, 52, 53, and 54, respectively] from the frame ends [32A, 32B, 32C, and 32D, respectively] of the work object [10]. The plane-projecting lasers [41, 42, 43, and 44] are red laser modules, having focused lines (3.5 v-4.5 v 16 mm 5 mw).

(21) The beam-projecting lasers [56 and 58] are focusable points that project the two laser beams emitted from the arm [26A] of the work object [10]. The beam-projecting lasers [56 and 58] are red laser modules, having focusable dots (3.5 v-4.5 v 16 mm 5 mw).

(22) FIG. 3 depicts an exploded view of the work object [10] for use with a weld gun. The tool contact point [60] of the weld gun is positioned with respect to the two beam-projecting alignment lasers [56 and 58]. FIG. 4 further depicts the addition of the four projected laser planes [51, 52, 53, and 54, respectively] from the plane-projecting lasers [41, 42, 43, and 44, respectively] for adjusting the roll, yaw, and pitch of the robot tool head [80].

(23) FIG. 5 depicts the work object [10] being mounted onto the fixture [90]. The robot tool head [80] is aligned to the two beam-projecting lasers [56 and 58] using the tool contact point [60]. FIG. 6 further depicts the four projected laser planes [51, 52, 53, and 54, respectively] from the plane-projecting lasers [41, 42, 43, and 44, respectively] of work piece [10], which are used to adjust the roll, yaw, and pitch of the robot tool head [80].

(24) FIG. 7 depicts the work object [10] mounted onto the fixture [90] with the robot tool [80] positioned with respect to the tool contact point [60] alignment laser beams [56 and 58] setting the X, Y, and Z coordinates.

(25) FIG. 8 depicts a second preferred embodiment of a work object [10] for use in the robotic work object calibration method of the present invention. In this embodiment, two projected laser planes [51 and 52] are emitted from two plane-projecting lasers [41 and 42, respectively] along the horizontal axis of the frame member [32] of the work object [10]. The robot tool [80] is aligned with the tool contact point [60] and with this pair of projected laser planes [51 and 52].

(26) FIG. 9 depicts a third preferred embodiment of the work object [210] for use in the robotic work object calibration method of the present invention. In this embodiment, two projected laser planes [53 and 54] are emitted from two plane-projecting lasers [43 and 44] are emitted along the vertical axis of the frame member [24] of the work object [210]. The robot tool [80] is aligned with the tool contact point [60] and with this pair of projected laser planes [53 and 54].

(27) FIG. 10 depicts yet another preferred embodiment of the work object [10] for use in the robotic work object calibration method of the present invention. In this embodiment, one plane projected laser [51] is emitted from plane-projecting laser along the vertical axis of the work object [10]. A beam-projecting laser [56] intersects with the vertical plane-projecting laser [53] at a tool contact point [60]. The plane projecting laser [51] has a rotating head capable of rotating 360, enabling the robot tool to align first on the x-axis, then on the y-axis after the laser head has been rotated.

(28) FIG. 11A depicts a robot [81] and a fixture [90] for use on a shop floor in a prior art embodiment without the work object of the present invention. FIGS. 11 B and 11C depict a similar robot [81], and fixture [90] with the work object [10], depicting how in a simplified manner the work object [10] is used to obtain a new zero location and calibrate the path between the fixture [90] and the robot [81].

(29) Using CAD simulation software, the CAD user selects a position on the tool to place that is best suited to avoid crashes with other tooling and for ease of access for the robot [81] or end-of-arm tooling. The offline programs are then downloaded relative to the work object [10]. The work object [10] is then placed onto the tool or work piece in the position that is defined by the CAD user on the shop floor. The robot technician then manipulates the tool contact point [60] of the robot tool [80] into the device and positions it with respect to the beam-projecting lasers [56 and 58] to obtain the difference between the CAD world and shop floor. This difference is then entered into the robot and used to define the new work object [10]. This calibrates the offline programs and defines the distance and orientation of the tool, fixture, and peripheral.

(30) The offline programming with the work object [10] on the fixture [90] enable the work object [10] to be touched up to the real world position of the fixture [90] relative to the robot [81]. If the fixture [90] ever needs to be moved or is accidently bumped, simply touch up the work object [10] and the entire path shifts to accommodate.

(31) The robotic work cell calibrations method of the present invention is compatible with robotic simulation packages, including but not limited to, ROBCAD, Process Simulate, DELMIA, Roboguide and RobotStudio CAD software.

(32) The beam-projecting lasers [56 and 58] and the projected laser planes [51, 52, 53, and 54] are projected onto known features of the robot tool [80], and then used to calibrate the path of the robot tool [80] and measure the relationship of the fixture relative to the robot tool [80].

(33) The CAD user initially selects a position best suited on a tool or work piece to avoid crashes with other tooling and for ease of access for the robot or end-of-arm tooling. The work object [10] preferably mounts onto a fixture [90] using a standard NAMM's hole pattern mount [40]. The mounts are laser cut to ensure the exact matching of hole sizes for the mounting of parts.

(34) The robotic work object cell calibration method of the present invention uses a work object [10] having a zero point, a zero reference frame, and a zero theoretical frame in space, which is positioned on the fixture [90].

(35) The work object [10] is placed onto the fixture [90] which visually represents the work object [10] enabling the tool contact point of the weld gun to be orientated into the work object [10] obtaining the real-world relationship of the robot tool [80] to the fixture [90] while updating the work object [10] to this real-world position.

(36) The robotic work object cell calibration system of the present invention requires that the position of the work object [10] correlate with the position of the robot tool [80] to calibrate the path of the robot tool [80] while acquiring the real-world distance and orientation of the fixture [90] relative to the robot tool [80].

(37) The robotic work object cell calibration method positions the robot tool [80] with the work object [10] and determines the difference.

(38) The robotic work object cell calibration method of the present invention is used to calibrate the work path of a robot tool based on a tool contact point (point in space) [60]. The calibration uses a known work object or frame (robotic simulation CAD software provided work object). The robotic work object cell calibration method of the present invention works by projecting laser beams to a known X, Y, and Z position and defining known geometric planes used to adjust the roll, yaw, and pitch of the robot tool [80] relative to the tool contact point [60].

(39) The laser is projected onto the robotic end of the robot arm tooling (weld guns, material handlers, mig torches, etc) where the user will manipulate the robot with end-of-arm tooling into these lasers to obtain the positional difference between the known off-line program (simulation provided work object) and the actual (shop floor) work object calibration. The reverse is also truefor instance; a material handler robot can carry the work object [10] to a know work piece with known features.

(40) The CAD model of the work object [10] is placed in the robotic simulation CAD world. The CAD user selects a position best suited on a toot or work piece to avoid crashes with other tooling and for ease of access for the robot or end-of-arm tooling. The off-line programs are then downloaded relative to this work object [10]. The work object

(41) will be placed onto the tool or work piece in the position that was defined by the CAD user on the shop floor. The robot technician then manipulates the tool contact point [60] into the device, aligning it to the laser beams to obtain the difference between the CAD world and shop floor. This difference is then entered into the robot and used to define the new work object, thus calibrating the off-line programs and defining the distance and orientation of the tool, fixture, peripheral, and other key components.

(42) The robotic work object cell calibration method of the present invention calibrates the paths to the robot [81] while involving the calibration of the peripherals of the robot.

(43) The laser plane generating system deployed in the robotic work object cell calibration method of the present invention is well known in the artsee for example U.S. Pat. No. 5,689,330 (Gerard, et al.), entitled Laser Plane Generator Having Self-Calibrating Leveling System; and U.S. Pat. No. 6,314,650 (Falb), entitled Laser System for Generating a Reference Plane.

(44) The robotic work object cell calibration method of the present invention aids in the kiting or reverse engineering of robotic systems for future use in conjunction with robotic simulation software allowing integrators the ability to update their simulation CAD files to the real world positions.

(45) The technology uses existing body-in-white procedures, personnel computers and software and ways of communicating information amongst the trades.

(46) Throughout this application, various Patents and Applications are referenced by number and inventor. The disclosures of these documents are hereby incorporated by reference into this specification in their entireties in order to more fully describe the state of the art to which this invention pertains.

(47) It is evident that many alternatives, modifications, and variations of the robotic work object cell calibration system of the present invention will be apparent to those skilled in the art in light of the disclosure herein. It is intended that the metes and bounds of the present invention be determined by the appended claims rather than by the language of the above specification, and that all such alternatives, modifications, and variations which form a conjointly cooperative equivalent are intended to be included within the spirit and scope of these claims.

PARTS LIST

(48) 10. work object (1.sup.st preferred embodiment) 22. horizontal frame member 24. vertical frame member 25 E-shaped structure 26A and 26B. arms 32A. left frame end (horizontal) 32B. right frame end (horizontal) 32C. upper frame end (vertical) 32D. lower frame end (vertical) 40. NAMM's mounting 41. plane-emitting laser from left-side of horizontal frame 42. plane-emitting laser from right-side of horizontal frame 43. plane-emitting laser from upper vertical frame 44. plane-emitting laser from lower vertical frame 51. projected laser plane from plane-emitting laser (41) 52. projected laser plane from plane-emitting laser (42) 53. projected laser plane from plane-emitting laser (43) 54. projected laser plane from plane-emitting laser (44) 56. laser beam from arm (26A) 58. laser beam from center of E 60. tool contact point 80. robot tool 81. robot 82. robot joint 85A. & 85B. robot linkages 87. robot base 90. fixture 110. 2.sup.nd work object 210. 3.sup.rd work object 310. 4th work object