Method and apparatus for manipulator welding apparatus with vision correction for workpiece sensing
First Claim
1. Control apparatus for manipulator welding apparatus, the manipulator apparatus having a manipulator arm controllable in one or more axes and arranged to perform a weld path on a workpiece at a workpiece station, the control apparatus comprising:
- means for storing manipulator arm position data during an initial teach phase representing a desired taught weld path with respect to a reference workpiece at a predetermined location at the workpiece station;
means for projecting a predetermined light pattern on the workpiece at said workpiece station;
means for storing a reference image of said projected predetermined light pattern during said teach phase;
means for moving said manipulator arm along said taught weld path in accordance with said stored manipulator arm position data during a first repeat phase with respect to a second subsequent workpiece;
means for sensing said predetermined projected light pattern on said second subsequent workpiece as said manipulator arm moves along said taught weld path during said first repeat phase;
image processing means responsive to said sensing means for generating deviation data representing the deviation between the actual weld path of said second workpiece and said path described by said manipulator arm during said first repeat phase;
means responsive to said generated deviation data for generating corrected weld path data representing said actual weld path on said second workpiece; and
means responsive to said corrected weld path data for moving said manipulator arm and controlling said manipulator welding apparatus to weld said second workpiece along said actual weld path during a second repeat phase.
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Accused Products
Abstract
Control apparatus for manipulator welding apparatus is provided that includes a vision correction system for workpiece sensing. During an initial teach mode, the manipulator is taught the desired welding path on a workpiece by the appropriate recording of data representing the welding path as an operator controls movement of the manipulator. In addition to the data representing the taught welding path, data representing a reference image or template is also recorded in the teach mode. The reference image or template data is provided by a vision system including a camera carried by the manipulator arm. As successive workpieces are presented to the manipulator for performing the desired welding path, in a repeat work cycle mode the manipulator is controlled to move in accordance with the recorded taught data in a first repeat pass wherein images of the welding seam region are detected at successive points. The vision system utilizing an image processor detects the deviation between the taught welding path and the actual welding path of the workpiece. The control apparatus in response to the deviation data provided by the image processor in the first repeat pass corrects the recorded taught data to provide corrected welding path data for the particular workpiece orientation and geometry encountered by the manipulator. During a second repeat pass of the repeat work cycle mode, welding of the actual workpiece seam is performed in accordance with the corrected welding path data obtained in the first repeat pass.
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Citations
47 Claims
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1. Control apparatus for manipulator welding apparatus, the manipulator apparatus having a manipulator arm controllable in one or more axes and arranged to perform a weld path on a workpiece at a workpiece station, the control apparatus comprising:
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means for storing manipulator arm position data during an initial teach phase representing a desired taught weld path with respect to a reference workpiece at a predetermined location at the workpiece station; means for projecting a predetermined light pattern on the workpiece at said workpiece station; means for storing a reference image of said projected predetermined light pattern during said teach phase; means for moving said manipulator arm along said taught weld path in accordance with said stored manipulator arm position data during a first repeat phase with respect to a second subsequent workpiece; means for sensing said predetermined projected light pattern on said second subsequent workpiece as said manipulator arm moves along said taught weld path during said first repeat phase; image processing means responsive to said sensing means for generating deviation data representing the deviation between the actual weld path of said second workpiece and said path described by said manipulator arm during said first repeat phase; means responsive to said generated deviation data for generating corrected weld path data representing said actual weld path on said second workpiece; and means responsive to said corrected weld path data for moving said manipulator arm and controlling said manipulator welding apparatus to weld said second workpiece along said actual weld path during a second repeat phase. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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- 14. A manipulator hand for a programmable manipulator having a manipulator arm movable in a plurality of controllable axes, the manipulator hand being carried at the end of said manipulator arm, said manipulator hand comprising means for carrying a weld gun, means for carrying a visual detection system, and means for selectively rotating either said weld gun or said visual detection system so as to be positioned in an operative orientation with respect to a reference point on said manipulator arm.
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15. Control apparatus for manipulator welding apparatus, the manipulator apparatus having a manipulator arm controllable in one or more axes and arranged to perform a weld path on a workpiece, the control apparatus comprising:
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means for storing a predetermined projected image pattern of a first workpiece at a predetermined location; means for moving said manipulator arm along a weld path on a second subsequent workpiece, defining a taught weld path; means for sensing said predetermined projected image pattern along said taught weld path and defining the actual weld path of said second workpiece; image processing means responsive to said sensing means for determining the deviation between said actual weld path and said taught weld path; means responsive to said image processing means for calculating corrected weld path data representing said actual weld path on said second workpiece; and means responsive to said corrected weld path data for welding said second workpiece along said actual weld path.
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16. A method for operating manipulator welding apparatus having a manipulator arm controllable in one or more axes and arranged to perform a welding path with respect to a workpiece located at a workpiece station, the method comprising the steps of:
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projecting a predetermined light pattern on said workpiece station; storing a reference template image of said projected light pattern on a reference workpiece at a predetermined location at said workpiece station; teaching a desired weld path representing manipulator arm position along said desired weld path on a workpiece; sensing said projected light pattern on a workpiece as said manipulator arm is moved over said taught weld path, said projected light pattern on said workpiece defining the actual weld path on said workpiece; calculating the deviation between said actual weld path and the path described by said manipulator arm during said sensing step in response to said sensing step; calculating corrected weld path data representing said actual weld path of said workpiece in accordance with said calculated deviation; and welding said actual weld path on said workpiece by controlling movement of said manipulator arm in accordance with said corrected weld path data. - View Dependent Claims (17, 18)
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19. A method for operating manipulator apparatus having a manipulator arm controllable in one or more axes and arranged to perform a welding path with respect to a workpiece located at a workpiece station, the method comprising the steps of:
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projecting a predetermined light pattern on the workpiece station; storing a reference image resulting from said projected light pattern on a reference workpiece at a predetermined location at the workpiece station; sensing the light pattern on a subsequent workpiece at the workpiece station resulting from said projected predetermined light pattern as said manipulator arm is moved over a predetermined path; calculating desired weld path data representing the desired weld path of the subsequent workpiece in accordance with said stored reference image and said sensed light pattern of said sensing step; and welding the desired weld path on the subsequent work piece by controlling movement of said manipulator arm in accordance with said desired weld path data of said calculating step. - View Dependent Claims (38)
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20. Control apparatus for manipulator welding apparatus having a manipulator arm controllable in one or more axes and arranged to perform a weld path on a workpiece at a workpiece station, the control apparatus comprising:
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means for projecting a predetermined light pattern on the workpiece at the workpiece station; means for storing reference image data representing the light pattern on a reference workpiece resulting from said projected predetermined light pattern; means for moving said manipulator arm during a first repeat phase along a predetermined path with respect to a subsequent workpiece and for sensing the light pattern on the subsequent workpiece resulting from said predetermined projected light pattern; and means jointly responsive to said sensing means and said reference image data for moving said manipulator arm and for controlling said manipulator welding apparatus to weld the subsequent workpiece along a desired weld path during a second repeat phase. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40)
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Specification