Method and apparatus for manipulator welding apparatus with vision correction for workpiece sensing

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:

• 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.

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:

• 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.

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:

• 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.

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:

• 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.