Assembly line fluid filling system and method

A method for fueling an automotive vehicle on a conveyer line, said conveyer line moving generally along a first axis, said method utilizing a robotic arm with an end effector for fueling a fuel stem of said vehicle, said robotic arm having a workspace within which the fuel stem must lie in order to be fueled, said method comprising:

• determining a first position of said fuel stem along said first axis;
• moving said robotic arm to position said end effector proximate to said first position such that said fuel stem lies within said workspace;
• determining a three-dimensional position of said fuel stem utilizing a vision system;
• moving said end effector proximate to said three-dimensional position to enable said end effector to mate with said fuel stem and moving said robotic arm relative to said first axis at a speed substantially equal to a speed of said conveyer line;
• and,
• fueling said fuel stem with said end effector.

A method for providing position data to a controller to enable a robotic arm controlled by said controller to move to a position of an object, said object lying within the workspace of said robotic arm, said method utilizing first and second cameras disposed at first and second coordinate systems, respectively, said method comprising:

• generating a first digital image of said workspace including said object utilizing said first camera;
• searching said first digital image with a first image template to determine a location in said first image where a first correlation score between that portion of said image being searched and said template is greater than a predetermined threshold;
• simultaneously generating a second digital image of said workspace including said object utilizing said second camera;
• searching said second digital image with a second image template to determine a location in said second image where a second correlation score between that portion of said image being searched and said template is greater than a predetermined threshold;
• calculating a three-dimensional position of said object with respect to a predetermined coordinate system responsive to said first and second digital images when said first and second correlation scores are both greater than a threshold correlation score;
• calculating a triangulation error of said position;
• and,
• transferring position data indicative of said three-dimensional position to said controller when said triangulation error is less than a threshold error value.

A fueling system for fueling an automotive vehicle on a conveyer line, said conveyer line moving generally along a first axis, comprising:

• a gantry having a carriage configured to move generally parallel to said first axis;
• a robotic arm attached to said carriage that moves with said carriage, said robotic arm having an end effector configured to mate with a fuel stem on said vehicle and to supply fuel to said fuel stem through a fuel hose;
• a vision system including first and second cameras for iteratively determining a three-dimensional position of said fuel stem relative to a predetermined coordinate system;
• a robot controller configured to command said carriage to move proximate said three-dimensional position and to move said end effector to said position to mate with said fuel stem, said robot controller being further configured to move said robotic arm relative to said first axis at a speed substantially equal to a speed of said conveyer line.

A method for providing updated kinematic parameters to a controller to enable a robotic arm controlled by said controller to compensate for dimensionally unstable portions of said robotic arm, said method comprising the steps of:

• providing one or more markers on an end effector of said robotic arm;
• positioning the markers within a workspace of said robotic arm;
• using a vision system associated with said robotic arm to determine respective three-dimensional locations of said markers;
• and
• calculating updated kinematic parameters by comparing the determined locations of said markers returned by said vision system to respective expected locations of said markers.