Automatic calibration for camera-robot system with tool offsets

A method for automatically calibrating a camera-robot system having tool offsets, comprising:

• creating an array having a plurality of measuring points for collecting observations in a robot workspace and a predetermined region of a camera;
• positioning a calibration target at a defined location;
• a robot moving the calibration target from the defined location to a first measuring point, the first measuring point corresponding to first robot coordinates of a default tool center point in a robot base coordinate system;
• a camera capturing an image of the calibration target and identifying a location of the calibration target at the first measuring point, the location at the first measuring point corresponding to first camera coordinates;
• saving the first robot coordinates and the first camera coordinates of the calibration target in a memory;
• the robot moving the calibration target from the first measuring point to the second measuring point, the second measuring point corresponding to second robot coordinates of the default tool center point in the robot base coordinate system;
• the camera capturing an image of the calibration target and identifying a location of the calibration target at the second measuring point, the location at the second measuring point corresponding to second camera coordinates;
• saving the second robot coordinates and the second camera coordinates of the calibration target in the memory;
• the robot repeating moving the calibration target to each of the remaining measuring points of the plurality of measuring points, capturing the image of the calibration target at each remaining measuring point and identifying a location of the calibration target corresponding to each remaining measuring point, and saving corresponding robot coordinates and camera coordinates in the memory;
• calculating camera-robot calibration values and the tool offsets according to the following equation:
• Poly (Cx, Cy)=[Rx;
• Ry]+Rot(Ru)*[Tx, Ty];
• setting the calculated tool offsets;
• and
• saving the camera-robot calibration values in the memory.