Within the last decade, laser trackers have improved greatly in functionality. One of the most significant improvements is the ability for a laser tracker to measure in a full Six Degrees of Freedom, or 6DoF. This capability allows robot manufacturers to correct the end effector of the robot during a calibration cycle with less poses, but it has also opened up new possibilities.
In the past when using a traditional 3-D laser tracker, multiple positions had to be measured to calculate the tooling center point (TCP) in 6D space. Now by using a 6DoF laser tracker, it is possible to know the exact location of the end effector in 6D space in real time. This innovation removes the need for robot calibration completely as the tracker can monitor and correct the position of the end effector in real time without the need to worry about what the robot is doing in “joint space.”
This advanced technology was recently applied at Premium Aerotec (Nordenahm, Germany) to automate the process of placing stringers for the fuselage section of the Airbus A350 XWB. Because the stringers were up to 18 meters long, the specified absolute accuracy of the robots being used still were not accurate enough to place them correctly. The team was only able to meet their stringent accuracy requirements by correcting the robots in real time based on feedback from the 6DoF Absolute laser tracker.
Automated cells based on robots and mobile measurement systems are no longer viewed as futuristic, and these implementations have grown substantially in a worldwide scale. As a result of this intelligence, a variety of manufacturers and industries are investigating their processes with fresh eyes, setting their sights on areas where measurement and inspection automation can play a vital role. In the midst of a paradigm shift, manufacturing history is changing right before our eyes.
Based on the article “Metrology Automation is Here and Now” published in Quality magazine.