MTC robot project closes in on improving manufacturing precision

THE Metrology Assisted Robotic Automation (MARA) project at the Coventry-based Manufacturing Technology Centre has solved a long-standing manufacturing problem with robotic accuracy, it has been suggested.

Those behind the project say this will result in major improvements in the precision and consistency of robotic operations.

Industrial robots have been used for repetitive tasks for many years, with good results, but the increasing use of offline computer programming has underlined the fact that industrial robots are generally not accurate devices.

Previous robot calibration fixes have improved accuracy to better than one millimetre which is adequate for most tasks. However, applications requiring a very high degree of accuracy have presented challenges.

The MTC project combines the robot with a high-speed, ultra-accurate laser tracker from Hexagon Metrology which can make real time corrections to the robot’s path during a process – something which has never been achieved before.

The result is accuracy of better than 0.2 millimetres for a robot working at a speed of 50 millimetres a second.

MTC project leader Richard Kingston said that the new process had the potential to transform precision, accuracy and consistency in robotic manufacturing operations, resulting in higher quality and a much lower defect rate.

“By combining the robot, the laser metrology device and a real-time controller we were able to ensure that the robot could follow complex paths with an extreme degree of accuracy not previously achievable. The project has proved that it is possible to correct a robot’s path in real time, which is another first,” he said.

“We are now continuing our work to improve accuracy and reliability still further, but this is a fantastic result.”