This project is a result of collaboration between the University of Trollhättan/Uddevalla and Volvo Aero Corporation, Trollhättan. An aerospace component, which is used in a process at Volvo Aero Corporation, is casted in one piece. A new way of manufacturing this component is under investigation.
Making this component from smaller pieces and weld them together is one option. The component is made of titanium, which is why it is difficult to manually weld the component together. A robot can weld it, but since the gap size is only <0.1 [mm] a sensor is needed to detect where the seam is located. The component has large flanges. They make it impossible to get the sensor closer than 70 [mm] from the seam at certain locations.
One of the purposes of the project was to suggest a seam tracker capable to trace the seam, another was to test a specific seam tracker at University of Trollhättan/Uddevalla. A computer simulation in IGRIP of the welding was also a part of this project. One sensor, M-spot 90, was borrowed from Lund Institute of Technology. This sensor was one part in a system that was tested at University of Trollhättan/Uddevalla to track the seam on the component.
The recommendation for Volvo Aero Corporation is to use one of the three following tracking systems: RAFAL from Servo-Robot inc, Long range MT10/10 from Meta Vision System or Circular Scanning long stand off from Oxford Sensor Technology Ltd. The suppliers claim that these three systems are capable of tracking the seam that Volvo Aero wants to weld. The best choice is the one from Oxford Sensor Technology Ltd, which uses a circular scanning method, which may increase the detection ratio.
The seam tracker borrowed from Lund did not have enough resolution to track the seam from the height of 70 [mm]. Only if the gap was bigger than 1.5 [mm] and from the height of 50 [mm] it was possible to trace the seam. In the simulation a text file with tracking values from the real sensor was used instead of the real sensor, since no real time communication could be established.
Source: University West
Author: Bergkvist, Per