Highlights
- Real Time Simulation and Monitoring
- RTV Navigation System
- NOMAD Vision Based Part Recognition System Developed
- New Autonomous Robot Transport Vehicle (RTV)
- All Positional Techniques For Autonomous Robotic Welding
- NOMAD Publications
Real Time Simulation and Monitoring
In industry today simulation and offline programming is normally a separate one way process.
NOMAD is developing integrated automated planning of the welding process, robot programming and Robot Transport Vehicle (RTV) positioning. This requires the simulation software to receive feedback from the welding cell environment as to location and orientation of both the RTV and component. An integrated hardware and software system optimises the position for the robot arm to carry out the welding process. The system is regularly updated, using positional feedback from the vision system.
RTV Navigation System
The NOMAD project has designed and built a vision system to enable accurate navigation for a Robot Transport Vehicle (RTV). The RTV is positioned by using information taken from the vision system. RTV positioning is carried out on an iterative basis by combining off-line programming with regular updates from the vision system.
NOMAD Vision Based Part Recognition System Developed
Using the same vision system as for navigation NOMAD is able to relate CAD data in the simulation system to a component placed in the welding cell. The system is then able to recognise the component orientation, type and location within the cell.
If the component type is changed the simulation system will try and relate the vision system image to the known CAD data, if this is unsuccessful the system will highlight that the component cannot be recognised. If the CAD data for the new component is available, recognition will take place.
New Autonomous Robot Transport Vehicle (RTV)
Autonomous vehicles are not widely used in industrial environments. Automated Guided Vehicles (AGV's) are used but as the name suggests they are guided by tracks laid in the floor and therefore, are not completely autonomous. The NOMAD RTV links with both global vision-based navigation systems and local navigation systems.
The robustness of the RTV is of prime importance, as it must not only operate in a welding environment but also carry the robot, the robot controller, PC and ancillary equipment. To ensure good accuracy the vehicle has been designed to be stable when carrying out the welding and sensing operations. The RTV has also been designed for smooth and rapid movement to minimise vibration and the floor to floor time of the system.
All Positional Techniques For Autonomous Robotic Welding
The robotic MIG arc welding process is limited in its application because of the influence of gravity on the molten pool. The NOMAD project is targeted at the welding of large structures which, would make the use of a workpiece manipulator, servicing only down hand welding, too costly or physically unfeasible. To overcome this, the NOMAD project is developing welding consumables and welding procedures to enable all position robot MIG welding.
NOMAD Publications
Papers
- MICAD 2002 International Exhibition and Conferences dedicated to CAD/CAM/CAE and New Technologies for Design and Manufacturing, 26 - 28 March 2002. Paris, France.
- Autonomous and Robotic systems, 25-26 June2002. IFF conference in Magdeburg, Germany.
- IIW commission XII welding conference 26-28 June held in Copenhagen.
- International Symposium on Robotics (ISR2002) Stockholm, Sweden Oct. 7-11, 2002.
Journals
- Heston, T. Fabrication and Metalworking (USA). Robotic Welding: Freeing Constained Manufacturing July 2002.
- Welding and Metal Fabrication. (UK) NOMAD Programme to Revitalise European Fabricators. April 2002.
- Mobile robots walk into the future. Industrial Robot: An
International Journal. Volume 29 Number 6 2002 pp 517-523.
The NOMAD projects' contribution to autonomous robotics is reviewed.
Copyright © 2003, TWI Ltd