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Matrox 4Sight Helps Automated Wing Assembly Take Flight
by Kelly Davis, Matrox Imaging - Matrox Imaging Posted 03/28/2002
Integrated industrial computer provides key vision component in Airbus UK's Automated Wing Box Assembly research project.
Matrox Imaging technology is currently helping Airbus UK test and evaluate a major R&D project. The Matrox 4Sight industrial computer is a key component of the vision and sensor systems being implemented in the Automated Wing Box Assembly (AWBA) project.
AWBA began in 1995 with the goal of reducing design and manufacturing costs, as well as time-to-market, enhancing product performance and thereby maintaining Airbus' competitive edge. There are many reasons for researching automated wing box assembly. Aside from the need to continually improve wing assembly technology, there is a reliance on manual processes and dedicated jigs and fixtures.
As part of the overall Airbus company, which became operational January 1, 2001, Airbus UK is responsible for designing and assembling wings, as well as supplying landing gear components, for the Airbus family of aircraft, ranging from the 107-seat A318 to the 380-seat A340-600. Additional components are designed and manufactured at Airbus' three other operational units in France, Germany and Spain.
During the first phase of the AWBA project, four individual demonstrators were developed to better understand robot handling, measuring and positioning, skin panel to rib feet robotic drilling, wing skin panel positioning, wrapping, fastening and process control. The goal of the £5-million second phase of the project (AWBA II), which began over two years ago, is to demonstrate flexible manufacturing by integrating these technologies in a single 8.5 metre-high Automated Assembly cell demonstrator.
AWBA II is a partnership of seven UK-based companies, each responsible for designing, manufacturing and evaluating different elements within the cell demonstrator. BAE SYSTEMS' Advanced Technology Centre at Filton (Bristol) is responsible for supplying the vision and sensor systems required to work in conjunction with two robotic systems utilised in the cell demonstrator. The vision and sensor systems aim to provide future automated assembly systems with the flexibility to adapt to different structures.
In September 2000, AWBA II implemented two Matrox 4Sight integrated industrial computers to provide high-accuracy guidance to both the internal robot, designed by RTS Advanced Robotics, and the external robot system, designed by BAE SYSTEMS' Advanced Technology Centre and based around a Kuka robot.
The 4Sight is a compact stand-alone subsystem that integrates capture, processing, display, networking and general-purpose I/Os. With its rugged enclosure and small dimensions (8.2' x 7.25' x 2.952'), the 4Sight was an ideal choice for the AWBA application, according to Raj Mistry, Engineering Group Leader.
'The 4Sight system provides us with a highly integrated, compact image processing solution that is fast and powerful enough for our image processing requirements. The system is also readily expandable with some of the required industrial automation hardware, due to its PC104-based design,' he says.
Mounted directly on top of the robots (see image below) to avoid excessive electromagnetic noise over the camera cables, the 4Sight and associated ADIMEC TMX10 cameras are used in both major image processing tasks required in the AWBA II cell demonstrator. The first task involves image processing to locate the external robot system for drilling the rib foot, stringer and skin assembly.
'We use two cameras connected to a 4Sight box to identify each end of the rib foot profile,' says Mistry. 'Range-finder readings from four lasers are also fed to the 4Sight via DeviceNet. This information is then combined with the profile extracted by the two-camera system to determine - in 3D space - the full position and orientation of the rib foot before drilling.'
The second task involves image analysis to locate the internal robot system, which performs the swaging (or bending) of the inserted fastener or 'pull in' lock bolt, which is 5/16 ' in diameter, and then places a collar on that swaged fastener.
'This task also utilises two cameras - only this time as a stereo-vision system in which both cameras are looking at the same inserted fastener. This allows us to calculate both the orientation of the bolt and the tip of the bolt - again in 3D space - thus allowing the internal robot to dock with it,' explains Mistry.
Both systems are running custom in-house software along with Matrox Imaging Library (MIL-Lite) - a high-level development library with a complete set of functions for image capture, transfer and display control. The internal sensor uses blob extraction to identify the body of the lock bolt, while the external sensor uses edge extraction to identify the main elements of the rib-foot profile.
'These vision and sensor systems provide the robots with the supplementary accuracy and guidance required for aerospace manufacturing,' says Mistry. 'More specifically, it is the accuracy of the robot relative to the rib that requires improvement through the use of the vision sensor.'
As of April 2000, the demonstrator cell had already proved the concept of wing skin panel wrapping as well as its ability to handle and position a six metre-high wing rib quickly and safely. All operations in the AWBA cell demonstrator are currently being evaluated to measure cost, accuracy and repeatability as compared to manual assembly methods. Airbus UK is also assessing 'scale up' implications, the impact on aerodynamics and systems, as well as health and safety.