Hole lot quicker

A lightweight, portable robot is claimed to drill holes into aircraft components, such as wing spars, faster and cheaper than current technology.

Roptalmu was designed at Spain's Fatronik-Tecnalia technology centre for Airbus España to move over aircraft components while they are fixed to a tool holder. The robot differs to other, heavier drilling machines, that are fixed to the floor.

The device is made up of an automatic moving platform and a three-axis drilling robot. Once the platform is positioned near the part to be machined, the robot fixes itself to the tool holder of the part and automatically moves over it. Roptalmu uses a set of sensors and control software to drill every point that needs to be worked automatically and safely.

The researchers designed the machine so it can drill a range of materials, including aluminium, titanium and carbon fibre.

A key feature of Roptalmu is its portability, said Valentin Collado, Fatronik-Tecnalia's robot project manager. 'If the production system is fixed to the floor, like traditional machinery, it is very expensive and time demanding to re-allocate it throughout the shop floor,' he said.

'Moreover, with a small and portable system such as Roptalmu, the production system is moved to the aerospace part to be manufactured, instead of moving these big components to the fixed-to-the-floor machine as happens now.'

Collado said a conventional heavy machine that can do the same job as Roptalmu could weigh 15 tonnes and require large amounts of electrical energy to move each of its axes. 'Roptalmu weighs only three tonnes,' he said, adding that it requires only a small fraction of the energy to move its axes. 'Hence, Roptalmu is also an eco-efficient production system,' he said.

In addition to its lighter weight and portability, the other main advantage of the robot is its full automatic capabilities. This is particularly important for large aircraft parts, which must be drilled with thousands of holes for assembly. Traditionally this has only been done with manual or semi-automatic tools.

'There have been various attempts to develop portable systems — made up of a moving platform with a commercial anthropomorphic robot on top of it — to do a similar job as Roptalmu,' said Collado.

'However, these are not accurate and robust enough to reach the high quality required. Therefore the main technical challenges at the beginning of this project were to develop a portable, lightweight production system that fulfilled the accuracy required by the aerospace standards, and could also bear the efforts of the drilling reaction forces.'

He claimed Roptalmu is as accurate as any heavy traditional heavy machine.

The prototype development costs of the Roptalmu robot were shared by project partners Fatronik-Tecnalia and Airbus España. The next step for the team is to manufacture the robot industrially.

Collado said his group is negotiating with several machinery manufacturers that are interested in the robot's industrialisation in three to four months.

Hugo Martinez de Lahidalga, the Fatronik-Tecnalia projects and marketing manager, said the use of Roptalmu would not be limited to the aerospace production industry. He said it could also be used in the renewable energy, shipping and construction sectors — anywhere, in fact, where large components need to be handled.