Mini Robots Take Over Engine Maintenance

Rolls-Royce plans to use mini robot for engine maintenance

A foreign body in the aircraft engine – just the thought of it sends the pulse rate of every aircraft mechanic sky high. But the British engine manufacturer Rolls-Royce, together with the University of Nottingham and Harvard University, aims to turn such “foreign bodies” into helpful colleagues for the service crew – in the form of small robots.

The idea behind it is convincing: within a few years, miniature robots could be used to carry out maintenance work right inside the engines. In many cases, the time-consuming and cost-intensive process of dismantling engines from the wings or fuselage of the aircraft would no longer be necessary, and the unit would be back in operation again more quickly. Rolls-Royce and the two universities are pursuing four ideas at once for the use of mini robots:

SWARM Robots – getting around the engine on four legs

With a diameter of around five centimeters, the first prototypes are still far too large for narrow engines, but the final model should have a diameter of around ten millimeters. According to Sébastien de Rivaz, a Research Fellow at the Wyss Institute at Harvard University, it may take another five to ten years before development is completed.

Using a kind of endoscope, the small, collaborative robot will then be “released” inside the engine and carry out visual examinations with a camera in places that are difficult to access. The mini robot will find its way through the drive system autonomously, i.e. without being controlled by a mechanic. It transmits the video images live “to the outside”, where they are then evaluated by experts. The chassis is made of plastic that is reinforced with carbon fiber.

Sébastien de Rivaz, Research Fellow at the Wyss Institute at Harvard University

INSPECT Robots – continuous self checks

The INSPECT robots currently in planning are designed in the shape of a pencil. Their name says it all: The periscope cameras are installed in the form of a network with a large number of sensors and enable the engine to continuously inspect itself and report any maintenance and repair work that may be required. The data recorded will be transferred via satellites. The greatest challenge currently facing the developers is to protect the INSPECT robots from the extreme heat inside the engine generated by combustion.

FLARE – inspection plus repair

In future, the sensitive insulation layers inside an engine could not only be inspected, but even repaired by robots. To achieve this, two snake-like robots, which also resemble an endoscope, are inserted into the engine. One robot checks the coating, while the other is responsible for repairing it if necessary.

Remote Boreblending – remote control blade repair

The rotor and guide blades in the compressor of an engine are also considered particularly sensitive components that are easily damaged in flight. Boreblending is a special repair method for damaged blades that allows the affected material to be ground off without having to disassemble the entire compressor. To date, specialists have travelled to the engine in question for this complex and delicate work, which costs a great deal of time and money. Remote boreblending means that it is no longer necessary for the experts to work on the engine themselves.

On one condition: A team on site installs a robot and then hands over the remote control to the experts. The robot scans the surface of the blades, inspects them for damage and transmits the images to the experts via a secure data link. Using a high-speed air spindle and a grinding attachment, the repair can then be carried out remotely, for example by the Rolls-Royce Aircraft Availability Centre.

Dr James Kell, On-Wing Technology Specialist at the engine manufacturer, thinks the research on remote boreblending is already well advanced: “While the SWARM robot technology is far from being part of everyday reality, we have already tested the remote boreblending robot extensively and will be able to introduce it in the next few years.”

In addition to the universities of Nottingham and Harvard, Kell relies on a whole range of other partners for robotics research. The Rolls-Royce network includes a total of 31 University Technology Centres (UTCs) in research institutes around the world, each UTC dealing with a specific key technology.

Photos and videos by Rolls-Royce Holdings plc
Text by Behrend Oldenburg