Future aircraft could have “smart skin” that enables them to instantly detect damage, if research by BAE Systems comes to fruition.
Researchers at the company’s Advanced Technology Centre (ATC) have developed a way to cover aircraft panels with an array of tiny sensors that enable the craft to analyse both its own condition and the environment around it in minute detail.
The company says the wireless sensor packages or “motes”, which could be made to measure a wide range of variables from temperature and wind speed to strain and corrosion, could eventually be shrunk to less than 1mm3 in size and power themselves using energy-harvesting technology.
‘[If] we can flood a surface with lots of sensing capability, it opens up different kinds of sensing we’ve not seen before,’ lead research scientist Lydia Hyde told The Engineer. ‘We can see an event with a multitude of sensors and track how it is happening.’
For example, airflow over a plane’s surface is usually modelled using computers and wind tunnel testing. But equipping an aircraft with wind speed, movement and accelerometer sensors would enable engineers to build a much more detailed and accurate picture of airflow. It could even provide the pilot with real-time information that would enable them to fly more smoothly in response to turbulence.
Alternatively, sensors that can detect specific areas of damage or decay could speed up costly maintenance procedures and allow small problems to be dealt with earlier before they become more serious.
To prove the concept, the BAE team covered a 1m-by-0.5m panel from a Typhoon fighter jet with a range of 20 different motes, each a few millimeters across and comprising a battery, control architecture, communication module and a different kind of sensor.
If one mote detects something unusual it can trigger others around it to start examining that event. This kind of collaboration enables the system to build a picture of the overall environment that makes sense of the huge amount of data coming from all the sensors and feeds it to the pilot via a display screen.
‘If you have a million sensors the pilot doesn’t want to know every event but he probably does want to know if a trail of them are detecting something,’ said Hyde. ‘It’s filtering all that data for you and saying “this is the stuff you need to be looking at”.’
Ensuring the motes could be embedded in the panel without compromising its structure meant they had to be wirelessly controlled. To do this, the ATC team drew on earlier work on wireless communication, using variations in otherwise unused frequency bands to transmit data between the many sensors without creating interference.
The researchers are now working on miniaturising the motes further and adding piezo-electric energy harvesting capability to give them their own power source, which in itself will require a redesign of the electronic architecture.
They are also looking at how each mote could include a single pixel light sensor that would effectively turn the entire surface of the aircraft into a giant camera.