Wireless makes sense

Airframe manufacturers are constantly striving to remove more weight whilst simultaneously reducing the amount of complex wiring harnesses and cables running throughout the aircraft. Mike Richardson reports.
In an effort to reduce the huge amounts of copper wiring in modern aircraft, wireless data transmission and the use of novel sensors to monitor engines and other aircraft systems is increasingly being viewed as a means of improving the methods in which aircraft instrumentation and test systems collect valuable data. Using wireless instead of fixed wiring solutions offers the potential to measure more parameters, save cost and weight and lead to lighter, more efficient future aircraft designs with a quicker time to market.
Led by technology and engineering consultancy TRW Conekt, a consortium of key players from the UK aerospace industry is helping to develop wireless data gathering and transmission technology for aircraft applications. With a total budget of £3.4million, the three year project was launched earlier this year with an investment of £1.6million from the Technology Strategy Board (TSB).
Known as WiTNESSS (WIreless Technologies for Novel Enhancement of Systems and Structures Serviceability), this collaborative project will research and de-risk wireless data transmission technology for key testing and structural health monitoring applications in aero engines and both fixed and rotary wing aircraft. The aim is to find solutions to the challenges which currently prevent deployment on aircraft, and through a phased testing and demonstration programme will prove the performance of the new wireless systems developed.
The WiTNESSS consortium comprises lead partner TRW Conekt, plus QinetiQ, QM Systems, Rolls-Royce, Airbus UK, BAE Systems, System Level Integration, GE Aviation, Bombardier Aerospace Belfast, Ultra Electronics BCF and AgustaWestland. The collaboration between large and small companies including aircraft manufacturers, technology developers and component/system suppliers brings together their key skills to maximise the effectiveness of the project.
TRW Conekt's Roger Hazelden is technical lead for WiTNESSS and chaired the strategic development of the project with the aim of bringing together key players from the UK aerospace industry interested in exploiting wireless transmission technology on aircraft.
“We recognise there are many technology issues that need addressing in terms of interference, data security, data transmission range, and power supply,” he begins. “We're collaborating with these companies to test, research and de-risk these technologies for the benefit of everyone in the UK's aerospace industry. It's such a new technology, so we're working at a pre-competitive level with our partners; it's in everyone's interest to get this stuff working.”
WiTNESSS doesn't just focus on one particular application; instead it consists of a generic framework that can be used for many aircraft applications. The project mainly centres on structural health and performance monitoring data applications for systems and subsystems.
“It's important to make the point that at this stage, the consortium isn't looking to use this technology for anything that is safety critical,” clarifies Hazelden. “We're moving one step at a time to introduce this technology because aerospace products are always based on a pedigree of what has gone before, and then making small step changes. We're taking big leaps with a disruptive technology, so there's much work to do before we can use this technology for real.”
WiTNESSS concentrates on collecting sensor data and transmitting it to data logging systems for processing. Using a wireless solution reduces the weight and complexity of the wiring required, which is particularly important for many aircraft testing and instrumentation applications.
“For example,” continues Hazelden, “during the testing and validation of a gas turbine engine for an aircraft, there are approximately 3,000 temperature sensors and several hundred vibration sensors which need to be wired back to the data logger. This involves a hugely complex wiring harness to connect it, increasing the possibility of making mistakes. If at least part of this function can be connected wirelessly then it could provide huge time savings for aircraft test beds requiring fitment of monitoring systems, as well as when modifications are made which require test flights to show that the modifications are correct.”
This normally requires temporary instrumentation to be installed, which again means complex wiring harnesses being retrofitted into conventional systems. Hazelden says that replacing these harnesses with wireless systems makes it much easier to instrument an aircraft for a test programme, as you no longer have to remove the temporary wiring afterwards: “It's easier to remove a few wireless sensors than it is to strip out an entire wiring harness,” he adds. Are you receiving me?
Part of WiTNESSS looks at finding a suitable radio transmission system that will transmit the amount of data required and that will work within different applications whilst still satisfying the communication regulatory requirements such as the use of certain frequency bands.
“Another technology barrier concerns power consumption and discovering a means of actually powering these devices,” explains Hazelden. “For example, if a sensor is transmitting data wirelessly from the end of the aircraft's wing, it makes sense to avoid installing more cabling to power the system. We're researching ways of self powering or providing long life batteries to power these systems.”
Conekt acts as an integration partner within WiTNESSS by using its expertise in hostile environment electronics gained in the aerospace, automotive and military sectors.
“We lead the requirements and integration activities to bring together the vital data that the other partners provide and integrate into complete systems that can be transferred to end user partners, such as Airbus, Bombardier and AgustaWestland - companies that will be using it for real on their aircraft,” notes Hazelden. “The consortium comprises a mixture of technology companies as well as those that already supply avionics systems, but want to add wireless technology to the systems they already manufacture.”
With similar projects taking place in the US and the Far East, there is the danger that without this work the UK aerospace industry will miss out in terms of the market share for wireless technologies.
“The consortium is looking to grow UK market share in the future and win new business as a direct result of being in pole position to offer wireless technology,” he avows. “We want to unlock new markets and protect existing ones too.”
The consortium already has plans for potential follow-on projects to address areas of technology that are gradually becoming clearer, but at present are beyond the scope of the existing project.
“We're at the first stage of discussions for the short term exploitation of wireless technologies for various test and instrumentation applications, and how we can build commercial alliances between the partners to start making money,” he concludes. “Longer term we'll be looking at wireless applications that will actually fly on civil airliners, although it may mean that further technology areas will need to be de-risked before this is feasible.” www.conekt.net
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