Aircraft sensors without batteries or cables

April 10, 2013 by Florian Aigner
Will planes soon take of with energy harvesters on board?

An idea from EADS and Vienna University of Technology is taking off: in a joint project, Energy Harvester Modules suitable for aircrafts have been tested, which should supply sensor nodes with electrical power in the future.

Like a nervous system in a human body, sensor networks attached to the will in future record and transmit essential data concerning the of the . Traditionally, wired sensor solutions are used, which are reliable, but introduce weight and increase the design complexity of an aircraft. To solve this challenging task EADS Innovation Works and Vienna University of Technology are in a close cooperation in developing a thermoelectric " Harvesting Module" with just a few centimetres in outer diameter, which will supply enough energy to wireless sensor nodes. The artificial temperature difference created when the aircraft takes off and lands is sufficient to generate the required electrical energy. A campaign on an Airbus aircraft with these "Energy Harvesting Modules" has been performed for the first time – with extraordinary success.

Cost factor: Aircraft maintenance

Maintenance is one of the largest expenses along with air crew salaries, fuel costs and depreciation a company has to incur over the lifetime of an aircraft and can be as high as 20% of its total cost. The autonomous wireless sensor nodes will monitor the health status of an aircraft and wirelessly transmit the data to the maintenance system of the aircraft.

The Energy-Harvester-Module.

"Such a system obviously has major advantages, however, the main problem lies in the energy supply", says Prof. Ulrich Schmid from the Institute of Sensor and Actuator Systems at Vienna University of Technology. "Conventional batteries are not designed for such large temperature difference to which an aircraft is continuously exposed during operation. In addition, nobody wants to regularly replace all the sensor batteries in the complete aircraft. Using conventional cabling, on the other hand, would significantly increase the weight of the aircraft." Together with EADS Innovation Works, Prof. Schmid has developed an approach to harvest electrical energy for the directly from the temperature changes present at fuselage of an aircraft during operation.

Energy from temperature differences

When two different electrically conductive materials are joined and their contact points have different temperatures, an electrical voltage is generated. This phenomenon is known as the "Seebeck effect". The outer hull of an aircraft undergoes a massive temperature change during take-off and landing, so that temperature differences occur on the fuselage. "We can make optimal use of these temperature gradients by attaching a small thermal mass to one side of the thermoelectric generator", explains Alexandros Elefsiniotis, one of Prof. Schmid's PhD students. "A water reservoir of about ten cubic centimetres freezes during take-off. It cools down at a slower rate than the fuselage, thus a thermoelectric generator located between these components creates electricity from that ." Inversely, during landing procedure, the fuselage temperature of the aircraft is warmer than that of the water reservoir and hence, energy is again generated. A tailored low-power management system ensures that the voltage output strongly varying in time is converted into constant and appropriate voltage levels, which can drive a sensor node most efficiently.

Successful tests at EADS

The start of the project involved simulations and climate chamber experiments. Based on these promising results, EADS Innovation Works has recently carried out the first test flights with Energy Harvesting Modules on an Airbus aircraft. Alexandros Elefsiniotis states: "We have been able to obtain around 23 joules of energy per flight, which is sufficient to power up a node." Depending on the outside , it is possible that alternative materials other than water could be more suitable – research is currently ongoing into appropriate strategies for extreme situations, for example for flight routes in very cold regions."EADS Innovation Works wants to use the best available technology for the autonomous sensors in future, therefore the new method is of great interest to us", explains Prof. Becker from EADS Innovation Works. "We are confident that energy autonomous will soon be flying in our aircrafts."

Explore further: Miniaturized power modules for aircraft bodies

Related Stories

Miniaturized power modules for aircraft bodies

June 14, 2011

Aircraft maintenance can be time consuming and expensive. It is much simpler if the airplane itself reports, where maintenance is required. The best solution is an approach for the sensor network, which even provides its ...

Energy-autonomous sensors for aircraft

October 1, 2009

Aircraft maintenance will be easier in future, with sensors monitoring the aircraft skin. If they discover any dents or cracks they will send a radio message to a monitoring unit. The energy needed for this will be obtained ...

Aircraft systems in the environmental chamber

June 8, 2011

How can air transport be made more environmentally compatible, economical and sustainable? The Fraunhofer flight test facility in Holzkirchen is soon to be expanded with the installation of a thermal test bench for aircraft ...

World's first aircraft with serial hybrid electric drive

June 24, 2011

Together with partners, Siemens has built the world’s first aircraft with a serial hybrid electric drive system. The two-seater motor glider DA36 E-Star is presented by Siemens, Diamond Aircraft and EADS at the Paris ...

Thermogenerator from the printer

November 15, 2012

Wireless sensor networks monitor machinery and equipment in factories, cars and power stations. They increasingly "harvest" the energy they need to transmit measurement data from the environment, thus making them self-sufficient. ...

Recommended for you

Microsoft aims at Apple with high-end PCs, 3D software

October 26, 2016

Microsoft launched a new consumer offensive Wednesday, unveiling a high-end computer that challenges the Apple iMac along with an updated Windows operating system that showcases three-dimensional content and "mixed reality."

Making it easier to collaborate on code

October 26, 2016

Git is an open-source system with a polarizing reputation among programmers. It's a powerful tool to help developers track changes to code, but many view it as prohibitively difficult to use.

Dutch unveil giant vacuum to clean outside air

October 25, 2016

Dutch inventors Tuesday unveiled what they called the world's first giant outside air vacuum cleaner—a large purifying system intended to filter out toxic tiny particles from the atmosphere surrounding the machine.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.