C3.3 - Energy-Autarkic Sensors in Aircrafts

SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
Proceedings SENSOR 2011
C3 - Wireless Sensors II
K. Bartholomé - Fraunhofer Institut für Physikalische Messtechnik, Freiburg (Germany)
417 - 423


Sensors are the eyes and ears in the service of people - especially in inaccessible areas where regular maintenance or battery replacement is extremely difficult. A solution can be the implementation of self-powered sensor networks that autonomously collect their required energy from their surroundings. After installation of the sensors they collect and transmit their data without any need for further maintenance like battery replacement.

In aeronautics, maintenance of airplanes is one of the major cost factors. To facilitate the future maintenance, sensor systems shall be employed to monitor the aircraft skin for the occurrence of dents or cracks. In order to save on cables and hence on weight, which is a particularly great benefit in aircraft construction, sensors are affixed to the inside of the aircraft fuselage in the form of a »smart patch«. This sensor patch is capable of collecting the required energy for powering the sensors and transmitting the data to a central unit from the temperature difference between ambient air temperature (minus 50°C – minus 20°C) and passenger cabin (20°C) using thermoelectric generators. Besides the quality of the thermoelectric generator, the optimization of the thermal integration into the aircraft body has a crucial influence on the efficiency of the system: target parameters are electrical outputs of greater than 10 mW at temperature differences of 25 °C.
Furthermore, the integration concept has to ensure the encapsulation of the thermoelectric generator for protection against corrosion and vibrations.

In this paper an optimized concept for the integration of thermoelectric generators into the airplane skin is introduced, maximizing the generated power output under the given boundary conditions.