Today, wired sensors are used for monitoring the condition of aircraft engines, structures, gear boxes, and so on. Wireless Sensor Network (WSN), i.e. smart sensors with radio interfaces, promise unprecedented operational benefits, such as reduced airplane sensor wiring costs and weight, as cabling is limited to specific scenarios and the flexibility to be deployed on-board aircraft without requiring a redesign of the data wiring layout. Such benefits are also important arguments for programs such as Green Regional Aircraft which aims at developing and installing sensors to continuously control accidental damage, environment effects, and consequently in-service structural degradation, targeting a 9% reduction of the empty weight of the aircraft.
To this end, AirWISE was developed in response to the requirements described in the Clean Sky call for proposals referenced under JTI-CS-2009-GRA-01-019 and named “Miniaturized Sensors”. AirWISE is focused on developing a generic hardware platform for airborne WSN nodes leveraging an existing low-power 2.4 GHz CSEM wireless module known as ZorgWave. The technical strategy was to evaluate, re-design and re-qualify the existing module to adapt it to the limitations and constraints imposed by operation in airborne environments in accordance with FAA regulations.
The design and development of the WSN hardware was performed by CSEM in accordance with the requirements described in the call for proposals. In order to fulfil these requirements, in particular those related to the aeronautics environment and regulations, CSEM collaborated with RUAG Aerospace who worked on this project as aeronautics advisors. RUAG Aerospace also advised on the quality assurance of the project CSEM brought to AirWISE with its long track record in WSN developments (resulting, for example, in the WiseNET Technology Platform) covering all building blocks of the radio system (IC design, full network stack design, antenna).
The AIRWISE project successfully studied, designed and tested a wireless sensor networks (WSN) node platform for operation in airborne environment and powered by batteries. In parallel a study of energy harvesting potential solutions versus power consumption of this low-power node has been performed. This study gives some future directions of the energy harvesting application for the autonomous wireless sensor nodes.
The AIRWISE platform is derived from an existing IEEE802.15.4 compliant module (ZorgWave) previously developed at CSEM. Given the specific requirements of the AIRWISE project and in particular the airborne context, the module had to be tested for conformance to derive the necessary modifications. The tests include conformance to specific chapters of the DO160 standard in terms of unintended emissions and vibration resistance. Resistance to the extended temperature range of +85 to -55 degrees of Celsius has also been verified. Finally, as operations of batteries are planned, energy consumption of the existing module operating in different modes has been measured.
The unintended emission and vibration tests were passed with success. The module was also able to operate over the entire temperature range (+ 85 to -55 degrees of Celsius) without any noticeable impact on packet transmission. Current consumptions were adequate for battery operations during 18 months and exploitation with energy scavengers was also possible under low duty cycles.
As a result, the AIRWISE node retained the ZorgWave circuits and schematics. It was adapted in terms of the mechanical design and connectivity based on the specifications provided by the topic manager. Five samples of the AIRWISE node including the ported TinyOS software platform have been delivered to the topic manager (HAI).
The results of AIRWISE project have been disseminated with a poster at CSEM booth during the ICT 2010 event in Brussels.