Final tests of CLOSE-SEARCH: successful unmanned aerial platforms in search missions

Updated: Mar 26, 2014

04 May 2012

Using an advanced navigation concept based on the European augmentation system EGNOS and low cost inertial measurement units, the UAV (Unmanned Aerial Vehicle) scans areas determined by the Search-And-Rescue (SAR) team. The scan is performed combining RGB and thermal vision. The CLOSE-SEARCH concept can now be fully integrated in actual SAR mission work flows.

Testing an Unmanned Areal Vehicle in Spain

Vehicle control is fully autonomous: given an alert and an initial estimation of the area where a person is lost, the SAR team defines the route to be followed. The vehicle then executes the take-off, search, return to base and landing automatically. The Civil Protection Directorate of Catalonia (DGPC) participates in the project and leads the User Advisory Board, a group of experienced end-users in the SAR field. The DGPC has also arranged the sites for the tests and demonstrations in the project, one of which was held recently in Copons, Spain.

Innovation in the use of UAVs

The Institute of Geomatics (IG) brings to the project a navigation concept for unmanned platforms based on the fusion of various sensors: on one side, a key component is the use of the GNSS satellite-based augmentation system. European EGNOS has brought the position accuracy down to 1 metre in horizontal and 3 meters in vertical (95%) distance. Another component of the navigation system is the Redundant Inertial Measurement Units (RIMUs), brought in by the École Polytechnique Fédéral de Lausanne, to investigate the use of low-cost inertial technology used to fit the high safety degree of the navigation system.

Other sensors such as Barometric Altimeters and Magnetometers are used to provide height and attitude control. The result is an unmanned platform featuring a low-cost, robust navigation system which incorporates integrity as a measure of safety in navigation.

Another innovative aspect of the prototype is the use of Worldwide Interoperability for Microwave Access (WiMAX) as a primary means for communication between the UAV and the ground control station. The Asociación de la Industria Navarra (AIN), creators and operators of the base platform, bring this communication technology to the project to demonstrate the validity of the so-called Beyond-Line-Of-Sight (BLoS) communication. That is, communication which does not require physical clearance between the emitter and the receiver. The use of such a technology would allow the platform to operate in zones of terrain abruptness without restrictions on the particular UAV-control station geometry. Such an approach is not yet implemented in conventional UAVs, which currently is limited by distance and obstacles.

Lower cost and risk, more applications and functionalities

The use of unmanned aerial vehicles in SAR missions has been consolidated in recent years, especially in vast, low populated areas such as in Canada or Australia. Generally, these systems are cheaper and the impact of a platform loss or the risk to which human operators are exposed is lower than with its homologous manned versions. In the aftermath of the 2005 Hurricane Katrina or the 2001 Fukushima nuclear tragedy, the unmanned vehicles provided aerial imagery and were able to approach much closer than ground teams or manned helicopters and planes. Particularly in CLOSE-SEARCH, the nocturne operability was a key requirement to be demonstrated.

Final Test campaign: integration of end-to-end SAR services

During the first weeks of March 2012, the final version of the prototype was tested and the main functionalities of the prototype were demonstrated. The first part of the testing campaign was carried on in Copons, in central Catalunya. There, the BLoS communication concept was tested and several users were able to assess its performance in a real situation. In addition, a search mission was simulated over a remote area. Several people were hidden and operators had to identify those persons by means of the imagery that the UAV sent to the station. These same ‘hidden’ participants were also geo-referenced to determine their exact locations. A second test was carried in Pamplona to assess the capability of the night operability of the prototype and its capacity to sense targets also during night. Videos of the tests can be viewed on the project’s YouTube channel:

The CLOSE-SEARCH project, funded by the European Comission under the 7th Framework Programme, is led by the Institute of Geomatics, Asociación de la Industria Navarra, École Polytéchnique Fédéral de Lausanne, DEIMOS Engenharia, Institut Cartogràfic de Catalunya and Direcció General de Protecció Civil.

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