There is a global need to develop technologies for earlier detection and monitoring of spores of plant pathogens EPP incursions[1,4]. This paper presents the hardware development and testing of a new concept for air sampling via the integration of a prototype spore trap onboard Unmanned Aerial System (UAS). The paper describes the integration of a prototype spore trap onboard UAS to allow multiple capture of spore pathogens in multiple remote locations at high or low altitude; otherwise not possible with stationary sampling devices.
Existing spore sampling devices are stationary at the sampling location. Location is important due to prevailing climatic conditions, and use of sampling devices in remote locations and where topography is severe is almost impossible. In such scenarios, airborne sampling has been suggested as a viable alternative [2,3]. Thus a new solution is desired which capability present to take spore samples in multiple locations and in remote regions where access to local sampling is difficult.
There is some research previously conducted in the area of airborne sampling using remotely controlled manned and unmanned aircraft variants[2,3,4]. Dynamic sampling systems have the potential to improve upon current static ground based sampling methods.
During autonomous operations, the onboard autopilot commands the servomotor to rotate the sampling device to a new indexed location once the UAS vehicle reaches the predefined waypoint or set of waypoints (which represents the region of interest). Time stamped UAS data is continuously logged during the flight to assist with analysis of the particles collected. Testing and validation of the autopilot and spore trap integration, functionality and performance is described.
Wind tunnel testing was performed and highlighted several issues such as dispersion of larger particles (> 3microns) and analysis of particles under fluorescent microscopes. Flight testing was conducted to verify the spore traps capability to capture spores in real world conditions. The spore trap was integrated with the test platform and onboard autopilot systems. Flight experiments demonstrated that the spore trap was able to successfully capture and geo-locate simulated spore particles during autonomous missions. It was shown that sample contamination could be avoided through the inclusion of neutral locations on the tape.
The tape rotation mechanism was programmed to automatically rotate the tape to the sampling location once the UAS entered the sampling region and shift the tape location to the neutral point once the UAS was outside the sampling region. Additionally all flight data was logged using the onboard autopilot data logger. A tape rotation algorithm was implemented to control the position of the drum to capture multiple samples without contamination. This allows for the geo-location of spores and for the characterisation of spores concentrations at discrete altitudes.
The sampling system has the ability to spatially monitor fungal spores, and protocols to interpret their spatial distribution. These tools greatly enhance the ability to detect new incursions of fungal pathogens and to enable more accurate delimiting of distribution. Overall, the use of this technology allows early detection of Emerging Plant Pest (EPP) incursions in remote or difficult areas.
%8 09/02/2011