Drone-based environmental odour monitoring
Mission of the project
SNIFFDRONE is an R&D project funded by the European Union through the ATTRACT initiative in 2019-2020. The main purpose of the project is the development of a drone with olfaction capabilities to provide spatially dense odour measurements and autonomously localise the source of odour nuisances in wastewater treatment plants (WWTPs). Drone-based measurements are quicker and cheaper than the method commonly used today, which involves collecting air samples on-site and taking them to a laboratory to be rated by a panel of humans. The real-time odour information that SNIFFDRONE can provide to plant managers will help them to make fast decisions and apply actions pre-empting potential odour nuisances to people living in proximity.
This development has involved a number of research challenges, namely: (i) To design an electronic system that predicts odour intensity from sensor readings in complex and time-varying odorous gas mixtures using machine learning algorithms, (ii) To integrate that system into a drone while minimizing the negative impact that the downwash airflow produced by the drone propellers may have in the measurements; and (iii) To develop algorithms that produce 2D maps of time-averaged odour distribution, despite of the well-known complexity of concentration distribution in turbulent plumes.
Main components of the system
Drone
A DJI Matrice 600 Pro is selected for this application due to its high payload capacity (6 kg) and moderate weight (10 kg). It also offers accurate GPS positioning and easy user interface.
Electronic nose
A custom electronic nose (RHINOS) is developed to measure odours in real-time. The device weighs only 1.3 kg (2.9 lb), making it easily mountable on a small commercial drone.
Odour sampler
Designed for 10-litre gas sampling bags, allows the collection of odour samples for post-flight dynamic olfactometry analysis and electronic nose calibration according to EN13725.
Integration
A lightweight mounting plate (180 g) was designed to easily install the electronic nose and the odour sampler in the M600 drone without affecting its center of mass.
Sampling system
Using a vacuum pump and a 10-m PTFE tube, the gas sample is delivered to the electronic nose and the odour sampler without being affected by the downwash from the drone propellers.
Graphical user interface
Allows the operator to visualize the sensor signals and the wind data in real-time, log the measurements into a file, and generate a 2D odour concentration map.
Status of the project
At the end of Phase 1 of the project (July 2020), the SNIFFDRONE prototype was tested and validated in a relevant industrial environment (mid-sized WWTP in Spain), so its development status at the end of this phase is close to TRL 5. We have filed a European patent (EP21382389.1) and are in negotiations with companies interested in commercializing the technology. We have also applied for funding to ATTRACT Phase 2 to scale up the technology to a pre-industrial product achieving TRL 8 (system complete and qualified). Our goals for Phase II include (i) improvements in the electronic nose to make it robust against temperature and humidity, (ii) validating the technology in at least four WWTPs and other industrial areas such as composting plants, landfills, and agriculture application of sludge, and (iii) establish general procedures and user manuals for a proper operation of the device by a technician with an appropriate training, including the definition of troubleshooting procedures.