Distributed sensor network systems are swarms of small flying sensors that can measure how temperature, pressure, etc. vary over time and space within the volume spanned by the swarm. How the swarm is transported by the wind, and the position of the different sensors within the swarm, also provide information on the flow velocity, gusts, etc. When equipped with cameras, sensors of electromagnetic fields, etc., they can observe and recognise targets on land and sea. The largest sensors (e.g. 10 cm) have some level of autonomy like small drones, whilst the smallest sensors (e.g. 1 mm) are dropped from altitude and gather information while falling. In both cases, the ability to remain airborne for a long period of time is critical to collect more data and avoid the need to be redeployed from altitude. The aim of this proposal is to discover how wind gust energy can be exploited to keep these sensors afloat.
The strength of these passively flying sensors is their ability to provide low-cost sensor coverage and reporting. Their delivery mechanism is part of its sensing capability, providing insights into the environment that cannot be detected by conventional sensors due to their carriage on conventional large-scale platforms. The ability to monitor in real time the environment within kilometres around us is opening up tremendous opportunities. Flying sensors are routinely used to monitor environmental conditions (wind, temperature, etc.) and air quality (pollutants, airborne virus, radiation, etc.), but also air traffic near airports, the movements of bird flocks near wind turbines, animal migrations, the patrol of remote areas (poaching control, sea patrol, etc.), to monitor ground vehicles and redirect traffics in case of congestions, etc. These sensors will contribute to addressing the fast-growing need for real-time information, which is set to dramatically increase in this new decade driven by the Internet of Things (IoT) and its inherent need for monitoring, measuring, inferring and understanding environmental indicators.
The main aim of this project is to unveil a wind gust energy scavenging mechanism that will enable small flyers (1-mm to 10-cm scale) to remain airborne for as long as the wind blows, enabling a step increase in the endurance of distributed sensor network systems. This aim is completely novel, high risk and high gain, and will address a critical industrial need with new fundamental science.
The second aim of this project is to develop a steering system for the proposed sensor platform. This aim has moderate risks because, while a high level of control is challenging to achieve, the spatial distribution of the swarm can be significantly modified by enabling only a small fraction of the mean wind velocity.
The third aim is to demonstrate the fluid mechanics findings of the previous two aims by physical testing of a prototype. This demonstration will underpin the development of a new class of sensing network systems translating into impact the fundamental fluid mechanics research undertaken in this project.
