|Paper title||SunRazor: a solar powered electric USV/UAV hybrid unit to assess the Sea Spray Aerosol environment|
|Form of presentation||Poster|
SunRazor is an integrated drone platform composed by a master unit (acquatic drone) and a slave unit (a quadcopter UAV). The focus of the drone project was to create an advanced platform with zero environmental impact, capable of merging the state of the art of the enabling technologies within a single system with next-generation operational capabilities. SunRazor was born from a vision focused on the application of the most advanced technologies existing today in the sectors of aerospace and nautical design, sensors, electronics and machine learning applied to the problems of environmental monitoring and safety.
Starting from the knowledge that the surface of the ocean, the atmosphere and the clouds form an interconnected dynamic system through the release and deposition of chemical species within the nano-particles, a phenomenon that relates these three environments to each other, which is called sea spray aerosol (SSA). In fact, at the interface between the sea surface and the air nano-particles are formed containing biogenic and geogenic compounds with concentration distributions along thermocline lines. So, from the ocean to the clouds, dynamic biological processes control the composition of seawater, which in turn controls the primary composition of SSA. The fundamental chemical properties of primary SSA regulate its ability to interact with solar radiation directly and indirectly (through the formation of cloud condensation nuclei (CCN) and ice nucleated particles (INP) and undergo secondary chemical transformations.
The SunRazor platform is able, thanks to the computing power installed on board and the powerful short and medium range communications infrastructure it is equipped with, to perform sampling and surveys not only in aquatic scenarios, but also in mixed air/water scenarios. In this configuration, the aquatic unit of the platform (master) operates in synergy with a second air unit (slave), a highly specialized multicopter tethered to the master unit, which becomes an integral part of the drone (see the figure).
During the development of a mission plan, the aquatic platform will be able to activate, following a predefined ruleset or in response to the detection of specific events, the air unit which can operate simultaneously and independently of the aquatic unit. However, in this mixed configuration, the air unit will also benefit from the computational and medium-range protected communication capabilities of the aquatic unit, which will constitute for it a real mobile command and control station. Thanks to this local topology, the two units can be focused on highly specialized operational tasks, minimizing the presence of duplicate and redundant components. The air unit can be equipped with a payload of sensors independent from those of the aquatic unit in order to monitor different aspects of the operating scenario within which the SunRazor platform operates.
The marine unit, i.e. the master, is equipped with a propulsion system based exclusively on renewable energy (solar energy and hydrogen cells), capable of operating in autonomous, semi-autonomous and supervised mode to perform monitoring missions, and environmental control for long periods of time (over 30 days of operational autonomy). In this way SunRazor is capable of carrying out sampling of the SSA in continuous mode and with a level of positional precision in the order of a few centimeters compared to the set mission target, making use of set of state-of-the-art proprietary sensors, through which it is possible to detect, simultaneously and in real time, a high number of critical quantities for the purposes of assessing the quality of the water and the environment at different heights between the sea surface and the air column to about 50m, thanks to the UAV component of the platform (the slave/multicopter). The main features of the drone are illustrated below.
1) A zero emission propulsion system since the SunRazor is able to carry out long-term detection missions, up to 30 days, using exclusively energy deriving from renewable sources that cause zero environmental impact. In fact, the marine unit is equipped with an all-electric power system that is powered by solar energy, thanks to the use of a large surface area of high-performance photovoltaic panels that entirely cover the upper part of the hull. The propulsion system consists of a highly innovative electric motor capable of delivering peak speeds of over 30 knots and cruising speeds of 6 knots. The photovoltaic panels are integrated by a secondary power system based on safe and modular hydrogen cells, which can be used to integrate the output of the photovoltaic panels in situations of limited production or particularly high power requirements (high-speed travel). The two power sources present on board of the master unit are constantly monitored by an advanced battery management infrastructure supported by forecast models based on machine learning techniques. The battery management module is also able to make accurate predictions relating to the residual operating autonomy of the platform by making use of forecasting systems based on recent chemical-physical models capable of representing the state of the battery system in an extremely precise manner.
2) A redundant telecommunications system thanks to which SunRazor is able to exchange information and command flows with ground stations. The system makes use of high bandwidth and low consumption radio modules that can be used in aggregate mode or individually in the event of malfunctions, in order to ensure high levels of redundancy in all operational scenarios, including the most critical ones. All communications are protected by state-of-the-art AHEAD-class cryptographic algorithms that combine military-grade security guarantees with high performance in the validation and decoding phases of the transmitted data.
3) An extremely advanced on-board ICT infrastructure, which effectively makes it a miniaturized mobile data center. The heart of SunRazor is in fact constituted by a parallel calculation system with reduced consumption which represents the central infrastructure for the collection of data coming from on-board sensors, for the communications management, mission planning and information processing. The architecture implemented makes pervasive use of virtualization techniques to ensure maximum safety of the operating environment and a high degree of redundancy in the event of malfunctions of one or more computing nodes of the system. The processing core of the drone is the infrastructure within which the forecast models and classifiers used to implement the autonomous analysis capabilities of SunRazor are run. The computational core of the drone makes use of specialized boards to ensure the real-time execution of all the expected artificial intelligence and control tasks, while constantly maintaining extremely low consumption levels. In addition, the modular design adopted allows to dynamically activate and deactivate portions of the architecture to constantly ensure the lowest possible level of consumption according to the operational tasks actually performed.
4) A wide range of sensors that allow SunRazor to acquire detailed information on the surrounding environment in continuous mode and to carry out the assigned monitoring tasks. The information thus acquired is stored in the on-board ICT system, processed, filtered, analyzed and automatically transmitted to the ground stations whenever it is possible to establish a radio/satellite data connection. The drone platform (acquatic/aerial) is capable of using a variable payload of highly innovative sensors, through which it is possible to detect various chemical-physical variables inherent to the state of the SSA.The SunRazor’s mission planning system allows the scheduling of sampling events according to independent timelines that can affect a different number of variables. Furthermore, the drone can be programmed at any time to make immediate changes to pre-existing sampling missions, in order to perform urgent monitoring in specific areas of the monitored areas. The control system will automatically perform merge operations that converge the drone's operations towards the standard scheduling, once the management of high priority critical issues is finished.
SunRazor, in addition to being a device with a particular vocation for the acquisition of chemical-physical information on the composition of SSA, will also be able to detect information on the presence of biogenic biomolecular structure of numerous cyclic peptides, synthesized by marine organisms, which are increasingly proving to have anticancer activities*. One of the operational possibilities that we intend to put in place is also that of monitoring the risk of pollutants of a fossil nature in a highly sensitive ecosystem, so much that it is considered an indicator of the well-being of the planet, which is the Beagle Channel in Tierra del Fuego in Argentina.
*Sergey A. Dyshlovoy (2021), Recent Updates on Marine Cancer-Preventive Compounds. Marine Drugs, 19, 558. https://doi.org/10.3390/md19100558