The Dagon AUV: Marine ecological monitoring

What it does

The Dagon combines autonomous underwater vehicle mobility and long-term marine buoy monitoring ability for mobile and energy-efficient ecological monitoring near oil transportation hubs. Any module for the Dagon can be changed on the fly.

Your inspiration

“Oil spill nears Corsica coast” - this and many other article titles become increasingly common in news feeds. Still, oil products provide over 90% of energy in almost all countries, and oil spills during its transportation and storage are, unfortunately, quite common. Due to their thick, sticky nature, such oil spills are incredibly harmful to plants and animals. It’s essential to detect spills timely and precisely. The faster they can be found, the easier it is to localize and clean up. We want to create an automatic robotic system for finding spills on-site near oil transportation hubs as the most probable areas of environmental pollution.

How it works

The Dagon AUV consists of four different replaceable modules: an autopilot module (motion control and propulsion system that consists of two rotatable thrusters), a connection module (GPS, Radio modem, and hydroacoustic modem), a payload module (a compact mass spectrometer in this case) and a landing module that consists of an anchor and a variable buoyancy system. The Dagon AUV global mission is the set of points of interest (POIs) around an oil transportation hub. The vehicle uses a propulsion system for periodically moving between POIs. At each point, the vehicle blows down the variable buoyancy system and anchors on the sea ground. This power-effective mode enables the vehicle for long-term oil spill monitoring at the point. In case of pollution concentration increased, the vehicle raises the anchor and moves along the concentration gradient. The AUV surfaces at the point of the pollution source and publishes the GPS coordinates of a potential disaster.

Design process

The initial idea was born three years ago on a conference discussion about the ecological application of AUV with a variable buoyancy system. We talked with David Fries, a scientist and entrepreneur from the USA, and he proposed using his compact mass spectrometer for on-site water sample collection and chemical analysis. For that, one would need an entirely new type of AUV, so we decided to make it from scratch. One year later, the Small Innovative Enterprises fund sponsored us to model and to prototype separate parts of the future vehicle. We decided to make the payload a detachable module for the vehicle during re-iterations of the design. We had an aim in mind to be able to attach different payload modules easily in the future. However, one day we suddenly realized that why not make each vehicle part as a separate, easily detachable module? This was a day when we decided to go with a fully modular AUV design. Currently, we have made all theoretical principles of innovative fast attaching modular design that allows us to assemble and reassemble a vehicle from modules without any electrical connections. Many vehicle parts were redrawn from scratch to adapt to the new design paradigm. Now this work is almost done.

How it is different

Our vehicle combines ordinary underwater vehicle maneuverability and speed with the long-term monitoring ability of marine buoys. We took the best from these underwater robotic systems. The second significant advantage is the modular vehicle design that we developed during the project. The modules within this approach connect completely wireless. Charging and inter-modular power balancing are provided by an inductive power transfer system. The Bluetooth provides wireless low-range data exchange between modules. As a result, any new payload module can be installed even onsite (in the sea). In addition, any part of the vehicle can be redesigned independently and installed instead of the old one in a few minutes. We are currently working on different types of propulsion systems and different types of payload systems, including water samplers, 360-cameras, and side profiles.

Future plans

We want to bring the vehicle that we devised in life. We are working for two years, and there is much more ahead before the first submerging. This year, we want to achieve 86% efficiency (that we obtained within the simulation) of the inductive power transfer system on real experient. Furthermore, we will develop a mesh network between all vehicle modules to make a reliable wireless peer-to-peer connection. Next year will be dedicated to assembling the vehicle and testing a compact mass spectrometer that Spyglass technologies company is ready to provide for testing purposes.

Awards

The project was chosen for Student Poster Competition at the international conference “Oceans 2021 Gulf Coast” (our article was titled “The Modular Approach for Underwater Vehicle Design”). The project was funded by the Small Innovative Enterprises fund (FASIE, Russia) 2019.