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Case Studies

Underwater drone Hydrus completes successful simulation to identify hazards in tropical waters

By Last edited June 3rd, 2024No Comments
Case Study | AIMS ReefWorks

Key Points

  • Advanced Navigation’s micro-AUV Hydrus successfully simulated its capability to autonomously scan a seabed to detect objects of interest.
  • The exercise showcased how Hydrus can achieve better outcomes than traditional methods while significantly lowering costs, logistics and human risk.
  • Highlighting one of Hydrus’ unique differentiators, it operated effectively in tropical waters, which present a host of challenges to underwater robotics. 
  • The exercise doubled as an opportunity to train Hydrus’ artificial intelligence model to enable high-accuracy localisation and inspection.
  • The simulation was carried out in collaboration with the Australian Institute of Marine Science (AIMS), utilising their tropical marine test range, ReefWorks.
ReefWorks Logo

AIMS is a tropical marine research agency with world class facilities around Australia. Established in 1972, the institute’s primary function is research for sustainable use and protection of the marine environment. It has highly developed capabilities in marine biodiversity; impacts and adaptation to climate change; and, water quality and ecosystem health. As a trusted name in marine science, AIMS’ research programs support the management of tropical marine environments around the world. 

Making a splash: An opportunity to showcase Hydrus’ capability at ReefWorks

Advanced Navigation collaborated with AIMS to conduct a simulation at the institute’s tropical marine test range, known as ReefWorks, located near Townsville, a city on the north eastern coast of Australia within proximity to the Great Barrier Reef. The test range, which opened its doors to industry in 2022, is one of the first marine technology test ranges in the world located in tropical waters.

For the exercise, Advanced Navigation’s underwater drone, or micro-autonomous underwater vehicle (micro-AUV), Hydrus, was tasked with autonomously mapping a predefined area of the seabed in search of specific points of interest—which, in this scenario, were hidden objects intended to represent underwater mines. 

Wading through troubled waters: Hydrus must prove itself in a minefield of hazards

Launching Underwater Drone Hydrus in the water

Numerous challenges accompany a scenario of this nature:

  • To begin, exercises of this kind typically entail significant costs and logistical complexities. Enlisting boats and highly trained specialists is not only expensive but also time-consuming. Moreover, deploying and recovering traditional AUVs necessitates the use of large equipment, such as cranes, which consumes valuable time that could otherwise be devoted to data collection.
  • Secondly, the operation required Hydrus to function in tropical waters, which are notoriously difficult for autonomous marine systems. Foremost, higher temperatures in tropical waters have the potential to cause robotic systems to overheat. Additionally, complex water flow and bottom topography in these regions can result in higher turbidity, causing water to become clouded with suspended sediment, reducing visibility and potentially causing thrusters to clog and seize operation.
  • Lastly, the simulation centered around a scenario where ensuring the safety of personnel was paramount. It focused on a situation in which a customer would deploy a drone to detect potential hazards, such as underwater mines, before advancing their vessel. Furthermore, the exercise introduced an element of unpredictability, as Hydrus had no prior knowledge of the placement of mine-like objects. This mirrored a real-world search in a hazardous and unfamiliar environment.

Turning the tide: Hydrus is well equipped to navigate these common challenges

Fortunately, Hydrus was purpose-built to address these very concerns. Thanks to its compact size and autonomous capabilities, the mission could be executed with cost-efficiency and minimal logistical complexities. To illustrate this, all of the necessary equipment for this exercise could be conveniently transported in just three transit cases, each weighing less than 21 kg. Hydrus itself, weighing a mere 7 kg, can be deployed and recovered by a single individual. This obviates the need for heavy transportation, on-site storage, large vessels, cranes, or a team of specialists.

Handling Hydrus during Micro-AUV mission

What truly distinguishes Hydrus is its ability to operate effectively within the challenging tropical waters environment, setting it apart from comparable products in the market. Being developed in Australia provided a local advantage, as Hydrus underwent extensive testing in warm tropical waters during its design phase. Additionally, its thrusters were thoughtfully designed with the challenges of suspended sediment in mind. The drone’s impellers offer a higher level of control authority than any comparable product on the market, rendering them resilient to suspended sediment and complex water flow.

Regarding safety, this simulation presented an opportunity for the Advanced Navigation team to showcase a unique solution aimed at minimising risk to personnel. Typically, USBL and GNSS systems are affixed to crewed boats. However, in this exercise, Advanced Navigation’s Subsonus and GNSS Compass were integrated onto Surfbee, an autonomous uncrewed surface vessel (USV). Leveraging the autonomous capabilities of Surfbee, this setup allowed the crew to maintain a safer distance from the scouting area.


Smooth sailing: The simulation was a resounding success

The end-to-end operation, from deploying to recovering Hydrus, took less than 30 minutes. Hydrus performed flawlessly right out of the box, requiring minimal mobilisation time and experiencing no delays. Coupled with the use of a small vessel, this efficiency allowed the team to swiftly gather the necessary data to complete the mission. In fact, due to the rapid turnaround time, the team ran the simulation two more times with each operation completed in under 30 minutes. 

Notably, by repeating the simulation, the team observed that the mine-like objects had shifted positions on the seabed between each operation. This not only highlights the complex currents in tropical waters but also underscores the potential safety risks had the operation been conducted only once, as typically expected with traditional systems.

Underwater Drone Hydrus set up by Advanced Navigation

To locate the objects, Hydrus autonomously followed a predefined search pattern within a set perimeter in the water, in a path akin to mowing a lawn. While executing the search pattern, Hydrus’ camera successfully identified points of interest and captured high-accuracy imagery of the target objects.

As is customary with all simulations involving Hydrus, the data collected during this exercise will be used to train Hydrus’ AI model, enhancing its capability to pinpoint and inspect points of interest on the seabed with even greater precision and detail. Conducting more simulations will continue to enrich Hydrus’ onboard AI, improving its overall capabilities.

The successful completion of this simulation at ReefWorks validates Hydrus’ ability to provide a data collection solution that not only minimises logistical effort but also allows for rapid deployment compared to other systems. Moreover, it does not require trained specialists, keeping the overall costs minimal. This enables users to deploy Hydrus quickly, safely and cost-effectively wherever it is needed.

AIMS, ReefWorks and Advanced Navigation together for Hydrus Underwater Drone mission

Hydrus takes the drone revolution underwater with the most
advanced sonar, navigation and communications systems of any
subsea vehicle. It contains a DVL, USBL, INS, acoustic and optical
modems, all tightly integrated. This enables highly reliable, fully
autonomous underwater missions at your fingertips. It also provides
obstacle detection and collision avoidance.