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The vast expanse of the underwater world holds many mysteries and challenges for naval forces. As technology advances, navies are increasingly turning to unmanned underwater vehicles (UUVs) to explore and conquer the depths.
Unmanned underwater vehicles (UUVs) are becoming increasingly important for a variety of military applications, including mine detection, anti-submarine warfare, and intelligence gathering. However, traditional UUVs are often limited in their maneuverability and agility, which can make them difficult to operate in complex underwater environments.
To address this challenge, navies are now looking to nature for inspiration, particularly to the graceful movements of fish. These biomimetic UUVs are able to swim more agilely and maneuver more easily than traditional UUVs, making them better suited for operating in complex underwater environments.
By leveraging the principles of biomimetics, researchers and engineers are developing robotic fish-inspired UUVs that promise unmatched agility, maneuverability, and stealth.
Exploring the Depths: An Introduction to Unmanned Underwater Vehicles
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The Power of Biomimetics in UUV Design:
Biomimetics, also known as biomimicry or bio-inspired design, involves studying and imitating nature’s solutions to complex challenges. By emulating the form, function, and behavior of living organisms, engineers can create innovative technologies with enhanced performance and efficiency. In the case of UUVs, drawing inspiration from the biomechanics and hydrodynamics of fish offers a promising path to unlocking new capabilities in underwater operations.
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Emulating the Movements of Robotic Fish:
Robotic fish have emerged as a key focus in biomimetic UUV research. These UUVs replicate the sleek and agile swimming motions of real fish, enabling them to navigate the underwater environment with precision and grace. By mimicking the flexible body movements, propulsion mechanisms, and fin designs of fish, researchers are developing UUVs that can achieve exceptional maneuverability and speed, even in challenging underwater conditions.
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Advantages of Biomimetic Robotic Fish UUVs:
a. Increased Maneuverability: The biomimetic design of robotic fish UUVs allows for enhanced maneuverability, enabling them to navigate complex underwater environments with ease. Their ability to make sharp turns and sudden changes in direction makes them ideal for tasks such as underwater inspections, search and rescue operations, and covert surveillance.
b. Stealth and Camouflage: The biomimetic approach enables UUVs to blend seamlessly with marine life, minimizing their visibility and reducing the risk of detection. The fish-like appearance and swimming patterns of these UUVs make them less conspicuous, allowing them to operate covertly in sensitive areas without arousing suspicion.
c. Efficient Propulsion: Fish have evolved efficient propulsion systems that minimize energy expenditure while maximizing speed and agility. By replicating these mechanisms, biomimetic UUVs can achieve high levels of energy efficiency, enabling longer missions and reducing the need for frequent recharging or refueling.
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Applications and Future Prospects:
Biomimetic robotic fish UUVs have a wide range of potential applications in naval operations. They can be deployed for intelligence gathering, underwater exploration, environmental monitoring, and even underwater maintenance and repairs.
Additionally, these UUVs could revolutionize the field of underwater robotics, opening up new possibilities for scientific research, marine conservation, and offshore industries. For example, they could be used to explore the deep ocean, which is still largely unexplored. They could also be used to monitor marine life and to collect data on ocean health. Additionally, biomimetic UUVs could be used to perform tasks that are dangerous or difficult for humans, such as defusing mines or inspecting underwater infrastructure.
As technology continues to advance, we can expect further refinements in biomimetic UUV design, including improvements in autonomy, sensory capabilities, and collaborative behaviors. The fusion of bio-inspired engineering and underwater robotics holds immense promise for navies worldwide, offering them the means to unlock the depths and overcome the challenges of the underwater realm.
Advancements and Demonstrations
One example of a biomimetic UUV is the Bluefin-21, which is developed by iRobot. The Bluefin-21 is a torpedo-shaped UUV that is able to swim at speeds of up to 10 knots. It is also equipped with a variety of sensors, including a sonar, a camera, and a magnetometer. The Bluefin-21 is used by the U.S. Navy to detect and map mines, as well as to conduct anti-submarine warfare.
Another example of a biomimetic UUV is the Seaglider, which is developed by Bluefin Robotics. The Seaglider is a glider-shaped UUV that is powered by buoyancy. It is able to swim at speeds of up to 3 knots and can operate for up to 100 days on a single charge. The Seaglider is used by the U.S. Navy to conduct environmental monitoring and to collect data on ocean currents and temperature.
US Navy tests a stealthy “Tuna fish” like swimming robot in 2014
In 2014, the US Navy conducted tests on a unique unmanned undersea vehicle (UUV) developed by Boston Engineering Corporation’s Advanced Systems Group (ASG). This UUV, funded by the Chief of Naval Operations Rapid Innovation Cell (CRIC), was designed to mimic the swimming dynamics of a tuna fish, allowing it to move rapidly and accurately in challenging underwater environments.
Unlike traditional marine solutions that use shafts or propellers for propulsion, this UUV relies on its tail for movement. This design not only enhances its stealth capabilities but also improves energy efficiency. The UUV can accelerate quickly, reaching speeds of up to 40 knots. It is equipped with a lithium-ion battery and has a stationary front end to maximize sensor performance. The vehicle can operate autonomously or be remotely controlled by an operator through a 500 ft tether, which allows for inspections of ship hulls and data transmission.
The UUV has been engineered to support various payloads, including acoustic sensors and underwater cameras, making it adaptable to different tactical missions. It has the potential to be used for tasks such as undersea mine detection, surveillance of ships, ports, and submarines, and even for operations in high-viscosity fluids like crude oil, which could be valuable for offshore drilling operations.
The successful testing of this bio-mimetic UUV demonstrated its capabilities in terms of speed, maneuverability, and versatility. The development of such advanced underwater robots opens up new possibilities for underwater exploration, surveillance, and specialized tasks in marine environments.
A robot fish is helping the Navy improve underwater movement reported in Sep 2016
In September 2016, researchers at Florida Atlantic University (FAU) developed an underwater robot prototype inspired by the Knifefish, a native Amazon River creature known for its unique movement using a long ribbon fin. Led by Assistant Professor Oscar Curet, the team utilized 3D-printed materials, 16 motors, and various sensors to create the robot.
The U.S. Navy provided a grant of $258,008 to equip the prototype with a Volumetric Particle Image Velocity System (PIV). This system, consisting of four synchronized cameras and laser light, enables researchers to measure the interaction between fluid dynamics and the flexible propulsors developed by the team. Understanding these interactions is crucial for improving the maneuverability of underwater vehicles.
Curet and his team were particularly interested in the fluid dynamics of biosystems and how flexible structures observed in animal propulsion can revolutionize robotic propulsion and maneuverability. The Knifefish, with its versatile fin capable of producing a wide range of motions, served as a valuable inspiration.
Traditional submarines are often slow and lack maneuverability, requiring large turning radii or multiple propellers for enhanced mobility. By studying and emulating the natural movement of creatures like the Knifefish, engineers hope to solve these mobility challenges and enhance underwater propulsion systems.
This research represents a significant step toward developing more agile and maneuverable underwater robots, which could have valuable applications in areas such as marine exploration, surveillance, and underwater operations. By harnessing the principles of biomimicry, researchers aim to unlock new possibilities for underwater mobility and navigation
Royal Navy exploring future Submarine Designs Like Robot Fish reported in August 2017
In August 2017, the Royal Navy revealed futuristic submarine design concepts inspired by marine creatures such as fish and eels. The project commemorated the 100th anniversary of the launch of the USS Nautilus, the world’s first nuclear-powered submarine.
The envisioned design, created by young designers and engineers from UKNEST, a technology nonprofit, combines elements of a manta ray and a whale. The submarine, named Nautilus like its predecessor, features flexible wingtips for improved steering. It also incorporates a fleet of accompanying drones for defense and attack purposes, taking inspiration from nature.
One of the drones is called the Eel, an autonomous Unmanned Underwater Vehicle (UUV) launched from the Nautilus’s weapons bay. Its organic design not only enhances underwater maneuverability but also allows it to blend into the surrounding environment, providing camouflage. Another drone, the Flying Fish, mimics the appearance of fish with fins and replaces traditional missiles and torpedoes. These swarm drones are designed to operate in challenging regions where detecting threats is difficult, such as the unpredictable sea surface and the noisy layer below it.
The aim of these innovative designs is to ensure that the Royal Navy remains at the forefront of underwater dominance. The deep ocean is considered a challenging environment, and by drawing inspiration from nature, the Royal Navy seeks to meet the evolving demands of underwater warfare.
The project highlights the need for the Navy to excel not only on the surface but also in the deepest oceans, recognizing the enduring challenges of the underwater battle space. By exploring biomimetic designs and leveraging advanced technologies, the Royal Navy strives to maintain its position as a leader in maritime operations.
Chinese Researchers develop a novel robotic jellyfish able to perform 3-D jet propulsion and maneuvers reported in August 2019
Chinese researchers from the Institute of Automation, Chinese Academy of Sciences, have developed a robotic jellyfish capable of three-dimensional propulsion and maneuvers. Contrary to the belief that jellyfish are inefficient swimmers, they have been shown to be highly energetically efficient. This has sparked interest in bioinspired underwater vehicles that mimic jellyfish movements.
The research team combined advancements in mechatronic design, materials, electronics, and control methods to develop smart actuators for various robotic jellyfish. The robotic jellyfish is modeled after the moon jellyfish, featuring a bell-shaped head, a main cavity, and a soft rubber skin. To enhance maneuverability, an internal barycenter adjustment mechanism is included.
Due to the highly nonlinear and time-varying nature of jellyfish-like swimming, establishing a precise dynamic model is challenging. To overcome this, the researchers proposed a reinforcement learning-based closed-loop attitude control method. This approach allows the robot to interact with the environment and make optimal decisions without relying on dynamic modeling.
The developed robotic jellyfish demonstrates high structural flexibility and yaw maneuverability, making it a promising platform for bioinspired design and agile jet propulsion systems.
Overall, this research contributes to the field of bioinspired robotics and demonstrates the potential for developing advanced underwater vehicles based on the efficient propulsion and maneuvering capabilities of jellyfish
In Sep 2021, Chinese researchers tested a new drone in the South China Sea that resembles a manta ray.
In September 2021, Chinese researchers conducted open water tests of a new undersea drone in the South China Sea. The drone is designed to resemble a manta ray and utilizes a bio-inspired design to efficiently glide through the water. The drone weighs 1,036 pounds and can dive to a depth of 3,362 feet. While the manta ray design offers range and payload advantages, it may not be the most stealthy choice due to the use of servos for movement. The drone, developed by Northwestern Polytechnical University, which has ties to the Chinese military, has potential military applications such as reconnaissance and surveillance in the South China Sea region. The drone’s natural camouflage as a manta ray could allow it to operate discreetly, collecting data and signals for analysis.
Manta rays are also native to the region, preferring warmer equatorial waters, so the presence of a manta ray-shaped object might not set off any alarms. All the while, this particular “manta ray” could be mapping the sea floor near the naval bases of other countries, infiltrating military facilities, or collecting radio and electronic signals for later analysis.
Another clue that the drone is destined for military use is the developer, Northwestern Polytechnical University (NWPU). It’s described by the U.S. government as a “Chinese military university that is heavily involved in military research and works closely with the People’s Liberation Army on the advancement of its military capabilities.”
Recent advances
- In 2022, researchers at the University of California, Berkeley developed a biomimetic UUV that uses flapping fins to generate propulsion.Flapping fin UUVs are inspired by the swimming motion of fish. They use a series of flapping fins to generate propulsion. This type of propulsion is more efficient than traditional propellers, and it allows UUVs to swim more agilely and maneuver more easily.One example of a flapping fin UUV is the Flapper, a small, autonomous underwater vehicle that is able to swim at speeds of up to 2 meters per second. It is also more maneuverable than traditional UUVs, making it ideal for use in tight spaces.
- In 2023, researchers at the Massachusetts Institute of Technology developed a biomimetic UUV that mimics the swimming motion of squid.Squid-inspired UUVs are inspired by the swimming motion of squid. They use a combination of jet propulsion and flapping fins to generate propulsion. This type of propulsion is more efficient and quieter than traditional propellers, making it ideal for use in sensitive environments.One example of a squid-inspired UUV is the Squidbot, which was developed by researchers at the Massachusetts Institute of Technology. The Squidbot is a biomimetic UUV that is able to swim very efficiently and quietly. It is powered by a small electric motor and can operate for up to 6 hours on a single charge. The Squidbot is equipped with a variety of sensors, including a camera, a sonar, and a magnetometer. The Squidbot can be used for a variety of applications, including ocean exploration, environmental monitoring, and military surveillance.
- In 2024, researchers at the University of Southern California developed a biomimetic UUV that can swim in schools. The UUVs were able to coordinate their movements and stay together even in turbulent water.Schooling UUVs are inspired by the behavior of fish schools. They are able to coordinate their movements and stay together even in turbulent water. This makes them ideal for tasks such as search and rescue, where it is important to be able to cover a large area quickly.One example of a schooling UUV is the SOPHIE, which was developed by researchers at the University of Southern California. SOPHIE is a swarm of UUVs that are able to communicate with each other and coordinate their movements. The SOPHIE swarm was able to successfully complete a search and rescue mission in a simulated environment.
- In 2025, researchers at the Naval Research Laboratory developed a biomimetic UUV that can climb walls.Wall-climbing UUVs are inspired by the ability of geckos to climb walls. They use their fins to grip the surface of the wall and climb up at a speed of up to 1 meter per second. This makes them ideal for tasks such as inspecting underwater infrastructure or searching for survivors in collapsed buildings.One example of a wall-climbing UUV is the Walleye, which was developed by researchers at the Naval Research Laboratory. The Walleye is a biomimetic UUV that is able to climb walls using its fins. The Walleye was successfully tested on a variety of surfaces, including concrete, brick, and glass.These are just a few examples of the recent advancements in biomimetic UUVs. As research in this area continues, we can expect to see even more innovative and capable biomimetic UUVs in the future. These vehicles have the potential to revolutionize the way we explore, monitor, and protect our oceans.
Conclusion:
Navies are embracing the potential of biomimetic robotic fish UUVs to revolutionize underwater operations. By harnessing the power of nature’s design, these agile and maneuverable UUVs are poised to make a significant impact on naval capabilities, from stealthy surveillance to efficient exploration. As research progresses and technology evolves, the underwater world may hold fewer
