Latest submarine: Japan’s fully unmanned large UUV

Latest submarine: Japan’s fully unmanned large UUV

・Large UUV remote operation at Iwakuni satellite

・UUV autonomy, long-term and long-distance operational tests

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Development of large UUV:

I took a look at the development base for “promising new equipment” being developed by the Defense Equipment Agency.

Underwater is attracting attention as a new stage for utilizing drones.

The development of large UUVs with long cruising ranges and operational periods is progressing in various countries.

American “Orca”,

France’s “OUDD”,

Such as South Korea’s “ASWUUV”.

Japan, which is surrounded by ocean on all sides, is no exception to this movement.

Defense Equipment Agency: Naval Equipment Research Institute

We are proceeding with the development of a large UUV, which is a long-term operation type UUV.

Ship name Long-term operational UUV

Ship type AUV

Shipowners Defense Equipment Agency Ship Equipment Research Institute

Design company Mitsubishi Heavy Industries, Ltd.

Construction company: Mitsubishi Heavy Industries, Ltd.

Completion date: December 20, 2022

Lpp × B × D – d10.1m × 1.8m × 1.8m

Gross tonnage 17.5 tons

Speed cruising 3-4 knots

Main engine electric motor (4 machines) No cargo loaded

Distinctive equipment: Forward sonar, all-around sonar

Iwakuni Marine Environment: Test Evaluation Satellite

We visited the Iwakuni Marine Environmental Testing and Evaluation Satellite, which conducts testing and evaluation of large UUVs.

In addition to covering the actual machine, we also confirmed the challenges of large-scale UUV development.

Modular structure of long-term UUV:

Long-term operational UUVs will have a modular structure.

Combine functional modules to build the entire UUV.

1. Main body module

The basic form is the “main body module”, the “head module” which contains the sensors necessary for navigation,

2. energy module

“Energy module” loaded with lithium-ion batteries,

3. tail module

It consists of three parts: the tail module, which includes the thrusters and rudder.

4. additional module

Depending on the application, different additional modules can be combined for each function.

If you add additional modules, it will grow to be nearly 16 meters long.

Underwater equipment installation module:

The existence of an underwater equipment installation module has already been revealed.

The purpose of this is to install monitoring sensors and underwater communication nodes.

Transport a certain amount of heavy objects and set up a crisis underwater.

 

Underwater communication means:

Unlike in the air, radio waves cannot be transmitted underwater.

There are also communication methods such as sound waves and light. However, it is limited to relatively short distances.

It is important for large UUVs to be able to be remotely operated from a long distance.

Remote operation of large UUVs:

Is it easy to make it do what you command it to do?

You need to follow the underwater route correctly, avoid dangerous objects on the ocean floor, and find your way.

Get your location right:

1. Figuring out your position underwater and heading in the right direction is not easy.

2. Due to the lack of radio waves, GPS cannot be used, and the island is constantly affected by changing ocean currents.

Self-location estimation of long-term operational UUV:

Long-term operational UUVs estimate their position using the following method.

3. Uses equipment that uses sound waves to measure relative speed to the ocean floor

4. It is also estimated by combining an inertial navigation device.

5. Observe your surroundings in the dark underwater using sound waves.

6. It is also necessary to recognize obstacles and make decisions to avoid them.

Iwakuni Marine Environment: Test Evaluation Satellite

The facility that tests UUV autonomous control is the Iwakuni Marine Environmental Test and Evaluation Satellite.

Underwater acoustic measurement device:

– A huge aquarium called an underwater acoustic measuring device

1. Accurately reproduces the underwater acoustic environment.

2. Simulate the same situation as under the sea.

This device allows long-term operational UUVs to make the right decisions.

HILS (Hardware In The Loop Simulation)

-Simulation device called HILS

A UUV “brain test” is being conducted in Iwakuni.

1. Reproduce the UUV model in virtual space.

2. Evaluate your ability to make decisions in the marine environment (bottom topography, water temperature, water current, etc.).

Japan’s long-term operational UUV:

Currently, 7 days of continuous operation is currently possible.

The 7 days are just a research milestone. We aim to operate it for a long time in the future.

U.S. Navy large UUV “Orca”:

Energy is an issue with large UUVs.

The US Navy’s large UUV “Orca” can operate for two months.

This is because the Orca is equipped with a diesel-electric engine.

Japan’s long-term operational UUV:

Japan’s long-term operational UUVs will be equipped with LIBs.

With current technology, fossil fuels have a higher energy density (amount of energy per volume) than LIB.

UUV covert operations:

The U.S. Navy’s Orca has a diesel engine and must float for air intake and exhaust.

This is a major disadvantage for UUVs that require covert operations.

Adoption of fuel cells and API institutions

In Japan, we are currently researching high-performance power sources such as fuel cells and API engines.

Large UUVs capable of long-term operation are essential defense equipment for the island nation of Japan.

https://news.yahoo.co.jp/articles/a4315b3432c4e1f03104a2024d001231f3f8cdc9