China’s self-developed AUV shows impressive capabilities in latest Arctic scientific expedition

As China’s polar icebreaker and scientific research vessel Xuelong 2 returned to the home port in Shanghai in late September after traveling 14,000 nautical miles for 79 days, the country’s 12th Arctic scientific expedition was successfully completed, in which China’s self-developed autonomous underwater vehicle (AUV) delivered impressive performance.

Operated by Shao Gang and three other scientific expedition members, the AUV, known as Tansuo 4500, completed scientific investigation tasks concerning sea ice-covered areas in the high latitudes of the Arctic. This is the first time that Tansuo 4500 has performed scientific tasks in the polar region and the first time that China has employed an AUV for near-seabed scientific research in the high latitudes of the Arctic.

The valuable data collected by the AUV is expected to provide strong scientific support for Arctic ecology protection.

Developed by the Shenyang Institute of Automation (SIA) under the Chinese Academy of Sciences, Tansuo 4500 looks just like a large yellow fish and features a higher level of automation than ordinary AUVs.

Compared with remotely-operated underwater robots, Tansuo 4500 doesn’t need to be connected to the mother ship by cables, which means that it can realize autonomous navigation and carry out detection without human intervention, said Li Yang, an associate research fellow at the SIA, adding that it has a longer battery lifespan and its activity scope is wider.

Considering the high-density sea ice-covered areas during the Arctic scientific expedition, the scientific research team has creatively developed an under-ice AUV retrieval technology that combines acoustic remote control and automatic guidance to ensure that Tansuo 4500 can dive into the sea continuously and be withdrawn safely.

“We have also added an emergency beacon so as to locate the AUV accurately when it gets stuck under the ice layers or its position is not visible to the naked eye,” Shao said.

Besides, the scientific research team has optimized the troubleshooting process of the AUV, allowing it to independently evaluate its own condition and then make decisions accordingly.

Many areas of the polar region are covered by sea ice all year round, and it is an important part of polar expeditions to investigate the characteristics of sea ice and sub-glacial waters.

Noting that polar scientific research has always been a key direction of the development of underwater robots, Li Shuo, deputy head of the SIA, pointed out that six underwater robots of four types from the institute have been employed in eight polar expeditions in recent years, contributing significantly to China’s investigation into the polar regions.

According to Li Yang, AUVs are mainly assigned three tasks in polar expeditions, including observing and detecting floating ice to learn about its thickness, condition and movements, collecting data about waters, including the depth, temperature and salinity, as well as carrying out fine exploration of seabed topography and landforms and searching for mineral resources on the seabed on this basis.

Traditional sea ice surveys require drilling holes in the sea ice, which was not efficient and could only collect a limited amount of data.

The AUV, however, is not affected by sea ice and can get to some areas beyond the reach of human beings, conducting scientific investigations into wider and deeper areas for a longer period of time.

It can collect sea samples more flexibly and accurately, guaranteeing higher quality and larger number of samples.

Scientific expedition members can observe the underwater world in the polar regions through the cameras, imaging sonar and other imaging devices installed on the AUV, Li Yang said.

Actively responding to the needs of the country, the SIA has been devoted to the development of AUVs suitable for various application needs in recent years.

It has developed AUVs that can reach as deep as 11,000 meters below the sea surface, with their ranges varying between several kilometers and several thousand kilometers.

In terms of main functions and performance indicators, China’s unmanned underwater robots have reached the international advanced level, Li Yang pointed out.

AUVs are expected to develop toward higher intelligentization in the future, with stronger adaptability to the environment and collaborative operation capabilities, according to experts.