Unmanned Technology Unveiling the Mystery of Antarctica — USV Fills Data Gap for Polar Expedition
Not long ago, China’s fifth Antarctic scientific research station – the Ross Sea Station officially laid its foundation stone on the Inexpressible Island(74°54’S 163°39’E). The full construction will take another 4 years to complete while preparation and research had already begun a few years ago.
In last November, four unmanned surface vessels(USVs) from Oceanalpha Co., Ltd teamed up with the Snow Dragon Antarctica expedition ship all the way south to the Ross Sea to assist the construction.
The USVs had been working for nearly 40 hours, completing a multi-beam full-cover seabed topographic survey of 5 square kilometers. This not only fills the data gap in the region but also provides spatial geographic data support for marine navigation and the construction of the new station.
Background: China to set up its fifth Antarctic research station
This is China’s 34th Antarctic expedition aiming to build its fifth Antarctic station following the Great Wall Station, Zhongshan Station, Kunlun Station and Taishan Station.
The expedition team consisted of 334 members from more than 80 companies and organizations.
During the expedition, the team made full use of the ship-based, ice-based, and sea-based platforms to conduct joint observations on land, ocean, atmosphere, ice shelf and organisms. Their investigations will also help to establish the national Antarctic Observation Network, protect marine environment and control pollution around the station.
Oceanalpha’s USV visit Antarctica for the first time
Changxin Liang, an engineer from Oceanalpha, was selected by the national expedition team last July. He boarded the mother ship, Snow Dragon, with two M80 USV and two SE40 USV to carry out the autonomous hydrographic survey mission.
In the past, hydrographic survey relies mainly on manned vessels which would post safety hazards against surveyors on-board and can only explore within channels.
The application of unmanned vessels enormously enlarges the survey area and reduces labor costs and fuel costs by running on electricity or diesel.
The specific tasks of the USVs at this expedition include bathymetric survey, seabed topography survey, water flow, and tides survey. Detecting the direction of water flow would provide a reference to the design of the water circulation system in the station; observing tides and finding the highest point of the sea level will determine the altitude position of the station so as to avoid being inundated by seawater.
It’s all about time, time and time
Application of USV is highly subjected to weather condition. When in terrible weathers, the team can only find 2 hours of unruffled time to get the USV working.
“Weather in Antarctica is unpredictable. When we were hanging down the USV, everything was fine, the weather was peaceful, as soon as the USV touched the sea surface, snow suddenly came and the temperature dropped instantly, it’s like the weather was challenging our resolution to continue, but we never gave up” told Liang.
While the mothership was carrying more than 200 missions, it’s never easy to find the overlapping interval. Liang said “We have to race against the weather, as well as coordinate with other 200 project teams that were waiting in line to get their missions done with the mothership within strictly limited time.”
Every project has a tight restriction on members and equipment. Each team can only be equipped with 2-3 staff members. Equipment should be highly integrated, an on-site assembly is unacceptable for which would take too much time and energy.
Dr. JinJing Pu, the marine application technology director of Oceanalpha as well as the leading R&D engineer and of the M80 USV claimed in an interview that “When developing the Antarctica expedition USV, the M80, we bear in mind all the limitations but never compromise in its multi-function and humanization. ”
Dr. Pu was originally a teacher at Qingdao Ocean University and once had spent more than 800 days at sea for researches. In 2016 he decided to leave the university and join Oceanalpha. The reason he made up her mind is that he can participate in the development of marine USVs which in the future can help her peers and juniors to conduct ocean expeditions that involve higher work intensity and bigger risks.
According to Dr. Pu, M80 is modular-designed so it can be assembled conveniently and gives large capacity to survey instruments. With the crane and hooking devices, the USV can be launched and retrieved easily. Its autonomous system requires only two to three operators to conduct multiple surveys in a time.
During the whole expedition, the team worked for 5 days while the Snow Dragon was unloading materials in the new station then had stopped for 10 days because the Snow Dragon was leaving for Zhongshan Station for other projects then got another 3 days time to continue when the Snow Dragon went back to the Ross Sea.
In the first five days, the team surveyed 3.6 square kilometers of sea area, and a total of nearly 5 square kilometers in two periods.
Surveying in Antarctica: Why USV can shoulder such a task?
Strong wind and water flow in Antarctica could bring a lot of ice floes which might bump survey vessel off its planned path or even cause a crash.
Dr. Pu introduced that drawing a precise survey line on water is an unparalleled advantage of USV which means it can sail in high accordance with the planned route enabling the mounted sensors to scan the seabed evenly and forms an accurate seabed topographic map.
Though the M80 was constantly hit by randomly drifting ice, its working pattern never got affected.
Dr. Pu revealed the secret of the M80 USV qualifying which for the polar expedition: “The adoption of artificial intelligence and advanced algorithms ensures the accuracy of the USV’s sailing route. When combining the autonomous obstacle avoidance system with the manual remote control mode, most emergencies can be resolved. The uniquely designed bulbous nose can also cushion the impact of waves and ice floes.
The second generation of M80 USV has improved in material from composite to aluminum. Aluminum alloy is more flexible so when a crash happens the USV got deformed at most, its hull won’t stop functioning; if the damage is serious, it can be repaired by cutting and welding easily.
Due to the low temperature, the lifetime of electric vessels is shortened sharply in Antarctica making which unqualified for Antarctica expedition. The M80 is powered by diesel which only freezes at -35℃.”