Nortek’s DVL helps students take on the world in AUV competition
Students at one of Norway’s leading universities have been using one of Nortek’s Doppler velocity logs (DVLs) when participating in an international competition for autonomous underwater vehicles (AUVs).
The Norwegian University of Science and Technology (NTNU) in Trondheim plays host to some of Norway’s leading marine technology research, so many of its graduates are likely be part of the subsea sector’s lifeblood in years to come.
A team of postgraduate and undergraduate students from various technological and engineering disciplines at NTNU are starting out on that path by participating in Vortex NTNU, an independent, student-led project designed to sharpen up their subsea technical skills.
At its inception in 2015, Vortex NTNU’s mission was to design and build a remotely operated autonomous vehicle (ROV) from scratch to compete in the MATE international ROV competition against other educational institutions from around the world.
Hands-on experience with underwater robotics
“The project is an extra-curricular activity involving students from many disciplines.
We’re not getting any university credits for it, but it gives us practical hands-on experience,” says Sarah Sayeed Qureshi, a cybernetics and robotics postgraduate student on the team.
The MATE competition, usually held in the USA, requires entrants to show what their ROV can do by completing a series of underwater tasks. Vortex entered an ROV three years running, improving on their technology each year.
“A lot of us are studying robotics, but we don’t get really hands-on experience working with real robots. So, it’s good to see how well we are doing, look at other solutions and get inspired for next year,” Sayeed Qureshi says.
In 2018, the team decided to move up a notch by upgrading its latest ROV, known as Manta, to an AUV, controlled wirelessly rather than via cable from the surface.
That meant entering Manta into a different competition, RoboSub, organized by RoboNation. Manta and its rivals had to negotiate such tasks as detecting a gate and navigating through it, avoiding obstacles in the water and being able to direct a projectile through a hole.
Major participants in the subsea industry sponsor the event and play close attention to the potential of the innovations on show to be incorporated into the next wave of AUVs in areas from the oil industry to oceanography and military applications.
A compact, accurate and lightweight DVL for a small AUV
To convert Manta into an AUV, the vehicle needed to be fitted with extra equipment, including instruments to determine its position and speed as precisely as possible. The added technology also needed to be compact and lightweight to fit Manta’s design.
The team looked at what was available and decided the Nortek DVL1000 would be ideal, so they got in touch with the company to see if they could borrow one for the competition.
“It was essential, because we only had an inertial measurement unit and you get drift in measurements from that, so we needed the DVL to correct it,” says Sayeed Qureshi.
“Also, our AUV is quite small compared to many others on the market, so we needed space-efficient equipment – and Nortek’s DVL1000 is one of the world’s most compact,” she adds.
Keen to assist the new generation of innovators, Nortek loaned the Vortex team a DVL1000 for 2019 and extended the loan for the following year, though the 2020 campaign was delayed by the impact of the Covid-19 pandemic.
“We suggested it should be a 300 m DVL1000, as it’s the smallest we have – in water it’s just 168 g. They also used our data format, which helps improve the accuracy of speed readings,” says Tom Christian Mortensen, a Sales Engineer based at Nortek’s Oslo headquarters.
The 1 MHz DVL1000 is a four-beam instrument capable of bottom-tracking in a wide range from just 0.2 m to 75 m above the seafloor. It comes in two versions – the shallower-water version can operate at up to 300 m, and the deepwater version can operate at up to 4,000 m depth. It is used by leaders in the subsea market due to its high accuracy and state-of-the-art technology.
Both sides report a positive experience.
“There was some back and forth at the start, but these are clever students. We provided the integration manual and they were able to integrate the DVL1000 without much help from us,” says Mortensen.
Sarah Sayeed Qureshi reports that Nortek were able to quickly resolve their early problems, when the team needed some assistance in calibrating the pressure sensor, and that the instrument has been operating smoothly.
“The DVL is working really well and we are happy with the results we’re getting,” she says.
Nortek recently opened an office in Trondheim, so staff from there have been able to drop by to see how testing was going at the NTNU facility.
There are benefits for Nortek too: assisting Vortex NTNU has provided a chance to get valuable feedback from the team on how they deploy the DVL, and, of course, has given the company an opportunity to make contact with the subsea industry’s future professionals.
“The people on the Vortex team are not your average students. They spend a lot of time working on these technological projects, so they are very interesting, because some could be future Nortek employees or users of our products, wherever they end up,” says Eskild Westby, Product Manager at Nortek’s Trondheim office.
DOPPLER VELOCITY LOG
DVL1000 - 300 m
Bottom-track from over 0.2 to 75 m range; 300 m max. operational depth