During the latest Polarstern expedition, researchers conducted an autonomous multicopter flight in the Fram Strait
How do you successfully pilot a remote-controlled helicopter in the remote expanses of the Arctic Ocean when the compass can’t provide reliable positioning data?
Engineers on board the Alfred Wegener Institute’s research icebreaker Polarstern specially programmed a multicopter, allowing it to navigate despite the deviations produced by the Earth’s magnetic field near the North Pole. The researchers recently celebrated the copter’s first successful autonomous flight and landing on an ice floe.
According to Sascha Lehmenhecker, an engineer at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), “At high latitudes, autonomous navigation is a major challenge.”
“Navigation systems normally use magnetic sensors. But near the poles, the lines of the Earth’s magnetic field are nearly perpendicular to the ground, making precise navigation extremely difficult. That’s why commercial multicopter control systems aren’t well suited for use in polar regions.”
Together with the PhD candidates Michael Strohmeier and Tobias Mikschl from the University of Würzburg, Lehmenhecker refined the control systems for multicopters –these roughly half-metre-long devices, powered by multiple propellers, are intended to land on ice floes and fly back to their “mother ship” autonomously several hours later.
The particular task: both the ice floe and the ship are in motion. The ship has to continue on its scheduled course to conduct other research, while wind, waves and currents cause the ice floe to drift. And it’s precisely the direction and speed with which it drifts that the multicopter needs to determine.
The development team pursued two approaches to allow the multicopter’s control system to compensate for the distortions in the positioning. “In the first approach, the multicopter remains in constant contact with a receiving station, which uses the copter’s GPS data to calculate the discrepancies. In other words, the multicopter transmits its GPS position to the station, which in turn transmits back the corresponding, adjusted coordinates,” explains Lehmenhecker.
“The second option: we use two onboard GPS receivers to calculate the actual change in the copter’s position. Though this is the better method, it’s also much more complex, and we’re still just starting to develop it,” clarifies the AWI engineer.
The system passed its first test, conducted on an ice floe in the arctic Fram Strait (79° N parallel), with flying colours: the team and copter were left on a floe. Now clear of the magnetic interference produced by electric motors on board the Polarstern, the team manually flew the copter roughly three kilometres out, to the edge of visual range. They then activated the autonomous return programme – and the multicopter flew to the pre-set coordinates and safely landed on its own.
Sascha Lehmenhecker and his colleagues in the AWI Deep-Sea Research Group came up with the idea for this development in connection with the use of sensitive devices under the ice. One example is the Group’s torpedo-shaped autonomous underwater vehicle (AUV) “Paul”, which explores the ocean beneath the sea ice. “In order to optimally plan its dives, it’s important to have precise information on the movement of the sea ice,” explains Lehmenhecker.
Conventionally, this was achieved by deploying “ice trackers” on floes with the help of a Zodiac boat or a helicopter – a difficult and time-consuming method. Further, the researchers generally try to avoid leaving the safety of the Polarstern wherever possible; after all, water temperatures hovering around the freezing point, jagged ice floes drifting to and fro, not to mention polar bears, represent additional risks and should be kept to a minimum.
The Deep-Sea Research Group first used a multicopter developed by the AWI during a 2012 expedition. Flying by remote control, it landed on the ice and used GPS to determine its position, then transmitted the data back to the research ship, which was monitoring Paul’s dive. In this way, the multicopter took on an important role, offering navigational support for the AUV.
Once each dive was complete, the ship had to return fairly close to the multicopter’s position: the pilot had to remotely guide the copter back to the ship, which was only possible in visual range. Extremely pleased by the successful test, which was conducted under the auspices of the Helmholtz Alliance “Robotic Exploration of Extreme Environments” (ROBEX), Sascha Lehmenhecker recaps what it means for researchers: “This new development will expand the service radius of our copters from visual range to as much as ten kilometres.”
Notes for Editors:
At our press office, Dr Folke Mehrtens (tel.: +49 471 4831-2007; e-mail: medien(at)awi.de) will be pleased to help you with any questions.
Please find printable images on: http://www.awi.de/en/about-us/service/press.html
The Alfred Wegener Institute conducts research in the Arctic, Antarctic and in the high and mid-latitude oceans. The Institute coordinates German polar research and provides important infrastructure such as the research icebreaker Polarstern and research stations in the Arctic and Antarctic to the national and international scientific world. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.
http://www.awi.de/en/about-us/service/press/press-release/programmierter-multiko... Press Release on AWI homepage
http://www.robex-allianz.de/en/ ROBEX homepage
Ralf Röchert | idw - Informationsdienst Wissenschaft
Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter
16.08.2018 | National Science Foundation
Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Power and Electrical Engineering
21.08.2018 | Life Sciences
21.08.2018 | Medical Engineering