07.06.2021

AGH Marines explore marine depths


Established only three years ago, they have already garnered several grants and ambitious projects. The AGH Marines Research Group is based with the Faculty of Mechanical Engineering and Robotics and deals with underwater robotics, exploration of marine depths and designing underwater and exploration robots. Members of the team are also actively involved in popular science as they disseminate knowledge about land and underwater robotics as well as marine environment.

One of the key projects undertaken by AGH Marines is a remotely operated underwater vehicle called “Guppy” (Polish: “Gupik”), which the students plan to enter for the world’s most prestigious ROV challenge - MATE International ROV Competition.

What are ROVs?

For a long time ROVs have been widely used, especially in marine and military sectors. Between 1990 and 2010 these were mainly large-scale units launched by oil companies, which operated at the depths of several hundred metres to a few kilometres below sea level. Currently, thanks to miniaturization, it is possible to build smaller robots capable of replacing divers when performing inspection, maintenance, manoeuvring or emergency actions, both in most demanding conditions but also as part of routine duties. They can reach places which are inaccessible or too hazardous for human personnel and perform complicated operations. Robots of this kind are used by scientists, shipowners, owners and administrators of harbours, marinas, surface and underwater installations, emergency teams as well as companies providing services for water-related industries. ROVs explore water depths as part of geological, biological, environmental or archaeological research. The market for ROVs is demonstrating a dynamic growth and the companies working in the sector are looking for innovative solutions.

Compact, quick and agile

“Guppy” will weigh less than 20 kilograms. It will be able to go down up to 20 metres below water surface while sea and ocean depths will be explored by means of high-resolution cameras and sensors. With a 3D SpaceMouse manipulator from 3D Conexxion control of the vehicle will be very intuitive.

Guppy’s essential components have been attached to its main board. The robot’s heart consists of a waterproof chamber containing its electronics responsible for communication, power supply, collection of data coming from cameras, drive control and pre-processing of sensor data. Communication between these systems has been made possible by the use of high quality cables connected to the chamber by means of waterproof links and cable glands. The chamber was made from polyamide using 3D-SLS printing and then lacquered in order to ensure that the design has a proper shape and is sufficiently waterproof.

“Guppy” is propelled by thrusters, which the team developed from scratch. The thrusters provide a 50% increase in thrust parameters and energy efficiency, compared to alternative solutions available on the market. They were designed with SolidWorks software, provided by the DPS Software Company, whereas the necessary simulations were carried out using ANSYS Software, supplied by MESco. Screws and nozzles of the thrusters were 3D printed using the FDM technology and an extremely sturdy, advanced material – carbon fibre-reinforced nylon (PA12+CF15) supplied by Fiberlogy.

One of the most innovative elements of the vehicle is its drive control system which ensures thrust vectoring. The solution is commonly used in large surface structures, yet extremely rare in underwater applications, owing to its considerable algorithmic complexity and structural challenges. Two of the five thrusters have been mounted on dry servomechanisms, therefore enabling their rotations, while the other three are rigidly mounted to the main board. This solution significantly enhances the vehicle’s manoeuvrability while greatly reducing electrical energy consumption.

The vehicle does not require any pneumatic or hydraulic installations, with all components being electrically powered. This makes “Guppy” lighter, yet more agile.

The team equipped their design with a full range of sensors: the pressure sensor provides depth measurements, the AHRS system used inertial navigation to determine the robot’s orientation and positioning, thermometers embedded in microcontrollers monitor temperature inside the vehicle whereas electronic systems take precise measurements of power consumption and set optimal performance parameters for the propulsion systems.

The streamlined casing of “Guppy” is a fully independent design by AGH Marines. For maximum reduction in flow resistance and the resulting power savings, the team used modern surface modelling techniques and numerical simulations. The challenge was real – ROVs move forward and backward, up and down as well as sideways. The casing was produced from ABS+ material and 3D printed using the FDM technology.

These visible modules are accompanied by an equally modern and innovative image processing system operating through the control station that controls the robot. The vehicle’s autonomy while performing its missions requires that the algorithms that process, recognise and interpret image be reliable and fast. What turned out to be extremely helpful was the environment created in MATLAB for working on the algorithms as well as the original control station software in which the algorithms were implemented.

In order to expedite the work and test selected solutions without actually launching “Guppy” a virtual simulation environment was created so that the vehicle’s behaviour could be accurately duplicated. The team also developed a complex mathematical model for underwater movements and recreated the conditions the robots will compete in during the actual event. This has given the team the possibility to fine-tune the control algorithms and train the operator outside the tank.

The development of ROV devices is a complex, multi-stage process. During the conceptual stage, the team developed a plan of action. Next, using state of the art software as well as programming and design technologies, the students moved on to develop virtual prototypes of the structure, followed by software and simulations, all of which helped to further improve the project. Once the final versions of the modules were ready, the team went on to produce subsequent components of the set-up, order parts for the robot’s systems and integrate them. Currently, the project has reached the stage of final assembly, testing and test launch.

Competition challenges

The MATE International ROV Competition is organised by Marine Advanced Technology Education (MATE) Center, based in Canada. Last year the competition was cancelled due to the COVID-19 pandemic. This year’s finals, scheduled for 5-7 August, will be held as a hybrid event (with some participants attending in person and some – remotely) at Tennessee State University in the U.S.

This is a multi-stage competition. Teams may qualify for the finals in two ways: by attending regional competitions or by submitting a set of properly prepared materials, including technical specification and a film showing the working robot in action. AGH Marines will follow the latter path. The results of the qualifications will be known in mid-July.

The participants are tasked with solving real-life problems. Such a formula aims to check the knowledge of engineering and robotics as much as collaboration skills, analytical thinking and business acumen. The participating teams must – besides designing and producing the robot – draw up technical documentation, deliver a final report and make a presentation to the judges.

If “Guppy” makes it through the qualifying stages, it will compete in the Explorer class (the other classes being “Scout”, “Navigator” and “Ranger”) to address tasks of high difficulty and complexity. These will involve:

  • servicing and conducting maintenance for devices removing plastic pollution and collecting debris,
  • autonomously flying a transect line over a coral reef, mapping and evaluation of the condition of the reef followed by culling an outbreak of voracious predators known as crown-of-thorns starfish,
  • collecting a sediment sample from the bottom of a tank, detection of pollution type and removing an eel trap from a designated area.

Common passion

The Marines Research Group was founded in September 2018 as an initiative of four Mechatronic Engineering students from the Faculty of Mechanical Engineering and Robotics: Filip Dudek, Patrycja Lisak, Tomasz Małachowski and Mateusz Stemplewski. The founders of the group were interested in robotics and marine world. Once at university, they decided to jointly pursue their common passion and start designing underwater robots. Currently, the Group has nine members active in three teams: programmers, electronic engineers and mechanics. The AGH Marines’ scientific supervisor is AGH UST Professor Bartłomiej Borkowski.

Photo by KSAF AGH UST

In 2020 AGH Marines received the Rector’s Grant. This year, they were granted funds under the „Student research clubs create innovations” awarded by the Ministry of Education and Science as well Rector’s Grant under the “Excellence Initiative – Research University” scheme.

Members of AGH Marines have successfully taken part in national conferences such as STUKNUT (Gdańsk 2019) XXIII Acoustic and Biomedical Engineering Conference (Zakopane, 2019). In addition, they took part in Global OCEANS (Singapore, 2020) – the world’s biggest conference related to marine and oceanic technology and science. The AGH UST students delivered a presentation during a technical panel session while their paper was included in conference proceedings.

 

Technical consultation – AGH Marines. Photographs and graphics contributed by AGH Marines.