Robot Ship Inspectors – To ensure a ship’s seaworthiness, regular inspections are a necessity. These inspections, however, are time consuming, laborious, dangerous and involve huge costs. People inspecting various aspects of a vessel very often get under the water and inspect the different parts of the ship such as the hull and ballast water tanks (BWT). More often than not, these inspections take place in smaller countries where the labour costs are minimal. They involve a large number of man hours and can be quite dangerous.
To minimise these issues, robots have entered the scene and are proving to be cost effective, safe and more efficient than their human counterparts.
The essential BWTs must be examined periodically to ensure safety at sea. However, after a long journey, the tanks become corroded with sea water, get filled with algae and give rise to marine and bio fouling. Also, since these tanks serve no purpose other than stabilising the ship when the load is insufficient, they are often oddly shaped and located at the bottom of ships so that they do not interfere with the normal running processes. This makes them difficult to reach and inspect. In addition, human inspectors can miss things and make mistakes. A robotic inspector is precise and can see some things that a human eye might miss. If something is even slightly off, then the robot can sense it and bring it to someone’s attention.
A group of Dutch and German technologists known as the RoboShip project, an alliance between the University of Twente, robotic technology developers DFKI Bremen from Germany and Imotec from the Netherlands, was formed to explore the potential of intelligent industrial robots in the shipping industry. In late 2014, the project unveiled a robot that can carry out the inspection of a BWT on an ongoing basis, without posing a health risk to workers and, crucially, without having to take the ship out of service. “I have had the opportunity of seeing the inside of a freighter’s ballast water tank,” says Dian Borgerink, a doctoral student in the robotics and mechatronics department of the University of Twente.
“After a voyage, it is slippery with seaweed and is full of noxious gases. Tanks like these are almost inaccessible due to ribs, pipes and cables. Realising that people actually need to go into them to carry out inspection work was what motivated me to develop the robotic arm.”
RoboShip has placed its robot on a set of rails built in to the ballast tank, neutralising the problems caused by variable tank design. Fitted with sensors and a video camera, the robot can move around the walls of the tank, inspect the surface and transmit data back to a central control centre. The robot emits a magnetic field, which allows the controller to identify its exact location and, by proxy, the location of the problem. This can help operators get a better understanding of problems as they unfold and allow them to better schedule planned maintenance.
The robot guides itself by taking several measurements including odometry, inertial measurement unit data and the magnetic field of the tank. “Each tank has a sort of magnetic signature,” Borgerink told futurenautics.com.
The Ship Inspection Robot (SIR) was developed by a student team from ETH Zürich and ZHdK. The prototype for robotic ship inspection is able to conduct visual inspection in vessels and incrases the mobility of present ship inspection units. The Ship Inspection Robot was intended to simplify the inspection process for huge cargo vessels and thus help cut costs. In particular, it increases security for inspectors as they will no longer have to climb into every nook and cranny of the vessel themselves. SIR’s user friendliness is guaranteed by easily swappable wheels, a quickly exchangeable battery and a detachable electronics box. To fulfill its task, SIR is remote-controlled from a base station. There, the operator uses a common gamepad to control all of the robot’s functions. He can monitor, other than the live video feed of the camera, the current speed and orientation of the robot, the battery usage and so on to have a complete overview of what is happening.
In April 2016, Kongsberg Maritime and Statoil signed an agreement with Eelume, a NTNU spin-off company, to accelerate new technology that will significantly reduce costs related to subsea inspection, maintenance and repair operations.
NTNU and Sintef have conducted research on snake robotics for more than 10 years. Eelume is now developing a disruptive solution for underwater inspection and maintenance in the form of a swimming robot. The idea is to let these robots do inspection and light intervention jobs on the seabed, reducing the use of large and expensive vessels. With its snake-like form, the slender and flexible body of the Eelume marine robot provides access to confined areas that are difficult to access with existing technology.
Eelume robots will be permanently installed on the seabed and will perform planned and on-demand inspections and interventions. The solution can be installed on both existing and new fields where typical jobs include; visual inspection, cleaning, and adjusting valves and chokes.
These jobs account for a large part of the total subsea inspection and intervention spend.
“With our unique expertise in the field of snake robotics Eelume is the first company in the world to bring these amazing robots into an industrial setting. Now we take the step from academia and into the commercial world to secure our place in the new and exciting subsea intervention landscape”, says Pål Liljebäck CTO Eelume. “This partnership offers the chance to bring radical technology to the market, not just in what the Eelume robot can do, but how it does it,” says Bjørn Jalving, Executive Vice President Subsea Division at Kongsberg Maritime. “It is a new tool that will enable operators to realise large scale cost savings by introducing new ways of conducting routine tasks and helping prevent unscheduled shutdowns by reacting instantly when required.”
“Eelume is a good example of how new technology and innovation contributes to cost reduction. Instead of using large and expensive vessels for small jobs, we now introduce a flexible robot acting as a self going janitor on the seabed. To support smaller companies in bringing new technology to the market is an important part of our research portfolio,” says Statoil’s Chief technology officer Elisabeth Birkeland Kvalheim.
Robotics News Feature, November 6
By Priyanka Ann Saini