Up to now we were focusing on the technologies onboard various maritime and offshore vessels. We were trying to share with you our thoughts, experience, procedures we know and professionals we follow. A lot of things happen above the keel, but some of them are taking place underwater. Subsea surveys, drilling, oil extracting, cable and pipe laying, installation of wind turbine jackets or monopoles to name a few. All this sophisticated operations require careful planning and execution to watch out for pipelines, cables, military areas and marine habitats. So how to monitor this execution? Well, You probably thinking “divers” and that’s correct, but there are some cases in which people just prove ineffective. The solution for this problem once again lies in robotics. That’s why, together with our guest Karol Jacob I would like to discuss underwater robots today: ROVs and AUVs.

Interview with our guest – Karol Jacob

Mateusz: Karol, I am really happy for this interview. We actually know each other quite well, but could You please introduce yourself to our readers?

Karol: My name is Karol Jacob and I am the Head of Engineering at MEWO Subsea Solution. I have been involved in the marine engineering industry for 10 years. I started as a service technician for autonomous marine survey systems and as a technical pilot for small inspection ROVs. Over the years I have gained experience on various types of ROVs – from inspection ROVs through light work class ROVs up to working class ROVs with special cages (TMS) and launch systems (LARS). Today I have the pleasure to lead, among others, the ROV department. With full awareness of my words I can say that I am proud to manage a group of one of the best ROV operators in Poland.

Types of underwater robots

Mateusz: That’s quite an achievement. I would like to ask You few questions about underwater robots. Let’s start with the basics first. What is the use of robots underwater?

Karol: In general, underwater vehicles are carriers of measurement equipment. The Robot itself is commercially worthless, only the sensors installed on it – so called Payload – make their use profitable. The world of underwater robots can be divided into two main groups: ROV and AUV. These are two completely different systems although they can perform very similar tasks.

Mateusz: What exactly are ROVs and AUVs?

Karol: ROVs are remotely operated vehicles connected by cable to a control room where there is an operator maneuvering the vehicle. AUVs are autonomous vehicles that perform pre-defined missions. These robots are not physically attached to the operator and their operation is limited to deploying the AUV into the water and recovering it from the water after completing the mission.

Classes of ROV

Mateusz: You mentioned, during your career you were working with different classes of ROVs. What are those?

Karol: Each of the above groups can be further divided and so, for example, ROV’s are distinguished by a class of light inspection robots consisting mainly of a camera – colloquially referred to as a camera on a cable (Eyeball). Later we have a light working class of robots that are already carrying a larger number of devices such as pipetracker, cabletracker, acoustic cameras, etc. However, they are limited by the carrying capacity and the number of interfaces. They are predominantly electric robots. Among the largest robots are Working Class ROVs equipped with hydraulic manipulators that mimic human arms. Due to their size (they can match the size of a small bus) their payload is basically unlimited. The type of task to be performed and the environment in which they operate determine the choice of the appropriate ROV.

AUVs are generally divided into similar groups and this applies to their size. They are similar in shape (they resemble torpedoes), but can weigh a few kilograms and have a length of 1m. There are also those that weigh several hundred kilograms and are even several meters long.

Difference between ROVs and AUVs

Mateusz: It seems to me, there is no big difference between ROVs and AUVs other than operator controlled or autonomous operation. Is that correct? I believe both of this technologies meet different restrictions and proves different challenges.

Karol: Although both ROV’s and AUV’s can perform similar tasks they are radically different. ROV’s are permanently tied by an umbilical cord to the vessel and operator. Thanks to this connection we have full maneuverability of the robot underwater, real-time readout of sensor data, and most importantly camera images. The downside of such a solution is the need to use an appropriate vessel, preferably with dynamic positioning (DP), which maintains itself over the set position without dropping anchor. These vessels are large and expensive. Therefore we are also limited by weather conditions, i.e. due to limitations by the ship’s performance, but also by the robot itself, which can fail in tidal waters, where the current is simply too strong. On top of all this there is a dedicated staff, which is on duty 24 hours a day and usually consists of 5 people.

Mateusz: Is it the same with AUVs?

Karol: AUV’s are practically the opposite of ROV’s. Sea conditions don’t matter that much (except for currents, although due to the shape of the torpedo they deal with it better). The ship doesn’t have to be big and it doesn’t have to be a DP ship. Of course, the size of the AUV itself determines the types of lifting equipment, but the vehicle can be deployed near the mission start point by “throwing” it overboard. There is no need to be qualified personnel to operate it. The ship’s crew is enough to deploy the AUV into the water. Specialized personnel are on the counter, servicing the device and programming missions. The downside of the AUV is the inability to view data in real time. It is possible to capture data online, but when the device is on the surface and not performing its mission. Despite the use of very complex algorithms, calculations and counts AUV can “stray” interrupting the mission. It is impossible to maneuver the AUV while it is performing its mission; moreover, to be maneuverable the robot must be in constant motion.

The prices of ROV’s and AUV’s performing similar tasks are similar and can reach up to several million EUR, and their selection depends on the assumptions of the whole project.

ROV operations

Mateusz: That’s very comprehensive answer. I think differences and the operational factors will be well understand for our readers now. Speaking of operations, we already know that underwater robots are carriers of the measurement equipment, but what equipment are we talking specifically?

Karol: When choosing the right sensor to install on a subsea vehicle, we are practically limited by our imagination, budget and customer requirements. Virtually every sensor used in subsea measurements can be implemented on the robot. These can include cable and pipeline detection and tracking systems, specialist sensor systems for shell thickness measurement, flooding, bathymetric or sonar mosaicking, photogrammetric systems and many more.

Mateusz: Well, that’s a lot of technologies and principles to be familiar with. That amount of data must require a complete chain of specialists to make whole operation successful. What is a recipe for successful ROV operation?

Karol: Determining the success of an ROV mission primarily includes the quality of the data collected. The robot itself as a carrier for measurement equipment does not make measurements. Specialists in hydrography, seismology, or geotechnics are both responsible for the proper configuration of the ROV systems and verification of the collected data. The success of ROV operations is also influenced by the execution time, which has a relative impact on the commercial profit.

Applications

Mateusz: What industries benefits the most on using underwater vehicles?

Karol: Underwater robots can be seen in almost every task of an offshore project. The oil & gas industry is dominated by underwater robots. Existing wind farms, as well as those that are being planned or built, also benefit from underwater robotics technology.

Mateusz: If robots serves offshore industry on every step, what are the dedicated tasks, where ROVs or AUVs can prove useful?

Karol: Starting with planning for investment, i.e. depth mapping, sonar mosaicking, checking the cleanliness of the seabed for potential hazards, inspecting the existing infrastructure for tracing buried cables and pipelines as well as checking flooding, the thickness of the cover and video inspections, ending with repair and maintenance of the infrastructure, e.g. turning on valves, replacing components, etc. Most of the above aspects are covered by ROV. Tasks involving surveys performed on transects or survey lines are performed by AUVs. More so if they are to work at significant depths e.g. below 500m.

Standards and certification

Mateusz: All offshore industry stands on standards of different organizations. Multiple training sessions and certification programs without a question enhances the safety of operation within industry. What organization is regulating the ROV’s certification?

Karol: There are no official standards for ROV operators in the world. Although it is much easier to meet the standards of some ROV federation than AUV. In the world, despite the lack of official regulations, it can be assumed that the regulations for ROV operators created by IMCA apply. As an accredited regulatory body, it offers a complete procedure with degrees of operator proficiency. Courses that can be found on the market concern the training according to IMCA procedures and each skill and experience gained is recorded in a special personal logbook.

Mateusz: We have a lot of students and entry level engineers among our reeders, who stand in the decision of choosing their career path. The question that comes to my mind is, if it is possible to be an ROV pilot without a completed course?

Karol: What counts in this industry is experience, which is gained by starting with small inspection robots. The simplest and cheapest ROVs can be bought on well known internet portals for few thousands EUR. Many of the world’s leading manufacturers of AUV’s and ROV’s offer training in service and repair of their products, and this is already a good introduction to a career in the industry.

Future of the ROVs

Mateusz: Sure, there is no substitute for hands on training and solid experience. As we are speaking about the future, what is the future of underwater robotics?

Karol: The definite future of underwater vehicles is renewable energy projects, with reduced commercial divers, 100% environmentally neutral. All of this is happening in small steps. On virtually every one of these fronts. It seems to me that additionally, the differences between ROVs and AUVs may be blurring. A breakthrough will be the development of technology that allows wireless underwater video streaming in real time at least 24 frames per second. At the moment, this is a topic of research at the level of PhDs and professorial dissertations. It seems to me that the complete elimination of umbilicals in ROVs will strongly expand the use of underwater vehicles.

Mateusz: What about the motion system? There are research labs, which are trying to create robots mimicking the movements of real animals, not only above the surface, but also underwater.

Karol: We can observe a trend, attempts to change the propulsion system in underwater robots. While observing the nature and underwater organisms we do not notice classical propellers. Instead, we can observe so-called wave or jet motion. Classical propulsion methods have some disadvantages. The rotary motion of the propeller causes the formation of cavitation. That is, air bubbles behind the propeller, which have a negative effect on the material and on the test results of the acoustic equipment. In contrast, they are uncomplicated and easy to operate.

Wave propulsion systems are definitely more energy efficient, but they are also more complicated. A classic screw is driven by a single motor. Wave motion is generated by several motors. Jet propulsion systems are practically not used at all in underwater robotics due to poor vehicle maneuverability at low speeds. Modern flexible robots imitate the movement of manta rays or squids. It is interesting to note that in Poland, wave motion research is conducted by a company from Krakow, that already offers its services with an underwater vehicle driven by wave motion. In my opinion, there is still a long way to go before we move to bionic propulsion. They need refining, testing and lobbying for this kind of power.

Future of the market

Mateusz: In our earlier interview with Jens Engelbrechtsen we discuss a lot about digitalization in maritime industry. Same like with other areas of life, robots are slowly replacing humans. Will the robots replace commercial divers or in this case will they serve as an aid to them?

Karol: In fact, it’s already happening. Robots are displacing professional divers. The issue is very simple – safety. In the offshore industry places the greatest emphasis on safety. At the moment it is impossible to completely eliminate the professional diver, however, in my opinion the world is moving towards this. I personally took part in the development of the method of inventory and collection of phytobenthos and zoobenthos from the hard bottom, just to eliminate the risk associated with the work of professional diver, who for many years (in fact, always) performed this task in the project. I can confidently say that the developed system mounted on ROV’s is innovative and not found more widely in the world. In addition, the availability and cost of purchase of specialized ROV is in principle equaled the cost of sending a professional diver, with a greatly reduced risk.

Mateusz: So what direction market is going right now?

Karol: Nowadays, everything strives to be green. Likewise in the underwater vehicle industry. Hydraulic robots are being replaced by fully electric ones. Invasive research methods are being replaced by non-invasive ones, e.g. acoustic (ultrasonic waves in water propagate 4 times faster and farther than in air). Additionally, there is a trend of using underwater robots. They used to be used in oil & gas industry for prospecting and inspecting oil rigs. Today, when the era of fossil fuels is replaced by the era of renewable energy, the same robots (with slight modifications) are used for planning the laying of cables for wind farms and inspection of the wind farms themselves.

Conclusion

We discussed both underwater robots solutions: ROVs and AUVs. Although they are taking a part in similar activities, they are two different technologies. Both of them are available at market and find extensive use in subsea surveys in oil & gas, offshore and renewable energy industries. Increased robotization which is taking the place in those industries will bring safer operations at similar cost, displacing the need of human to the work underwater. Technology is still evolving and there are some advancements in the field of underwater vehicles, but some things can still be improved.

At Vessel Automation we are looking forward to this improvements, as much as we are looking forward for Your feedback. Do You have any questions about underwater robots or do You have own experiences in this area, which would You like to share? I hope You enjoy this interview as much as we did. Let us know in comment section!