The North Sea has provided the UK with 46 billion barrels of oil, since extraction began in the 1960’s. However energy extraction from the North Sea is changing, the UK is targeting 50GW of offshore wind by 2030, to achieve this we will need to build a new turbine every day for a decade.

There are fewer than 200 oil rigs in the North Sea today, but to reach offshore wind targets we will need thousands of turbines turning in the North Sea. Those turbines need to be built, checked and maintained, and so the offshore industry is turning to robotics.

From maintaining wind farms located far away from human settlements to conducting inspections and interventions in the deep ocean, the role of robots and autonomous vehicles is gaining prominence. In this article, we delve into the insights shared by Yvan Petillot, a robotics expert from Heriot Watt University, and Francesco Giorgio-Serchi, a researcher from the University of Edinburgh, on the evolution of offshore robotics and the potential of bio-inspired designs in creating efficient and agile machines for underwater exploration and intervention.

The Evolution of Offshore Robotics

Yvan Petillot explains that the use of remotely operated vehicles (ROVs) has been the norm since he began his career 25 years ago. But the autonomy was very limited and had a tether that limited the amount of information being carried to and from the ROV. He spent the first 10 to 15 years of his career looking at what could be done to make these vehicles smarter.

Over the following decade the ROV’s did get smarter. “So those robots got smarter and smarter, but at some point, they get so smart, that the human operator goes, ‘I don’t really understand what’s going on.’” says Petillot.

Around this time uncrewed surface vessels emerged, which removed some of the limitations. Petillot says, “All of a sudden, you had the best of both worlds, because you could take all the smart autonomy we had done for underwater and use it for robots, which now tether to the surface vessel. And so if it gets complicated, you can always take over. But more importantly, you can bring all the data back so you can really explain to the operator what’s going on. And so the level of trust in the autonomous system becomes so much higher.

Petillot expects the trend of more advanced and more independent robots taking on more of the role of offshore inspections, “So at an inspection, I think in five years, I’ll be surprised if you still have people hanging off ropes offshore to do the inspection, or divers diving down to do inspections.”

The Rise of Soft Robotics

While robots are becoming more and more capable of undertaking inspection tasks, creating robots both advanced enough and dexterous enough to do maintenance work is more complicated. 
Francesco Giorgio-Serchi, from the University of Edinburgh’s Institute for Integrated Micro and Nano Systems, highlights the importance of incorporating flexibility and softness into robotics.

Soft bodied robots were studied in Japan as early as the 1990s. Their soft surfaces make them safer for human interaction, and, in industry, more resilient to collisions. They can work without stringent collision avoidance. However, they can be more difficult to model and control.

Giorgio-Serchi says “I regard soft robotics, you know, this sort of new field in robotics as a, you know, very interesting niche of work, that should complement what already is there in traditional robotics. Now, what’s interesting is that being able, so having the maturity now, technological maturity to design robots, which are partly soft, allows us to better copy nature.”

The Power of Bio-Inspiration

Soft robotics can also gain inspiration from the natural world. After all, animals are not rigid like traditional robots, they are soft and flexible.

“So when it comes to strength, usually strength is associated with flexibility. And, you know, if you really look around nature, many of the organisms are flexible, or to some degree, they are soft.” Explains Giorgio-Serchi.

Francesco Giorgio-Serchi highlights how squids and octopuses, in particular, have inspired the field of robotics, specifically in terms of propulsion and manipulation. Squids and octopuses were not always considered to be the most efficient swimmer as Giorgio-Serchi explains, “This has been regarded for many, many years as a very inefficient way of propelling a vehicle or an animal, for the simple reason that half of the cycle is spent ingesting the fluid, and only half of the cycle of the procession, or the propulsion, routine is expended to actually generate the jet. But it turns out that what these animals do is exploiting the elasticity of their body.”

By exploiting the natural frequency of their elastic bodies, these creatures can generate powerful jet pulses for propulsion. They exploit resonance. The same phenomenon where if you push someone on a swing, and time the push perfectly, the oscillations amplify. This theory of energy efficient propulsion actually makes jellyfish the oceans best swimmers.

This form of propulsion has inspired Giorgio-Serchi’s robot designs “So we stick some elastic, let’s say mechanical component in the actuator that drives these ingestion, ingestion and expulsion of fluid. And by matching the spontaneous, let’s say frequency of operation of this elastic term, we are able to minimise the energy needed to perform propulsion.”

It’s not just in propulsion, robotics is also being inspired by nature to design manipulators. Rather than rigid traditional robot manipulators have a far smaller degree of mobility than a single body of elastic material.

Nature also is inspiring ways to improve the controllability of manipulators as Giorgio-Serchi explains “Now an easy way to do that is to use cables, which are similar to tendons we have in our arm. And at that point, the only real constraint is the number of cables that you can put in place. So the more you put in there, the more you can control the motion of this object. If you start placing another cable, somewhere along the length, maybe it’s the mid length of this arm, you would be able now to have two points where you can tweak the motion, so maybe the deep cable would pull in one direction and the mid cable in the opposite direction.”

 Francesco’s research focuses on integrating elastic components into robotic systems to achieve similar efficient propulsion mechanisms. Furthermore, by using cables similar to tendons in human arms, soft robotic manipulators can achieve maximum mobility and dexterity. However, the challenge lies in controlling the various parts of the manipulator, as the complexity increases with the number of cables.

The development of bio-inspired robots requires collaboration between roboticists and biologists. Roboticists gain insights from nature’s design iterations, spanning billions of years, to create machines that are better adapted to the marine environment.

 By emulating the efficiency and agility of marine creatures, offshore robots can perform tasks with enhanced precision and force. The interaction between researchers in these fields has paved the way for the future of offshore robotics, combining the best of both nature and technology.

For offshore wind farms to be built and maintained on the scale we need, the use of autonomous robots will be crucial. However, the limitation on their usage is not on the technological or data processing capabilities of the robots, but rather the physical limitations of how far they can go untethered and how well they can perform dexterously complex tasks. And it is by being inspired by the billions of years of natural selection that has been taking place in the Earth’s oceans that we can overcome these limitations.