A robotic shrimp that climbs the underwater foundation of an offshore wind turbine, inspecting the structure, reading sensor data and even repairing damaged paint? It sounds like the sequel to “District 9,” but that's exactly what it is Crawfish, a new experimental underwater robot, can do. Developed by the scientists of the research group Fraunhofer Smart Ocean Technologies in Germany, this innovative device promises to revolutionize the maintenance of offshore renewable energy platforms.
An all-round shrimp
The Crawfish is not the usual ROV (Remotely Operated Vehicle). In reality, it consists of two parts: a BlueROV2, a commercial ROV produced by the Californian company Blue Robotics, and a crawler unit equipped with four direct-drive elastomer wheels and various tools such as a camera, a brush and a special head reading the sensors.
Thanks to its weight of only 22 kg, the Crawfish can be lowered into the water by two or three human operators, without the need for a crane. Once submerged, an operator on the surface guides the device towards the structure using the BlueROV2's camera and thrusters.
Underwater grip and mobility
When it reaches the vertical surface of the platform, the Crawfish shows its true capabilities. The robotic shrimp's thrusters apply a "downward" (or horizontal, depending on your point of view) force of up to 90 Newtons, keeping it firmly in place. The robot can then move along the surface using its motorized wheels.
During this process, the robot's camera is used to remotely check for damage to the structure's anti-corrosion paint, while it wirelessly collects and transmits data to and from sensors located at various points on the platform, monitored via ultrasound. If paint damage is found, it can be repaired using a two-component coating material that is injected into the shrimp robot's remote-controlled brush. Even faulty welds could theoretically be repaired using an on-board welding head.
In its current form, the Crawfish can descend to a maximum depth of 50 meters, and move for 25 minutes per battery charge. These characteristics make it a truly tireless shrimp and always ready for action. Got it, Spongebob?
A revolution for offshore renewable energy
There is little to do. Wind? Of the tides? Of wave motion? Offshore renewable energy, of all kinds, is increasingly important in the transition to a low-carbon future. Maintenance of these structures, however, can be a challenge, especially when it comes to underwater work. This is why Crawfish can make the difference. By offering a cheap, efficient and safe alternative to human divers, the underwater shrimp could revolutionize maintenance in this industry. She can climb, inspect, read data. Even repair. And she stands to become a key ally in our pursuit of a cleaner, more sustainable energy future.
He may not be the most glamorous of clean energy heroes, but he could certainly be one of the most important.
