As part of a project by the Fraunhofer Institute for Applied Systems Technology (AST) in Ilmenau and the Rostock-based Fraunhofer Institute for Large Structures in Production Technology (IGP), an underwater robot is currently being developed to repair coating damage on maritime structures. The aim is to make maintenance work more efficient and safer in future.
Coatings provide maritime structures with effective protection against corrosion. However, damage to the anti-corrosion coating can occur during transportation and installation as well as during long periods of operation. As a result, there is an immense need to repair coating damage. This is currently covered by the use of divers. As part of the Fraunhofer Smart Ocean Technologies research group, a so-called ROV (Remotely Operated Underwater Vehicle) is currently being developed for this work.
However, the applicator and its adjustable speed of movement, the coating material and the material flow rate are decisive for the quality of the coating applied by this underwater robot. An application technique selected in the test setup was equipped for underwater use and the motor and control units were adapted for field use by means of waterproof housings. In initial tests, the parameters defined in the laboratory were used to successfully apply a coating to a steel sheet with a prepared surface lying vertically one meter below the waterline. However, the mechanized application technique alone does not enable immersion-free coating repair, as surface preparation is also an important part of the repair process. A combined process of surface preparation and coating application is therefore to be developed in a follow-up project.
