DFKI-Led Consortium Develops Autonomous Underwater Welding Robot for Maritime Repairs

Welding torches and stereo cameras on the robot end effector during test preparations in the DFKI Maritime Exploration Hall in Bremen. © DFKI, Christian Koch

(IN BRIEF) Researchers led by the German Research Center for Artificial Intelligence have developed an AI-enabled underwater welding robot capable of performing welding tasks largely autonomously. Created within the government-funded MARIOW project, the system combines a deep-sea robotic arm, AI-based weld path planning, and a continuous wire welding process. Successfully demonstrated in an underwater test basin, the technology aims to reduce reliance on industrial divers, improve safety, and deliver consistent, high-quality welds for maritime infrastructure.

(PRESS RELEASE) KAISERSLAUTERN, 8-Jan-2026 — /EuropaWire/ — A research consortium led by the German Research Center for Artificial Intelligence has developed a groundbreaking robotic system designed to automate underwater welding, offering a new approach to maintaining and repairing maritime infrastructure without relying solely on professional industrial divers.

Robot and weld seam, here a build-up weld in a horizontal position, after a test. Test setup in the black basin (20 m / 3.4 m x 2.6 m x 2.5 m). © AMT GmbH, Dirk Rößeler

The system was created within the MARIOW (Maritime AI-Guided & Remote Operated Welding) project, funded by Germany’s Federal Ministry for Economic Affairs and Energy. By combining artificial intelligence, advanced sensor technology, and a robotic underwater manipulator, the solution enables largely autonomous welding operations beneath the surface.

Underwater welding is traditionally performed manually, often under hazardous conditions and with limited visibility. At the same time, the maritime sector faces a growing shortage of skilled divers. The MARIOW system addresses these challenges by transferring physically demanding and high-risk welding tasks to a robot, while delivering more consistent and precise weld seams, even in poor visual environments.

Modular robotic arm for deep-sea applications

At the core of the system is a modular underwater manipulator developed by the DFKI Robotics Innovation Center in Bremen. The robotic arm is designed for deployment at depths of up to 6,000 metres and offers a reach of approximately two metres. Its modular design allows it to be adapted to a wide range of maritime repair scenarios, from port facilities to offshore structures.

The robot performing autonomous welding of a fillet weld in the black test tank. © DFKI, MARIOW Team

Through a combination of decentralised joint control and high-level motion planning, the manipulator can execute welding movements with a high degree of accuracy and repeatability.

AI-driven weld path planning

A key innovation of the MARIOW system lies in its AI-based determination of welding paths. A stereo camera system developed by the Fraunhofer Institute for Computer Graphics Research IGD captures high-resolution images directly at the welding torch. Using this visual data, AI models developed by the Laboratory for Autonomous Systems at TH Köln automatically identify welding joints as well as their start and end points.

Based on this analysis, the AI calculates the optimal robot trajectory, enabling autonomous execution of the welding task without continuous human intervention.

Continuous wire welding enables automation

Another major advance is the use of an underwater flux-cored arc welding process. Developed by the Institute for Materials and Process Technology at TH Köln in collaboration with AMT GmbH, the method replaces traditional stick electrodes with a continuous wire feed. This uninterrupted material flow is essential for stable, controlled, and repeatable welding, making automated underwater welding viable for the first time.

Successful system demonstration

All system components were integrated and tested during the final project phase at DFKI’s underwater test facility in Bremen. The demonstration included AI-based weld seam detection, automated path planning, and autonomous execution of the welding process using the flux-cored wire technique.

Christian Koch, project manager at the DFKI Robotics Innovation Center, said the results confirm the feasibility of automated submerged welding and represent a significant technological step forward for the maritime sector. He added that the technology has strong potential for industrial application and reinforces Germany’s position as a leader in advanced maritime robotics.

Next steps toward real-world deployment

Building on the project’s results, the consortium plans to further refine the system for real-world harbour and offshore environments. Future development will focus on adapting the technology to saltwater conditions, currents, waves, and increased pressure at depth. Additional enhancements, including the integration of a laser system to remove welding slag, are also planned.

Media Contact:

Christian Koch, M.Sc.
Christian.Koch@dfki.de
Phone:  +49 421 17845 3415

Press contact:

Communications & Media Bremen
communications-hb@dfki.de
Phone: +49 631 20575 0

SOURCE: DKFI