Seam-welds inspection of underwater structures using submersible mobile robot

The paper reports on a project with the objective to inspect seam welds on underwater structures (e.g. oil platforms). A robot is mounted to a submersible vehicle which also carries the required equipment and tools for cleaning, measuring and inspection. The robot's tasks as well as the path of the submersible vehicle are preprogrammed using an off-line programming and simulation system developed at the IPK. In the first phase of the project, the overall concept was simulated by computer. Additionally, a laboratory model was constructed using a Manutec R 15 industrial robot and a tube intersection of a research platform in order to test the system. In further project phases, real underwater experiments are planned. Design work has begun concerning a waterproof robot and a mechanical interface between submersible vehicle and robot. This includes additional translational and rotational axes for robot positioning. The execution of robot tasks and the transport of the robot by the submersi ble vehicle to the underwater docking position have to be executed autonomously. For autonomous transport, a navigation system is required. Therefore, a feasibility study concerning analytical principles and performance evaluation was conducted in combination with a market survey of available components. Some of the study results are briefly presented in the paper.