Frankenstein Goes Swimming: Software Architecture of a Modified BlueROV2 Heavy for Underwater Inspection and Maintenance

Inspecting and maintaining large man-made underwater structures, like piles of wind turbines in the open sea, has long been a job performed by professional divers. With the aim of reducing both the hazards to the divers and the costs that come with such missions, efforts have been made to develop remotely operated underwater maintenance robots that can undertake these missions in the future. One such robot that has recently been developed by the Fraunhofer research group Smart Ocean Technologies in Germany is introduced in this paper. An existing BlueROV2 Heavy from Blue Robotics was modified by adding a crawling skid underneath the robot, to which either a linear unit for anti-corrosion coating or a reading device for ultrasonic fatigue crack detection could be attached. While the project presented interesting challenges in both hardware and software integration, this paper focuses on the software architecture of the modified robot and its periphery.

I. Introduction

During the last century, advances in engineering and industrialisation have spurred the utilisation of the oceans as a resource. Shoreline stabilisation in harbours and rivers using sheet pile walls, off shore platforms for oil and gas production, or, more recently, wind energy farms, have seen an increasing amount of large metal structures being placed in conditions where they require heightened maintenance efforts. A typical inspection involves the deployment of professional divers in a series of missions that need to be organised well in advance and depend on favourable weather. Apart from the hazards that come with diving in the open sea, each dive is limited by the amount of oxygen in the diver’s tank, resulting in a lengthy, dangerous, and costly process. In addition, the number of structures that need to be inspected has been growing faster than the number of available trained divers. It would, therefore, be beneficial to automate the maintenance process, at least partly, with the help of remotely operated vehicles (ROVs). The software of one such ROV, dubbed Frankenstein due to its modular architecture, is introduced in this paper.