Royal IHC and research institute MARIN have completed dynamic positioning (DP) assessment tests for the autonomous T60-18 service operation vessel (SOV). The data gained will provide input for an SOV simulator and should eventually lead to the development of a prototype, according to the shipbuilder.

For the project (part-funded by a subsidy from TKI Wind Op Zee), IHC has developed technology that will allow one of its SOVs to navigate safely through an offshore wind farm and provide access to the turbines. Plans are for operations to be executed by the vessel’s autonomous software while under the supervision of a duty officer at the wheelhouse.

The goal is to make vessel operation easier through an integrated solution that provides enhanced workability by incorporating the dynamic positioning system (DPS), the motion-compensated gangway and vessel movements. The autonomous operation of the SOV has been in development for several years. By providing an integrated approach to the SOV design and mission equipment, high performance standards are said to be achieved.

Autonomous SOV simulator

Following the powering and seakeeping tests, the DP assessment was the final series of model tests for the vessel, and will provide input for the ship models in IHC’s autonomous SOV simulator. At the same time, the tests have proven the motion characteristics and position keeping capabilities of the SOV, as well as IHC’s DPS. The tests were conducted at MARIN’s basins in Wageningen, the Netherlands.

Upon completion of the project in December 2020, a simulator will be in operation that encompasses all functional systems of the autonomous vessel. The simulator will then be used to demonstrate the feasibility of the system and benchmark efficiencies. By improving safety, increasing workability and reducing operational expenses, it is expected that the implementation of the autonomous SOV will lead to a significant reduction in service and maintenance costs of the offshore wind farm.

‘A next phase of the project will focus on the further development of the autonomous navigation and control functionality,’ says MARIN’s team-lead Autonomy & Decision Support Egbert Ypma. ‘This project provides an excellent case in demonstrating the full potential of an autonomous functionality in an operational setting. The challenges lie not only in the development of this functionality, but also in the validation and testing of the whole system in order to prove its robustness against malfunctioning sensors and subsystems.’

He adds: ‘In addition, a validated simulation environment – with the ability to interface with the DPS and other automation systems – provides the opportunity to safely test the vessel to its limits and beyond. The follow-up to this project will present many opportunities for IHC and MARIN to jointly explore the challenges that lie ahead.’

Towards a prototype

‘We tested the vessel’s seakeeping behavior and position keeping in challenging environmental conditions similar to central North Sea with 3 to 3.5 metres significant wave height,’ explains IHC’s product manager Jeroen Hollebrands. ‘These tests have given us great insight in the performance of the vessel and IHC DP system and gives us confidence to build SOVs capable of operating in these conditions.’

With the simulator, IHC wants to show the vessel in action to industry stakeholders. ‘Moreover, we can then take the next steps towards the development of an autonomously operating SOV as a prototype,’ concludes Hollebrands.