Overview
Oceanbird are developing wing sails for ocean going vessels with the overall purpose to reduce the CO2 emissions from shipping. The wings are fully automated and automatically trim themself according to the current wind conditions. The current trimming strategy use a feed-forward approach based on measured wind conditions. The drawback with the feed forward approach described above is that it relies heavily on models describing the reaction forces based on measurements on the inflow (wind). It is not certain that those models are accurate enough to actually find the trim angles that maximizes the thrust in any given situation. Further, those models needs to be adapted for each installation since the wind interactions with the ship affect both wind sensor readings as well as the aerodynamic performance of the wing. Therefore we at Oceanbird wants to explore the possibilities to use more feedback into the trimming control. Feedback parameters could be measured thrust force, measured ship speed, engine torque, engine power etc.
Objectives
The following steps are foreseen to be included in the thesis:
- Build a simulation environment that connects ship model, environmental models (wind waves), and wing models. This part of the work will be based on already existing models at Oceanbird, but they need to be connected and used in a little bit different way than today,
– Create basic controllers for the engine , e.g.
– Constant engine power control
– Constant ship speed controller
– Constant engine RPM controller - Evaluate the ship response when adding one or several wing sails in terms of speed and fuel consumption. Evaluate the different control modes described above.
– Define one or several evaluation cases, consisting of weather situations, distance to travel, ship target speed, etc. These cases shall be used to compare the impact of different control strategies. - Explore different wing trimming control strategies in the evaluation cases described above.
– Wing thrust feedback control
– Engine torque feedback control
– Ship speed feedback control
– A combination of all, including feed forward elements (e.g. apparent wind angle, AoA).
In this thesis it is important to not use ideal models of sensors, deliberately adding disturbances to measured signals will be important for making the correct conclusions. Further, if time allows, adding complexity to the physical models will also be valuable. Examples include 2d-ship model considering rudder angles to compensate for side-force, non-ideal aerodynamic models, atmospheric boundary layer etc. The goal is not to reach physical model that catches the exact same phenomena that we see in reality, but rather to add disturbances to the model that makes a pure feed forward control strategy less attractive
Skills
We are looking for a driven student with strong research mindset, with ability to design experiments, analyze results, document and iterate solutions. It is beneficial to have strong background in controls theory and simulation, and some basic software skills. It is possible to tweak the proposal and objectives to align with your interests and your degree requirements.
Contact
Akash Singh, Control System Engineer, akash.singh@theoceanbird.com