Digital Twin of Vessels in Arctic Environments: Extending a Simulation Environment to allow for External Control of Multiple Vessels

This thesis presents the work performed on extending and improving a numerical ice tank simulator developed by ArcISo AS called Simulator of Arctic Marine Structures (SAMS). The main work for this thesis has been on extending SAMS, so external software can connect to, and control, a vessel in SAMS. To allow for such a connection, SAMS has been modified to work as a server which clients in external software can connect to over a TCP/IP connection. The simulator itself was also modified with the added ability for multiple vessels as well as several minor improvements. An external software for manual control of a vessel was also created. The main external software used in this thesis have been Simulink, and several controllers have been implemented in Simulink for the various simulations performed in this thesis. These controllers includes a PID-, an acceleration feedback-, a velocity- and an ice management-controller. With these controllers a nonlinear observer and a thruster allocation was also implemented. Simulations regarding ice management and dynamic positioning have been conducted together with simulations to verify the simulator against full-scale sea trial data and empirical formulas.