Simulations of Autonomous Ship Collision Avoidance System for Design and Evaluation

The main features of our simulation platform aimed for autonomous marine navigation research are described in this paper. The platform includes a Collision Avoidance System featuring two sub-systems: a decision-making protocol and an autopilot. The decision-making subsystem navigates the vessel according to the collision avoidance regulations (COLREGs), whereas the autopilot commands propulsors and control de, vices. The utilized autopilot features three modes: track-, heading- and docking modes. During an evasive action, the autopilot mode is changed from the track mode to heading mode. However, the location of the ship related to the track and track limits is monitored in the heading mode also. For harbor maneuvering, the function of the track mode is extended to slow speeds. The system has been implemented to a ship handling simulator environment and selected simulation scenario with object crossings is presented in this paper. The developed system can be used for the design and evaluation of autonomous ship systems. More specifically, we suggest the following application fields for the system: 1) development of autonomous navigation systems, 2) human factors studies with potential users, 3) verification and validation activities, and 4) scenario tests before real implementations on autonomous vessels. Finally, the general requirements and boundary conditions related to autonomous navigation systems are also discussed in the paper.