AbstractThis thesis documents an investigation into the automatic provision of reasonably realistic motion for the computer generated target ships in a marine simulator. The thesis explores: automatic collision avoidance between the target ships; automatic track keeping for the target ships; the use of sea stabilised and land stabilised motion for the target ships; some issues of software fault tolerance in marine simulators; message frameworks for use in a Multi-Agent System (MAS) simulation; the opportunity to provide different manoeuvring characteristics for different target ships; and the use of autonomous agents to control the target ships.
A software system has been developed to facilitate this research. Entitled "A Multi-Agent Realm for Investigating Navigators' Educational Simulators" (MARINES), the software is a MAS providing much of the functionality of a marine simulator instructor station; basic functions are encapsulated into the instructor environment and additional features are provided by processes that connect to the environment using Dynamic Data Exchange. The processes can also connect to each other and, in MARINES, co-operate to navigate the ships. These co-operative, autonomous processes are the agents that together form a MAS. A simple 3D view is also connected, enabling the view from the bridge of a specific target ship to be assessed. The MARINES software is written using C++ to run under Microsoft Windows v3.1. Therefore, the processes multi-task co-operatively.
In MARINES each target ship can be made to perform in an individual manner; manoeuvring and performance characteristics can be customised to simulate a specific ship type. Additionally, the agents performing collision avoidance can be given rule sets that interpret the International Regulations for the Prevention of Collisions at Sea in subtly different ways, and the track-keeping agents can have different beliefs about the manoeuvring capabilities of the vessels they control. Automatic collision avoidance and track keeping is performed for two-ship situations even when the set and drift of a current is introduced. A comparison is made with the tracks of land stabilised targets. This shows how aspect, course and speed are affected by ignoring the effects of the current, and demonstrates the need for an accurate simulation.
|Date of Award||Jul 1997|
|Supervisor||Douglas Tudhope (Supervisor)|