Development of a simple navigation system for the Autosub autonomous underwater vehicle

Autosub is a project funded by the Natural Environment Research Council in the UK, with the aim of developing unmanned autonomous underwater vehicles to carry out long range scientific missions in the deep ocean. The navigation system is critical to the survival of the vehicle, and so it is important that appropriate software engineering methods are used. Structured analysis and design methods are useful in helping to capture the requirements of the system, and in producing a well structured design that encourages re-use of code and data. This is necessary but not sufficient. We must also address implementation issues such as multi-tasking, sharing of hardware resources, and message passing and testing. The author describes the methods that he has used in developing the navigation system and gives a personal account of the problems that he has encountered