For participants only. Not for public distribution.

Note #23
Top-level control

John Nagle
Last revised May 11, 2003.

DRAFT

Driving control is generally in one of the following states:

State
Actions
Road
following
Maps indicate that a road should be in the area and going towards the next waypoint. Road follower has primary control.
Road
search
Maps indicate that a road should be in the area and going towards the next waypoint, but road follower does not see a road. Off-road driving control is primary, with the goal direction changing so that the vehicle executes a search pattern of shallow S-turns generally heading towards the next waypoint.
Off
road
Maps do not indicate a usable road in the area. Off-road driving control is able to move towards the next waypoint without encountering a major obstacle.
Maze
solving
An obstacle has been encountered that cannot be easily bypassed. A simple path-planning algorithm like A* is used to try to get out of the problem.
Stationary mapping
The vehicle is stopped, and steerable sensors are used to build up as much map information as possible.
Stopped
The vehicle is stopped and not doing anything.