Autonomous vehicle control is a fancy way of saying a vehicle is self guided, based upon onboard sensor input. GPS, Sonar, IR, and other sensors can help a unmanned vehicle (plane, boat, car, etc.) navigate on it's own with out human input. There are tools available to enable this. The main tool is called Ardupilot. Failsafe ability allows a remote control link to take over if Ardupilot loses control.
Learn how to build your Arduino guided vehicle at http://diydrones.com/profiles/blogs/ardupilot-main-page.