Levels of autonomy for driverless cars

As driverless car technology progresses, there is considerable misunderstanding about the different flavors of autonomous vehicle technology. When car makers talk about driver assistance systems, they have to address some very different issues than when researchers look towards fully autonomous systems which are capable of completely independent (possibly even off-road) operation. We propose to distinguish the following three different levels of autonomous operation (Assistive, Managed, Independent) and provide an explanation of some of the unique issues that need to be addressed for each of these levels.

Levels of autonomy Characteristics Examples Unique problems
Assistive (lowest) Driver assistance system can perform certain driving tasks autonomously, human driver is always needed. Intelligent cruise control keeps lane, manages speed and brake on highways, intelligent parking, …
Mercedes Distronic Plus, Lexus Advanced Pre-Collision System, Volvo Pedestrian Detection
Switching between human driver and driver assistance system. Understanding driver’s intentions; deciding when to act autonomously without driver consent (e.g. pre-crash braking); deciding when situation is too complex for driver assistance system
Managed (medium) Car drives fully autonomously but relies on regularly updated external knowledge (and possibly services) provided remotely Google driverless car; compares environment to continually updated 3D map from Google servers; car can not miss known stop lights because of the map; data exchange is two-way: driving updates the map; Map may include predefined routes for areas that are difficult to navigate. Operation may be limited to mapped area. Building the initial map, maintaining it, interfacing with third-party data sources to keep map up to date.
Propagating changes to vehicles.
Coping with perceived changes to the environment which are not yet in the shared map (e.g. new construction zone: update map; missing stop light: may need additional (human?) verification to avoid sensing errors)
Independent (high) Car operates fully autonomously and matches human driving ability even in unknown terrain without external communication. Mostly research prototypes, e.g MuCar3. Usage scenarios that may require independence: military, off-road, emergency response. Requires a very high level of contextual knowledge and reasoning.
What is the minimum level of prior map knowledge required for safe operation in normal traffic in this mode?
© 2013 Hars, A.: driverless-future.com