Autonomous vehicles are cars or trucks that perform functions to support dependent on connecting devices with intelligence such as lights, radars, steering etc. to situation awareness and planning. The fusion of components and intelligence is what makes AV different from regular vehicles.
We differentiate autonomous vehicles from autonomous transport systems. Whereas autonomous transport systems are interconnected fleets of vehicles owned by a business to service a particular need systematically, autonomous vehicles serve individual passengers (who may or may not own the vehicle).
Autonomous vehicles are widely divided into five degrees of autonomy. The movement towards greater autonomy is impacted by technical, environmental, and regulatory or legal factors. A given vehicle may be technically capable of an advanced level of autonomy but be unable to perform to that level in a highly chaotic environment or may be prevented by regulatory prohibition or legal risk.
Level Zero – No Automation
At level zero, the operator performs all tasks. The vehicle has no autonomy.
Level One – Driver Assistance
At level one, the vehicle can assist with specific functions such as applying modest breaking force when the vehicle approaches too close to an obstacle. However, the vehicle operator is responsible for accelerating, braking, and monitoring of the surrounding environment.
Level Two – Partial Automation
At level two, the vehicle can assist with steering or acceleration functions and allow the operator to disengage from some of their tasks for a limited duration. However, the operator must always be ready to take control of the vehicle and is responsible for safety-critical functions and monitoring of the environment. Many vehicle manufacturers are developing vehicles at this level.
Level Three – Conditional Automation
At level three, the vehicle controls all monitoring of the environment using sensors such as LiDAR. The operator's attention remains critical but the operator can disengage from “safety critical” functions like braking and expect the vehicle to navigate safely under normal conditions. In the case of trucks, many level three vehicles require no human attention to the road at speeds under 37 miles per hour.
Level Four – High Automation
At level four, the vehicle is capable of steering, braking, accelerating, and monitoring the vehicle and environment, and responding to unexpected events in most driving conditions. At level four, the vehicle notified the driven when conditions are safe for autonomous transportation. The vehicle is then expected to be able to operate as well as a typical human operator. However, the vehicle may request to transfer control back to the human operator under highly dynamic circumstances.
Level Five – Complete Automation
At level five, no human attention is required. Level five vehicles do not require space for an operator. Likewise, there is no need for pedals, brakes, a steering wheel or other manual controls. The autonomous vehicle system controls all critical tasks, monitoring of the environment and identification of unique operating conditions.
As noted above, it is significantly easier to reach level five automation in a controlled environment such as a mine or metro track than in a highly dynamic environment such as a city road.