- Autonomous Vehicles - Home
- Autonomous Vehicles - Introduction
- Autonomous Vehicles - Types
- Autonomous Vehicles - Needs
- Autonomous Vehicles - Advantages
- Autonomous Vehicles - Possible Impact
- Autonomous Vehicles - Levels of Autonomy
- Autonomous Vehicles - Technology
- Autonomous Vehicles - Risks
- Autonomous Vehicles - Applications
Levels of Autonomy in Driving
Autonomous vehicle technology is not a futuristic dream; instead it has become a rapidly evolving reality. Autonomous or self-driving technology is revolutionizing and transforming the transportation industry. It is increasing the driving comfort and road safety and changing our way of interacting with vehicles.
Self-driving technology has different levels of autonomy. Based on the autonomy levels, vehicles can be classified into six different classes, ranging from fully manual to completely autonomous. This classification of levels of autonomy in driving is done by the Society of Automotive Engineers (SAE).
In this chapter, we will explain each level of autonomy in driving and will understand its technology, capabilities, and current status of use. This understanding of levels of autonomy is important for gaining insights into the future of autonomous vehicles.
What is Autonomy Level in Driving?
The extent to which a vehicle can perform driving functions autonomously, without any human intervention, is referred to as autonomy level in driving. Autonomy level basically describes the involvement of a human driver to control the vehicle operations.
Autonomy level can vary from zero automation to full automation, depending on the vehicle's control capabilities by the human driver. This concept is primarily used to clarify the capabilities and limitations of a vehicle with respect to self-driving technology.
Levels of Autonomy in Driving
The Society of Automotive Engineers (SAE) has defined six levels of autonomy in driving, depending on their features, capabilities, and limitations. These six levels of driving autonomy are explained here in detail −
Level 0 No Driving Automation
The SAE level 0 is termed as No Driving Automation. At level 0 autonomy, the vehicles are fully manual and need a human driver to perform all driving tasks and control the vehicle.
However, these vehicles are equipped with some basic safety and warning features like emergency braking and lane change warning. These features just assist the human driver, but do not provide any driving automation in the vehicle. Most cars and other vehicles, we see on the roads today are level 0 autonomous vehicles and fully controlled by the human drivers.
Level 1 Driver Assistance
The SAE level 1 is termed as Driver Assistance. At level 1 autonomy, the vehicles are capable in providing driver assistance with either steering or acceleration but not both at the same time. Hence, in these vehicles, the driver requires to have a constant oversight on the vehicles operation.
The most commonly used technologies in level 1 vehicles include adaptive cruise control (ACC) and lane-keeping assistance. ACC is responsible for maintaining a constant speed and safe distance between the vehicle and the vehicle in front of it. Hence, cars with features like cruise control, park assistant, etc. fall in this category.
Level 2 Partial Driving Automation
The SAE level 2 is referred to as Partial Driving Automation. The level 2 vehicles are capable in providing assistance with both steering and acceleration simultaneous under a specific driving environment. However, it is important that the human driver must continuously monitor the surrounding and be ready to take over when needed.
The level 2 vehicles use Advanced Driver Assistance Systems (ADAS) to perform autonomous steering, speed control, and breaking functions. Some common examples of currently available level 2 autonomous driving systems include Tesla's Autopilot, GMs Super Cruise, etc.
Level 3 Conditional Driving Automation
The SAE level 3 is referred to as Conditional Driving Automation. The level 3 vehicles are capable in detecting environment conditions dynamically and make decisions based on that. For example, these vehicles can autonomously accelerate past a slow-moving vehicle. However, a human driver is still required for continuous oversight. The driver must be ready to take control if the autonomous system is unable to perform the function.
Vehicles of this category are equipped with advanced sensors and AI (artificial intelligence) technologies. Using these technologies, the level 3 vehicles can perform traffic navigation and speed adjustment, but under the supervision of a human driver. Audi's A8L with Traffic Jam Pilot is a common example of level 3 autonomous vehicle.
Level 4 High Driving Automation
The SAE level 4 is termed as High Driving Automation. At level 4, the vehicles are capable in performing full driving automation within a specified geofencing area. Also, these vehicles do not need a human driver under normal conditions and the specified area.
In level 4 vehicles, the most widely used technologies include HD mapping, robust artificial intelligence technologies, and redundant systems. All these technologies together allow this category vehicles to operate safely without any human intervention. Although, the level 4 vehicles are still unable to operate in unrestricted environments autonomously.
Examples of level 4 autonomous vehicles include Waymo's driverless taxi and Navya's autonomous shuttle.
Level 5 Full Driving Automation
The SAE level 5 is the Full Driving Automation. At level 5, the vehicles are capable in performing all driving tasks under all conditions without any human intervention. Hence, level 5 vehicles are referred to as completely autonomous vehicles. These vehicles do not have human driver controls like steering wheel, brake pedals, etc.
In these vehicles, advanced artificial intelligence technologies and smart sensor suite are used to provide accurate and reliable monitoring of the surrounding environment. These vehicles can understand the road conditions, traffic flow, road signs and signals autonomously. Therefore, level 5 vehicles can be termed as completely driverless cars or self-driving cars.
Summary of Driving Autonomy Levels
| SAE Level | Name of Level | Driver Responsibility | Vehicles Capabilities | Examples |
|---|---|---|---|---|
| Level 0 | No Driving Automation | Driver has full control | Basic safety features, but no driving automation | Most vehicles on the road today |
| Level 1 | Driver Assistance | Driver has full control with some basic assistance. | Either speed or steering control, but not simultaneously | Vehicles with adaptive cruise control |
| Level 2 | Partial Driving Automation | Driver must monitor and be ready to take control if system fails. | Steering and acceleration at the same time | Teslas Autopilot and GMs Super Cruise |
| Level 3 | Conditional Driving Automation | Driver has to take control when required. | Full driving control in specific conditions, and it alerts driver to assist when required | Audis Traffic Jam Pilot |
| Level 4 | High Driving Automation | No human driver is required within a geofenced area. | Complete autonomous driving in specified areas, also can handle emergencies. | Waymo driverless taxi |
| Level 5 | Full Driving Automation | No human driver needed under any conditions. | Fully autonomous under all conditions, no need of human controls | Under development |
Conclusion
In conclusion, the SAE has defined total six driving autonomy levels. Each level has its own features and capabilities. Today, most vehicles that we see on the roads fall under the level 2 category of driving autonomy, as they provide only assistance to human driver rather than full driving automation.
Level 3 vehicles are close to production and commercialization but pending for regulatory approval in many countries. Level 4 and Level 5 vehicles are under the development and testing stage. However, with the technological advancement, full autonomy is expected in the near future. Lets move to the next chapter and learn about Technologies Inside Autonomous Vehicles.