Levels of Automation
Especially the so-called SAE levels (levels that classify assisted, automated and autonomous driving according to the SAE standard J3016) have become established for the definition of the respective continuous driving automation. The following SAE levels are described by the SAE standard:
The Federal Highway Research Institute (BASt), as the central research institution of the Federal Ministry of Digital and Transport (BMDV), has introduced a further subdivision based on the SAE levels and focusing on the role of "today's driver". The three central modes of the BASt (see BASt-Website) are intended to simplify the classifications that are widespread among experts and to provide users with an overview of the human roles that are emerging with increasing vehicle automation. The user-centred simplification is shown in the figure below:
The figure provides two bars for each mode, which are to be understood as a timeline from left to right. The upper bar (yellow) represents the operating time of the human driver. The lower bar (green) in turn represents the operating time of the respective assisting, automating or autonomous function.
The assisted mode is characterised by the fact that the driver is responsible for the driving task during the entire driving time. The driver is supported by functions such as adaptive cruise control during the journey. In addition, the driver can also be supported by other systems such as the lane departure warning system, which keeps the vehicle in the centre of the lane.
These systems thus influence the longitudinal and lateral guidance of the vehicle.
The automated mode allows the driver to completely hand over his driving task to the system. However, this is only possible within a defined area, the so-called domain of the system. The system recognises its domain independently and offers its activation to the driver. After the driver has activated the system, the system takes over the driving task completely and the driver changes into the role of the user. As a user, the person in the driver's seat can turn to other activities. The prerequisite is that the user remains attentive enough so that he or she can resume the driving task when prompted by the system. This becomes necessary when the system recognises that it will soon leave its domain. In this case, the system requests its user to take over the driving task with at least 10 seconds lead time. After taking over by deactivating the system, the person in the driver's seat is again in the driver role and is again fully responsible for the driving task.
The autonomous mode is characterised by the fact that there is no longer a driver as long as the mode is active. All persons in the vehicle are therefore only passengers who do not have any driving-related tasks. The system is able to take over all driving tasks.
A vehicle that has an autonomous mode can (but does not have to) have pedals and a steering wheel.
As already mentioned, the three modes of the BASt are based on the SAE levels, which classify and define assisted, automated and autonomous driving (SAE- Standard J3016). How the SAE levels are divided among the previously described roles and what characterises the SAE levels can be taken from the following illustration.
Classification of the functions according to the SAE levels
| SAE-Level 0 | There is no continuous or automating function present. However, this does not preclude the presence of other automated functions or warning functions in the vehicle, such as the lane departure warning system (LDWS). SAE Level 0 is not associated with the assisted mode. |
| SAE-Level 1 | The included functions support the driver in steering (lateral guidance) or braking/accelerating (longitudinal guidance). |
| SAE-Level 2 | The included functions support the driver in lateral and longitudinal guidance. |
Quelle: BASt und SAE Standard J3016
| SAE-Level 3 | If the system is within the system limits, where the automated mode can be activated or used (within the domain), it can take over the driving task. The driver must be ready to take over the driving task again (e.g. when approaching a system boundary). |
Quelle: BASt und SAE Standard J3016
| SAE-Level 4 | The system is able to take over the driving task completely within its domain. If the system is no longer able to perform the driving task (e.g. immediate departure from the domain) and a driver does not take over control of the vehicle, the system automatically initiates the vehicle to engage a minimum-risk state. |
| SAE-Level 5 | The system is able to take over the driving task completely. A driver or an intervening person in the vehicle is not required. |
Quelle: BASt und SAE Standard J3016