If the driver remains passive, due perhaps to a health issue, the final phase – emergency intervention – initiates. The warning signal becomes piercing, the safety belt is fully tightened. The A8 slows in its lane to a standstill and at the same time switches on the hazard lights. Once the sedan has come to a complete stop, the system activates the parking brake, shifts the tiptronic to its P setting, unlocks the doors, switches on the interior light, and then sends an emergency call via the mobile network if no response from the driver can be detected. This type of emergency stop in slow-moving traffic makes sense because it prevents the A8 from moving forward uncontrollably.
In trials with test subjects at Audi, most drivers responded during the first phase of the prompt to take over. The traffic jam pilot remains on standby until the driver switches it off with the Audi AI button. If the conditions are right for using it again, the system indicates its availability in the Audi virtual cockpit. The driver then merely needs to take their hands from the steering wheel to activate the traffic jam pilot.
While traffic jam pilot is activated, the speed of the Audi A8 is limited to 60 km/h
(37.3 mph). If the traffic begins to clear and the vehicles ahead accelerate, the system remains active a few more seconds after a prompt to take over, until the driver has resumed driving.
Comprehensively connected: the sensors in the new Audi A8
The basic requirement for use of the traffic jam pilot in the Audi A8 is the highly detailed collection of data about the environment surrounding the car. The flagship car accomplishes this with a new complete set of sensors:
- twelve ultrasonic sensors on the front, sides and rear,
- four 360 degree cameras on the front, rear and exterior mirrors,
- one front camera on the top edge of the windscreen,
- four mid-range radar sensors at the vehicle’s corners,
- one long-range radar sensor on the front,
- one laser scanner on the front,
- driver observation camera in the top of the instrument panel.
High-tech data center: the central driver assistance controller (zFAS)
Data from the laser scanner and all other systems are combined in the central driver assistance controller known as zFAS. The roughly tablet-sized computer continuously monitors the signals to create an image of the car’s surroundings. In sum, the control unit has more power than all of the systems in the previous model of the A8. The sensor data is read into the “fusion” layer in the zFAS unit and combined into a sophisticated environment model. To further increase safety during piloted driving, Audi has given the system a redundant design that uses a second data fusion taking place in the control unit of the long-range radar. Data from the other sensors is also processed here.
The legal situation
Introduction of the Audi AI traffic jam pilot requires both clarity regarding the legal parameters for each country and specific adaptation and testing of the system. Moreover, varying worldwide homologation procedures and their deadlines must be observed. For these reasons, Audi will initiate series production of the traffic jam pilot in the new A8 incrementally.
A question of responsibility: the levels of automation
In the classification of automated driving, the responsible bodies in Europe and the United States – for example, the German Federal Highway Research Institute and the SAE Institute – have agreed on six levels.
- Level 0 – No Automation: The driver is continuously responsible for longitudinal and lateral control.
- Level 1 – Driver Assistance: The system is able to take over either continual longitudinal or lateral control of the vehicle. The driver is supported by the system but remains responsible. The driver must be ready to take over the driving task immediately when needed. An example of a level 1 system of this type at Audi is the adaptive cruise control (ACC) system.
- Level 2 – Partial Automation: In certain situations, the driver can delegate continuous combined longitudinal and lateral control of the vehicle to the system but retains the monitoring and overriding function at all times. The driver therefore always maintains responsibility. An example is the traffic jam assist from Audi. it assumes the tasks of braking and accelerating the car in slow-moving traffic up to 65 km/h (40.4 mph), and also takes charge of steering on better roads.
- Level 3 – Conditional Automation: The driver no longer has to continuously monitor and can carry out other activities supported by on-board equipment. The system autonomously recognizes its own limits – that is, the point at which the ambient conditions no longer match the range of functions of the system. In these cases, the vehicle prompts the driver several seconds in advance to take over the task of driving. The new traffic jam pilot from Audi fulfills these criteria.
- Level 4 – High Automation: Systems with Level 4 function do not require drivers to assist or take over the driving but their function is limited to a specific area – such as on highways or in a parking garage. In these situations, the driver can completely transfer the task of driving to the system. The driver only needs to resume the task when the car leaves the area defined for fully automated driving. Future scenarios such as robot taxis in city centers are another example of such a system. They take over all driving tasks within a restricted speed range and on a limited route.
- Level 5 – Full Automation:The car assumes complete longitudinal and lateral control. Level 5 systems do not need help from the driver in any situation.
The legal parameters: registration laws and regulations
The introduction of the traffic jam pilot is subject to varying legal parameters worldwide. Many legislators are currently dealing with the issue. They want to create regulations for automated and autonomous systems or appropriately adapt existing provisions. This applies both to laws governing approvals and to regulatory laws regarding conduct. The former govern the technical requirements for the piloted system the car manufacturer must fulfill in order to obtain approval of the system in a particular country. Regulatory laws regarding conduct or road traffic laws, on the other hand, govern the use of the system by the driver and the driver’s conduct on public roads.
The required conditions for approving the traffic jam pilot are currently being revised in many countries around the world. Audi expects to obtain the required authorizations for the use of the traffic jam pilot successively and for individual countries.
Lawmakers are also actively working on road traffic laws and support the introduction of automated driving functions. The government in Germany, for instance, modified the regulations in late June 2017 to allow driving cars with conditional and fully automated functions “within the designated parameters for use.” Audi hopes that other countries will follow in the next few months.
Data logging: liability in an accident
In the case of an accident in automated driving mode, it must be determined who was carrying out the task of driving when the accident occurred – the driver or the system. In Germany, for example, the car insurance company is initially liable to the other party in the accident. In the second step, the insurance company would then – as it is the case today – hold the manufacturer liable, provided that a product defect of the car, or of the system, led to the damage.
In an A8 with Audi AI traffic jam pilot, the data memory for automated driving (DAF) documents who is performing the driving task. When the traffic jam pilot is activated, this legally mandated data logger registers the handover between the driver and car as well as the prompts to take over. As required by law, the information is stored in the memory for six months. The DAF parallely records various indicators from situations in which contact with other vehicles almost or actually occurs, or in which certain acceleration thresholds are exceeded. An event of this type can include an airbag deployment or automatic emergency braking, for example. The indicators are continuously recorded in the control unit. These do not permit the identification of persons or vehicles, such as faces or license plates. When the ignition is switched off, the data is deleted.
In the case of a collision, the DAF permanently saves the data packet from the last few seconds prior to the accident. The following criteria are stored here:
- Driver interaction (e.g. braking by the driver or steering angle)
- Status of the traffic jam pilot function (e.g. “traffic jam pilot was activated”)
- Vehicle dynamics (e.g. longitudinal and lateral acceleration)
- Environment (e.g. sensor information)
- When the traffic jam pilot is activated: readiness of the driver to take over (e.g. “the anonymized input data of the camera indicate that the driver was ready to take over”)
Data packets of an accident that have already been saved cannot be overwritten but those of automatic emergency braking can. If existing memory capacities are full and another accident or another event that triggers data recording occurs, the oldest data packet that can be overwritten is always replaced by the new data packet.
Processing and storage of the information described above is carried out locally in the car. There is no automatic transmission to AUDI AG or another third party, such as through the Cloud. Control over the data lies with the owner or driver. AUDI AG has no access to it.