The adaptive cruise assist (ACA) assists the driver with longitudinal and lateral control over the entire speed range – substantially enhancing comfort on long journeys, in particular. It incorporates the functions of adaptive cruise control, traffic jam assist and active lane assist. Depending on the model, the ACA uses the radar sensor in the nose of the vehicle, the laser scanner, the front camera and the ultrasonic sensors to permanently monitor the vehicle’s surroundings.

Depending on the sensor set, the system detects lane markings, roadside structures, vehicles in adjacent lanes and vehicles driving ahead. The ACA uses this information to derive a virtual vehicle path and “guides” the vehicle within it. The system also includes helpful steering intervention so that the vehicle remains in the center of the lane. In some models based on the modular longitudinal platform, the system uses also the laser scanner: The ACA detects if the lane is too narrow to allow side-by-side driving and enables offset driving through narrow stretches.

The adaptive cruise assist maintains proper speed and following distance via targeted acceleration and braking. The car automatically adapts its speed to the traffic situation and the route, for example at curves and cross-ways. In stop-and-go traffic as well as traffic jam situations, the ACA can bring the car to a complete stop. Depending on the duration of the stop, the car can start automatically again.

The Audi pre sense 360˚ detects collision hazards all around the car and initiates specific safety measures. It includes the following driver assistant systems:

• Audi pre sense front
• Audi pre sense rear
• Audi pre sense basic
• Audi pre sense side

Audi pre sense front and Audi pre sense city utilize the data of radar sensors and/or the front camera, depending on the car model, to compute the probability of a collision. Within the limitations of the system, it warns of collision threats and initiates braking at specific vehicle speeds. Vehicles are detected in the driving speed range of up to 250 km/h (155.3 mph), pedestrians up to around 65 km/h (40.4 mph) or 85 km/h (52.8 mph) depending on the model, as well as cyclists, depending on the system.

If a collision is imminent, the system warns the driver with visual, acoustic and haptic warnings based on a multistage warning concept. If necessary, the system provides braking assistance to reduce vehicle speed or initiates a full brake application to avoid the collision under certain circumstances. Actions are also taken to protect occupants. The hazard warning lights are activated, the seat belts are reversibly pretensioned, the seat position is optimized, and the windows and optional panoramic glass sunroof are closed.

Audi pre sense side reacts in the event of a collision from the side. Amongst ohthers it uses the radar sensors of the crossing assist to calculate the probability of an accident involving traffic approaching from the side. The system can detect the threat of side collisions at speeds of up to approx. 60 km/h (37.3 mph) and apply preventative measures to help protect occupants. These include: activating the hazard lights, tensioning the safety belts, optimizing the seating position, and closing windows as well as the optional panoramic glass roof.

In an impending lateral collision at more than 25 km/h (15.5 mph), the suspension actuators of the optional Audi AI active suspension raise the body on the side exposed to the danger by up to 80 millimeters (3.1 in) within half a second. The other vehicle therefore hits the car in an even more impact-resistant zone. The side sills and floor structure accommodate a large portion of the impact forces. Deformation of the cabin and the loads acting on the occupants, above all to the chest and abdomen areas, are reduced by up to 50 percent compared with a lateral collision with no raising of the suspension.

arking system plus informs the driver, visually and audibly, about obstacles in front of and behind the vehicle. The warnings are made when the distance to a detected object in the path of driving is less than 90 cm (35.4 in) – depending on the specific model – after the driver has engaged reverse gear and activated the system by pushing a button on the center console.

Ultrasonic sensors measure the distance, the MMI display depicts it visually. A white segment shows a detected object outside of the driving path. Red segments represent detected objects within the driving path. The virtual driving path display also shows lateral guide lines which are precalculated based on the currently selected steering input. Increasing frequency of the audible warning indicates that the distance to the obstacle is decreasing.

Together with the long-range radar and the front camera, the laser scanner forms a trio of sensors with various strengths that complement each other. It is these sensors and the central driver assistance controller (zFAS), which generates an image of the surroundings from all the sensor data, that make automated driving possible in the first place.

The laser scanner covers a field approximately 80 meters (262.5 ft) long, with an opening angle of 145 degrees. The roughly fist-sized component is mounted in the front bumper and, regardless of speed, emits moderated pulses of light on multiple vertical levels, which a mirror scatters in the shape of a fan. Having a wave length in the near-infrared range, the extremely short flashes of light are invisible and harmless to the human eye. They are reflected by objects in front of the car and return to the laser scanner in less than one microsecond, where photo diodes detect them.

The result is a detailed, deeply contoured, static image of the surroundings. The laser scanner displays other vehicles as measured cuboids, and it also measures such information as distance and orientation, which it distributes to the partner control units. With its large horizontal aperture, it detects cars entering the lane very early. Detailed information about structures on the side of the road, such as guardrails, round out the spectrum. Like radar, the laser scanner also works in the dark. Automatic cleaning and heating of the covering panel keep it operational even in inclement weather and spray as long as the conditions aren’t too extreme.

The night vision assist that Audi offers for multiple full-size models uses a far infrared camera. It reacts to the heat given off by objects. Converted to black and white images, the information can be viewed in the instrument cluster or Audi virtual cockpit. The cooler surroundings appear dark, while animals and people appear strikingly bright.

The system, which has a range of up to 300 meters (984.3 ft), can detect people and larger wild animals at distances between roughly 10 and 90 meters (32.8 and 295.3 ft) and highlights them with yellow markings. If a hazardous situation is detected, a warning sound is emitted. A warning symbol appears in the instrument cluster as well as in the head-up display. Depending on the headlights persons outside of town limits are illuminated with three short flashes of light.

Park assist can automatically steer the car into parallel or perpendicular parking spaces. It uses ultrasonic sensors located in the front and rear bumpers and on the sides. The driver only has to accelerate, brake and shift gears.

The sensors measure parking spaces along the road while driving past them at moderate speed – a maximum of 20 km/h (12.4 mph) for perpendicular parking spaces and a maximum of 30 km/h (18.6 mph) for parallel spaces. A message appears on the MMI display when the system finds a suitable spot. The only actions required of the driver while parking are accelerating, shifting gears and braking. The system handles the steering. In addition, audible signals help the driver. Park assist will make multiple maneuvers, forwards and backwards, if necessary. It can also exit from parallel parking spaces. Depending on the model, the driver activates the system via either a button on the center console or a button in the lower infotainment display. The maximum speed for all maneuvers is 7 km/h (4.3 mph).

The reversing camera simplifies maneuvering by showing the zone behind the vehicle on the MMI display. It shows the calculated driving track based on the steering angle as well as auxiliary lines and guide lines. For parallel parking, the latter lines precisely direct steering into the parking space in conjunction with steering reversal points. The blue pictured surface in the camera image indicates where the vehicle will be positioned after the parking procedure. The reversing camera is inconspicuously integrated into the handle trim strip of the luggage compartment lid. It is activated as soon as the driver engages reverse gear or pushes the respective button.

The four 360 degree cameras on the vehicle scan the immediate vicinity and display obstacles within. Drivers can choose from different views that simplify parking and maneuvering. A virtual overhead view shown in the MMI display gives the driver an overview of the overall parking situation. The panoramic view to the front and rear covers an angle of nearly 180 degrees and provides better visibility when exiting tight parking spaces, courtyard entrances and confusing intersections. Guide lines in the reversing camera view make it easier to park in perpendicular spaces and to hitch trailers. The view from the front camera helps when maneuvering, as it detects obstacles in front of the car. The system is automatically activated when driving in reverse or by pushing a button.

An additional feature for some models is a virtual 3D view. The driver can use the touchscreen to steplessly swivel and zoom the image of the car and the actual vehicle surroundings. There is also a view of the front or rear tires so that the driver can pull the car up right next to the curb.

Conditional automated driving at level 3 is based on two innovations: a sensor set with the laser scanner and a central driver assistance controller known as zFAS, for short. The roughly tablet-sized computer constantly processes sensor signals and uses them to create a complete image of the car’s surroundings. To do this, it uses processors from leading global companies – NVIDIA (Tegra K1), ALTERA (Cyclon V), Infineon (Aurix) and Mobileye with the EyeQ3 image processing engine.

The sensor data is read into the “fusion” layer in the zFAS unit and is merged to generate a sophisticated model of the surroundings. It includes moving objects, stationary obstacles and a road model. The latter is generated from the conventional navigation map and from road markings and borders that the sensors detect. The vehicle is guided precisely within its lane in the model, and this positional information flows into the navigation map that the driver sees. This information offers the driver many benefits, such as in complex intersection situations.

The zFAS serves as the central interface for piloted driving functions and for nearly all of the assistance systems. Whether the given system is the crossing assist, the emergency braking function, adaptive driving assistant or traffic jam pilot – its functions are no longer coupled to just a specific sensor. Each system makes use of the vehicle surroundings model and can operate more effectively as a result of this model’s high precision. This makes it possible for the vehicle, for example, to recognize the tail end of a traffic jam and brake appropriately.

The principle of a central fusion level based on standardized sensor interfaces gives Audi another advantage – independence from the specificity of sensors. Developers can replace individual sensors whenever better devices are market-ready.