Audi is the driving force in the driver assistance systems space. Audi developers are constantly working on new technologies that provide drivers with even better assistance. Assistance systems are rapidly increasing in importance - in the near future we will see systems that are able to assume the complete driving task for a limited period of time, if so desired by the driver. Audi refers to this concept as piloted driving.
Driver assistance systems of today
From Audi adaptive cruise control with Stop & Go function to traffic sign recognition – right across its model range, Audi offers a broad assortment of assistance systems that make driving even more relaxed and under control. The assistance systems are closely integrated, providing them with a high degree of intelligence and outstanding capabilities.
Audi adaptive cruise control with Stop & Go function
Adaptive cruise control (ACC) with Stop & Go function acts as the core component of the Audi driver assistance systems. The system regulates the speed and the distance from the vehicle in front over a range of zero to 250 km/h (zero to 155.34 mph).
The ACC Stop & Go function employs one or two rear-mounted radar sensors depending on the configuration. The sensors transmit radar waves in order to detect objects up to 250 meters (820.21 ft) ahead of the vehicle. The driver can vary the distance to the vehicle ahead and the control dynamics in multiple levels - from sporty to comfortable. In stop & go traffic the system slows down the car to a standstill. After a brief stop, such as at a traffic light, it automatically drives off and follows the vehicle ahead; after a longer stop, the driver must tap the accelerator pedal or briefly activate the control stalk. Audi adaptive cruise control with Stop & Go function interacts closely with other driver assistance systems; it utilizes the data from almost 30 control units to analyze all of the vehicle’s surroundings. The system uses this broad knowledge base to recognize complex scenarios and offer anticipatory support to the driver. Because it works in conjunction with the MMI Navigation plus, it knows which route lies ahead and can use this information to control the vehicle’s speed.
Audi offers a number of versions of adaptive cruise control for different model series – including without the Stop & Go function. The individual versions differ slightly in their mode of operation due to the different degrees of networking and configurations.
Audi active lane assist
Audi active lane assist is available for most model lines which feature electromechanical power steering. It detects the road markings at a distance of over 50 meters (164.04 ft) and a scanning angle of about 40 degrees using a camera mounted in front of the rearview mirror. Software detects the lane markings and the car’s actual course between them. If the vehicle approaches a line without the turn signal being activated, the system helps the driver to steer back into the lane by intervening discretely in the steering.
The driver uses the MMI to set how soon the intervention should occur and whether it should be combined with vibration feedback in the steering wheel. If the driver opts for early intervention, the system keeps the car centered in the lane.
The camera of the Audi active lane assist provides differentiated information. For example, it can differentiate between the yellow lines in construction zones and white lines.
Audi side assist
The lane change assistant Audi side assist is available for various Audi models. It monitors traffic behind the vehicle and warns the driver of critical lane changes as necessary. The system begins to operate at a speed of about 30 km/h (18.64 mph). Two radar sensors in the rear monitor what is happening behind the vehicle up to a distance of 70 meters (229.66 ft). A computer analyzes the data from these sensors.
If a vehicle is riding in the blind spot or approaching rapidly from the rear, the information stage is activated. A yellow LED indicator lights up in the housing of the driver’s exterior mirror; the driver sees it when looking into the mirror. If the driver nevertheless activates the turn signal to change lanes, the indicator becomes brighter and flashes multiple times. The optical signals are aimed at the driver. Their brightness varies according to the ambient light level and can be set individually via the MMI.
The night vision assistant
The core component of the night vision assistant is a thermal imaging camera with a 24-degree scanning angle located at the front of the vehicle. The camera, which operates in the far infrared region (FIR), registers heat radiated by objects in the field of view. A computer converts the information from the camera into black and white images and shows them on the central instrument display.
Far infrared technology can look up to 300 meters (984.25 ft) ahead – far beyond the range of the high beams – and it is not affected by glare from headlights or similar light sources. People tend to be conspicuously bright and thus easy to spot in the image due to the heat they give off, whereas the cooler surroundings appear dark.
The image processing software can detect persons up to a range of approximately 100 meters (328.08 ft) within the system constraints. In analyzing the data, it specifically seeks out characteristics of pedestrians, e.g. their contours; any person detected is highlighted in yellow on the screen. If the system predicts a hazard – for example, because a person is crossing the road in front of the car – the person is marked in red and a warning tone sounds. A warning also appears in the optional head-up display.
Audi’s automatic parking systems operate by means of either ultrasound or cameras, which display images via the onboard monitor. One particularly convenient solution is park assist. When backing into a parking space, it performs all the necessary steering movements; it can handle both parallel parking and parking perpendicular to the street. The system finds a parking space with ultrasound sensors that scan the roadside in two dimensions while driving at moderate speed. The system notifies the driver via a message in the display once the sensors have found a space which is large enough.
If the driver wishes to park in the space, he or she shifts into reverse and the park assist system takes over the steering. The driver must accelerate, shift gears, and brake. When parallel parking, the detected space is large enough if it is about 80 centimeters (2.62 ft) longer than the vehicle itself. Park assist can perform multi-point parking maneuvers and also offers support in leaving parallel parking spaces.
Another technology from Audi is the parking system plus with surround view cameras. Four small cameras – in the single-frame grille, at the rear and in the side mirror housings – record the vehicle’s immediate surroundings. The driver can call up a variety of views on the large onboard monitor, including a top-down virtual view. On corners or junctions with an obstructed view, the system can analyze cross-traffic otherwise invisible to the driver in front of or behind the vehicle.
Speed limit display
The camera-based speed limit display shows the driver the detected maximum allowable speed in the instrument cluster or head-up display. The camera mounted behind the rearview mirror serves as the primary sensor. Within system constraints, it detects speed limit signs posted on the side of the road, as well as digital speed signs. The system compares the signs against the data from the navigation system, the maximum permissible speeds in the respective country and information from the vehicle, such as whether the wipers are on and the current time.
Audi pre sense
Audi pre sense is a safety package that is available in several Audi model series, including in the new Audi A3, in a number of different configurations. Audi pre sense basic – the system evaluates information from the ESP sensors. If they signal full braking or skidding, depending on the situation, the system activates the hazard warning lights and begins to close the windows and sunroof; it also pretensions the front seat belts. This pretensioning process, which is initiated by small electric motors, is reversible.
The safety system’s configurations are: Audi pre sense front, Audi pre sense rear and Audi pre sense plus. They work closely together with the Audi adaptive cruise control with Stop & Go function and Audi side assist driver assistance systems.
Audi pre sense front monitors traffic in front of the car for potential collision hazards. The system provides multiple levels of driver support. The first stage consists of a visual and audible signal, the second is a jolt caused by briefly applying the brakes to warn the driver. If the driver begins braking, then the system helps by adjusting the required brake pressure.
Should the driver remain passive, partial braking follows as the third stage. This initially decelerates the vehicle with about one-third of the possible brake force. Windows and the sunroof begin to close, the hazard warning lights are activated and the seat belts are tensioned.
If the car has the full version of Audi pre sense plus, a fourth stage comes into play: a second round of partial braking – but this time at a moderate level – followed by maximum braking, during which the seat belts are fully pretensioned. This occurs shortly before impact, when a collision cannot be avoided any longer. Audi pre sense plus reduces the vehicle’s speed by up to 40 km/h (24.85 mph) before impact, which helps mitigate accident severity.
On some models, Audi pre sense front includes an additional function to protect against rear-end collisions at low speeds. At speeds under 30 km/h (18.64 mph) the function automatically brakes the car in critical situations, regardless of whether the vehicle in front is moving or stationary. Under 20 km/h (12.43 mph) this function can prevent an accident entirely under certain circumstances. In other cases, it reduces the vehicle’s speed at impact.
Audi pre sense rear utilizes the Audi side assist sensors and reduces the severity of a rear-end collision. Here, too, it closes the windows and sunroof, and pretensions the seat belts. If the car has optional front memory seats, they adjust to a more favorable position for passenger safety.
Piloted driving: the new dimension in driving pleasure
In future, Audi’s driver assistance systems will be even smarter and more capable than today’s solutions. The key concept in this respect is “piloted driving”. If desired by the driver, the new systems will be able to assume the driving task for a limited period of time, and so contribute to more comfort during the ride.
Piloted driving assists in traffic jams
Audi’s piloted driving in traffic jams will in future reduce the driver’s workload in stressful situations, such as in congested traffic. At speeds between zero and 60 km/h (37.28 mph), the system helps to steer the car within certain constraints. It also accelerates and brakes autonomously.
The new system is based on the functionality of Audi adaptive cruise control with Stop & Go, extended by adding the component of lateral guidance. Two radar sensors monitor everything up to 250 meters (820.21 ft) ahead of the vehicle, at a scan angle of around 35 degrees. A wide-angle video camera monitors the lane markings; it can also detect objects such as pedestrians, other vehicles, and guardrails. Eight ultrasonic sensors monitor the zones directly in front of the car and at its corners. A laser scanner is also used which provides highly precise data over a scanning angle of around 140 degrees up to 80 meters (262.47 ft) in front of the vehicle.
The Audi system for piloted driving in a traffic jam continuously analyzes the car’s speed and the speeds of nearby vehicles. If it detects a traffic jam from the data at speeds below 60 km/h (37.28 mph), the driver can activate the assistance function. By broadly scanning its surroundings, the system can also work in a de facto lane even in the absence of lane markings. The system behaves exactly like the Audi ACC Stop & Go function when moving off and braking; it also reacts cooperatively to cars moving into or out of the lane.
As an assistance function, piloted driving in a traffic jam enables the driver to devote their attention, within certain limits, to other activities while the system is operating. If the vehicle reaches the limits of the function, for instance the traffic jam disperses, the driver is prompted to take over control.
Piloted driving for parking maneuvers at the roadside and in garages
Parking often ends up being so tight that the driver must struggle to get out of the car afterward. Thanks to Audi’s piloted driving, the driver will be able to easily get out of the car in front of the garage or in a tight parking spot and instruct it to autonomously park itself via the remote key fob or smartphone.
With the help of its sensors, the car drives autonomously into the parking space or the garage under the driver’s supervision, stopping immediately if it detects an obstacle. Upon reaching its final position, it shuts off the engine, deactivates the ignition and locks the doors. Finally, it sends a confirmation to the driver.
Getting out of your own garage or a parking space is just as convenient and easy at the push of a button. As soon as the vehicle has completed the maneuver to get out of the garage, the driver and passengers can easily get in and drive off.
Piloted driving for parking maneuvers in parking garages
In another configuration Audi cars are able to get in and out of spaces autonomously in parking garages and underground garages. The driver activates the futuristic technology with the aid of a smartphone app. The parking facility’s central computer takes over part of the control function and guides the vehicle via WLAN to the nearest available parking space. The vehicle’s movements are recorded via external laser sensors and processed with additional movement data by the parking facility’s computer to pinpoint the vehicle. The parking facility’s computer also has a map of the parking garage and records parking space occupancy. This information is used to plan the route, thus ensuring that the vehicle can actually drive from the starting point to its destination. The information is transmitted to the vehicle. The vehicle also monitors its surroundings using twelve ultrasound sensors as it moves. In future, four video cameras will also be used. Audi is currently in the process of equipping a parking garage in Ingolstadt with the relevant technology. The system saves drivers time and makes parking less stressful.
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.