September 11, 2019

The four-seater Audi AI:TRAIL quattro combines the capacity for automated driving with superb off-road capabilities. The glass surrounding the cabin extends all the way to ground level, providing unrivaled all-round visibility. The ample battery capacity ensures sufficient range even away from dense networks of charging stations.

The “Trail” part of the name evokes the idea of exploring nature. That is why there are no big screens on board for streaming TV series or videoconferencing; instead, broad glass surfaces provide a clear view of the surroundings. 

Technology that’s plain to see—the exterior

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With an exterior length of 4.15 meters and a width of 2.15 meters, the brawny Audi AI:TRAIL’s potential away from paved roads is immediately apparent. The roof height of 1.67 meters and the enormous 22-inch wheels with 850 mm tires hint at the vehicle’s excellent off-road capabilities even when it is standing still. With a ground clearance of an impressive 34 centimetres, it can ford through water more than half a meter deep.

On rough, rocky terrain, this architecture provides plenty of agility without the battery unit integrated in the floor coming into contact with the ground.

The cabin itself is an extensively glazed space surrounded by polygonal shapes, with room for up to four people. One characteristic feature—and one that indicates the vehicle’s kinship with Aicon and AI:ME—is the protruding ridge halfway up the side windows. This line continues to both the front and rear and acts as a waistline uniting the entire body in one monolithic whole. With the electric drive system arranged around the axles and the battery in the floor, there is no need for overhanging sections or separate attachments for the motor or batteries. 

Light weight and maximum body stiffness are, of course, important technical objectives for off-roaders in particular. That is why the body of the Audi AI:TRAIL is made of a mixture of high-tech steel, aluminum and carbon fiber. As a result, it weighs just 1,750 kilograms despite its high-capacity battery.

Helicopter-style all-round visibility

The windshield wraps around the front of the vehicle like the cockpit of a helicopter. Passengers have an unobstructed view of the road or trail both in front and to the sides. Nor is it just the front and sides that are transparent and covered in glass. Almost the entire roof, from the top of the windshield to the rear spoiler, allows a clear view of the sky and the landscape. Even the vertical Singleframe is glazed, with only the four rings of the badge sitting in their customary position in what is otherwise a glass octagon.

Both the windshield and the tailgate open wide, providing easy access to large storage compartments with straps to keep luggage secure in transit. Integrated in the bumper at the rear is another separate compartment for dirty items such as hiking boots, climbing gear or wet clothing.

The side sills beneath the opposing doors act as retractable running boards. This makes it easier to load and unload the roof rack. Instead of bulky wheel wells, horizontal fenders are all that sit above the four wheels. That makes it possible to see the suspension in action from the cockpit even during travel.

The tires feature variable, sensor-controlled air pressure regulation. Optical sensors and electronic stability control (ESC) work together to detect the condition of the road surface and adjust the air pressure in the tires accordingly. As regards traction, it can be useful to reduce the pressure, such as when driving on sand, and thereby increase the tire contact patch. By the same token, increasing the pressure again when switching to asphalt increases drive stability.

Reduction as a principle of style—the interior

The interior of the Audi AI:TRAIL is tidy and spacious, and it has just a few visible control elements. There are two comfortable-looking, almost delicate seat shells in the front row, both equipped with four-point seat belts. Light colours dominate the upper interior area down to the level of the seat cushion and the low dashboard. The openness to the outside world appears all the more present; the occupant’s eye is drawn to the large glass areas in the front and side sections and guided through the almost fully glazed roof.

The whole colour concept with its blue and grey surfaces and earthy tones emphasises the connection between the interior and the surrounding nature. The sense of touch adds to this perception, with rough, granular surfaces indicating functional qualities. Smooth wool felt in the luggage compartment provides a cozy contrast. Like in previous concept cars, the Audi designers also use recycled materials in the AI:TRAIL. The carpet is made of reprocessed wool with recycled leather, both of which are sustainable and durable, and feature excellent acoustic and climatic properties.

There is storage space between the seats and also under the windshield. Tensioning straps secure any stowed objects, which can also be loaded from the outside through the upward-folding windshield. Seat belt retractors ensure that the tensioning straps always have optimum tension.

The second row features a novelty in the form of two seats designed like hammocks. When taut and tensioned in a transportable tubular frame, panels of fabric form a comfortable seating surface and backrest, and the backrest that is drawn around to the side even provides lateral support. These seats are good for relaxation in more ways than one, as they can even be taken out of the AI:TRAIL and used as mobile outdoor chairs.

Eyes in the sky

Mobility and multifunctionality are features of the Audi AI:TRAIL’s light sources as well. Instead of conventional headlights, self-contained light sources sit below the A-pillars and can shine both outward and inward. These LED elements are dimmable and adjustable and can be used as interior lighting as well as for lighting the vehicle’s path. The rear light operates in a similar way. Extending across the full width of the rear section, this element can be used to illuminate the luggage compartment and as distinctive signature lighting for the exterior.

Instead of conventional low beams and high beams, the Audi AI:TRAIL is equipped with a total of five rotorless, triangular, electrically operated drones with integrated matrix LED elements. They are capable of landing on a roof rack or directly on the roof of the vehicle, and docking onto the inductive charging elements.

The flying objects are Audi Light Pathfinders, which generate their lift in the same way as bladeless fans produce their air flow. Thanks to their markedly lightweight design, they can fly ahead of the AI:TRAIL, consuming comparably little energy in the process, and illuminate the path ahead, thereby replacing headlights entirely. If desired, the on-board cameras generate a video image that can be transmitted to the display in front of the driver via Wi-Fi, turning the Pathfinders into eyes in the sky.

When the AI:TRAIL is stationary, the drones can also illuminate the surrounding area from their position on the roof; for example, when the occupants are enjoying a picnic next to the vehicle. They can also illuminate the interior through the transparent panoramic roof if the occupants prefer to remain inside the vehicle.

Audi AI—on the road to smart mobility

Audi AI is the code for a variety of electronic systems that relieve strain on drivers and simultaneously offer them new ways to use the time spent in the car. To this end, Audi AI also uses strategies and technologies from the field of artificial intelligence and machine learning. Audi AI combines vehicle intelligence, which makes automated driving possible in the first place, and interaction intelligence, which turns the vehicle into the occupants’ partner.

Audi AI systems are capable of learning and thinking, while also being proactive and personal. Thanks to Audi AI, models bearing the four rings will be both intelligent and empathetic in the future. They will be able to continually interact with their surroundings and passengers and thus adapt themselves in a better way than ever before to the requirements of those on board.

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Automated driving on roads, driver assistance in rough terrain

What is already established in rail transportation and aviation is now at the threshold of a breakthrough in automotive transportation—automated driving. The Audi AI:TRAIL is designed for driving on roads up to level 4.

Level 4 is the second-highest level on a standardised international scale for increasing automation. Although systems in this category do not require any assistance on the part of the driver, their function is limited to a specific area—such as highways or areas of inner cities equipped with suitable infrastructure. In these places, the driver can completely transfer the task of driving to the system. The driver needs to resume the task only when the car leaves the area defined for fully automated driving. The Audi AI:TRAIL is therefore equipped with the traditional steering wheel and pedals.

The driver will need them when going off-road at the latest. After all, although even unpaved dirt tracks and forest paths have been mapped extensively through digital cartography, the way in which their surfaces frequently erode makes them too variable to allow their limits and any damage to be digitalised for automated driving reliably and for any extended period. Automated driving in the reduced-speed level 3 range can therefore be possible on dirt roads only in exceptional cases and at low speeds. In these situations, the driver will have several seconds to take over.

But the sensors and assist systems don’t leave the driver of the AI:TRAIL alone, even off-road. First of all, there is the tried and tested sensor system for the ESP on board, of course. The data for friction values and slip, longitudinal and lateral acceleration provide the electronics with all necessary parameters they need in order to optimise drive stability. There is also a whole range of sensors that can detect both the road surface and obstacles; they work with optical systems such as cameras and lasers, as well as with ultrasound and radar. The data that they provide enables the central driver assistance system to avoid collisions by intervening with the steering and braking as needed.

Discovering life at a slower pace—the drive system

The performance specifications for the Audi AI:TRAIL are markedly different from those for conventional automobiles. That is because the car’s development was not about achieving remarkably quick acceleration or hitting breathtaking speeds on the autobahn.

Given that the AI:TRAIL is intended for use in areas without charging infrastructure, the thing that really draws the attention is its range. The stated target with its lithium-ion battery is 400 to 500 kilometres on roads or easy off-road terrain (in line with the WLTP). On rough ground, where the almost constantly elevated wheel slip alone means that energy consumption is higher, the limit is still an impressive 250 kilometres.