Presented at the 2019 Frankfurt Motor Show, the Audi AI:Trail quattro Concept joins the Audi Aicon, AI:ME, AI:RACE (which is the new name given to the 2018 Audi PB18 e-tron) to form a quartet of design studies focused on the future of mobility.
The Audi AI:TRAIL quattro combines automated driving with off-road capabilities, and is characterized by a cabin entirely surrounded by glass all the way to ground level, providing extreme 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.
Marc Lichte, Audi’s Head of Design, describes the main idea: “With the AI:TRAIL […] we designed a monolithic basic vehicle body with maximum glazing to create an intense connection to the surroundings. A concept for sustainable mobility on demand.”
The car has an exterior length of 4.15 meters (13.5 ft) and a width of 2.15 meters (7.05 ft). The roof height of 1.67 meters (5.5 ft) and the 22-inch wheels with 850 mm (33.5 in) tires hint at the vehicle’s off-road capabilities even when it is standing still.
The main design feature is the cabin, an extensively glazed space surrounded by polygonal shapes, with room for up to four people.
The protruding ridge halfway up the side windows is a styling element shared with the Aicon and AI:ME concepts.
This line continues to both the front and rear and acts as a waistline uniting the entire body in one monolithic whole.
Thanks to the electric drivetrain, the car has no overhanging sections and uses a one-box layout which according top Audi will be a common choice for future EVs.
The Audi AI:TRAIL is also equipped with of five rotorless, triangular, electric drones with integrated matrix LED elements that generate their lift in the same way as bladeless fans produce their air flow and can fly ahead of the AI:TRAIL illuminating the path ahead, 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.
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.
Bulky transverse links and MacPherson suspension struts with coil springs and adaptive dampers provide suitable robustness and ensure safe driving stability.
The special tire design becomes apparent at first glance, as the profile appears to be drawn all the way up into the high tire sidewalls. However, behind it lies a structure of supporting struts, which are integrated in the treads, and the actual surface.
This design allows the tires themselves—in addition to the suspension struts—to contribute a further 60 millimeters (2.4 inches) of suspension travel. Aside from improved off-road capability, this provides the occupants with an enormous amount of additional comfort.
The tires also 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.
The interior of the Audi AI:TRAIL is tidy and spacious, and it has just a few visible control elements. There are two seat shells in the front row, both equipped with four-point seat belts.
Light colors 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.
Pedals, a yoke for a steering wheel, a few buttons, and a smartphone attached to the steering column as a display and control center for vehicle functions and navigation—those are all the elements there are for the interaction between the driver and the vehicle.
The whole color concept with its blue and gray surfaces and earthy tones emphasizes 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.
Given that the AI:TRAIL is intended for use in areas without charging infrastructure, the lithium-ion battery stated target range is 400 to 500 kilometers (248.5 to 310.7 mi) 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 250 kilometers (155.3 mi).
In order to meet these requirements, the vehicle is designed to reach a maximum speed of 130 km/h (80.8 mph) on the road. The vehicle electronics continuously monitor the energy flow and consumption, thereby ensuring maximum economy even during off-road driving.
In terms of drive hardware, the Audi AI:TRAIL is equipped with four electric motors installed near the wheels, each of which propels one wheel directly. As is typical for Audi, the off-roader is therefore a true quattro. The maximum system output is 320 kilowatts and the maximum torque is 1,000 Newton-meters (737.6 lb-ft). Usually only a fraction of this power is mobilized; the drive of just one axle is often sufficient.
Due to the individually propelled wheels, the vehicle can do without differentials and locks, which also consume energy. Thanks to the moderately calculated maximum speed, the gear ratio can be designed such that every wheel is provided with enough torque even without a multi-speed transmission.
The electronics coordinate driving stability and traction. If energy-consuming slip can be avoided, it reduces the supply of torque to the affected wheel. However, in situations in which slip is useful, such as on low-grip uphill stretches, the system permits it automatically. The large amounts of reserve power of the AI:TRAIL allow it to conquer challenging stretches even in difficult conditions—confidently, safely and always without emissions.