Audi continued to push the boundaries of possibility last night at the 68th Frankfurt International Motor Show (IAA), unveiling the fourth of its visionary AI vehicles, the AI:TRAIL quattro off-roader concept.

A striking departure for the brand visually, the AI:TRAIL quattro is a purpose-built off-road vehicle that uses an emissions-free all-electric drive, offers completely automated driving as required and demonstrates superb off-road capabilities. 

The Audi AI:TRAIL quattro is the fourth in the series of concept cars with electric drive systems, which began with the presentation of the Audi Aicon at the 2017 Frankfurt Motor Show. This was followed by the high-performance Audi PB18 e-tron (AI:RACE) in 2018 and the autonomous city car, the Audi AI:ME introduced at the 2019 Shanghai Auto Show.

Made of a mixture of high-tech steel, aluminium and carbon fibre, the Audi AI:TRAIL weighs just 1750kg despite its high-capacity battery which is designed for maximum range for extended journeys away from the networks of charging stations.

The AI:TRAIL  quattro features myriad design elements developed specifically for a vehicle of this type, with extensive use of glass in its ‘monolithic body’ for maximum visibility, and an obvious absence of screens so that the four occupants can concentrate on the great outdoors all around them. Indeed the ‘helicopter style’ all-round visibility was specifically designed to give occupants the best possible view of nature and their surroundings, breaking the boundaries between the interior and the world outside.

In addition to the glass front and sides, almost the entire roof, from the top of the windscreen to the rear spoiler, allows a clear view of the sky and the landscape. 

Sitting on massive 22-inch wheels with 850mm tyres, the AI:TRAIL boasts 34 centimetres of ground clearance, allowing it to ford water more than half a metre deep and more than enough clearance to keep the battery unit well away from obstacles.

Indeed, given that the electric drive system is 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, giving the vehicle even greater agility in rough terrain. 

Even the tyres themselves are a work of art, featuring a structure of supporting struts, which are integrated in the treads, and the actual surface. This design allows the tyres themselves – in addition to the suspension  – to contribute a further 60 millimetres of suspension travel. The tyres also feature variable, sensor-controlled air pressure regulation, with optical sensors and electronic stability control (ESC) working together to monitor the road surface and adjust the air pressure accordingly. 

Inside the architecture is spacious with minimal control elements. In the front are two, slimline bucket seats, pedals, a yoke for a steering wheel, minimal control buttons, and a smartphone attached to the steering column as a display and control centre for vehicle functions and navigation.

Materials are all natural and recycled – the leather for example is recycled and the carpet is made of reprocessed wool.

There is ample storage space between the seats and also under the windscreen, with straps to secure any stowed objects, which can also be loaded from the outside through the upward-folding windscreen.

The second row of seats are designed like hammocks, which can even be taken out of the AI:TRAIL and used as mobile outdoor chairs. 

Audi has also taken its reputation for automotive lighting excellence to new heights.

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.

More impressive still, the Audi AI:TRAIL quattro is equipped with a total of five rotorless, triangular, electrically operated drones with integrated matrix LED elements, that are capable of landing on a roof rack or directly on the roof of the vehicle, and docking onto the inductive charging elements.

These special drones are called Audi Light Pathfinders and generate their lift in the same way as bladeless fans produce their air flow. These Audi Light Pathfinders fly in front of the AI:TRAIL and illuminate the path ahead, doing away with conventional headlights completely. The on-board cameras can also generate a video image that can be transmitted to the display in front of the driver via Wi-Fi.

The fully automated drones usually operate in pairs, but can provide additional light intensity or illuminate the area around the vehicle by coming together to form groups of up to five. 

There is also the  Audi Light Companion which is a torch-like device magnetically attached to the front side of the seat where it provides ambient light. It can also be removed from the vehicle and used as a freestanding light, while its in-built cameras allow it to scan the way ahead or take videos.

When integrated with the AI:TRAIL’s navigation system, the Audi Light Companion is also capable of projecting directional symbols and even written information onto a route and thereby helping AI:TRAIL users to find their way around when hiking.

The Audi AI:TRAIL is designed for driving on roads up to level 4 which 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, they do require supporting infrastructure like highways or areas that are clearly defined. In these sorts of areas, the driver can completely transfer the task of driving to the system but needs to resume driving when the car leaves the designated area. To that end, the Audi AI:TRAIL is equipped with the traditional steering wheel and pedals for when the vehicle leaves the road for dirt trails and often changing off-road surfaces too changeable to digitally map.

But automated driving in the reduced-speed level 3 range is possible on dirt roads in exceptional cases and at low speeds, giving the driver several seconds to take over as required.

The AI:TRAIL quattro boasts an array of driver assistance systems, such as ESP, as well as sensors that can detect both the road surface and obstacles that allow the central driver assistance system to avoid collisions by intervening with the steering and braking as needed. These systems can also keep the vehicle on track, within the limits of the system – much like a lane-keeping assist working in concert with cruise control. 

Obviously for a vehicle designed for use in areas without charging infrastructure, range is of great importance. The AI:TRAIL’s lithium-ion battery is capable of 400 to 500 kilometres on roads or easy off-road terrain (in line with the WLTP), while in rough terrain, where energy consumption is higher, the limit is still an impressive 250 kilometres.

As a result, the AI:TRAIL is designed with a maximum speed of 130 km/h on the road, while the vehicle electronics continuously monitor the energy flow and consumption, ensuring maximum economy even during off-road driving. 

Four electric motors installed near the wheels provide the drive, with each motor directly driving one wheel – making it a true quattro. The maximum system output is 320kW and the maximum torque is 1000Nm, but often only a fraction of this power is mobilised, with the drive of just one axle usually sufficient. Differentials and diff locks aren’t required because of the individually propelled wheels, contributing to energy savings.

The electronics co-ordinate driving stability and traction. If energy-consuming slip can be avoided, it reduces the supply of torque to the affected wheel. However, in situations where slip is useful, like low-grip uphill stretches, the system permits it automatically. 

This is a vehicle specifically designed and imagined to fulfil a specific role in the future, where customers will be able to order this or any of the specialist Audi models from an Audi on demand vehicle pool to suit their personal needs and to lease them for the desired period. Until that becomes a working reality, the AI:TRAIL quattro remains a stunning vision of the future and what could be possible just around the corner.