At the IAA 2019, Audi revealed an electric off-road concept, completing a quartet of visionary vehicles with specific “use cases”—the Audi Aicon, AI:Me, AI:Race. The four-seat AI:Trail Quattro combines systems for assisted and automated driving and four electric motors for all-wheel drive. Enjoying nature is a primary focus of the concept, so an abundance of glass surrounds the cabin for all-round visibility, and there are no big screens on board for streaming TV or for videoconferencing.
“With the AI:Trail, we are showing an off-road concept with an emissions-free electric drive for an innovative driving experience away from paved roads,” said Marc Lichte, Audi’s Head of Design. “Consistent with this, we designed a monolithic basic vehicle body with maximum glazing to create an intense connection to the surroundings.”
Off-roading potential is immediately apparent, with big wheels and short overhangs. The concept is 4.15 m (13.5 ft) long, 2.15 m (7.05 ft) wide, and 1.67 m (5.5 ft) tall. Its large 22-inch wheels with 33.5-in tires provide an impressive ground clearance of 34 cm (13.4 in), which enables fording through water more than 0.5 m (1.6 ft) deep and keeping its floor-mounted battery unit away from hard rocks and earth. Light weight and maximum body stiffness were goals, so the concept uses a mixture of high-tech steel, aluminum, and carbon fiber for an overall mass of 1750 kg (3858 lb) despite having a high-capacity battery.
One characteristic design feature common with the previous Aicon and AI:Me is the line about halfway up the side windows that continues to both the front and rear. Inside the window line gives passengers space where they need it the most—around their shoulders and elbows. The side windows extend down from the line, the aim of the designers was to give the best possible view of nature and their surroundings. That same aim went into the windshield that wraps around the front of the vehicle “like the cockpit of a helicopter.” And, almost the entire roof, from the top of the windshield to the rear spoiler, allows a clear view of the sky and the landscape.
Horizontal fenders above the four wheels make it possible to see the suspension in action from the cockpit. That suspension uses transverse links and MacPherson suspension struts with coil springs and adaptive dampers. A special tire design allows them to contribute 60 mm (2.4 in) of suspension travel. The tires also feature variable air-pressure regulation, with optical sensors and electronic stability control working together to detect the surface and adjust air pressure accordingly.
Body overhangs were minimized by a battery pack in the floor between an electric drive arranged around the axles. Since the concept is intended for use in remote areas without charging infrastructure, range was a focus. The stated WLTP target for its lithium-ion battery is 400 to 500 km (248 to 310 mi) on roads or easy off-road terrain. On rougher terrain with almost constant wheel slip, range is still 250 km (155 mi). To meet these requirements, maximum vehicle speed is limited to 130 km/h (80 mph).
Given its off-road mission, the AI:Trail is equipped with an electric motor near each wheel so the vehicle can do without energy-consuming differentials and locks. Maximum system output is 320 kW and 1000 Nm (738 lb·ft). In most cases, energy-consuming slip is avoided by reducing the supply of torque to an affected wheel, but in situations in which slip is useful, such as on low-grip uphill stretches, the system permits it automatically.
Artificial intelligence and machine learning, combined with vehicle intelligence, is said to enable automated driving on roads up to SAE Level 4, the function limited to specific areas, such as highways or areas of inner cities, equipped with suitable infrastructure. Although unpaved dirt tracks and forest paths have been mapped extensively, Audi says that surface erosion and variability means that automated driving off-road is limited to the reduced-speed Level 3 range, the driver having several seconds to take over when needed.
At a lower driver-assist level, the range of camera, laser, ultrasound, and radar sensors detects detect driving surfaces and obstacles to avoid collisions by intervening with steering and braking. For example., when the vehicle is tilted or on particularly challenging incline, the systems warn when critical limits are about to be exceeded. They can also keep the vehicle on track much like a lane-keeping assist working in concert with cruise control.
Inside are two front-row seats with four-point seatbelts and just a few visible control elements including pedals, a steering wheel yoke, and a few buttons. A smartphone, docked on the steering column, acts as a display and control center for vehicle functions and navigation. In addition to space between the front seats, there is storage under the windshield that can be loaded from outside through the upward-folding windshield. The two second-row seats are designed like hammocks they can be taken out and used as mobile outdoor chairs.
In the spirt of mobility and multifunctionality, self-contained forward light sources sit below the A-pillars, their LED elements dimmable and adjustable for interior and exterior lighting. Rear lighting is similar, extending across the full width of the rear section to illuminate the luggage compartment and providing a distinctive signature lighting for the exterior.
This lighting can be supplemented by five rotorless electrically operated drones with integrated matrix LED lights, Capable of landing on the roof or roof rack and docking onto the inductive charging elements, these Audi Light Pathfinders can fly ahead of the AI:Trail. In addition to lighting the path ahead, they can transmit a video image to the display in front of the driver via Wi-Fi.