Audi e-tron Concept

Audi e-tron Concept

The Audi e-tron Concept is able to freely distribute the powerful torque of its four electric motors to the wheels as required. This so-called torque vectoring allows for dazzling dynamics and an undreamed-of level of agility and precision when cornering.

Audi has taken a new and in some cases revolutionary approach to many of the technical modules. A heat pump is used to efficiently warm up and heat the interior. The drive system, the power electronics and the battery are controlled by an innovative thermal management system that is a crucial component for achieving the car's range without compromising its high level of interior comfort. Networking the vehicle electronics with the surroundings, which is referred to as car-to-x communication, opens new dimensions for the optimization of efficiency, safety and convenience.
The Concept
Electric drive systems are still very much outsiders. The first vehicles of this type took to the roads around 1900, yet in 2009 no volume car manufacturer has a car powered exclusively by batteries in its lineup. Fewer than 1,500 electric vehicles are currently registered in Germany, corresponding to only 0.035 percent of all registered vehicles.

Audi e-tron Concept - The Holistic Approach
The most important development related to batteries for electric drives are lithium-ion cells. Numerous experts throughout the world are working on their further development for use in cars, with the primary objectives being to reduce weight and increase capacity and performance. Audi has also opted for this technology, both for use in a hybrid production vehicle, such as the upcoming Q5 hybrid, and in the e-tron test platform.

The Audi team therefore focused its attention on the total vehicle, which is reflected in the comprehensive requirement specification.
* The reduction of road resistances and the resulting increase in range plays a major role with electric vehicles. Lightweight construction was therefore a top priority for the Audi e-tron Concept car. The body, in particular, combines low weight with supreme strength and rigidity. An intelligent aerodynamics concept with active elements helps to reduce consumption.
* The package ensures the safe integration of the electric drive system and the battery. Placing the battery in front of the rear axle ensures an optimal axle load distribution without compromising the compact overall design and the generous amount of interior space.
* Advanced battery technology enables a practical range. The battery system is water-cooled for optimal performance and service life.
* A needs-based energy management system controls all functions for the chassis, convenience equipment and other auxiliary consumers.
* The innovative thermal management system with optimally matched cooling and heating components considers the cooling requirements of the battery and the drive system in addition to the interior temperature.
* Driving dynamics and road comfort are what Audi customers have come to expect in the sports car segment.
* Vehicle safety is on par with the best of today's production vehicles.
* The driver is provided with clear and comprehensive information.
* The Audi e-tron Concept car uses car-to-x communication technology developed by Audi to improve the efficiency of conventionally powered vehicles. For example, information about traffic light cycle times and the flow of traffic - provided by the infrastructure and other vehicles - is used to compute an optimal driving strategy. Audi has already modeled such a solution in Ingolstadt as part of its "travolution" project.

The Design and Package
The caliber of the car is apparent to the observer at first glance. The Audi e-tron Concept has a wide, powerful stance on the road. The car body seems almost monolithic; the closed rear end appears powerful and muscular. The trapeze of the single-frame grille dominates the front end and is flanked by two large air intakes. The top of the grille merges into the flat strips of the adaptive matrix beam headlamp modules with their clear glass covers. High-efficiency LED technology is used for all lighting units - a matter of honor for Audi as the worldwide pioneer in this field.

The Interior and Control Concept
Optical and functional references to the new drive concept characterize the interior design. They establish an advanced connection between proven Audi genes and new formal hallmarks. Typical for the Audi design language is the reduction of the architecture, controls and flow of information to the essential in favor of visible lightweight construction and a tidy overall impression.

The cockpit of the Audi e-tron Concept is also oriented toward the driver - a further characteristic Audi trait. Instead of the classic instrument cluster, the concept car is the first Audi to be equipped with a large, fold-out central display with integrated MMI functions. It is flanked by two round dials.

Drive System and Energy Supply
The top speed is limited to 200 km/h (124.27 mph), as the amount of energy required by the electric motors increases disproportionately to speed. The range in the NECD combined cycle is approximately 248 kilometers (154 miles). This good value is made possible by the integrated concept: technology specially configured for the electric drive system combined with state-of-the-art battery technology. The battery block has a total energy content of roughly 53 kilowatt hours, with the usable portion thereof restricted to 42.4 kWh in the interest of service life. Audi uses liquid cooling for the batteries.

The battery is charged not only when the car is stationary, but also when it is in motion. The keyword here is recuperation. This form of energy recovery and return to the battery is already available today in a number of Audi production models. During braking, the alternator converts the kinetic energy into electrical energy, which it then feeds into the onboard electrical system.

The Audi e-tron Concept, which is slowed by four lightweight ceramic brake discs, takes the next large step into the future. An electronic brake system makes it possible to tap into the recuperation potential of the electric motors. A hydraulic fixed-caliper brake is mounted on the front axle, with two novel electrically-actuated floating-caliper brakes mounted on the rear axle. These floating calipers are actuated not by any mechanical or hydraulic transfer elements, but rather by wire ("brake by wire"). In addition, this eliminates frictional losses due to residual slip when the brakes are not being applied.

Making its Automotive Debut: The Heat Pump
The heat pump - used here for the first time ever in an automobile - also serves to increase efficiency and range. Unlike a combustion engine, the electric drive system may not produce enough waste heat under all operating conditions to effectively heat the interior. Other electric vehicles are equipped with electric supplemental heaters, which consume a relatively large amount of energy. The heat pump used by Audi - and commonly used in buildings - is a highly efficient machine that uses mechanical work to provide heat with a minimum input of energy.

The drive system is heated if temperatures are cool, and cooled if hot. This preconditioning can also be extended to the interior, if necessary, so that the passengers can step into a cabin that has been heated or cooled as appropriate for their comfort.

The Driving Dynamics
The normal distribution of the tractive power is clearly biased toward the rear axle in accordance with the weight distribution of the Audi e-tron Concept. Similarly to a mid-engined sports car, roughly 70 percent of the power goes the rear and 30 percent to the front. If an axle slips, this balance can be varied by means of the four centrally controlled electric motors. The electric vehicle from Audi thus enjoys all of the advantages of quattro technology.

The Car-to-x Communication
The electronics development engineers at Audi not only aimed to make the Audi e-tron Concept as efficient and fun to drive as possible, they were also very concerned with safety and traffic management. The technical concept car includes a prototype of an information processing system. Future generations of these systems will usher in a new era in the networking of road traffic, particularly in regions and countries with a high volume of traffic. This progress is made possible by the rapid advancements in computing power, software and communication technology.

The buzzword "car-to-x communication" refers to the direct exchange of information in flowing traffic and to the traffic environment. The letter "x" is a free variable that can refer just as easily to other vehicles as to fixed infrastructure such as traffic lights. In contrast to today's telematic systems, car-to-x communication no longer requires a central service provider to quickly and effectively pool and process information. The participants themselves perform these tasks by spontaneously networking with one another.
These transmitters can be used to open up many new practical applications. Below are just four examples showing the possibilities offered by car-to-x communication.