The new Audi A6 Avant stands for first-class travel. Adaptive air suspension, all-wheel steering, MHEV plus, and other technologies make for a comfortable ride and dynamic handling. Engineers drive countless test kilometers to gather subjective impressions, which are then reconciled with objective evaluation criteria. The result: perfectly calibrated and balanced driving systems.
When you drive an A6 Avant, you feel it right away: this is a real Audi! Thanks to its extremely comfortable ride, the vehicle’s strengths are particularly apparent on longer journeys. The A6 Avant embodies the business class experience like no other model. Adaptive air suspension and all-wheel steering for the quattro variants make a key contribution here, significantly improving maneuverability at low speeds and noticeably increasing precision and stability at high speeds. The standard and sports suspensions – both with steel springs – and the adaptive air suspension all feature a new tuning. The latter in particular lets the driver experience the wide range of options between Audi drive select modes comfort, balanced, and dynamic.
“The A6 Avant focuses on combining a very smooth, comfortable ride with sporty handling,” says Peter Knauer, who is responsible for the development and validation of suspension characteristics at Audi. “Whether on long stretches of highway or winding roads, on even routes or bumpy surfaces, in stop-and-go traffic or when passing: the A6 Avant delivers a first-class driving feel in all situations,” Knauer adds.
The result is a perfect blend of driving characteristics typical of Audi: precise, controlled, solid, connected, and well-balanced. This DNA can be experienced in every Audi, but the configuration varies in each model, depending on its concept. “After we determine a model’s basic setup during the concept phase, each individual crew fine-tunes their contribution, such as the ESC control system, shock absorber tuning, and torque vectoring,” explains Peter Knauer. “Only when all systems are perfectly balanced do we achieve the typically Audi driving experience.”
Extensive fine-tuning: how evaluations are performed
To achieve this, computer simulations and extensive test drives yield both subjective and objective evaluation criteria. Basic target measurements must be met, but not every aspect can be verified by numbers alone: the subjective evaluation of experienced Audi developers is not only an included, but a necessary component.
Examples of evaluation criteria include steering feedback, steering effort, and tracking in specific driving situations such as ABS braking from different speeds and with different friction coefficients – e.g. aquaplaning, icy conditions, and high grip. The models are also tested on rough roads with transverse and longitudinal irregularities, where the vehicle must stay stable and exhibit comfortable suspension and damping. “When driving over large corrugations, we make sure that the suspension has harmonious expansion and compression action,” explains suspension designer Knauer. “The new A6 seems to float over the road, especially with the comfortable air suspension.”
High-speed tests and handling courses also help to achieve the perfect balance between stability and steering precision. Among other things, Audi defines controlled handling through precise, predictable turn-in when cornering. In load transfer situations, the A6 Avant is designed to respond more comfortably and less agilely than a model focused only on sportiness, although both vehicles have to meet predefined target specifications and values. Finally, the vehicle’s excellent maneuverability at low speeds in city traffic and straight tracking at high speeds on highways make the A6 Avant easy to control.
Important factor for handling: MHEV plus technology
To ensure a typically Audi driving experience, all driving systems must interact harmoniously. The engine and transmission management as well as the suspension control systems in the new A6 Avant are fine-tuned to work perfectly together. In terms of setup, the hybrid powertrain offers new possibilities and poses new challenges. “We had to balance comfort and spontaneous responsiveness as much as possible,” says Steffen Zäpfel, driving and energy system developer at Audi. “MHEV plus technology makes partially electric driving possible, provides additional torque, but also allows the vehicle to recovery energy. The powertrain generator switching on and off is completely unnoticeable to the driver. But he or she will notice the more spontaneous and more direct response to the accelerator pedal, which a result of the additional power, while maintaining the same level of traction,” explains Steffen Zäpfel.
As with acceleration, sophisticated technologies working together intelligently are also used during deceleration – without the driver noticing at all. The MHEV plus system feeds electrical energy with up to 25 kW of power back into the battery. The integrated, blending-capable brake control system ensures pressure-free braking and the best possible regeneration, in most cases without the use of the friction brake. The vehicle does not apply friction braking until the brake pedal is pressed harder. From day one, development focused on achieving the perfect balance between the systems to provide the highest possible level of ride quality.
The developers document all fine-tuning work in the form of a radar chart – a pattern that is used on a model-specific basis for every Audi in the portfolio. At the end of the day, the more balanced and sensitive the suspension and drive are calibrated to each other, the more controlled and dynamic the driving feel – both in everyday driving and at the handling limits.
Article source: www.audi-mediacenter.com