Downhill skiing on a mogul piste is great fun, provided that visibility is good. The skier has to be able to find the ideal track, bend and stretch the legs at just the right moments and float rhythmically and in a seemingly effortless way over the peaks and valleys.
"Even today, when a car is driven over an uneven surface, it's like a skier tackling a mogul run in thick fog!" says Dr. Andreas Schindler of Audi's chassis pre-development department. "The skier and the driver don't know what's ahead of them. They can't react until they sense the first movements through the skis or the wheels. Our task is to improve this situation."
Some years ago Audi began to equip its cars with predictive intelligence. Radar- and camera- based assistance systems such as adaptive cruise control und Audi active lane assist support the driver and enhance driving comfort. The technologies that will follow in the next few years will give this trend fresh impetus; examples are the traffic jam assistant, the intersection assistant or predictive suspension.
A year ago Audi announced an innovation that will increase occupant comfort: elimination of lateral forces. A video camera identifies bends as the car approaches them and an active mechanism in the suspension, which consumes only a small amount of energy, tilts the car's body so that the passengers are only aware of a minimum amount of centrifugal force acting on them. Predictive suspension uses a similar principle, but minimizes vertical rather than lateral forces.
The biggest challenge that Audi's pre-development team had to face was locating suitable sensors for their project. These have to respond to changes within an area up to 20 meters long ahead of the car, even in difficult conditions such as wet roads with shiny surfaces, or after dark. Very high-resolution road-surface images are needed so that possible obstacles can be located within a tolerance of a few millimeters – and, for instance, to distinguish potholes in the road from cross-joints or plastic bags.
An algorithm in the system's control unit analyzes information on road surface irregularities and the car's own movements, and supplies the appropriate suspension control signals. Simulations of this area of the project are already operating very reliably, and concept development of the high-resolution sensors is now going ahead rapidly.
Audi's sensor technology engineers make use of the extensive experience they gain from their work on future driver assistance systems, where extremely varied technologies are being tested, from PMD (photo-mixed detector) sensors through radar-sensors and laser scanners. Stereo cameras are also a promising development in the predictive suspension area. The outcome – which technology will be first across the finishing line – is still undecided, but one thing is certain: Audi will adopt nothing less than a no-compromise solution, as it has in all
its development projects.
