Audi has revealed that a new generation of active suspension has been developed for the A8, which is claimed to be able to offer a range of driving modes, made possible by a 48-volt (48V) electrical system. The new A8 will be the first Audi vehicle to feature a 48V architecture as the main electrical system, and the car will make its world debut at the Audi Summit in Barcelona on July 11.
According to Audi, the suspension is a fully active, electromechanical suspension system, which will drive each wheel individually and adapt to road conditions. Each wheel will have an electric motor, powered by the 48V main electrical system. Additional components include gears, a rotary tube, together with internal titanium torsion bar and a lever which will exert up to 1,100Nm (811.3 lb-ft) on the suspension via a coupling rod.
A camera at the front of the car scans the road ahead for bumps (18 times a second) and if any are detected, the active suspension is adjusted by actuators in preparation, so that when the tires reach the bump, the forces transmitted to the cabin is minimized. Audi has also revealed that the active suspension influences and minimizes roll movements when cornering, and pitch movements when braking or accelerating, for instance.
The new A8 suspension would appear to be a good design for achieving sportiness and comfort without compromise, and the dynamic all-wheel steering function takes this a step further by combining dynamic and rear axle steering (pictured below) to achieve agility and stability. The steering feel can be adjusted to create ‘feel’ ranging from comfortable cruising to intense feedback. The system also endows the A8 with a turning circle smaller than that of the smaller A4 model.
In conjunction with Audi’s pre sense 360˚ safety system, which can scan the road for hazards and assist with the controls to help prevent collisions, the active suspension on the A8 further increases passive safety. The system uses the sensors networked in the central driver-assistance controller (zFAS) to detect risks of a collision around the car. In the event of an imminent side impact at more than 15.5mph (25km/h) the suspension actuators raise the body on the exposed side by up to 3.1in 80mm within half a second. As a result, the collision is directed to the stronger areas of the vehicle, such as the side sills and floor structure. According to Audi, this setup can reduce the load on vehicle occupants during a side impact by up to 50%.
So what’s next?
The A8 will be officially revealed on July 11, but there are much bigger implications for its technology: namely eROT, a clever system that combines simiular benefits to the A8 setup with energy recuperation functions. The system is so clever, it won the Innovation of the Year category of the Vehicle Dynamics International Awards 2017. Small wonder Audi’s dynamicists also won the Team of the Year category.