German car manufacturer Audi is working on recovering energy currently being absorbed by the car's suspension.
“Every pothole, every bump, every curve induces kinetic energy in the car. Today’s dampers absorb this energy, which is lost in the form of heat,” said Audi's Dr Stefan Knirsch. “With the new electromechanical damper system in the 48 V electrical system, we put this energy to use. It also presents us and our customers with entirely new possibilities for adjusting the suspension.”
The prototype, called eROT, replaces the hydraulic dampers with electromechanical rotary dampers which respond quickly and with minimal inertia. A lever arm absorbs the motion of the wheel carrier and transmits this force via a series of gears to an electric motor, which converts it into electricity. The output varies from 3 W on a freshly paved freeway to 613 W on a rough secondary road with the typical average in the 100-150 W range.
The system also eliminates the mutual dependence of the rebound and compression strokes that limits conventional hydraulic dampers. With eROT, the compression stroke is configured to be comfortably soft without compromising the taut damping of the rebound stroke.
The company says it could also offer a design advantage. By replacing the upright telescopic shock absorbers with horizontally arranged electric motors in the rear axle area, there is potential for additional space in the luggage compartment
Audi says initial test results for the technology are promising. A prerequisite for this is the 48-volt electrical system, which is a central component of the company's electrification strategy. In the next version planned for 2017, the 48 V system will serve as the primary electrical system in a new Audi model and feed a high-performance mild hybrid drive. It will offer potential fuel savings of up to 0.7 L/100 km.
[An illustration of how the electronic damping system works. Image: Audi]
Transport/Infrastructure will be a major topic of discussion at the Australian Engineering Conference 2016 in Brisbane on November 23-25.