Audi will be using kinetic energy generated when driving over bumps on the road to put more energy and fuel efficiency back into new 48-volt electrical systems.
As Audi follows the auto industry trend to roll out new 48-volt models to improve fuel economy, its new technology, which it calls eROT, could give it a competitive edge. Using electromechanical rotary dampers can give the driver better ride control while generating more energy that will be stored in the battery, Audi says.
“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,” says Stefan Knirsch, board member for technical development at Audi. “With the new electro-mechanical damper system in the 48-volt electrical system, we put this energy to use.”
Instead of vertical dampers typically used in cars these days, consisting of shock absorbers made from metal tubes filled with oil, Audi says that eROT will use horizontally mounted devices that have electric motors inside. The motors allow precise control over wheel movements, and can also harvest some of that motion to generate small amounts of electricity stored in the battery.
Knirsch says that eROT presents Audi and Audi owners “with entirely new possibilities for adjusting the suspension.” The eROT system provides control over ride and handling, and can be customized to each driver’s personal driving style and ride preferences.
Fuel savings also come from the 48-volt system powering auxiliary systems like power steering, air conditioning, power windows, stereo systems, and small electric motors used to start the car. The gasoline engine has less power to give away with support from the efficient 48-volt system.
Carbon dioxide emissions can be reduced up to nearly five grams per mile. That comes from the eROT system producing up to 613 watts per mile of energy driving on a rough road with plenty of bumps and potholes, and three watts on a smooth highway.