E-ROT: a terrible name for a really clever new damper
CLEARLY, the marketers did not get to meet the engineers before they decided to name their new prototype electric damping system the e-ROT.
Spelling it with capitals, as Audi does, just makes it worse, so expect a name change soon.
But also expect to hear a lot more about electromechanical rotary dampers.
These replace the hydraulic dampers used in all cars today to provide what Audi says is an even more comfortable ride, but their use is dictated not by the smooth ride, but their ability to capture kinetic energy to be turned into electricity.
The principle behind e-ROT is easily explained: “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 Stefan Knirsch, a board member for technical development at Audi AG.
“With the new electromechanical damper system in the 48-volt electrical system, we put this energy to use. It also presents us and our customers with entirely new possibilities for adjusting the suspension.”
The e-ROT system responds quickly and with minimal inertia. As an actively controlled suspension, it adapts ideally to irregularities in the road surface and the driver’s driving style. With e-ROT, Audi configures the compression stroke to be comfortably soft without compromising the taut damping of the rebound stroke. Another advantage of the new damper system is its geometry.
The horizontally arranged electric motors in the rear axle area replace the upright telescopic shock absorbers, which allows for additional space in the luggage compartment.
The e-ROT system enables a second function besides the freely programmable damper characteristic: it can convert the kinetic energy during compression and rebound into electricity.
To do this, a lever arm absorbs the motion of the wheel carrier. The lever arm transmits this force via a series of gears to an electric motor, which converts it into electricity. The recuperation output is 100 to 150 watts on average during testing on German roads, from three watts on a freshly paved freeway to 613 watts on a rough secondary road.
Under customer driving conditions, this corresponds to a CO2 savings of up to three grams per kilometre.
The new e-ROT technology is based on a high-output 48-volt electrical system. As currently configured, its lithium-ion battery offers an energy capacity of 0,5 kilowatt hours and peak output of 13 kilowatts. A DC converter connects the 48-volt electrical subsystem to the 12-volt primary electrical system, which includes a high-efficiency, enhanced output generator.
Initial test results for the e-ROT technology show potential fuel savings of up to 0,7 litres per 100 kilometres. Thus its use in future Audi production models is certainly plausible.
A prerequisite for this is the 48-volt electrical system. But when Audi rolls out this phase of its electrification strategy, the marketers will hopefully have come up with another name.
Audi’s prototype e-ROT electric dampers capture kinetic energy to help charge the car’s 48 Volt electric system.