Audi's eROT System

Audi’s recent announcement of their eROT system adds yet another kinetic energy recovery system to the ever-growing list. Their electronic rotary dampers function to harness kinetic energy of the suspension’s damper.

eROT diagram, per Audi’s website.

eROT diagram, per Audi’s website.

eROT is based on a 48 watt electrical system, capable of an energy capacity of 0.5 kilowatt hours and peak system output of 13 kilowatts. Instead of focusing this innovation primarily on fuel savings, however, Audi claims that this new system is focused on providing a more adaptable and adjustable suspension system. As Dr.-Ing. Stefan Knirsch explains, “It… presents us and our customers with entirely new possibilities for adjusting the suspension.” Audi explains that because it can “ideally” adjust to imperfections in road surfaces, a more optimal ride may be created. Additionally, CO2 savings from system implementation are estimated at up to three grams per kilometer. Audi also claims minimal fuel savings as a result of this new damper system, claiming ~0.7 Liters  per 100 kilometers, a figure which seems to stress that this system is not focused primarily on fuel savings.

Drawbacks

As with any new innovation, there are a number of potential drawbacks. As we’ve seen with the big-three in the past, good German over-engineering could lead to unit failures in the first iteration. Furthermore, replacement costs for an eROT unit could potentially be astronomical, given the complicated nature of the unit itself. We might even have a system that could put Mercedes’s air-suspension to shame, a suspension setup which can cost upwards of $2000 to replace one broken airbag. Seeing as the system is being designed by VW AG, we’ll have to hope they don’t manage to somehow cheat when it comes to implementing eROT.

Future Uses

Though Audi did not go in depth about the scope of use for their eROT system, it is potentially far reaching. Obviously, VW AG intends to use the system primarily in the consumer car industry. However, Industrial use in freight, for example, could provide even more substantial energy savings on trucks with more than just two axles. Furthermore, there may be a potential use for the system in racing, though this seems far less likely. A modification of the system to favor fuel savings could also prove to be an interesting investment in the future. By potentially using energy from this system to charge a hybrid’s battery, Audi could revise their system to favor improved CO2 output and MPG’s.