Audi has used the Audi Future Performance Days innovation conference to unveil a world first suspension technology that allow the manufacturer to harness energy from a vehicle's suspension dampers that would otherwise be lost as heat.
The eROT (electromechanical rotary damper) replaces a traditional hydraulic damper that would normally release stored energy in the form of heat as the car travels over imperfections in the road.
A strong lever arm moves up and down with each damper articulation and using a set of gears, it creates a current that can be used to generate and store power in batteries, which can then be used later to power components of the car.
Alexander Kruse, a member of Audi's powertrain development team, explained that over a test loop that covered three sets of terrain — highway, country roads and the Nurburgring — the team was able to generate between 3W (on a smooth highway) and 613W (on a poorly maintained country road) over the given drive.
While it may not seem like much, it's enough to bring CO2 emissions down by 2g over the given drive. The other advantage is that the mechanism used to support this technology uses much less space and weighs around 10kg less than a regular hydraulic damper, giving engineers more room to work with for extra features.
The system uses a set of ohmic resistors to increase resistance (to create a firmer ride) and can vary the amount of current generated based on level of resistance. So, if the driver wants a firmer ride and then drives over a bumpy road, the system will be generating the maximum possible power.
Further to the removal of hydraulic suspension dampers, Audi is also developing a 48V electromechanical system to actively decouple opposing stabiliser bars via an electronically operated three-stage planetary gear set.
The system can decouple stabiliser bars on the run (even at low speeds) to increase driving comfort during cornering and can then recouple the stabiliser bars and apply an opposing force of up to 1200Nm to improve ride and handling as the driver calls for flatter cornering.
Similar to the regeneration method of eROT, the EAWS system can recoup energy as wheels deflect individually, working as a generator to capture kinetic energy that would otherwise be lost as heat.
Audi expects this technology to be seen on the first production vehicle next year and pairs with Audi's vision for mild-hybridisation to be enabled on all its vehicles by 2026.