A conventional stabilizer operates passively, in other words, it just balances the suspension movements on both sides by means of mechanical coupling. By contrast, electromechanical roll stabilization can be specifically controlled. The system consists of two stabilizer halves per axle, with an electric motor operating between them on both the front and rear axle. It can rotate the stabilizer halves in opposite direction of each other and thus generate torque that counteracts body roll torque – individually for each wheel. As a result, it reduces the body roll angles and actively supports them against the physical effects of the driving situation.
The system receives its commands via control units on the front and rear axle, which are part of the Electronic Chassis Platform (ECP). The ECP is the central brain of the chassis. Within milliseconds, it matches a variety of parameters such as speed, ride height, roll and pitch movements of the car, the friction coefficient of the road surface, the current driving condition such as under- or over-steer, plus the data of the chassis systems involved. From this input, the system calculates the ideal responses for the integrated components and adjusts them quickly and precisely to each other.
The required electrical energy is supplied to the eAWS by a powerful 48-volt onboard electrical system. Within milliseconds, the system calculates suitable actuation values for the stabilizers. The electric motors deliver their power output via three-stage planetary gearboxes, with torque levels of up to 1,200 Nm being generated at the stabilizers.