What is Active Body Control?

Since 1978, Mercedes-Benz, a German car manufacturer, had been developing the Active Body Control (ABC) system with the hope that someday it could be integrated as an additional safety feature in their vehicles. Finally, over twenty year later, in 1999, Mercedes-Benz first presented the Active Body Control (ABC) device in their CL (Comfort Light) class vehicles.

While other car manufacturers may have active suspension features in their cars, the "Active Body Control system" is the brand name given to Mercedes-Benz's technology. The ABC system continuously monitors how much the car leans outwards or dips down when it accelerates, brakes or makes sharp turns. If needed, the system will correct any problems involving the positioning of the vehicle to prevent the car from rolling or otherwise losing control.

Active Body Control has three main components: the vehicle's sensors, a microprocessor (ABC controller), and hydraulic servomechanisms. A hydraulic servomechanism is a mechanism that uses automatic feedback and hydraulics to correct the performance of a machine. Basically, the microprocessor retrieves information from the sensors, determines whether the car is in a safe or unsafe situation, and directs the hydraulic servomechanisms on how to correct the car's positioning.

Thirteen sensors are used in the Active Body Control system. One level sensor near each wheel measures how level the ride is. Five different sensors measure the acceleration of the vehicle and the change rate of acceleration if needed. Lastly, four hydraulic sensors measure the amount of hydraulic pressure that has been used in braking.

The four servomechanisms make the actual corrections. Their sole purpose is to correct any flaws in the weight distribution or angle of the vehicle that would possible result in the body of the vehicle rolling. When the microprocessor determines that the car is out of position, the servomechanisms counterbalance the positioning within a fraction of a second.

Since the success of integrating the Active Body Control into their CL class vehicles, Mercedes-Benz has integrated the system into its SL (Sport Light) and S (Sedan) class vehicles as well.