- Active Body Control
Active Body Control, or ABC, is the
Mercedes-Benz brandname used to describe fully- active suspension, that allows control of the vehicle body motions and therefore virtually eliminates body roll in many driving situations including cornering, accelerating, and braking.
In the ABC system, a computer detects body movement from sensors located throughout the vehicle, and controls the action of the active suspension with the use of
hydraulic servomechanisms. The hydraulic pressure to the servos is supplied by a high pressure radial piston hydraulic pump. A total of thirteen sensors continually monitor body movement and vehicle level and supply the ABC controller with new data every ten milliseconds. Four level sensors, one at each wheel measure the ride level of the vehicle, 3 accelerometers measure the vertical body acceleration, one acceleration sensor measures the longitudinaland one sensor the transversebody acceleration. At each hydraulic cylinder a pressure sensor monitors the hydraulic pressure. As the ABC controller receives and processes data, it operates four hydraulicservos, each mounted in series on a spring strut, beside each wheel. Almost instantaneously, the servo regulated suspension generates counter forces to body lean, dive, and squat during various driving maneuvers. A suspension strut, consisting of a steel coil spring and a shock absorberare connected in parallel, as well as a hydraulically controlled adjusting cylinder, are located between the vehicle body and wheel. These components adjust the cylinder in the direction of the suspension strut, and change the suspension length. This creates a force which acts on the suspension and dampening of the vehicle in the frequency range up to five hertz.
The system also incorporates
height adjustable suspension, which in this case lowers the vehicle up to eleven millimeters between the speeds of 60 km/h (37 mph) and 160 km/h (99 mph) for better aerodynamics, fuel consumption, and handling.
The ABC system also allows
self-levelling suspension, which raises or lowers the vehicle in response to changing load (i.e. the loading or unloading of passengers or cargo). Each vehicle equipped with ABC has an “ABC Sport” button that allows the driver to adjust the suspension range for different driving style preferences. This feature allows the driver to adjust the suspension to maintain a more level ride in more demanding driving conditions.It was introduced in 1999 on the top-of-the-line Mercedes-Benz CL-Class.This system is standard on all Mercedes-Benz SL and CL Class models and on some S Class models sold in the U.S.
Citroën DShad hydropneumatic suspension, which had the height adjustable suspensionand self-levelling suspensionfeatures of ABC, but controlled purely by hydraulicaction, since computers in that era were larger than an automobile
Mercedes-Benz 450SEL 6.9had the height adjustable suspensionand self-levelling suspensionfeatures of ABC
Lotus Carsexperimented with active suspensionlayouts, combining hydraulicand electronic components.
Citroën XMhad a similar electronic control of hydraulic suspension, branded Hydractive.
Toyota Soarerhad a fully active hydraulic suspension system on the 1991 UZZ32 model.
Citroën XantiaActiva variant introduced a fully active suspension
* [http://www.mbusa.com Mercedes-Benz USA]
* [http://www.mercedesbenz.com Mercedes-Benz International]
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