Active Body Control, or ABC, is theMercedes-Benzbrand name used to describe electronically controlledhydropneumatic suspension.[1][2]
This suspension improves ride quality and allows for control of the vehicle body motions, reducingbody roll in many driving situations, includingcornering,accelerating, andbraking.[2]
Mercedes-Benz has been experimenting with these capabilities for automobile suspension since theair suspension of the1963600 and thehydropneumatic (fluid and air) suspension of the19746.9.
ABC was only offered onrear-wheel drive models, asall-wheel drive4MATIC models were available only withAirmatic semi-activeair suspension, with the 2019Mercedes-Benz GLE 450 4MATIC being the first AWD to have ABC available.[2]
The production version was introduced at the 1999Geneva Motor Show on the newMercedes-Benz CL-Class C215.[3]
In the ABC system, a computer detects body movement from sensors located throughout the vehicle, and controls the action of theactive suspension with the use ofhydraulicservomechanisms. The hydraulic pressure to the servos is supplied by a high-pressure radial piston hydraulic pump, operating at 3,000psi. Accumulators regulate the hydraulic pressure by means of an enclosed nitrogen bubble separated from the hydraulic fluid by a membrane.[1]
A total of 13 sensors continually monitor body movement and vehicle level and supply the ABC controller with new data every tenmilliseconds.[1] Four level sensors, one at each wheel measure the ride level of the vehicle, three accelerometers measure thevertical body acceleration, one acceleration sensor measures the longitudinal and one sensor thetransverse body acceleration. As the ABC controller receives and processes data, it operates fourhydraulic servos, each mounted on anair and pressurized hydraulic fluidstrut, beside each wheel.[4]
Almost instantaneously, the servo-regulated suspension generates counter forces tobody lean, dive and squat during various driving manoeuvres. A suspension strut, consisting of a steel coil spring and ashock absorber connected in parallel, as well as a hydraulically controlled adjusting cylinder, is located between the vehicle body and wheel. These components adjust thecylinder in the direction of the suspension strut, and change the suspension length. This creates a force which acts on the suspension and damping of the vehicle in the frequency range up to fivehertz.[1]
The system also incorporatesheight adjustable suspension, which in this case lowers the vehicle up to 11 mm (0.43 in) between the speeds of 60–160 km/h (37–99 mph) for betteraerodynamics, fuel consumption, and handling.[1]
The ABC system also allowsself-levelling suspension, which raises or lowers the vehicle in response to changing load (i.e. the loading or unloading of passengers or cargo).[1] 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.
The reliable function of the ABC system requires a regular hydraulic oil change and filter replacement.
The 1991Mercedes-Benz C112, 1995Mercedes-Benz Vario Research Car[5] and the 1996Mercedes-Benz F200 already featured prototype versions of ABC.
The first complete and ready-for-production version of ABC was introduced in 1999 on the top-of-the-lineMercedes-Benz CL-Class (C215).
In 2006, theMercedes-Benz CL-Class (C216) introduced the second generationActive Body Control suspension, referred to asABC Plus orABC II in technical documentation. This updated suspension reduced body roll by 45%[6] compared to the first-generation ABC suspension. ABC Plus had an updated hydraulic system design, with shorter hydraulic lines, and the pulsation damper was relocated to be mounted directly on the tandem pump.
In 2010, acrosswind stabilization function was introduced. In strong gusts of crosswind, and depending on the direction and intensity of the wind having an effect on the vehicle, this system varies the wheel load distribution in such a way that the effects of winds are largely compensated or reduced to a minimum. For this purpose the ABC control unit uses the yaw rate, lateral acceleration, steering angle and road speed sensors of theElectronic Stability Program ESP®.[7]
In 2007, theMercedes-Benz F700 concept introduced thePRE-SCAN suspension, an early prototype road scanning suspension, usinglidar sensors, based on Active Body Control.
In 2013, theMercedes-Benz S-Class (W222) introduced the series production version of PRE-SCAN, but with astereo camera instead of laser projectors. The system dubbedMagic Body Control is fitted with a road-sensing system (Road Surface Scan) that pre-loads the shocks for the road surface detected. Using astereo camera, the system scans the road surface up to 15 meters ahead of the vehicle at speeds up to 130 km/h (81 mph), and it adjusts the shock damping at each wheel to account for imperfections in the road. Initially only available on 8-cylinder models and above, Magic Ride Control attempts to isolate the car's body by predicting rather than reacting to broken pavement and speed humps.[8][9] The ABC has undergone major modifications for the new S-Class: the wheel damping is now continuously adjustable, the spring strut response has been improved and the pump efficiency has been further enhanced. A digital interface connects the control unit and the sensors, while the fastFlexRay bus connects the control unit and the vehicle electronics. Processing power is more than double that of the previous system.[10]
In 2014 the new C217S-Class Coupe introduced an update to Magic Body Control, calledActive Curve Tilting.[11] This new system allows the vehicle to lean up to 2.5 degrees into a turn, similar to atilting train. The leaning is intended to counter the effect ofcentrifugal force on the occupants and is available only on rear-wheel drive models[12][13]
In 2019 Mercedes-Benz introduced a new generation of its active suspension system calledE-Active Body Control (also writtenEABC), debuting on the fourth-generationMercedes-Benz GLE (V167).[14][15]
E-Active Body Control combines the air-spring elements of theAIRMATIC suspension with a 48-volt electrohydraulic system that actively controls spring and damping forces individually at each wheel. Unlike earlierABC systems, which counteracted body roll and pitch primarily through high-pressure hydraulics, E-Active Body Control can also manage wheel-specific vertical movement to improve ride comfort and off-road capability.
Using a network of sensors, cameras, and the onboard control unit, the system scans the road ahead and prepares each wheel for uneven surfaces. This predictive function, derived from the earlierMagic Body Control camera-based system, further refines comfort by pre-adjusting damping forces.[16]
The 48-volt network allows greater hydraulic response and energy recovery, enabling features such as “Free Driving Assist,” which lets the vehicle rock itself free when stuck in sand or snow. The system was first offered on theMercedes-Benz GLE andMercedes-Benz GLS and later extended to theMercedes-Benz S-Class (W223).[17]
E-Active Body Control represents the evolution of Mercedes-Benz’s fully active suspension systems, integrating air suspension, hydraulics, and real-time predictive control under a single electronic architecture.
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