Adaptive damping system (ADS), function - GF32.32-P-0002GZ
MODEL 164.1 /8 with CODE (489) Airmatic (air suspension with level adjustment and adaptive damping system ADS)
Overall ADS function
The "adaptive damping system" (ADS) adapts the damping forces to the road surface condition and driving style or driver's wishes. The AIRmatic control unit (N51) determines the vertical speed using the signals from the left front body lateral acceleration sensor (B24/3), right front body lateral acceleration sensor (B24/4) and right rear body lateral acceleration sensor (B24/6). The signals of the wheel speeds and steering angle sensor (N49) are used to calculate longitudinal and lateral acceleration. The AIRmatic control unit controls the damping force at each wheel by means of the left front axle damping valve unit (Y51), right front axle damping valve unit (Y52), left rear axle damping valve unit (Y53) and right rear axle damping valve unit (Y54).
Each individual damping valve unit can thus be actuated using a different characteristic. The extremely short adjusting time (milliseconds) means that an optimum damping force setting is available almost immediately if sudden changes in the vehicle level are required.
Evaluation of the stop lamp switch signal enables brake applications to be quickly detected and any vehicle pitch motion to be reduced through suitable damper settings.
The driver can select between a comfort-oriented, automatic and a sporty map using the Comfort/Sport switch (ADS) (N72/1s31).
Skyhook algorithm (control algorithm)
A decisive criterion for determining suitable damper force stages (damper adjustment) for each respective driving situation is the direction of movement taken by the vehicle body. In the event of an upward movement the damper must provide a firm rebound stage and a soft compression stage. In the event of a downward movement a soft rebound stage and a firm compression stage are required, this is the principle on which the skyhook algorithm operates.
Shown on the left front suspension strut
The damping force setting is regulated in the damping valve units. Each wheel has one damping valve unit installed between the upper and lower chambers of the single-pipe gas-filled shock absorber.
Function shown on left front axle suspension strut
The damping force setting is regulated in the left front axle damping valve unit. The front axle damping valve unit on the left front wheel is located between the upper and lower chambers of the single-pipe gas-filled shock absorber. The damping valve unit contains the solenoid valve 1, left front and solenoid valve 2, front left, which depending on actuation via the Airmatic control unit 4 enable different damper force ratings to be achieved.
| AIRmatic with ADS control unit, component description | GF32.22-P-5108GZ | ||
| Suspension strut component description | GF32.25-P-5101GZ | ||
| Damper valve, component description | GF32.31-P-5112GZ | ||
| Acceleration sensor, component description | GF32.31-P-5106GZ | ||
| Steering angle sensor, component description | GF42.45-P-5107GZ |