In the adaptive damping system (ADS) of Mercedes-Benz, whose system functions are comparable to those of the EDC system, the damping adjustment which is dependent on the road irregularities takes place in 4 steps according to a characteristic map which considers a comparative values both for the spectral power density of the irregularities and the undulations w of the road being driven on, see figure.
An effective value H of the course of irregularity h(t) in the frequency range 0.5 - 20 Hz, (φ'=H(0.5 - 20 Hz)) determined by exponential smoothing is used as a comparative value for the spectral power density Φ(Ωo).
The comparative value for undulations is formed as a quotient resulting from the respective effective values for the ranges of body and axle resonance.
(w' = H (0.5 - 2 Hz) / H (8 - 20 Hz) )
The characteristic of the road irregularity h(t) is indirectly determined by the measurement of wheel acceleration and body acceleration.