Finally, an adaptive control law for a modified skyhook,
formerly presented in [3], is employed. The adaptation law
uses an online Fourier transformation of the road signal
estimate ˆxg to determine the characteristic of the road profile
at the body and the wheel eigenfrequencies. On the basis
of its excitation intensity the road disturbance is classified
into various road conditions defined as ISO road classes, [4].
F∗≡Fd, rams is obtained from (3) by applying dsky=¯dsky(ˆxg)
and dc, p = ¯dc, p(ˆxg), where the adaptation logic schedules
optimal skyhook-groundhook gains ¯dsky(ˆxg) and ¯dc, p(ˆxg)
depending on the quality of the ground surface. The optimal
gains for the different road classes have been optimized based
on simulations. For good road conditions the objective is to
improve ride comfort while at rougher roads ride safety has
to be focussed. In this work the estimation of the road profile
is carried out by means of a Kalman filter.