Since the PI-controller is found to be superior to the Pcontroller,
it has also been tested with the signal-based feedback,
referred to as FB-PIs, meaning that the acting damper
force is calculated from (2). The simulation results including
the feedback loop are also given in Table I. Resulting from
a smaller force tracking error, the data show significant
improvements in ride comfort as well as in road-holding,
achieved by the dynamic feedforward approach when the
feedback component is disabled. Both feedback controllers
can improve ride comfort even further, however, at the cost
of a slight decrease in road-holding. Since the same damper
model is used in both the model-based feedback loop and
in the simulation model of the quarter-car, the results for
FB-PIm and FB-PIs are quite similar. Differences arise only
from imprecisions in the mass estimation process.