Example

Consider
again the two-mass/spring/damper system shown in Figure 0.1. Assume that
*F**1* is the
control force, *F**2** *is the disturbance force, and the
measurements of *x**1* and *x**2* are corrupted by measurement noise:

Our
objective is to design a control law so that the effect of the disturbance force *F**2* on the
positions of the two masses *x**1* and *x**2*, are reduced in a
frequency range 0ŁwŁ2.