This result shows clearly that it is very hard to reject the
disturbance effect on both positions at the same time. The
largest singular value Bode plots of the closed-loop system
are shown in Figure 0.28. We note that the H¥ controller
typically gives a relatively flat frequency response since it
tries to minimize the peak of the frequency response. On the
other hand, the H2 controller would
typically produce a
frequency response that rolls off fast in the high-frequency
range but with a large peak in the low-frequency range.