Control law design for robustness and performance

In this chapter the theme is again control law (or controller) design but here we allow uncertainty in the model structure. The uncertainty allowed is described by particular model structures, some of which have already been introduced in Chap. 5. The resulting control law design algorithms can be computed using LMls and are based on H-infinity, H-2, and mixed H-infinity/H-2 techniques. Illustrative examples are given as appropriate. The results in this chapter represent some of the latest available in the subject area but by no means exhaust the possibilities. Rather they provide an essential basis for the eventual development of a comprehensive control systems theory, coupled with numerically reliable control law design algorithms, for these processes.