An alternative solution to the weakened anti-windup problem for LFT perturbed plants

The problem of robust in the large anti-windup compensation (in the “weakened” anti-windup sense) is solved using a different control structure based on the two degrees-offreedom control and focusing on general stable uncertain systems in LFT form. It is shown that, whenever a suitable “certificate” of robust stability of the plant exists, then the weakened anti-windup problem can be solved (even in cases where the natural anti-windup problem can not be solved). A design approach is proposed relying on μ−synthesis, thus imposing less restrictions than previous designs based on small gain reasonings for additive uncertainties.