The discrete-time controller for the H∞/LTR problem with mixed-sensitivity properties

In this technical communique is presented a new design procedure that can be used to obtain analogous results to the continuous-time H∞/LTR control on the discrete-time case. By directly designing the controller on discrete-time, equivalent mixed-sensitivity properties to the continuous-time H∞/LTR control can be guaranteed with a non-strictly proper H∞ controller. The main feature of the proposed procedure is a constraint that allows the designer to effectively bound the complementary sensitivity frequency peak and, consequently, reduce the overshoot on the system's response.