The minimum entropy controller as a mixed H2/H∞ controller: the time-varying case

In this paper we have given an interpretation of the entropy, defined for discrete-time time-varying systems. The interpretation shows why minimum entropy controllers have an advantage over other H^∞ controllers, in the sense that the difference in norms of the input and output signals will be relatively high for signals not equal to the worst-case one. This is in favor of the goal that H^∞ control wants to achieve. Furthermore we showed that minimizing the entropy in general results in a relatively low quadratic cost, which indicates why minimum entropy controllers are in general good mixed H²/H^∞ controllers