Robust control of uncertain systems with combined H ∞and LQG optimizations

The design of robust control systems in the presence of real-parameter uncertainty and high-frequency unmodelled dynamics is considered. Concepts of applying H ∞ and LQG optimizations to a surrogate system representation of an uncertain system are discussed. An algorithm is explicitely stated which details the design of control laws guaranteeing both robust stability and robust performance for the uncertain system. Advantages and limitations to this design procedure are outlined, and possible directions for future research are revealed.