A successful controller design paradigm must take into account both model uncertainty and performance specifications. Model uncertainty can be used successfully addressed using the Hoo robust control framework. However, this framework cannot accommodate the realistic case where in addition to robustness considerations, the system is subject to both time and frequency domain performance specifications. In this research we propose to develop a robust control framework that takes explicitly into account these specifications. Specifically, the objectives of the proposed research are: 1) Development of a set of simple measures to describe how well a given set of performance specifications is satisfied in the presence of uncertainty. 2) Development of a controller synthesis procedure that uses extra degrees of freedom available in the problem to maximize an appropriate performance measure over the set of controllers that achieve a desired robustness level. This research will use the Youla parametrization to cast the problem into constrained optimization form. This research effort will result in an expanded Hoo framework, capable of addressing realistic problems without necessitating approximations nor multiple trial and error type iterations, thus leading to improved and less costly designs. The resulting framework will be used to design controllers for thermal power plants and flexible structures. As part of the research effort, these controllers will be tested both using simulations and prototype structure.
