Robustness analysis with mixed performance objectives

Mixed performance control problems have been the object of much attention lately. These problems allow for capturing different performance specifications without resorting to approximations or the use of weighting functions. However, up to date most of the work concerning multiobjective control is limited to guaranteeing nominal performance and robust stability. In this paper we analyze robust performance for a class of mixed problems. The main results of the paper furnish sufficient conditions for guaranteeing performance (in the l_∞ sense) under model perturbations having an l₂ to l₂ bounded norm. These condition can be combined with previously proposed multiobjective control synthesis techniques to obtain controllers guaranteeing robust performance