Frequency domain conditions for robust H/sub 2/ performance

Presents frequency domain conditions to analyze H/sub 2/ performance in the worst case over structured uncertainty in the system. These conditions are convex feasibility tests in terms of linear matrix inequalities across frequency, of the same nature as tests available for robust stability or H/sub /spl infin// performance. By introducing a deterministic generalization of the H/sub 2/ criterion, the different versions of this test are characterized as necessary and sufficient for robust performance under corresponding classes of dynamic uncertainty.