Controller validation for stability and performance based on a frequency domain uncertainty region obtained by stochastic embedding

This paper presents a robustness analysis for an uncertainty set deduced from stochastic embedding techniques and made up of ellipsoids at each frequency in the Nyquist plane. Our robustness analysis focuses on the validation of a controller both for robust stability and for robust performance, over all systems in such frequency domain uncertainty region. Our validation procedure for stability ensures that the controller stabilizes all systems in this nonstandard uncertainty set. Our validation procedure for performance computes the worst case performance over all closed loop systems made up of the controller and all plants in the frequency domain uncertainty region