Structural Information in Robustness Analysis

Two topics on using structural information in the robustness analysis of control feedback systems are presented. First, we describe how to identify sensitive direction for perturbations to individual components (subsystems) of larger systems. This technique is then applied, to parameter variation analysis. Also we discuss the role of the control weighting matrix in the robustness analysis of the linear quadratic (LQ) desigjn, using a 2×2 example. In particular, it is shown that the structure of the control weighting matrix can be used to classify sensitivities of the control system to model uncertainties.