Robust eigenstructure assignment with structured state-space uncertainty and unmodelled dynamics

New time domain stability robustness results have been obtained for a non-strictly proper linear time-invariant plant which is subject to simultaneous time-varying structured state-space uncertainly and norm bounded unmodelled dynamics. Sufficient conditions for robust stability are obtained both for a constant gain output feedback controller and an output feedback dynamic compensator. The robustness conditions are explicitly in terms of the closed-loop eigenvalues and eigenvectors so that these new results are especially well suited for a robust eigenstructure assignment design method. An example is presented of a robust eigenstructure assignment autopilot using dynamic compensation for the yaw/roll dynamics of a bank-to-turn missile.