Structural insensitivity versus identifiability

This correspondence is focused on the connection between a structural system property, such as the parameter insensitivity of state or output trajectories, and the accuracy achievable in the identification procedure. A geometric approach is used to synthesize, whenever possible, a controller, such that the Cramer-Rao lower bound of the parameter covariance function for the overall system is structurally not finite, i.e., for any input signal. This feature might be useful in connection with some evasion strategy problems and differential games.