Asymptotic Tracking of Uncertain Systems in the Absence of Matching Conditions

We consider the tracking problem for linear systems with uncertainty in the system matrix and the input matrix. Previous tracking results for this problem require that certain matching conditions be satisfied. We do not impose such conditions here. Our results lead to a linear state feedback controller which guarantees that the output asymptotically tracks the command reference input for all allowable parameter values if a certain measure of mismatch does not exceed the critical mismatch threshold. An example is included to illustrate the application of the results.