  The robust tracking and model following problem of linear discrete-time
systems is investigated in this paper. An approach to design robust tracking
controllers is proposed. The system is controlled to track dynamic inputs
generated from a reference model. By using the solution of the Lyapunov
equation, the convergence of the tracking error to the origin, is proved. The
proposed approach employs linear controllers rather than nonlinear ones.
Therefore, the designing method is simple for use and the resulting controller
is easy to implement. An application of the proposed approach for a class of
perturbed systems is also considered. Finally, numerical examples are given to
demonstrate the validity of the results.
