  We develop a method for the model reference adaptive control (MRAC) of LTI
systems via Extremum Seeking (ES). Our proof of global asymptotic tracking
enables design of the adaptive controller to satisfy averaging requirements,
and convergence of tracking error. Our method is novel, with the additional
advantage that no perturbations need be added to the reference trajectory and
no a priori knowledge of parameter signs is needed. We illustrate our results
for a simulated second order system.
