  We study the robust output regulation of linear boundary control systems by
constructing extended systems. The extended systems are established based on
solving static differential equations under two new conditions. We first
consider the abstract setting and present finite-dimensional reduced order
controllers. The controller design is then used for particular PDE models:
high-dimensional parabolic equations and beam equations with Kelvin-Voigt
damping. Numerical examples will be presented using Finite Element Method.
