Nonlinear Stabilization of Shock-Like Unstable Equilibria in the Viscous Burgers PDE

We stabilize the unstable ldquoshock-likerdquo equilibrium profiles of the viscous Burgers equation using control at the boundaries. These equilibria are not stabilizable (even locally) using the standard ldquoradiation feedback boundary conditions.rdquo Using a nonlinear spatially-scaled transformation (that employs three ingredients, of which one is the Hopf-Cole nonlinear integral transformation) and linear backstepping, we design an explicit nonlinear full-state control law that achieves exponential stability, with a region of attraction for which we give an estimate. The region of attraction is not the entire state space since the Burgers PDE is known not to be globally controllable.