International Journal of Control, Vol.90, No.5, 1063-1076, 2017
Stabilisation of parabolic semilinear equations
We design here a finite- dimensional feedback stabilising Dirichlet boundary controller for the equilibrium solutions to parabolic equations. These results extend that ones in Barbu (2013), which provide a feedback controller expressed in terms of the eigenfunctions fj corresponding to the unstable eigenvalues {.j} Nj =1 of the operator corresponding to the linearised equation. In Barbu (2013), the stabilisability result is conditioned by the require of linear independence of {... fj} Nj =1, on the part of the boundary where control acts. In thiswork, we design a similar control as in Barbu (2013), and showthat it assures the stability of the system. This time, we drop the require of linear independence and any other additional hypothesis. Some examples are provided in order to illustrate the acquired results. More exactly, boundary stabilisation of the heat equation and the Fitzhugh- Nagumo equation.