Unknown Input Observers for a class of distributed parameter systems

The objective of this note is to extend the results of disturbance decoupling observers to a class of infinite dimensional systems. Using the fact that the operator describing the disturbance distribution is known, but with the disturbance being an unknown signal, an Unknown Input Observer is proposed for a class of infinite dimensional systems with bounded observation operators. The solvability of the problem hinges on the solution to a corresponding operator equation and which subsequently yields exponential convergence of the state observation error to zero. A numerical study of a 1-D parabolic system is included to provide insight into the implementation of UIO for infinite dimensional systems.