Design of unknown inputs observer for a chemical process: Analysis of existence and observability based on phenomenological model

This paper explains the existence and observability conditions for the design of an Unknown Inputs Observer (UIO) for a chemical process. First, a phenomenological interpretation for the existence of the observer is given from the transfer function of the linearized system. And secondly, the existence and observability conditions of the observer are verified algebraically evaluating the rank of a defined observability matrix. Both ways of verification are compared. Finally, an UIO is implemented and simulation results are presented.