Fault-tolerant control and diagnosis for a non-linear system with an Unknown Input Observer

An Unknown Input Observer design for the sensors fault diagnosis of a non-linear system is the aim of this paper. To detect the faulty sensor, the method based on output residual is used. To obtain such a residual signal, an observer-based approach is proposed. How to design such observer is explained in details. Moreover, the two-tank system fault-tolerant control method is proposed. An experimental verification, which presents the performance of the proposed approach is given in the final section of this paper.