Robust Fault Estimation based on Interval Takagi-Sugeno Unknown Input Observer

This paper proposes a discrete-time robust fault estimation scheme based on an interval Takagi-Sugeno Unknown Input Observer (UIO). The designed observer allows the interval estimation of states and faults by considering that the uncertainty is modelled in a deterministic bounded context. Furthermore, in the observer design, the effect of uncertainty is minimized using the H ∞ criterion using a LMI formulation. The proposed estimation scheme allows not only to provide the nominal value for states and faults but also an uncertainty interval where they should lie. A permanent magnet DC motor is used as a case study to assess the proposed approach.