Novel unknown input observer for fault estimation of gas turbine dynamic systems

Abstract

In this paper, an innovative unknown input observer (UIO) is developed to estimate the faults of the system subjected to faults and process disturbances. By representing the concerned faults as auxiliary states, an augmented system is constructed. By designing an unknown input observer for the augmented system, the simultaneous estimations of the system states and concerned faults can be obtained readily. In this study, the unknown input disturbance is not assumed to be decoupled completely. The integration of the UIO technique and the linear matrix inequality (LMI) optimization technique is proposed to decouple and attenuate the input disturbances. The existence condition of such an observer and the design method of the observer gains by using the LMI are addressed as well. Finally, the proposed algorithm is applied to the simulation study of a three shaft gas turbine system to show the excellent fault estimation performance.

Sensor Fault-Tolerant Control Design for Mini Motion Package Electro-Hydraulic Actuator

“…without loss of generality, the matrix Σ can be defined: (27) where δ 1 ∈ R nxp and δ 2 ∈ R pxp are arbitrary matrices. By solving (26) and (27), we obtain:…”

“…The two main tasks of this technology are to determine the estimated fault and to perform fault compensation. To obtain the estimated fault, some advanced observer methods are proposed, such as the sliding mode observer [15,24], the augmented observer [12,[16][17][18][25][26][27][28], and sensor fault reconstruction [29,30]. In particular, a UIO of the system variable reconstruction has the benefits of not only estimating the state vector, but also the fault estimation, as shown in [18,29,30].…”

Nonlinear Moving Horizon Estimator for Online Estimation of the Density and Viscosity of a Mineral Slurry

“…Ref. [21][22][23] are not useful tools for the transport model since it is not possible to apply any useful mathematical transformation. 1…”

“…Based on these equations, the model nonlinearities can be noticed, such as the logarithm function in eq , which involves the properties to be estimated (density and viscosity). Due to the nature of these equations (obtained from different conservation principles) and the resulting structure, the nonlinear state transformation-based techniques proposed for the design of nonlinear observers (see, e.g., refs , , and ) are not useful tools for the transport model since it is not possible to apply any useful mathematical transformation …”