A discrete-time LQ control with actuator failure is considered with directional change in controls phenomenon taken into account, as a result of actuator saturation case included. The control problem is analyzed in terms of algebraic Ricatti equations. Computer simulations of two-input two-output system are given to illustrate the performance of the reliable LQ controller.

 This paper presents a new approach to active fault-tolerant control for non-linear systems, based on fault estimation and compensation for time-varying faults. The work is a motivation for utilising the extension of the well known so-called fast adaptive fault estimation strategy to non-linear systems via a multiple-model strategy involving Takagi-Sugeno (T-S) fuzzy observer-based estimation and linear model-reference state tracking control. Moreover, the proposed strategy handles the case of unmatched uncertainty in the tracking error dynamics. The stability proof of the appropriate non-linear augmented system is derived via a Lyapunov condition and formulated as an efficient one step Linear Matrix Inequality (LMI) problem constraining the time-varying system eigenvalues to lie within specified regions in the complex plane. The fault compensation strategy is illustrated using a non-linear example of an inverted pendulum which includes Stribeck friction and a loss-of effectiveness actuator fault.

 In this paper, an innovative baseline control strategy for the linear-quadratic class of stochastic fault-tolerant control systems with performance risk aversion has been obtained. Moreover, an efficient paradigm of determining mathematical statistics associated with performance robustness is developed, upon which the model uncertainties of time-varying parameter perturbations and critical actuator failures of the stuck-type ones are also treated in the stochastic framework. The synthesis of risk-averse state feedback control law is shown feasible by the use of adapted dynamic programming approach to the optimal statistical control problem considered herein.

 This paper describes the robust performance of a novel active Fault Tolerant Control (FTC) approach for a nonlinear Unmanned Aerial Vehicle (UAV) during weapon delivery and with battled damaged wing, both considered as fault effects.The aircraft dynamics with mass variation and variable wing parameters are introduced and approximately linearized on-line using dynamic inversion controller based on differential geometry theory. For the linearized system, an active FTC scheme is accomplished via a linear matrix inequality (LMI) approach, based on a simultaneous state/faults observer by solving Lyapunov equation. The simulation results demonstrate the robust stability and satisfactory fault tolerant control performance of the proposed design.

 This paper presents a methodology to evaluate the admissibility of actuator fault configurations (AFC) when Linear Constrained Model Predictive Control (LCMPC) is used. The methodology combines the use of structural and feasability analysis. Structural analysis allows to evaluate the loss of reachability after a fault occurrence. The results of the structural analysis can be complemented with the feasibility analysis of the MPC problem taking into account the effect of actuator constraints after the fault occurrence. Additionally, a degradation analysis of the systems performance can also be included. The proposed methodology is tested in the Barcelona water network.

 In this paper, a Fault Tolerant Control (FTC) scheme using virtual actuators for discrete-time polytopic Linear Parameter Varying (LPV) systems subject to actuator saturations is proposed. The plant with the faulty actuator is augmented to take into account the saturations and modified adding the virtual actuator block that masks the fault. The elements of the FTC control loop are designed using Linear Matrix Inequalities (LMIs) in order to achieve the Pole Placement and the H2 norm specifications. To assess the performance of the proposed approach an aeronautical application is used.