Fault Tolerant Tracking Controller Design Research Articles

Robust fault-tolerant tracking control for a class of T-S fuzzy systems subject to actuator failure and external disturbance

Based on the Takagi-Sugeno (T-S) fuzzy model approach, this study discusses the robust fault-tolerant tracking controller design for non-linear systems affected by external disturbances, uncertainties, and actuator failures. In contrast to existing results, this study assumes the actuator fault model includes linear and nonlinear terms, and a state feedback controller is designed to improve the tracking and stability of the system when actuators fail. Using a non-quadratic Lyapunov function, new sufficient conditions for L_2-gain tracking performance analysis are derived to determine simultaneously the minimal level of the L_2-gain and controller gains. The robustness of the proposed approach is also investigated. An illustration of the theoretical developments is provided by a Duffing forced oscillation system.

Emerging approaches for nonlinear parameter varying systems

Emerging approaches for nonlinear parameter varying systems

A reconfigurable PID fault tolerant tracking controller design for LPV systems

This paper considers the design of a reconfigurable PID Fault Tolerant Tracking Controller (PID-FTTC) for Linear Parameter Varying (LPV) systems affected by actuator faults with the presence of disturbance. The LPV systems are represented through a polytopic LPV description with measurable gain scheduling functions. A new PID-FTTC scheme with a model reference, an adaptive PID controller and an Adaptive Polytopic Observer (APO), is developed. The main idea is to improve and to compare performances with this developed PID-FTTC versus previous similar FTC techniques especially about the settling time, the overshoot and integral error indices. By the way, this paper can reduce the conservatism of previous methods with more parameters design so as to avoid their disadvantages and to give better control loop performances especially in terms of accuracy and speed of trajectory tracking even when a fault occurs. So, in order to establish the stability of the reconfigured PID-FTTC, a new theoretical study is developed through the use of Linear Matrix Inequality (LMI). This new method is illustrated through a two-tank process where the results compared to previous ones, underline the improvements.

Data-Driven Output-Feedback Fault-Tolerant Tracking Control Method and Its Application to a DC Servo System

The paper is concerned with the problem of data-driven output-feedback fault-tolerant tracking control design for unknown discrete-time linear systems with stochastic measurement and process noise. With the aid of a proposed input-output data-based online iterative identification algorithm, this study presents a fault detection strategy, an approximate dynamic programming approach to performance optimization, and a method for the achievement of tracking control via a pre-filter. The resulting fault-tolerant control (FTC) scheme is applied to a practical DC servo motor system with load fluctuations and nonlinearity. Finally, the experimental test demonstrates that the proposed FTC strategy (including a methodology for compensating load variations and nonlinearity) has better applicability and practicability than the one given by the previous work, where a load needs to be held constant and it is required that the motor run in a nearly linear small working region.

Adaptive Observer-Based Fault-Tolerant Tracking Control for T–S Fuzzy Systems With Mismatched Faults

This paper is concerned with the observer-based fault-tolerant tracking controller design problem for a class of T–S fuzzy systems with mismatched faults and disturbances. First, a sequence of adaptive observers are constructed, based on which an iterative algorithm is given to obtain the estimations of the system states and the fault signals simultaneously. Different from the existing results which mainly focus on the compensation of matched faults, by employing an equivalent matrix transformation technique and the backsteppinglike technique, a novel observer-based fault-tolerant tracking control scheme is developed to compensate the effects of the mismatched faults and achieve the output tracking objective. Furthermore, it is proven that all the signals of the resulting closed-loop fuzzy system are uniformly ultimately bounded and the output tracking error converges to a bounded region whose upper bound is relevant to the design parameters and the estimate errors. Finally, two simulation examples are provided to illustrate the validity of the proposed controller design method.

Active Fault-Tolerant Control for Wind Turbine with Simultaneous Actuator and Sensor Faults

The purpose of this paper is to show a novel fault-tolerant tracking control (FTC) strategy with robust fault estimation and compensating for simultaneous actuator sensor faults. Based on the framework of fault-tolerant control, developing an FTC design method for wind turbines is a challenge and, thus, they can tolerate simultaneous pitch actuator and pitch sensor faults having bounded first time derivatives. The paper’s key contribution is proposing a descriptor sliding mode method, in which for establishing a novel augmented descriptor system, with which we can estimate the state of system and reconstruct fault by designing descriptor sliding mode observer, the paper introduces an auxiliary descriptor state vector composed by a system state vector, actuator fault vector, and sensor fault vector. By the optimized method of LMI, the conditions for stability that estimated error dynamics are set up to promote the determination of the parameters designed. With this estimation, and designing a fault-tolerant controller, the system’s stability can be maintained. The effectiveness of the design strategy is verified by implementing the controller in the National Renewable Energy Laboratory’s 5-MW nonlinear, high-fidelity wind turbine model (FAST) and simulating it in MATLAB/Simulink.

Robust fault tolerant tracking control design for a linearized hypersonic vehicle with sensor fault

In this study, the robust fault tolerant tracking problem is investigated for a linearized hypersonic vehicle model with the bounded external disturbance and the sensor fault. Firstly, the nonlinear longitudinal dynamics of hypersonic vehicle is linearized as a linear time-invariant system with sensor fault, a reference model is introduced for the aim of fault tolerant tracking control. And then an observer-based fault tolerant output feedback tracking controller design approach is proposed by using the linear matrix inequalities (LMIs) technique. The asymptotic stability of the whole closed-loop system is analyzed using the well-known Lyapunov stability method. Finally, the simulation results are presented to verify the applicability of the developed fault tolerant approach.

Dynamic Surface Fault Tolerant Tracking Control Design for UAV with Transient Performance

In this paper, a novel fault tolerant control (FTC) approach is proposed for the attitude control systems of unmanned aerial vehicle (UAV) using dynamic surface control technique. Firstly, the nonlinear attitude dynamic models of UAV with actuator faults are given, which represent the dynamic characteristics of UAV. Then, a fault tolerant control scheme is proposed, which guarantees the asymptotic tracking and ultimate uniform boundedness of the closed-loop attitude control systems of UAV in the presence of an actuator fault. Further, a transient performance is considered in the designing of FTC, which characterizes the convergence rate and maximum overshoot of the attitude tracking error. Finally, simulation results are given to illustrate the effectiveness of the developed FTC algorithm.

Robust Adaptive Fault-Tolerant Tracking Control of Three-Phase Induction Motor

This paper deals with the problem of induction motor tracking control against actuator faults and external disturbances using the linear matrix inequalities (LMIs) method and the adaptive method. A direct adaptive fault-tolerant tracking controller design method is developed based on Lyapunov stability theory and a constructive algorithm based on linear matrix inequalities for online tuning of adaptive and state feedback gains to stabilize the closed-loop system in order to reduce the fault effect with disturbance attenuation. Simulation results reveal the merits of proposed robust adaptive fault-tolerant tracking control scheme on an induction motor subjected to actuator faults.

Fault-Tolerant Control of High-Speed Trains with Parameter Uncertainty

This paper studies the robust fault-tolerant control problem against actuator faults and parameter uncertainty for High-Speed Trains. First, models of actuator faults and parameter uncertainty are presented. Then a robust fault-tolerant tracking controller design method is developed. This method is based on the mixed Linear Matrix Inequalities (LMI)/Lyapunov stability theory. Tracking control examples and simulations are given, and the response curves of the fault system and the system with the fault-tolerant tracking controller are presented.

Robust fault tolerant tracking controller design for a VTOL aircraft

This paper deals with the fault tolerant control (FTC) design for a Vertical Takeoff and Landing (VTOL) aircraft subject to external disturbances and actuator faults. The aim is to synthesize a fault tolerant controller ensuring trajectory tracking for the nonlinear uncertain system represented by a Takagi–Sugeno (T–S) model. In order to design the FTC law, a proportional integral observer (PIO) is adopted which estimate both of the faults and the faulty system states. Based on the Lyapunov theory and ℒ2 optimization, the trajectory tracking performance and the stability of the closed loop system are analyzed. Sufficient conditions are obtained in terms of linear matrix inequalities (LMI). Simulation results show that the proposed controller is robust with respect to uncertainties on the mechanical parameters that characterize the model and secures global convergence.

Robust fault tolerant tracking controller design for unknown inputs T–S models with unmeasurable premise variables

This work concerns the tracking problem of uncertain Takagi–Sugeno fuzzy continuous systems with unmeasurable premise variables and affected by unknown inputs. The aim is to synthesize a fault tolerant controller (FTC) ensuring trajectory tracking of a desired reference model. To emit the original plant system, a norm bounded parametric uncertainty is employed in building the T–S model. The control scheme is based on a fuzzy observer to estimate both faults and faulty system states; a proportional integer (PI) observer to estimate constant faults is then adopted. Using descriptor redundancy property and L2 optimization to attenuate the unknown inputs effect, a solution is proposed in terms of bilinear matrix inequalities (BMIs). The performances of the proposed approach are pointed out by accentuating on a model of wastewater treatment plant (WWTP) through numerical results.