Adaptive Fault Estimation Algorithm Research Articles

Practical fixed-time distributed adaptive fault estimation for attitude synchronization control systems

In this paper, the distributed adaptive fault estimation issue using practical fixed-time design is investigated for attitude synchronization control systems. A distributed fault estimation observer is proposed based on the fixed-time technique. Meanwhile, a novel fixed-time adaptive fault estimation algorithm is also constructed to guarantee convergence rate and improve estimation rapidity. The fault estimation error is uniformly ultimately bounded and is practically fixed-time stable, which converges to the neighborhood of the origin in a fixed time. Finally, simulation results of an attitude synchronization control system are presented to verify the effectiveness of proposed techniques.

Fast Active Fault-Tolerant Control for a Quadrotor UAV Against Multiple Actuator Faults

This paper proposes a fast adaptive fault estimator-based active fault-tolerant control strategy for a quadrotor UAV against multiple actuator faults. A fast adaptive fault estimation algorithm is designed to estimate the unknown actuator fault parameters. By synthesizing the fast adaptive fault estimator with the embedded control law, an active fault-tolerant control mechanism is established to compensate the adverse effects of multiple actuator faults. The effectiveness of the proposed strategy is validated through both numerical simulations and experimental tests.

Adaptive Fault Estimation and Fault Tolerant Control for Polynomial Systems: Application to Electronic and Mechanical Systems

This paper presents a sum of squares (SOS) approach for active fault tolerant control (AFTC) of nonlinear polynomial systems. A polynomial adaptive fault estimation algorithm for polynomial systems is firstly proposed. Then, sufficient conditions for the existence of the fault estimator are given in terms of SOS which can be numerically (partially symbolically) solved via the recently developed SOSTOOLS. Based on the obtained online fault estimation information, a fault-tolerant control strategy is designed for both compensating the effect of actuator faults in real time and stabilizing the closed-loop system. Finally, tunnel diode circuit and mass-spring-damper systems are used to demonstrate the applicability of the proposed approach.

Fault tracking sliding-mode controller design for fuzzy fractional-order system subject to actuator saturation

This paper brings forth the fault tracking(estimation) problem for Fractional-Order Takagi-Sugeno Fuzzy(FOTSF) uncertain model subject to time-varying actuator fault and actuator saturation. In order to maintain the stability of considered system, fuzzy fault-tolerant sliding-mode controller is constructed based on fast adaptive fault estimation algorithm. Precisely, stability analysis is performed for the FOTSF model based on state and fault estimations by using the Lyapunov’s stability theorem. More precisely, the sufficient constraints for stability of formulated model are built in proposed theorems. Eventually, two numerical exemplars including one chaotic model of Rossler are issued to support the proposed results and to demonstrate the efficacy of prescribed controller.

Robust fault estimation controller for fractional-order delayed system using quantized measurement

This work is concerned with the problem of actuator fault detection for the class of linear and nonlinear fractional-order systems with differentiable time-varying delays using quantized measurement. Our observation is focused on the modelling of non-fragile fault detection controller which is constructed by using an adaptive fault estimation algorithm to ensure asymptotic stability of the considered system with suggested $$H_\infty $$ performance. By considering suitable Lyapunov–Krasovskii functional and using some fractional-order calculus properties for resolvability of labelled problem are derived in terms of linear matrix inequalities. Finally, the simulation studies are included to demonstrate the validity of proposed control design.

Improved adaptive fault‐tolerant control design for hypersonic vehicle based on interval type‐2 T‐S model

SummaryThis study proposes an improved adaptive fault estimation and accommodation algorithm for a hypersonic flight vehicle that uses an interval type‐2 Takagi‐Sugeno fuzzy model and a quantum switching module. First, an interval type‐2 Takagi‐Sugeno fuzzy model for the hypersonic flight vehicle system with elevator faults is developed to process the nonlinearity and parameter uncertainties. An improved adaptive fault estimation algorithm is then constructed by adding an adjustable parameter. The quantum switching module is also applied to the estimation part to select an appropriate algorithm in different fault cases. The estimation results from the given fuzzy observer are used to design a type‐2 fuzzy fault accommodation controller to stabilize the fuzzy system. The stability of the proposed scheme is analyzed using the Lyapunov stability theory. Finally, the validity and availability of the method are verified by a series of comparisons on numerical simulation results.

Robust Fault Detection and Estimation in Nonlinear Systems with Unknown Constant Time-Delays

This paper studies the problem of fault detection and estimation in nonlinear time-delayed systems with unknown inputs, where the time-delays are supposed to be constant but unknown. A new fault detection filter, which can estimate online the time-delays, is first introduced. Then, a reference residual model is proposed to formulate the robust fault detection filter design problem as an H∞ model-matching problem. Furthermore, by a novel robust adaptive fault estimation algorithm, the classical assumption that the time derivative of the output error should be known is removed. In addition, applying a robust H∞ optimization control technique, sufficient conditions for the existence of the fault detection filter (FDF) are derived in terms of linear matrix inequality (LMI). Finally, simulation results are presented to illustrate the effectiveness of the proposed algorithm.

Adaptive Observer-Based Fault-Tolerant Control Design for Uncertain Systems

This study focuses on the design of the robust fault-tolerant control (FTC) system based on adaptive observer for uncertain linear time invariant (LTI) systems. In order to improve robustness, rapidity, and accuracy of traditional fault estimation algorithm, an adaptive fault estimation algorithm (AFEA) using an augmented observer is presented. By utilizing a new fault estimator model, an improved AFEA based on linear matrix inequality (LMI) technique is proposed to increase the performance. Furthermore, an observer-based state feedback fault-tolerant control strategy is designed, which guarantees the stability and performance of the faulty system. Moreover, the adaptive observer and the fault-tolerant controller are designed separately, whose performance can be considered, respectively. Finally, simulation results of an aircraft application are presented to illustrate the effectiveness of the proposed design methods.

Fault estimation for T-S fuzzy Markovian jumping systems based on the adaptive observer

The adaptive fault estimation problem is studied for a class of stochastic Markovian jumping systems (MJSs) with time delays and nonlinear parameters. By means of Takagi-Sugeno fuzzy models, the dynamics of observer error generator and the fuzzy error dynamical system are constructed. Based on the selected Lyapunov-Krasovskii functional framework, the adaptive fault estimation algorithm is proposed to enhance the rapidity and accuracy performance of fault estimation. In terms of linear matrix inequalities techniques, a sufficient condition on the existence of the adaptive observer is presented and proved. Moreover, the presented results are also extended to multiple time-delayed nonlinear MJSs. A numerical example is given at last to illustrate the effectiveness of the proposed approach.

Fault‐tolerant output synchronisation control of multi‐vehicle systems

This study presents a fault-tolerant output synchronisation control approach for a class of non-linear multi-vehicle systems. Firstly, adaptive fault diagnosis observers are designed for vehicle systems by utilising local measurements. Adaptive thresholds for distributed fault-detection of each vehicle system are derived. Then an adaptive fault estimation algorithm is proposed. Using the online obtained fault information, an adaptive fault-tolerant control protocol is designed to ensure the output synchronisation of the networked vehicle systems. It is proved that the proposed active fault-tolerant control protocol is capable of maintaining the output synchronisation performance of the multi-vehicle systems, at an acceptable level, in the presence of faults. Finally, simulation results are presented to show the effectiveness of the proposed algorithms.

Multiple model–based fault detection and diagnosis for helicopter with actuator faults via quantum information technique

A multiple model–based fault detection and diagnosis approach for a helicopter with actuator faults and disturbances is developed in this article. Particularly, the actuator is locked in-place and does not respond to subsequent commands. A multiple model scheme is proposed to detect and isolate the faults. In the multiple model scheme, a series of parallel observers are constructed, each of which is based on a model that describes the system in the presence of a particular actuator fault. In addition, quantum information technique is used to choose which model matches the current system. Furthermore, to estimate the locked position, a robust fast adaptive fault estimation algorithm based on linear matrix inequality technique is proposed by considering the disturbances. Finally, the simulation results show the efficiency of this scheme.

Fault tolerant control scheme design for the formation control system of unmanned aerial vehicles

In this article, a fault tolerant control approach is proposed for the formation control system of unmanned aerial vehicles with bounded external disturbance and unknown fault using both adaptive sliding mode control and [Formula: see text] control techniques. First, a linearized formation model of unmanned aerial vehicles is established under a straight and level formation flight condition. A reference model is introduced for the aim of the fault tolerant control problem. Then a sliding mode surface is designed for the deduced error dynamics, an virtual adaptive sliding mode controller and an adaptive fault estimation algorithm are proposed, which can drive the error dynamics onto the predefined sliding mode surface, and guarantee the property of asymptotical stability with a given disturbance attenuation level. On the basis of the normal proportional plus integral formation controller and the estimated fault information, a compensated control–based fault tolerant formation control scheme is proposed to ensure that the formation geometry is maintained in fault case. Finally, simulation results are given to show the effectiveness of the result obtained in this study.

Adaptive fault tolerant synchronization with unknown propagation delays and actuator faults

The paper addresses a practical issue in adaptive fault tolerant synchronization of masterslave systems with a constant signal propagation delay and actuator faults. First, a new concept of chaos synchronization is proposed, where the real value of the propagation delay can be estimated online by a proper adaptation mechanism; then, a novel adaptive fault estimation algorithm is proposed which removes the classical assumption that the time-derivative of the output errors should be known. Further, based on a proper Lyapunov-Krasovskii function, a novel delay-dependent adaptive fault tolerant synchronization scheme is proposed where the synchronization criterion is derived. Finally, simulation results of the chaotic system demonstrate the effectiveness of the proposed approach.

Adaptive Observer‐Based Fault Estimation for Stochastic Markovian Jumping Systems

This paper studies the adaptive fault estimation problems for stochastic Markovian jump systems (MJSs) with time delays. With the aid of the selected Lyapunov‐Krasovskii functional, the adaptive fault estimation algorithm based on adaptive observer is proposed to enhance the rapidity and accuracy performance of fault estimation. A sufficient condition on the existence of adaptive observer is presented and proved by means of linear matrix inequalities techniques. The presented results are extended to multiple time‐delayed MJSs. Simulation results illustrate that the validity of the proposed adaptive faults estimation algorithms.

Fault Estimation for Nonlinear Dynamic Systems

In this paper, the problems of fault detection and estimation for nonlinear dynamic systems are considered by using fault detection observer and adaptive fault diagnosis observer. Based on Lyapunov stability theory and linear matrix inequality (LMI) techniques, a new sufficient condition in terms of LMIs for the proposed problem is derived. At the same time, we get the adaptive fault estimation algorithm. The LMI condition can be easily solved by MATLAB LMI toolbox. Finally, a flexible joint robotic example is given to illustrate the efficiency of the proposed approach.

Fault estimation and accommodation for switched systems with time-varying delay

This paper considers the problem of fault estimation and accommodation for a class of switched systems with time-varying delay. An adaptive fault estimation algorithm is proposed to estimate the fault, moreover, constant or time-varying fault can be estimated. Meanwhile, a delay-dependent criteria is obtained with the purpose of reducing the conservatism of the fault estimation algorithm design. On the basis of fault estimation, an observer-based fault tolerant controller is designed to guarantee the stability of the closed-loop system. Additionally, simulation results are presented to illustrate the efficiency of the proposed results.

Fast adaptive fault estimation and accommodation for nonlinear time‐varying delay systems

AbstractThis paper studies the problem of fault estimation and accommodation for a class of nonlinear time‐varying delay systems using adaptive fault diagnosis observer (AFDO). A novel fast adaptive fault estimation algorithm that does not need the derivative of the output vector is proposed to enhance the performance of fault estimation. Meanwhile, a delay‐dependent criteria is obtained based on free weighting matrix method with the purpose of reducing the conservatism of the AFDO design. On the basis of fault estimation, an observer‐based fault‐tolerant controller is designed to guarantee the stability of the closed‐loop system. In terms of matrix inequality, we derive sufficient conditions for the existence of the adaptive observer and fault‐tolerant controller. Simulation results are presented to illustrate the efficiency of the proposed method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society