scholarly journals FTC with Dynamic Virtual Actuators: Characterization via Dynamic Output Controllers andH∞Approach

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Dušan Krokavec ◽  
Anna Filasová ◽  
Vladimír Serbák
Keyword(s):  
Fault Tolerant ◽  
Tuning Parameter ◽  
Linear Matrix ◽  
Closed Loop System ◽  
Control Structures ◽  
Output Controller ◽  
Bounded Real Lemma ◽  
Dynamic Output ◽  
Control Scheme ◽  
Time Linear

The paper presents new conditions, adequate in design of dynamic virtual actuators and utilizable in fault-tolerant control structures (FTC) for continuous-time linear systems, which are stabilizable by dynamic output controllers. Taking into account disturbance conditions and changes of variables in FTC after virtual actuator activation and applying the nominal control scheme relating to the biproper dynamic output controller of prescribed order, the design conditions are outlined in terms of the linear matrix inequalities within the enhanced bounded real lemma forms. Using a free tuning parameter in design, and with suitable choice of the controller order, the approach provides the way to obtain acceptable dynamics of the closed-loop system after activation of the dynamic virtual actuator.

scholarly journals Virtual Actuator Design for Uncertain Metzler Systems

2021 ◽  
Vol 2 ◽  
Author(s):  
Dušan Krokavec ◽  
Anna Filasová
Keyword(s):  
Fault Tolerant ◽  
Interval Uncertainty ◽  
Linear Matrix ◽  
Actuator Faults ◽  
Closed Loop System ◽  
Matrix Representations ◽  
Output Control ◽  
Control Structures ◽  
Actuator Design ◽  
Static Output

The paper presents the design conditions adequate in design of virtual actuators and utilizable by nominal static output control structures in fault-tolerant control for strictly Metzler systems. The positive stabilization with H∞ norm performance is also addressed for virtual actuator design for strictly Metzler systems with interval uncertainty matrix representations of single actuator faults. Taking into account disturbance conditions and changes of values of variables after the virtual actuator activation, the design conditions are outlined in the terms of linear matrix inequalities. The approach provides a way to obtain acceptable dynamics of the closed loop system after virtual actuator activation.

scholarly journals H∞Control of Pairwise Distributable Large-Scale TS Fuzzy Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-18
Author(s):  
Anna Filasová ◽  
Dušan Krokavec
Keyword(s):  
Fuzzy Systems ◽  
Large Scale ◽  
Tuning Parameter ◽  
Linear Matrix ◽  
Matrix Inequalities ◽  
Bounded Real Lemma ◽  
Control Scheme ◽  
State Controller ◽  
Lyapunov Matrix ◽  
Takagi Sugeno

The paper presents new conditions suitable in design of the stabilizing state controller for a class of continuous-time nonlinear systems, which are representable by pairwise distributable Takagi-Sugeno models. Taking into account the affine properties of the TS model structure and applying the pairwise subsystems fuzzy control scheme relating to the parallel distributed output compensators, the extended bounded real lemma form and the sufficient design conditions for pairwise decentralized control are outlined in terms of linear matrix inequalities. The proposed procedure decouples the Lyapunov matrix and the system parameter matrices in the LMIs and, using free tuning parameter, provides the way to obtain global stability of such large-scale TS systems and optimizes subsystems interactionH∞norm bounds.

scholarly journals A Robust Fault-Tolerant Predictive Control for Discrete-Time Linear Systems Subject to Sensor and Actuator Faults

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2307
Author(s):  
Sofiane Bououden ◽  
Ilyes Boulkaibet ◽  
Mohammed Chadli ◽  
Abdelaziz Abboudi
Keyword(s):  
Model Predictive Control ◽  
Linear Systems ◽  
Predictive Control ◽  
Robust Stability ◽  
Discrete Time ◽  
Fault Tolerant ◽  
Linear Matrix ◽  
Input Constraints ◽  
Actuator Faults ◽  
Time Linear

In this paper, a robust fault-tolerant model predictive control (RFTPC) approach is proposed for discrete-time linear systems subject to sensor and actuator faults, disturbances, and input constraints. In this approach, a virtual observer is first considered to improve the observation accuracy as well as reduce fault effects on the system. Then, a real observer is established based on the proposed virtual observer, since the performance of virtual observers is limited due to the presence of unmeasurable information in the system. Based on the estimated information obtained by the observers, a robust fault-tolerant model predictive control is synthesized and used to control discrete-time systems subject to sensor and actuator faults, disturbances, and input constraints. Additionally, an optimized cost function is employed in the RFTPC design to guarantee robust stability as well as the rejection of bounded disturbances for the discrete-time system with sensor and actuator faults. Furthermore, a linear matrix inequality (LMI) approach is used to propose sufficient stability conditions that ensure and guarantee the robust stability of the whole closed-loop system composed of the states and the estimation error of the system dynamics. As a result, the entire control problem is formulated as an LMI problem, and the gains of both observer and robust fault-tolerant model predictive controller are obtained by solving the linear matrix inequalities (LMIs). Finally, the efficiency of the proposed RFTPC controller is tested by simulating a numerical example where the simulation results demonstrate the applicability of the proposed method in dealing with linear systems subject to faults in both actuators and sensors.

Stabilization of Fractional-Order Systems Subject to Saturation Element Using Fractional Dynamic Output Feedback Sliding Mode Control

2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Esmat Sadat Alaviyan Shahri ◽  
Alireza Alfi ◽  
J. A. Tenreiro Machado
Keyword(s):  
Fractional Order ◽  
Output Feedback ◽  
Sliding Mode ◽  
Linear Matrix ◽  
Linear Component ◽  
Dynamic Output Feedback ◽  
Closed Loop System ◽  
Fractional Systems ◽  
Dynamic Output ◽  
System States

This paper addresses the design of a robust fractional-order dynamic output feedback sliding mode controller (FDOF-SMC) for a general class of uncertain fractional systems subject to saturation element. The control law is composed of two components, one linear and one nonlinear. The linear component corresponds to the fractional-order dynamics of the FDOF-SMC, while the nonlinear component is associated with the switching control algorithm. The closed-loop system exhibits asymptotical stability and the system states approach the sliding surface in a finite time. In order to design the controller, a linear matrix inequality (LMI)-based procedure is also derived. Simulation results demonstrate the feasibility of the FDOF-SMC strategy.

Robust attitude fault-tolerant control for unmanned autonomous helicopter with flapping dynamics and actuator faults

2018 ◽  
Vol 41 (5) ◽  
pp. 1266-1277 ◽  
Author(s):  
Kun Yan ◽  
Mou Chen ◽  
Qiangxian Wu ◽  
Ke Lu
Keyword(s):  
Closed Loop ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Loop System ◽  
System Stability ◽  
Actuator Faults ◽  
Closed Loop System ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Autonomous Helicopter

In this paper, an adaptive robust fault-tolerant control scheme is developed for attitude tracking control of a medium-scale unmanned autonomous helicopter with rotor flapping dynamics, external unknown disturbances and actuator faults. For the convenience of control design, the actuator dynamics with respect to the tail rotor are introduced. The adaptive fault observer and robust item are employed to observe the actuator faults and eliminate the effect of external disturbances, respectively. A backstepping-based robust fault-tolerant control scheme is designed with the aim of obtaining satisfactory tracking performance and closed-loop system stability is proved via Lyapunov analysis, which guarantees the convergence of all closed-loop system signals. Simulation results are given to show the effectiveness of the proposed control method.

Positive Finite-Time Stabilization for Discrete-Time Linear Systems

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Wenping Xue ◽  
Kangji Li
Keyword(s):  
Linear Systems ◽  
Discrete Time ◽  
Finite Time ◽  
State Feedback ◽  
Closed Loop ◽  
Linear Matrix ◽  
Closed Loop System ◽  
Initial State ◽  
Finite Time Stability ◽  
Time Linear

In this paper, a new finite-time stability (FTS) concept, which is defined as positive FTS (PFTS), is introduced into discrete-time linear systems. Differently from previous FTS-related papers, the initial state as well as the state trajectory is required to be in the non-negative orthant of the Euclidean space. Some test criteria are established for the PFTS of the unforced system. Then, a sufficient condition is proposed for the design of a state feedback controller such that the closed-loop system is positively finite-time stable. This condition is provided in terms of a series of linear matrix inequalities (LMIs) with some equality constraints. Moreover, the requirement of non-negativity of the controller is considered. Finally, two examples are presented to illustrate the developed theory.

Study on Fault-Tolerant Control Scheme for a Helicopter via Adaptive H∞ Control

2013 ◽  
Vol 455 ◽  
pp. 395-401 ◽  
Author(s):  
Xi Chen ◽  
Fu Yang Chen ◽  
Bin Jiang
Keyword(s):  
State Feedback ◽  
Fault Tolerant ◽  
Adaptive Method ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Flight Performance ◽  
Actuator Faults ◽  
Stabilization Problem ◽  
Control Scheme ◽  
Tolerant State

In this paper, the stabilization problem for the 3 Degree of Freedom (3-DOF) hovering system of Quadrotor with actuator faults is investigated. To handle the helicopter system, an H robust fault-tolerant state feedback control is proposed. In addition, an adaptive method is combined with fault-tolerant H control to improve the flight performance. A more practical actuator fault is built, and the model of the system is presented. The design operates in Linear Matrix Inequality (LMI) technique. Finally, the design was verified on both MATLAB and 3-DOF platform to exam the feasibility and stability of the method.

scholarly journals Dynamic Output Feedback Based Active Decentralized Fault-Tolerant Control for Reconfigurable Manipulator with Concurrent Failures

2015 ◽  
Vol 2015 ◽  
pp. 1-14
Author(s):  
Yuanchun Li ◽  
Fan Zhou ◽  
Bo Zhao
Keyword(s):  
Output Feedback ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Fault Detection And Isolation ◽  
System Model ◽  
Linear Matrix ◽  
Dynamic Output Feedback ◽  
Actuator Fault ◽  
Dynamic Output ◽  
Reconfigurable Manipulators

The goal of this paper is to describe an active decentralized fault-tolerant control (ADFTC) strategy based on dynamic output feedback for reconfigurable manipulators with concurrent actuator and sensor failures. Consider each joint module of the reconfigurable manipulator as a subsystem, and treat the fault as the unknown input of the subsystem. Firstly, by virtue of linear matrix inequality (LMI) technique, the decentralized proportional-integral observer (DPIO) is designed to estimate and compensate the sensor fault online; hereafter, the compensated system model could be derived. Then, the actuator fault is estimated similarly by another DPIO using LMI as well, and the sufficient condition of the existence ofH∞fault-tolerant controller in the dynamic output feedback is presented for the compensated system model. Furthermore, the dynamic output feedback controller is presented based on the estimation of actuator fault to realize active fault-tolerant control. Finally, two 3-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in simulation. The main advantages of the proposed scheme lie in that it can handle the concurrent faults act on the actuator and sensor on the same joint module, as well as there is no requirement of fault detection and isolation process; moreover, it is more feasible to the modularity of the reconfigurable manipulator.

scholarly journals Relaxed formulation of the design conditions for Takagi-Sugeno fuzzy virtual actuators

2016 ◽  
Vol 26 (2) ◽  
pp. 199-221 ◽  
Author(s):  
Anna Filasová ◽  
Dušan Krokavec ◽  
Pavol Liščinský
Keyword(s):  
Linear Matrix ◽  
Actuator Faults ◽  
Output Controller ◽  
Bounded Real Lemma ◽  
Continuous Time Systems ◽  
Tank System ◽  
Takagi Sugeno ◽  
Time Systems ◽  
Relaxed Formulation ◽  
Static Output

Abstract The H∞ norm approach to virtual actuators design, intended to Takagi-Sugeno fuzzy continuous-time systems, is presented in the paper. Using the second Ljapunov method, the design conditions are formulated in terms of linear matrix inequalities in adapted bounded real lemma structures. Related to the static output controller, and for systems under influence of single actuator faults, the design steps are revealed for a three-tank system plant.

scholarly journals Fault Tolerant Control of Vehicle Lateral Dynamic Using a New Pneumatic Forces Multiple Model

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 120
Author(s):  
Imane Abzi ◽  
Mohammed Nabil Kabbaj ◽  
Mohammed Benbrahim
Keyword(s):  
Fault Tolerant ◽  
Longitudinal Velocity ◽  
Fault Tolerant Control ◽  
Small Variation ◽  
Linear Matrix ◽  
Multiple Model ◽  
Control Scheme ◽  
Sufficient Stability ◽  
Vehicle Dynamic Model ◽  
Takagi Sugeno

This paper presents a new accurate multiple model of nonlinear pneumatic lateral forces. The bicycle representation is used in order to build up an easy implemented vehicle dynamic model. Moreover, the Takagi–Sugeno fuzzy approach is applied in order to handle the vehicle model nonlinearities. This structure allows for taking into account the small variation of the vehicle longitudinal velocity. Subsequently, a Fault Tolerant Control strategy that is based on a bank of fuzzy Luenberger observers is proposed. The robustness of the control scheme against external noises is guaranteed by applying H∞ performance. Sufficient stability conditions that are based on Lyapunov method are formulated as Linear Matrix Inequality. Thus, allowing the computation of the observers’ and the controllers’ gains by using MATLAB. Finally, the simulation examples are performed to show the effectiveness of our proposal.

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