Fault tolerant control for unstable systems: a linear time varying approach

2004 ◽  
Author(s):  
J. Stoustrup ◽  
H. Niemann
Keyword(s):  
Fault Tolerant ◽  
Linear Time ◽  
Fault Tolerant Control ◽  
Time Varying ◽  
Unstable Systems

Fault-Tolerant Control for Linear Time-Variant Impulsive Singular Systems Subject to Actuator Saturation and L∞ Disturbances

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Mahmood Khatibi ◽  
Mohammad Haeri
Keyword(s):  
Control Problem ◽  
State Feedback ◽  
Actuator Saturation ◽  
Fault Tolerant ◽  
Linear Time ◽  
Singular Systems ◽  
Viscoelastic Model ◽  
Domain Of Attraction ◽  
Fault Tolerant Control ◽  
Time Varying

This paper explores the fault-tolerant control problem for uncertain impulsive singular linear time-variant (LTV) systems in the presence of bounded-power or L∞ disturbances. Here, a saturation avoidance mechanism is employed to prevent faulty actuators from overloading. Also, the conflict between attenuating the effect of L∞ disturbances and enlarging the domain of attraction is tackled by proposing a nonconstant state feedback controller. In addition, the proposed method is capable of tolerating time-varying faults. The suggested method is implemented on a mechanical viscoelastic model of cortical bone with impulsive and time-varying nature to evaluate its competency.

scholarly journals Fault-Tolerant Control Strategy with Asymmetric Phase Currents for Single to Four-Phase Open-Circuit Faults of Six-Phase PMSM

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3163
Author(s):  
Chen Huang ◽  
Lidan Zhou ◽  
Zujia Cao ◽  
Gang Yao
Keyword(s):  
Working Conditions ◽  
Control Strategy ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Open Circuit ◽  
Time Varying ◽  
Electromagnetic Torque ◽  
Control Loops ◽  
Phase Current ◽  
Multi Phase

Multi-phase motors and generators are regarded with great fault tolerance capability, especially on open-circuit faults. Various mathematics analytical methods are applied for their fault control. In this paper, a fault-tolerant control strategy with asymmetric phase current for the open-circuit faults with arbitrary phases in the six-phase PMSM (six-phase permanent magnetic synchronous motor, 6P-PMSM) system, is proposed for better electrical and dynamical performance of the machine. An innovative mathematical model for PMSM under one to four-phase-open circuit faults are established considering the asymmetry of the machine. Combining with time-varying relations in machines’ working conditions, targeted decoupling transformation matrixes of every kind of open-circuit faults are settled by voltage equations under different faults. Modified control strategy with a connection between the neutral point and the inverter’s DC side is presented, which aims at increasing the system redundancy and reducing the amplitude of phase currents. Besides, improved control loops with two layers are put forward as well, with which the PMSM system acquires fewer harmonics in phase current and smoother electromagnetic torque. Simulation and experimental results of open-circuit faults are provided for verification of the theoretical analysis.

A finite frequency domain-based approach for active fault tolerant control of linear time-delay systems with residual feedback

2017 ◽  
Vol 40 (10) ◽  
pp. 2991-2998
Author(s):  
Quanchao Dong ◽  
Hongyan Yang
Keyword(s):  
Time Delay ◽  
Fault Detection ◽  
Active Fault ◽  
Fault Tolerant ◽  
Linear Time ◽  
Fault Tolerant Control ◽  
Finite Frequency ◽  
Fault Detection Filter ◽  
Active Fault Tolerant Control ◽  
Detection Filter

This paper presents a finite frequency-based active fault tolerant control approach for the compensation of unknown failures in linear time-delay plants. An integration of fault detection filter based on observer technology and [Formula: see text] controller in residual feedback form is considered in the active fault tolerant control system. Different from the traditional schemes, exact fault estimation is not necessary in the proposed active fault tolerant control. To achieve the desired system performance when a fault occurs, the residual is directly embedded in the control loop as a feedback term to compensate the influence of fault. By employing the Generalized Kalman–Yakubovich–Popov lemma, we derive the sufficient conditions of the existence of such an active fault tolerant control plant, and iterative algorithms are applied to obtain the solutions to the fault detection filter and controller parameter matrices. Finally, simulation results are proposed to demonstrate the effectiveness of the developed scheme.

scholarly journals Active Fault-Tolerant Control of a Quadcopter against Time-Varying Actuator Faults and Saturations Using Sliding Mode Backstepping Approach

2019 ◽  
Vol 9 (19) ◽  
pp. 4010 ◽  
Author(s):  
Ngoc Phi Nguyen ◽  
Sung Kyung Hong
Keyword(s):  
Fault Diagnosis ◽  
Active Fault ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Lyapunov Theory ◽  
Fault Estimation ◽  
Time Varying ◽  
Actuator Faults ◽  
Active Fault Tolerant Control

Fault-tolerant control is becoming an interesting topic because of its reliability and safety. This paper reports an active fault-tolerant control method for a quadcopter unmanned aerial vehicle (UAV) to handle actuator faults, disturbances, and input constraints. A robust fault diagnosis based on the H ∞ scheme was designed to estimate the magnitude of a time-varying fault in the presence of disturbances with unknown upper bounds. Once the fault estimation was complete, a fault-tolerant control scheme was proposed for the attitude system, using adaptive sliding mode backstepping control to accommodate the actuator faults, despite actuator saturation limitation and disturbances. The Lyapunov theory was applied to prove the robustness and stability of the closed-loop system under faulty operation. Simulation results show the effectiveness of the fault diagnosis scheme and proposed controller for handling actuator faults.

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