Interval observer‐based fault tolerant control strategy with fault estimation and compensation

2021 ◽  
Author(s):  
Yu Shan ◽  
Fanglai Zhu
Keyword(s):  
Control Strategy ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Fault Estimation ◽  
Interval Observer

scholarly journals Adaptive Observer-Based Fault Detection and Fault-Tolerant Control of Quadrotors under Rotor Failure Conditions

2020 ◽  
Vol 10 (10) ◽  
pp. 3503 ◽  
Author(s):  
Yu-Hsuan Lien ◽  
Chao-Chung Peng ◽  
Yi-Hsuan Chen
Keyword(s):  
Fault Detection ◽  
Flight Control ◽  
Control Strategy ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
External Disturbance ◽  
Fault Tolerant Control ◽  
Adaptive Observer ◽  
Fault Estimation ◽  
Failure Conditions

This paper aims to propose a strategy for the flight control of quad-rotors under single rotor failure conditions. The proposed control strategy consists of two stages—fault detection (FD) and fault tolerant control (FTC). A dual observer-based strategy for FD and fault estimation is developed. With the combination of the results from both observers, the decision making in whether a fault actually happened or the observed anomaly was caused by an external disturbance could be distinguished. Following the FD result, a control strategy for normal flight, as well as the abnormal one, is presented. The FTC considers a real-time coordinate transformation scheme to manipulate the target angles for the quad-rotor to follow a prescribed trajectory. When a rotor fault happens, it is going to be detected by the dual observers and then the FTC is activated to stabilize the system such that the trajectory following task can still be fulfilled. Furthermore, in order to achieve robust flight in the presence of external wind perturbation, the sliding mode control (SMC) theory is further integrated. Simulations illustrate the effectiveness and feasibility of the proposed method.

A novel fault-tolerant control strategy based on inverse bicausal bond graph model in linear fractional transformation

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110598
Author(s):  
Yacine Lounici ◽  
Youcef Touati ◽  
Smail Adjerid ◽  
Djamel Benazzouz ◽  
Billal Nazim Chebouba
Keyword(s):  
Time Delay ◽  
Control Strategy ◽  
Fault Tolerant ◽  
Graph Model ◽  
Fault Tolerant Control ◽  
Bond Graph ◽  
Pi Controller ◽  
Control Signal ◽  
Linear Fractional Transformation ◽  
Fault Estimation

This article presents the development of a novel fault-tolerant control strategy. For this task, a bicausal bond graph model-based scheme is designed to generate online information to the inverse controller about the faults estimation. Secondly, a new approach is proposed for the fault-tolerant control based on the inverse bicausal bond graph in linear fractional transformation form. However, because of the time delay for fault estimation, the PI controller is used to reduce the error before the fault is estimated. Hence, the required input that compensates the fault is the sum of the control signal delivered by the PI controller and the control signal resulting from the inverse bicausal bond graph for fast fault compensation and for maintaining the control objectives. The novelties of the proposed approach are: (1) to exploit the power concept of the bond graph by feeding the power generated by the fault in the inverse model (2) to suitably combining the inverse bicausal bond graph with the PI feedback controller so that the proposed strategy can compensate for the fault with a very short time delay and stabilize the desired output. Finally, the experimental results illustrate the efficiency of the proposed strategy.

Active fault tolerant control of turbofan engines with actuator faults under disturbances

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan-Hua Ma ◽  
Xian Du ◽  
Lin-Feng Gou ◽  
Si-Xin Wen
Keyword(s):  
Active Fault ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Feedback Controller ◽  
Actuator Faults ◽  
Error Feedback ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Interval Observer ◽  
State Error

AbstractIn this paper, an active fault-tolerant control (FTC) scheme for turbofan engines subject to simultaneous multiplicative and additive actuator faults under disturbances is proposed. First, a state error feedback controller is designed based on interval observer as the nominal controller in order to achieve the model reference rotary speed tracking control for the fault-free turbofan engine under disturbances. Subsequently, a virtual actuator based reconfiguration block is developed aiming at preserving the consistent performance in spite of the occurrence of the simultaneous multiplicative and additive actuator faults. Moreover, to improve the performance of the FTC system, the interval observer is slightly modified without reconstruction of the state error feedback controller. And a theoretical sufficiency criterion is provided to ensure the stability of the proposed active FTC system. Simulation results on a turbofan engine indicate that the proposed active FCT scheme is effective despite of the existence of actuator faults and disturbances.

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.

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