Fault-tolerant control allocation of a flexible satellite with an infinite-dimensional model

2021 ◽  
pp. 095441002199127
Author(s):  
Leila Ashayeri ◽  
Ali Doustmohammadi ◽  
Farhad Fani Saberi
Keyword(s):  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
System Stability ◽  
Control Law ◽  
Control Allocation ◽  
Sliding Surface ◽  
Dimensional Model ◽  
Infinite Dimensional ◽  
Virtual Control ◽  
Control Scheme

Fault-tolerant control allocation (FTCA) strategy is proposed for attitude stabilization of a flexible satellite with actuator redundancy. The control scheme is based on the infinite-dimensional model of a flexible satellite with no discretization, so the spillover instability is eliminated. This is one of the important benefits of the proposed control scheme over the previous FTCA schemes that have been used for the flexible satellite. The proposed scheme contains two modules. The first module provides a virtual control law to meet stabilization and vibration control objectives in the presence of uncertainties and external disturbances. There is no need to implement in-domain actuators on panels to stabilize their vibration. In this module, the virtual control is designed using adaptive integral sliding mode approach where the sliding surface includes angular velocities, internal reaction torques, and nominal control for healthy system. The second module, based on fault/failure information and using a control allocation scheme, provides redistribution of the virtual control law among the available actuators. Due to simultaneous actuator faults and control constraints, there is an error between the actual virtual control and the designed control that affects the overall system stability. To eliminate this error, gain of the virtual control signal is adjusted by an adaptive updating law. The closed-loop system stability is guaranteed for small changes in a neighborhood of the sliding surface with simultaneous vibration damping. A numerical example illustrates the effectiveness of the proposed control 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.

scholarly journals Fault-Tolerant Control for Three-Tank System in Case of Sensor Faults

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mondher Amor ◽  
Taoufik Ladhari ◽  
Salim Hadj Said ◽  
Faouzi M’Sahli
Keyword(s):  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Operating Mode ◽  
High Gain ◽  
Fault Detection And Isolation ◽  
Control Law ◽  
Sensor Faults ◽  
Control Scheme ◽  
Tank System ◽  
Benchmark System

This research paper would be devoted to the application of a fault-tolerant control (FTC) for a benchmark system composed of three interconnected tanks in case of sensor faults. The control scheme includes two blocks: fault detection and isolation (FDI) block and a control law reconfiguration block. The strategy of the FDI method is based on a bank of high gain observers; each of them is constructed to estimate the system state vector. Thus, the diagnostic signal-residuals are generated by the comparison of measured and estimated outputs and the faulty sensor is isolated. The reconfiguration block performs an update of the controller parameters according to the operating mode. The application of this method to a pilot plant demonstrates that the hydrographic system maintains quite performances after sensor faults occurrence.

Fault tolerant control using integral sliding modes with control allocation along the null-space

2020 ◽  
Vol 42 (11) ◽  
pp. 2011-2019
Author(s):  
Chengcheng Ma ◽  
Chunsheng Liu ◽  
Jiazhen Yao
Keyword(s):  
Actuator Saturation ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Null Space ◽  
Fault Tolerant Control ◽  
Control Allocation ◽  
Control Scheme ◽  
Small Gain ◽  
Actuator Constraints ◽  
The Stability

In this paper, a new fault tolerant control scheme with control allocation is presented. The pseudo-inverse along the null-space control allocation is applied to the fault tolerant control system to handle the actuator constraints. The stability of the overall closed-loop system is proved via the small gain theory. The null-space vector is viewed as uncertainty, and is disposed by an integral sliding mode controller and a robust controller. The simulation results show that the new method can solve both failure scenarios and actuator saturation problems well.

scholarly journals Research of Conventional and Observer Based Controller for Three Tank Interacting System

2019 ◽  
Vol 8 (6S4) ◽  
pp. 1527-1531
Keyword(s):  
Pid Controller ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Control Law ◽  
Feed Forward ◽  
Single Input Single Output ◽  
Single Output ◽  
Control Scheme ◽  
Single Input ◽  
Forward Gain

In many Industries, the fault tolerant control scheme have been accepted and used from many decades. In this paper, the observer and the observer based Controller is designed for the three tank interacting system. Initially in this work, the three tank interacting system with Single Input Single Output configuration is modeled and conventional PID controller has been implemented, finally the performances are analyzed. Then the observer is designed for the three tank interacting system. Inorder to design the observer based controller, the control law and the feed forward gain value is calculated and described by Chakrabarti A et al.[4]. Finally the observer based controller performances are also analyzed. In this work, the sensor is replaced by the state observer. The observer based controller provides better performance than the conventional PID controller. This work may lead to design fault tolerant control for three tank interacting system in future.

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