Adaptive Fractional-Order Fault-Tolerant Tracking Control for UAV Based on High-Gain Observer

2017 ◽  
Author(s):  
Ziquan Yu ◽  
Youmin Zhang ◽  
Yaohong Qu ◽  
Zhewen Xing
Keyword(s):  
Fractional Order ◽  
Tracking Control ◽  
Fault Tolerant ◽  
External Disturbance ◽  
Tracking Error ◽  
Small Region ◽  
High Gain ◽  
Actuator Fault ◽  
High Gain Observer ◽  
Flight Path Angle

This paper is concerned with the fractional-order fault-tolerant tracking control design for unmanned aerial vehicle (UAV) in the presence of external disturbance and actuator fault. Based on the functional decomposition, the dynamics of UAV is divided into velocity subsystem and altitude subsystem. Altitude, flight path angle, pitch angle and pitch rate are involved in the altitude subsystem. By using an adaptive mechanism, the fractional derivative of uncertainty including external disturbance and actuator fault is estimated. Moreover, in order to eliminate the problem of explosion of complexity in back-stepping approach, the high-gain observer is utilized to estimate the derivatives of virtual control signal. Furthermore, by using a fractional-order sliding surface involved with pitch dynamics, an adaptive fractional-order fault-tolerant control scheme is proposed for UAV. It is proved that all signals of the closed-loop system are bounded and the tracking error can converge to a small region containing zero via the Lyapunov analysis. Simulation results show that the proposed controller could achieve good tracking performance in the presence of actuator fault and external disturbance.

Neural network-based adaptive fault tolerant tracking control for unmanned autonomous helicopters with prescribed performance

2019 ◽  
Vol 233 (12) ◽  
pp. 4350-4362 ◽  
Author(s):  
Kun Yan ◽  
Mou Chen ◽  
Qingxian Wu
Keyword(s):  
Fault Tolerant ◽  
External Disturbance ◽  
Tracking Error ◽  
Fault Tolerant Control ◽  
Actuator Fault ◽  
Error Performance ◽  
System Uncertainty ◽  
Prescribed Performance ◽  
Medium Scale ◽  
Autonomous Helicopter

In this paper, the issue of prescribed performance-based fault tolerant control is investigated for the medium-scale unmanned autonomous helicopter with external disturbance, system uncertainty and actuator fault. The altitude and attitude combination unmanned autonomous helicopter model is established. An error transformation function is proposed to guarantee that the tracking error satisfies the prescribed performance. The parameter adaptation method is adopted to handle the external unknown disturbance and the radial basis function neural networks are employed to approximate the interaction functions including the system uncertainty. The auxiliary system is introduced to weaken the effect of actuator fault, which can effectively avoid the singularity. Based on the backstepping control technology, an adaptive neural fault tolerant control scheme is developed to ensure the boundness of all closed-loop system signals and the specified tracking error performance. Simulation studies on the medium-scale unmanned autonomous helicopter are performed to demonstrate the efficiency of the designed control strategy.

scholarly journals Fractional-Order Finite-Time, Fault-Tolerant Control of Nonlinear Hydraulic-Turbine-Governing Systems with an Actuator Fault

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3812
Author(s):  
Ying Yang ◽  
Bin Wang ◽  
Yuqiang Tian ◽  
Peng Chen
Keyword(s):  
Power Systems ◽  
Power System ◽  
Fractional Order ◽  
Finite Time ◽  
Control Method ◽  
Fault Tolerant ◽  
External Disturbance ◽  
Fault Tolerant Control ◽  
Hydraulic Turbine ◽  
Actuator Fault

Hydropower units undertake tasks such as peak shaving, frequency modulation, and providing accident reserves in the power system. With the increasing capacity and structural complexity of power systems, hydropower units have become more important. Hydraulic-turbine-governing systems (HTGSs) need to have higher control performance and automation levels to meet the higher regulatory requirements of the power system. To achieve high-quality control, we proposed a new finite-time, fault-tolerant control method for HTGSs with an actuator fault. First, a fractional-order model for HTGSs with uncertainty, external disturbance, and an actuator fault was introduced. Second, a fault estimator that could quickly track the fault signal for an actuator fault was proposed. Then, based on the fractional-order finite-time stability theorem, a finite-time, fault-tolerant controller was proposed for the stabilization of an HTGS. Furthermore, a controller was developed as a fractional differential form combined with a smooth bounded arctangent function to effectively suppress jitters and uncertainties. Finally, numerical experimental results verified the validity and robustness of the proposed scheme.

Parameter-dependent actuator fault estimation for vehicle active suspension systems based on RBFNN

2021 ◽  
pp. 095440702199301
Author(s):  
Wenping Xue ◽  
Pan Jin ◽  
Kangji Li
Keyword(s):  
Fault Tolerant ◽  
External Disturbance ◽  
Active Suspension ◽  
Fault Estimation ◽  
Linear Matrix ◽  
Actuator Fault ◽  
Mass Variation ◽  
Fe Method ◽  
Comparison Results ◽  
Parameter Dependent

The actuator fault estimation (FE) problem is addressed in this study for the quarter-car active suspension system (ASS) with consideration of the sprung mass variation. Firstly, the ASS is modeled as a parameter-dependent system with actuator fault and external disturbance input. Then, a parameter-dependent FE observer is designed by using the radial basis function neural network (RBFNN) to approximate the actuator fault. In addition, the design conditions are turned into a linear matrix inequality (LMI) problem which can be easily solved with the aid of LMI toolbox. Finally, simulation and comparison results are given to show the accuracy and rapidity of the proposed FE method, as well as good adaptability against the sprung mass variation. Moreover, a simple FE-based active fault-tolerant control (AFTC) strategy is provided to further demonstrate the effectiveness and applicability of the proposed FE method.

scholarly journals Fixed-Time Sliding-Mode Fault-Tolerant Control of Waste Heat Power Generator Systems

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zhi Wang ◽  
Yateng Bai ◽  
Jin Xie ◽  
Zhijie Li ◽  
Caoyuan Ma ◽  
...  
Keyword(s):  
Fault Tolerant ◽  
Waste Heat ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Tracking Error ◽  
Fixed Time ◽  
Fault Estimation ◽  
Actuator Fault ◽  
Heat Power ◽  
Time Control

In order to overcome disturbances such as the instability of internal parameters or the actuator fault, the time-varying proportional-integral sliding-mode surface is defined for coordinated control of the excitation generator and the steam valve of waste heat power generation units, and a controller based on sliding-mode function is designed which makes the system stable for a limited time and gives it good performance. Based on this, a corresponding fault estimation law is designed for specific faults of systems, and a sliding-mode fault-tolerant controller is constructed based on the fixed-time control theory so that the systems can still operate stably when an actuator fault occurs and have acceptable performance. The simulation results show that the tracking error asymptotically tends to be zero, and the fixed-time sliding-mode fault-tolerant controller can obviously improve the dynamic performance of the system.

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