Fractional-Order Sliding-Mode Fault-Tolerant Neural Adaptive Control of Fixed-Wing UAV With Prescribed Tracking Performance

In this paper, a fault-tolerant control system based on back-stepping integral sliding mode controller (BISMC) is designed and analyzed for both nonlinear translational and rotational subsystems of the quadrotor unmanned aerial vehicles (UAVs). The novelty of this paper is about combination of a classic controller with a repetitive algorithm to reduce the response time to actuator faults and have better tracking performance. The actuator fault is defined based on the loss of effectiveness and bias fault. Next, the iterative learning control algorithm (ILCA) is used to compensate for the unknown fault input according to previous recorded experiences. In the normal condition (without actuators fault), BISMC can force the actual trajectories toward the desired commands and reduce chattering about control signals, and in the presence of the actuators fault or external disturbances, the mentioned learning algorithm can incline the accuracy of the tracking performance and compensate for the occurred error. The Lyapunov theory illustrates that the proposed control strategy can stabilize the system despite the actuators’ fault and external disturbances. The simulation results show the effectiveness of the proposed scheme in comparison with another method.

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Maximum Power Extraction from Wind Turbines Using a Fault-Tolerant Fractional-Order Nonsingular Terminal Sliding Mode Controller

Energies ◽

10.3390/en14185887 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5887

Author(s):

Yashar Mousavi ◽

Geraint Bevan ◽

Ibrahim Beklan Küçükdemiral ◽

Afef Fekih

Keyword(s):

Fractional Order ◽

Wind Turbines ◽

Fault Tolerant ◽

Sliding Mode ◽

Power Production ◽

Maximum Power ◽

Production Performance ◽

Terminal Sliding Mode ◽

Power Extraction ◽

Nonsingular Terminal Sliding Mode

This work presents a nonlinear control approach to maximise the power extraction of wind energy conversion systems (WECSs) operating below their rated wind speeds. Due to nonlinearities associated with the dynamics of WECSs, the stochastic nature of wind, and the inevitable presence of faults in practice, developing reliable fault-tolerant control strategies to guarantee maximum power production of WECSs has always been considered important. A fault-tolerant fractional-order nonsingular terminal sliding mode control (FNTSMC) strategy to maximize the captured power of wind turbines (WT) subjected to actuator faults is developed. A nonsingular terminal sliding surface is proposed to ensure fast finite-time convergence, whereas the incorporation of fractional calculus in the controller enhances the convergence speed of system states and simultaneously suppresses chattering, resulting in extracted power maximisation by precisely tracking the optimum rotor speed. Closed-loop stability is analysed and validated through the Lyapunov stability criterion. Comparative numerical simulation analysis is carried out on a two-mass WT, and superior power production performance of the proposed method over other methods is demonstrated, both in fault-free and faulty situations.

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Fractional-Order Variable-Gain Super-Twisting Control With Application to Wafer Stages of Photolithography Systems

2020 International Symposium on Flexible Automation ◽

10.1115/isfa2020-9635 ◽

2020 ◽

Author(s):

Zhian Kuang ◽

Liting Sun ◽

Huijun Gao ◽

Masayoshi Tomizuka

Keyword(s):

Fractional Order ◽

Sliding Mode ◽

Response Speed ◽

Tracking Performance ◽

Sliding Surface ◽

Variable Gain ◽

Equivalent Control ◽

Order Variable ◽

Twisting Control ◽

Super Twisting Control

Abstract In this paper, a novel fractional-order variable-gain super-twisting control (FVSTC) scheme is proposed and applied to improve the tracking performance of wafer stages in the photolithography systems. The FVSTC overcomes the drawbacks of the super-twisting control (STC) such as slow response speed and incomplete compensation to disturbances. First, to improve the dynamics of the states on the sliding surface, a fractional-order sliding surface is designed. Moreover, to improve the dynamics of the sliding mode variable, an equivalent-control-based method is utilized, and a switching controller based on a variable-gain super-twisting algorithm is deployed. Via such designed schemes, the proposed controller is robust against external disturbances and model uncertainties. Stability proof of the closed-loop system is provided. Numerical simulations to track a sinusoidal signal and experiments on a wafer stage testbed are conducted. The results show that the proposed FVSTC scheme can achieve much better tracking performance than conventional methods.

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Neural Adaptive Fault Tolerant Control of Nonlinear Fractional Order Systems Via Terminal Sliding Mode Approach

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4042141 ◽

2019 ◽

Vol 14 (3) ◽

Cited By ~ 2

Author(s):

Bijan Hashtarkhani ◽

Mohammad Javad Khosrowjerdi

Keyword(s):

Fractional Order ◽

Finite Time ◽

Fault Tolerant ◽

Sliding Mode ◽

Fault Tolerant Control ◽

State Feedback Control ◽

Time Stability ◽

Terminal Sliding Mode ◽

Finite Time Stability ◽

Output Tracking

This article proposes an adaptive neural output tracking control scheme for a class of nonlinear fractional order (FO) systems in the presence of unknown actuator faults. By means of backstepping terminal sliding mode (SM) control technique, an adaptive fractional state-feedback control law is extracted to achieve finite time stability along with output tracking for an uncertain faulty FO system. The unknown nonlinear terms are approximated by radial-basis function neural network (RBFNN) with unknown approximation error upper bound. Using convergence in finite time and fractional Lyapunov stability theorems, the finite time stability and tracking achievement are proved. Finally, the proposed fault tolerant control (FTC) approach is validated with numerical simulations on two fractional models including fractional Genesio–Tesi and fractional Duffing's oscillator systems.

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A Fractional Order Sliding Mode-based Fault Tolerant Tracking Approach for a Quadrotor UAV

2018 IEEE Conference on Control Technology and Applications (CCTA) ◽

10.1109/ccta.2018.8511457 ◽

2018 ◽

Author(s):

Seema Mallavalli ◽

Afef Fekih

Keyword(s):

Fractional Order ◽

Fault Tolerant ◽

Sliding Mode ◽

Quadrotor Uav

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A New Adaptive Control for Five-Phase Fault-Tolerant Flux-Switching Permanent Magnet Motor

International Journal of Rotating Machinery ◽

10.1155/2016/3792645 ◽

2016 ◽

Vol 2016 ◽

pp. 1-14

Author(s):

Hongyu Tang ◽

Wenxiang Zhao ◽

Chenyu Gu

Keyword(s):

Adaptive Control ◽

Sliding Mode Control ◽

Permanent Magnet ◽

High Efficiency ◽

Control Method ◽

Fault Tolerant ◽

Sliding Mode ◽

Backstepping Method ◽

Control Laws ◽

Mode Control

The five-phase fault-tolerant flux-switching permanent magnet (FT-FSPM) motor can offer high efficiency and high fault-tolerant capability. In this paper, its operation principle is presented briefly and its mathematical model is derived. Further, a new adaptive control for an FT-FSPM motor, based on the backstepping method and the sliding mode control strategy, is proposed. According to the backstepping method, the current controllers and voltage control laws are designed to track the speed and minimize the current static error, which enhance the dynamic response and the ability to suppress external disturbances. In order to overcome the influence of parameter variations, according to sliding mode control theory, the virtual control variables and the adaptive algorithm are utilized to approach uncertainty terms. Three Lyapunov functions are designed, and the stability of the closed-loop system is analyzed in detail. Finally, both simulation and experimental results are presented to verify the proposed control method.

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