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

Author(s):  
Kun Yan ◽  
Mou Chen ◽  
Qingxian Wu

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.

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Liang Zheng ◽  
Xuelian Dong ◽  
Qian Luo ◽  
Menglan Zeng ◽  
Xinping Yang ◽  
...  

In this paper, an adaptive sliding mode fault tolerant control (ASMFTC) approach is proposed for a class of nonlinear systems with actuator fault, uncertainty, and external disturbance. Specifically, first, a novel observer is proposed to estimate the state, actuator fault, and external disturbance. Then, by utilising the observed information, a novel output sliding mode observer is constructed. In the control method, an adaptive law and two compensators are designed to attenuate the unknown estimation errors, actuator fault, and disturbance. Furthermore, the reaching ability of the sliding motion is analysed and the H-infinite performance is introduced to ensure the robustness of the system. Finally, a flexible single joint manipulator system and a two-cart system are used to verify the effectiveness of the proposed method.


Author(s):  
Ziquan Yu ◽  
Youmin Zhang ◽  
Yaohong Qu ◽  
Zhewen Xing

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.


Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Zhongtian Chen ◽  
Qiang Chen ◽  
Xiongxiong He ◽  
Mingxuan Sun

In this paper, an adaptive finite-time fault-tolerant control scheme is proposed for the attitude stabilization of rigid spacecrafts. A first-order command filter is presented at the second step of the backstepping design to approximate the derivative of the virtual control, such that the singularity problem caused by the differentiation of the virtual control is avoided. Then, an adaptive fuzzy finite-time backstepping controller is developed to achieve the finite-time attitude stabilization subject to inertia uncertainty, external disturbance, actuator saturation, and faults. Through using an error transformation, the prescribed performance boundary is incorporated into the controller design to guarantee the prescribed performance of the system output. Numerical simulations demonstrate the effectiveness of the proposed scheme.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jing Zhao ◽  
Sen Jiang ◽  
Fei Xie ◽  
Zhen He ◽  
Jian Fu

A fault tolerant control (FTC) scheme based on adaptive sliding mode control technique is proposed for manipulator with actuator fault. Firstly, the dynamic model of manipulator is introduced and its actuator faulty model is established. Secondly, a fault tolerant controller is designed, in which both the parameters of actuator fault and external disturbance are estimated and updated by online adaptive technology. Finally, taking a two-joint manipulator as example, simulation results show that the proposed fault tolerant control scheme is effective in tolerating actuator fault; meanwhile it has strong robustness for external disturbance.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3812
Author(s):  
Ying Yang ◽  
Bin Wang ◽  
Yuqiang Tian ◽  
Peng Chen

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.


2017 ◽  
Vol 14 (1) ◽  
pp. 172988141668713 ◽  
Author(s):  
Bing Huang ◽  
Aijun Li ◽  
Bin Xu

In this article, an adaptive fault tolerant control strategy is proposed to solve the trajectory tracking problem of a generic hypersonic vehicle subjected to actuator fault, external disturbance, and input saturation. The longitudinal model of generic hypersonic vehicle is divided into velocity subsystem and altitude subsystem, in which dynamic inversion and backstepping are applied, respectively, to track the desired trajectories. For the unknown maximum disturbance upper bound, actuator fault, and input saturation constraint, adaptive laws are proposed to estimate these information online. Finally, numeric simulation is conducted in the cruise phase for generic hypersonic vehicle. Simulation results show that the controllers designed in this article can make generic hypersonic vehicle track the desired trajectories in the presence of actuator fault, external disturbance, and input saturation.


Author(s):  
Wenping Xue ◽  
Pan Jin ◽  
Kangji Li

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.


2015 ◽  
Vol 30 (2) ◽  
pp. 375-392 ◽  
Author(s):  
Marcin Witczak ◽  
Mariusz Buciakowski ◽  
Christophe Aubrun

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zhi Wang ◽  
Yateng Bai ◽  
Jin Xie ◽  
Zhijie Li ◽  
Caoyuan Ma ◽  
...  

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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