scholarly journals A Robust Fault-Tolerant Control for Quadrotor Helicopters against Sensor Faults and External Disturbances

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ban Wang ◽  
Peng Huang ◽  
Wei Zhang

This paper presents an active fault-tolerant control strategy for quadrotor helicopters to simultaneously accommodate sensor faults and external disturbances. Unlike most of the existing fault diagnosis and fault-tolerant control schemes for quadrotor helicopters, the proposed fault diagnosis scheme is able to estimate sensor faults while eliminating the effect of external disturbances. Moreover, the proposed fault-tolerant control scheme is capable to eliminate the adverse effect of external disturbances as well by designing a disturbance observer to effectively estimate the unknown external disturbances and integrating with the designed integral sliding-mode controller. In this case, the continuous operation of the quadrotor helicopter is ensured while avoiding the unexpected control chattering. In addition, the stability of the closed-loop system is theoretically proved. Finally, the effectiveness and advantages of the proposed scheme are validated and demonstrated through comparative numerical simulations of the quadrotor helicopter under different faulty and uncertain scenarios.

2020 ◽  
Vol 42 (11) ◽  
pp. 2011-2019
Author(s):  
Chengcheng Ma ◽  
Chunsheng Liu ◽  
Jiazhen Yao

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.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1139 ◽  
Author(s):  
Ngoc Nguyen ◽  
Sung Hong

Fault-tolerant control has drawn attention in recent years owning to its reliability and safe flight during missions. In this article, an active fault-tolerant control method is proposed to control a quadcopter in the presence of actuator faults and disturbances. Firstly, the dynamics of the quadcopter are presented. Secondly, a robust adaptive sliding mode Thau observer is presented to estimate the time-varying magnitudes of actuator faults. Thirdly, a fault-tolerant control scheme based on sliding mode control and reconfiguration technique is designed to maintain the quadcopter at the desired position despite the presence of faults. Unlike previous studies, the proposed method aims to integrate the fault diagnosis and a fault-tolerant control scheme into a single unit with total loss of actuator. Simulation results illustrate the efficiency of the suggested algorithm.


2021 ◽  
Vol 6 (1) ◽  
pp. 229-241
Author(s):  
Fouad Haouari ◽  
Salaheddine Messekher ◽  
Noureddine Bali ◽  
Mohamed Tadjine ◽  
Mohamed Seghir Boucherit

Abstract Due to the external disturbances, model uncertainties, strong coupling, and occurred faults, the winding machine presents a great control challenge. In order to deal with these problems, this paper presents the formulation of a novel scheme of fault tolerant control (FTC) for three-motor web-winding systems; it is concerned with the nonlinear robust backstepping control based on the combination of RST and backstepping controllers where the process is modelled by a nonlinear model. The main contribution of the paper is that the approach developed here summarises the performance of RST and backstepping controllers in order to design a robust controller capable of eliminating external disturbances and sensor faults affecting the system. The stability of the whole system is proven using the Lyapunov theory. Finally, analysis in comparison with the conventional backstepping controller and simulations in the MATLAB environment are accomplished to confirm the efficiency of the proposed method.


Author(s):  
Qibao Shu ◽  
◽  
Pu Yang ◽  
Yuxia Wang ◽  
Ben Ma

An active fault-tolerant control scheme for a quadrotor unmanned aerial vehicle (UAV) with actuators faults is presented in this paper. The proposed scheme is based on model predictive control (MPC) and the discrete-time sliding mode observer. Considering the impact of disturbances on fault diagnosis, a discrete-time sliding mode observer with simple structure and strong robustness against the disturbances is designed to isolate the actuator faults and estimate the control effectiveness factors accurately. Using the fault diagnosis information, a model predictive active fault tolerant controller with embedded integrator is proposed to compensate parameter uncertainty and bounded disturbances in the realistic control system of the quadrotor. The advantages of the proposed control scheme are the ability of dealing with the control constraints, improving the fault-tolerant control precision and getting better real-time and anti-interference performance. The algorithm comparison experimental results on the quadrotor semi-physical simulation platform validate the feasibility and effectiveness of the proposed control scheme.


Author(s):  
Neng Wan ◽  
Weiran Yao ◽  
Mingming Shi

External perturbations and actuator faults are two practical and significant issues that deserve designers' considerations when synthesizing the controllers for spacecraft rendezvous. A composite robust fault-tolerant control (FTC) scheme that does not require the fault information is proposed in this paper for limited-thrust rendezvous in near-circular orbits. Within the control scheme, a reliable integral sliding mode (ISM) auxiliary controller and a modified guaranteed cost FTC are, respectively, developed to attenuate the external disturbances and to stabilize the nominal rendezvous system with actuator faults. Comparisons with previous works as well as a more practical and challenging simulation example are presented to verify the advantages of this composite control scheme.


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

In this paper, a distributed adaptive fault-tolerant cooperative control (FTCC) scheme is developed for flying multiple unmanned aerial vehicles (UAVs) with consideration of actuator and sensor faults. The communication network is an undirected, fixed topology and only a subset of UAVs has access to the common reference. By using a sliding-mode observer, the common reference is estimated by each UAV. The lumped uncertainties including external disturbances, actuator and sensor faults are estimated by an adaptive mechanism. On the basis of the estimated reference and lumped uncertainties, dynamic surface control technique is utilized to eliminate the computational burden inherent in the traditional backstepping control architecture. The highlight is that external disturbances, actuator and sensor faults are considered in the distributed control scheme for multi-UAVs simultaneously. By using graph theory and Lyapunov-based method, it is proved that all signals in the closed-loop system are bounded. Furthermore, simulation results are exhibited to demonstrate the effectiveness of the proposed control scheme.


Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.


Author(s):  
Jun Zhou ◽  
Jing Chang ◽  
Zongyi Guo

The paper describes the design of a fault-tolerant control scheme for an uncertain model of a hypersonic reentry vehicle subject to actuator faults. In order to improve superior transient performances for state tracking, the proposed method relies on a back-stepping sliding mode controller combined with an adaptive disturbance observer and a reference vector generator. This structure allows for a faster response and reduces the overshoots compared to linear conventional disturbance observers based sliding mode controller. Robust stability and performance guarantees of the overall closed-loop system are obtained using Lyapunov theory. Finally, numerical simulations results illustrate the effectiveness of the proposed technique.


Author(s):  
Majied Mokhtari ◽  
Mostafa Taghizadeh ◽  
Pegah Ghaf Ghanbari

In this paper, an active fault-tolerant control scheme is proposed for a lower limb exoskeleton, based on hybrid backstepping nonsingular fast terminal integral type sliding mode control and impedance control. To increase the robustness of the sliding mode controller and to eliminate the chattering, a nonsingular fast terminal integral type sliding surface is used, which ensures finite time convergence and high tracking accuracy. The backstepping term of this controller guarantees global stability based on Lyapunov stability criterion, and the impedance control reduces the interaction forces between the user and the robot. This controller employs a third order super twisting sliding mode observer for detecting, isolating ad estimating sensor and actuator faults. Motion stability based on zero moment point criterion is achieved by trajectory planning of waist joint. Furthermore, the highest level of stability, minimum error in tracking the desired joint trajectories, minimum interaction force between the user and the robot, and maximum system capability to handle the effect of faults are realized by optimizing the parameters of the desired trajectories, the controller and the observer, using harmony search algorithm. Simulation results for the proposed controller are compared with the results obtained from adaptive nonsingular fast terminal integral type sliding mode control, as well as conventional sliding mode control, which confirm the outperformance of the proposed control scheme.


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