scholarly journals Fault-Tolerant Control of a Nonlinear System Actuator Fault Based on Sliding Mode Control

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Jing He ◽  
Lin Mi ◽  
Songan Mao ◽  
Changfan Zhang ◽  
Houguang Chu
Keyword(s):  
Sliding Mode Control ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Variable Structure ◽  
Fault Tolerant Control ◽  
Original System ◽  
Control Law ◽  
Actuator Faults ◽  
State Variables ◽  
Mode Control

This paper presents a fault-tolerant control scheme for a class of nonlinear systems with actuator faults and unknown input disturbances. First, the sliding mode control law is designed based on the reaching law method. Then, in view of unpredictable state variables and unknown information in the control law, the original system is transformed into two subsystems through a coordinate transformation. One subsystem only has actuator faults, and the other subsystem has both actuator faults and disturbances. A sliding mode observer is designed for the two subsystems, respectively, and the equivalence principle of the sliding mode variable structure is used to realize the accurate reconstruction of the actuator faults and disturbances. Finally, the observation value and the reconstruction value are used to carry out an online adjustment to the designed sliding mode control law, and fault-tolerant control of the system is realized. The simulation results are presented to demonstrate the approach.

scholarly journals An adaptive sliding mode actuator fault tolerant control scheme for octorotor system

2019 ◽  
Vol 16 (2) ◽  
pp. 172988141983243 ◽  
Author(s):  
Fatima Ejaz ◽  
Mirza Tariq Hamayun ◽  
Shariq Hussain ◽  
Salman Ijaz ◽  
Shunkun Yang ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Adaptive Sliding Mode Control ◽  
Actuator Faults ◽  
Control Approach ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Control Scheme

In this article, an adaptive sliding mode control is used in the framework of fault tolerant control to mitigate the effects of actuator faults without requiring the actuator health information. Since unmanned aerial vehicles are being used in multiple fields such as military, surveillance, media, agriculture, communication and trading sector, therefore it is of vital importance to overcome the effects of actuator faults that can decline system performance and can even lead to some serious accidents. The proposed adaptive sliding mode control approach can handle actuator faults directly without requiring any faults information and adaptively adjusts controller gains to maintain acceptable level of performance. To validate the effectiveness of the proposed adaptive fault tolerant control scheme, it has been tested in simulations using non-linear Benchmark model of Octorotor system and its performance is compared with the optimal LQR control approach.

scholarly journals Finite-Time Attitude Fault Tolerant Control of Quadcopter System via Neural Networks

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1541 ◽  
Author(s):  
Ngoc Phi Nguyen ◽  
Nguyen Xuan Mung ◽  
Le Nhu Ngoc Thanh Ha ◽  
Tuan Tu Huynh ◽  
Sung Kyung Hong
Keyword(s):  
Sliding Mode Control ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Terminal Sliding Mode Control ◽  
Actuator Faults ◽  
Model Uncertainties ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Fast Terminal Sliding Mode

This study investigates the design of fault-tolerant control involving adaptive nonsingular fast terminal sliding mode control and neural networks. Unlike those of previous control strategies, the adaptive law of the investigated algorithm is considered in both continuous and discontinuous terms, which means that any disturbances, model uncertainties, and actuator faults can be simultaneously compensated for. First, a quadcopter model is presented under the conditions of disturbances and uncertainties. Second, normal adaptive nonsingular fast terminal sliding mode control is utilized to handle these disturbances. Thereafter, fault-tolerant control based on adaptive nonsingular fast terminal sliding mode control and neural network approximation is presented, which can handle the actuator faults, model uncertainties, and disturbances. For each controller design, the Lyapunov function is applied to validate the robustness of the investigated method. Finally, the effectiveness of the investigated control approach is presented via comparative numerical examples under different fault conditions and uncertainties.

Fault tolerant control based on backstepping nonsingular terminal integral sliding mode and impedance control for a lower limb exoskeleton

2021 ◽  
pp. 095440622110357
Author(s):  
Majied Mokhtari ◽  
Mostafa Taghizadeh ◽  
Pegah Ghaf Ghanbari
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Impedance Control ◽  
Fault Tolerant Control ◽  
Integral Type ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Control Scheme

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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