scholarly journals Cloud-Based Fault Tolerant Control for a DC Motor System

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Xiao He ◽  
Yamei Ju ◽  
Yang Liu ◽  
Bangcheng Zhang

The fault tolerant control problem for a DC motor system is investigated in a cloud environment. Packet dropout phenomenon introduced by the limited-capacity communication channel is considered. Actuator faults are taken into consideration and fault diagnosis and fault tolerant control methods towards actuator faults are proposed to enhance the reliability of the whole cloud-based DC motor system. The fault diagnosis unit is then established with purpose of obtaining fault information. When the actuator fault is detected by comparing the residual signal with a predefined threshold, a residual matching approach is utilized to locate the fault. The fault can be further estimated by a least-squares filter. Based on the fault estimation, a fault tolerant controller is designed to guarantee the stability as well as the control performance of the DC motor system. Simulation result on a DC motor system shows the efficiency of the fault tolerant control method proposed in this paper.

2019 ◽  
Vol 9 (19) ◽  
pp. 4010 ◽  
Author(s):  
Ngoc Phi Nguyen ◽  
Sung Kyung Hong

Fault-tolerant control is becoming an interesting topic because of its reliability and safety. This paper reports an active fault-tolerant control method for a quadcopter unmanned aerial vehicle (UAV) to handle actuator faults, disturbances, and input constraints. A robust fault diagnosis based on the H ∞ scheme was designed to estimate the magnitude of a time-varying fault in the presence of disturbances with unknown upper bounds. Once the fault estimation was complete, a fault-tolerant control scheme was proposed for the attitude system, using adaptive sliding mode backstepping control to accommodate the actuator faults, despite actuator saturation limitation and disturbances. The Lyapunov theory was applied to prove the robustness and stability of the closed-loop system under faulty operation. Simulation results show the effectiveness of the fault diagnosis scheme and proposed controller for handling actuator faults.


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.


Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 108
Author(s):  
Yishi Liu ◽  
Sheng Hong ◽  
Enrico Zio ◽  
Jianwei Liu

Active fault-tolerant control systems perform fault diagnosis and reconfigurable control. There is a bidirectional uncertainty between them, and an integrated scheme is proposed here to account for that. The system considers both actuator and sensor faults, as well as the external disturbance. The diagnostic module is designed using an unknown input observer, and the controller is constructed on the basis of an adaptive method. The integrated strategy is presented, and the stability of the overall system is analyzed. Moreover, different kinds of anti-windup techniques are utilized to modify the original controllers, because of the different controller structures. A simulation of the integrated anti-windup fault-tolerant control method is demonstrated using a numerical model of Boeing 747. The results show that it can guarantee the stability of the post-fault aircraft and increase the control performance for the overall faulty system.


Author(s):  
Gao Ming-Zhou ◽  
Chen Xin-Yi ◽  
Han Rong ◽  
Yao Jian-Yong

To suppress airfoil flutter, a lot of control methods have been proposed, such as classical control methods and optimal control methods. However, these methods did not consider the influence of actuator faults and control delay. This paper proposes a new finite-time H∞ adaptive fault-tolerant flutter controller by radial basis function neural network technology and adaptive fault-tolerant control method, taking into account actuator faults, control delay, modeling uncertainties, and external disturbances. The theoretic section of this paper is about airfoil flutter dynamic modeling and adaptive fault-tolerant controller design. Lyapunov function and linear matrix inequality are employed to prove the stability of the proposed control method of this paper. The numeral simulation section further proves the effectiveness and robustness of the proposed control algorithm of this paper.


Author(s):  
Jinhua Fan ◽  
Youmin Zhang ◽  
Zhiqiang Zheng

A challenging problem on observer-based, integrated fault diagnosis and fault-tolerant control for linear systems subject to actuator faults and control input constraints is studied in this paper. An adaptive observer approach is used for the joint state-fault magnitude estimation, and a feedback controller is designed to stabilize the closed-loop system without violating the actuator limits in the presence of actuator faults. Matrix inequality conditions are provided for computation of design parameters of the observer and the feedback controller, and the admissible initial conditions and estimation errors are bounded by invariant ellipsoidal sets. The design results are closely related to the fault magnitude and variation rate, and a necessary condition on the admissible fault magnitudes dependent on the control limits is directly obtained from the design process. The proposed design framework allows a direct application of the pole placement method to obtain stabilization results. To improve the system performance, a nonlinear programming-based optimization algorithm is proposed to compute an optimized feedback gain, whereas the one obtained by pole placement can be taken as an initial feasible solution for nonlinear optimization. Numerical studies with two flight control systems demonstrate the effectiveness of proposed design techniques.


2014 ◽  
Vol 635-637 ◽  
pp. 1199-1202 ◽  
Author(s):  
Zheng Gao Hu ◽  
Guo Rong Zhao ◽  
Da Wang Zhou

For the chattering problem in the traditional sliding mode observer-based fault estimation, a second order sliding mode observer based on the Super-twisting algorithm was proposed. In order to avoid the cumbersome process of proving the stability of the Super-twisting algorithm, a Lyapunov function was adopted. An active fault tolerant control law was designed based on the fault estimation. Finally, simulation show the effectiveness of the proposed approach.


Author(s):  
Rongrong Wang ◽  
Junmin Wang

This paper presents an in-wheel motor fault diagnosis and fault-tolerant control method for four-wheel independently actuated (4WIA) electric vehicles. The 4WIA electric vehicle is one of the promising architectures for electric vehicles. While such a vehicle architecture greatly increases the flexibility for vehicle control, it also elevates the requirements on system reliability, safety, and fault tolerance due to the increased number of actuators. A fault diagnosis approach for finding the faulty in-wheel motor/motor driver pair is developed. The proposed diagnosis approach does not need an accurate knowledge on tire-road friction coefficient (TRFC) and is robust to tire force modeling inaccuracies. Based on the in-wheel motor/motor driver fault diagnosis mechanism, a control-allocation based vehicle fault-tolerant control system is designed to accommodate the in-wheel motor/motor driver fault by automatically allocating the control effort among other healthy wheels. Simulations using a high-fidelity, CarSim®, full-vehicle model show the effectiveness of the proposed in-wheel motor/motor driver fault diagnosis and fault-tolerant control approaches.


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