Sensor Fault Identification and Decentralized Fault-Tolerant Control of Reconfigurable Manipulator Based on Sliding Mode Observer

Author(s):  
Du Yan Li ◽  
Li Yuan Chun
2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Hongju Wang ◽  
Qiliang Bao ◽  
Wenshu Yang ◽  
Zidong Liu ◽  
Jing Tian

The aim of this paper is to present a sensor fault-tolerant control (FTC) scheme for a two-axis fast steering mirror (FSM) system with minimum power consumption and without changing the controller structure. In this paper, an adaptive PI-based sliding mode observer (APISMO) is adopted firstly to estimate the fault signal, which does not require any prior knowledge of the fault. The estimation is then used by the fault isolation logic to identify the fault. The redundant sensor would be powered up to replace the faulty one when faults occur. During the backup sensor booting up, for maintaining the normal performance of the closed-loop system approximately, a fault-free estimation of the position provided by the APISMO is used as feedback signal. Experimental studies on a prototype system show that the proposed APISMO can effectively reconstruct the fault signals even when the two primary position sensors are faulty simultaneously. Meanwhile, the effectiveness and performance of the proposed scheme have been verified.


2020 ◽  
Vol 10 (4) ◽  
pp. 1278
Author(s):  
Zhilu Zhang ◽  
Benxian Xiao

For the problem of multiple sensor fault detection and reconstruction in the forklift fault-tolerant control system, a sliding mode observer (SMO) with adaptive regulation law is proposed. Based on the three-degree-of-freedom (3-DOF) model of forklift, a linear state equation with output disturbance is designed as its equivalent sensor fault model. The sensor fault is converted into an actuator fault by defining an auxiliary state variable as an output signal filter. Then the SMO-based method of sensor fault detection and reconstruction is given. Without knowing the upper bound of an unknown fault, an adaptive sliding mode observer (ASMO) can also be effective through the adaptive algorithm. Finally, experimental results further verify the effectiveness of the method, and provide a foundation for forklift fault-tolerant control.


Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1695 ◽  
Author(s):  
Qinyue Zhu ◽  
Zhaoyang Li ◽  
Xitang Tan ◽  
Dabo Xie ◽  
Wei Dai

Due to the use of multiple observers and controllers in multi-sensor fault-tolerant control of PMSM drive systems, the algorithm is complex and the system control performance is affected. In view of this, the paper studies multi-sensor fault diagnosis and active fault-tolerant control strategies based on a composite sliding mode observer. With the mathematical model of PMSM built, a design method of the composite sliding mode observer is proposed. A single observer is used to observe and estimate various state variables in the system in real time, which simplifies the implementation of observer-related algorithms. In order to improve the diagnostic accuracy of different types of sensors under different faults, a method for determining fault thresholds is proposed through global search for the maximum residual value. Based on this, a fault diagnosis and active fault-tolerant control strategy is proposed to realize fast switching and reconstruction of feedback signals of closed-loop control systems under different faults of multiple sensors, thus restoring the system performance. Finally, the effectiveness of the proposed algorithm and control strategy is verified by simulation experiments


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Bo Zhao ◽  
Yuanchun Li

This paper concerns with a fault identification scheme in a class of nonlinear interconnected systems. The decentralized sliding mode observer is recruited for the investigation of position sensor fault or velocity sensor fault. First, a decentralized neural network controller is proposed for the system under fault-free state. The diffeomorphism theory is utilized to construct a nonlinear transformation for subsystem structure. A simple filter is implemented to convert the sensor fault into pseudo-actuator fault scenario. The decentralized sliding mode observer is then presented for multisensor fault identification of reconfigurable manipulators based on Lyapunov stable theory. Finally, two 2-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in numerical simulation. The results demonstrate that one joint’s fault does not affect other joints and the sensor fault can be identified precisely by the proposed decentralized sliding mode observer.


2018 ◽  
Vol 22 (2) ◽  
pp. 788-802
Author(s):  
Ledi Zhang ◽  
Shousheng Xie ◽  
Yu Zhang ◽  
Litong Ren ◽  
Bin Zhou ◽  
...  

Author(s):  
Bingqian Li ◽  
Wenhan Dong ◽  
Xiaoshan Ma

In this paper, a backstepping fault-tolerant control based on sliding-mode observer is proposed for the unmanned thrust-vectoring aircraft (UTVA) control. First, the UTVA model with the uncertainty, control surface damage and actuator faults is described, which is divided into fast loop and slow loop. Next, the cascade observers including a high-order SMO and the discontinuous projection adaptive law are proposed to estimate the states with compensating the uncertainty and control surface damage, and the sliding-mode observer is designed to identify actuator faults and estimate fault parameters. Then, the backstepping fault-tolerant control combining the estimation of states and fault parameters is proposed to achieve the global fault-tolerant control, which compensates the uncertainty, control surface damage and actuator faults. Finally, simulation results are given to demonstrate the effectiveness for UTVA.


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