scholarly journals Adaptive Robust Fault-Tolerant Synchronization Control for a Dual Redundant Hydraulic Actuation System with Common-Mode Fault

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Ting Li ◽  
Ting Yang ◽  
Yuyan Cao ◽  
Rong Xie ◽  
Xinmin Wang

This paper investigates the fault-tolerant synchronization control (FTSC) problem for a dual redundant hydraulic actuation system (DRHAS), which works on active/active (A/A) mode and suffers from a kind of common-mode fault (CMF), i.e., internal leakage faults occurring in both hydraulic actuator (HA) channels simultaneously due to a common cause. Firstly, in order to follow the position command and synchronize the force outputs of the two channels, a desired trajectory generator derived from the dynamics of the control surface is employed. Then, considering model uncertainties and nonlinear dynamics of the plant, an FTSC controller is designed based on adaptive robust control (ARC) theory and backstepping technology. The controller parameters, closely related to the fault parameters, are updated online to make the controller adapt to the fault condition only when the system performance degradation exceeds a prescribed tolerable level. It has been verified that the proposed FTSC scheme can guarantee the bounded stability of output tracking error system under common-mode fault. Finally, simulation results under two scenarios demonstrate the effectiveness of the proposed FTSC scheme.

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.


2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Ali Maddahi ◽  
Nariman Sepehri ◽  
Witold Kinsner

Abstract Design of fault-tolerant controllers (FTC) for hydraulic actuators is one of the challenges in the area of fluid power systems. In real applications, it is not possible to model or measure some faults accurately. For example, an accurate model for the actuator internal leakage has not been well-established. To prevent the actuator malfunctioning due to the faults (e.g., the internal leakage), there is a need for designing a fault-tolerant control system. In this paper, a methodology is proposed to design an FTC for the hydraulic actuators using experimental data only. In the proposed design procedure, there is no need for either having a prior knowledge about the system and fault models or measuring and detecting the fault during the experiments. The methodology is based on introducing synthetic errors into the hydraulic actuator that is otherwise operating in the healthy mode. Synthetic errors are used to emulate the effect of the fault on the system response. The wavelet transform (WT) is utilized to quantify the effect of the synthetic errors on the error between the desired and actual displacement data. Results of the wavelet analysis are then employed for designing a fractional-order proportional-integral-derivative (FOPID) controller tolerant to the fault. The proposed approach is exemplified with the design of a controller tolerant to the internal leakage. Several experiments are conducted to verify the efficacy of the FOPID-based FTC. The experimental results prove that the proposed methodology works well for the hydraulic actuation system experiencing the internal leakage.


Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 152
Author(s):  
Litong Lyu ◽  
Xiao Liang ◽  
Jingbo Guo

Segment assembling is one of the principle processes during tunnel construction using shield tunneling machines. The segment erector is a robotic manipulator powered by a hydraulic system to assemble prefabricated concrete segments onto the excavated tunnel surface. Nowadays, automation of the segment erector has become one of the definite developing trends to further improve the efficiency and safety during construction; thus, closed-loop motion control is an essential technology. Within the segment erector, the lifting gantry is driven by dual cylinders to lift heavy segments in the radial direction. Different from the dual-cylinder mechanism used in other machines such as forklifts, the lifting gantry usually works at an inclined angle, leading to unbalanced loads on the two sides. Although strong guide rails are applied to ensure synchronization, the gantry still occasionally suffers from chattering, “pull-and-drag”, or even being stuck in practice. Therefore, precise motion tracking control as well as high-level synchronization of the dual cylinders have become essential for the lifting gantry. In this study, a complete dynamics model of the dual-cylinder lifting gantry is constructed, considering the linear motion as well as the additional rotational motion of the crossbeam, which reveals the essence of poor synchronization. Then, a two-level synchronization control scheme is synthesized. The thrust allocation is designed to coordinate the dual cylinders and keep the rotational angle of the crossbeam within a small range. The motion tracking controller is designed based on the adaptive robust control theory to guarantee the linear motion tracking precision. The theoretical performance is analyzed with corresponding proof. Finally, comparative simulations are conducted and the results show that the proposed scheme achieves high-precision motion tracking performance and simultaneous high-level synchronization of dual cylinders under unbalanced loads.


IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 30750-30760
Author(s):  
Van Du Phan ◽  
Cong Phat Vo ◽  
Hoang Vu Dao ◽  
Kyoung Kwan Ahn

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Dongming Chen ◽  
Xinyu Huang ◽  
Tao Ren

Aiming at the abrupt faults of the chaotic system, an adaptive observer is proposed to trace the states of the master system. The sufficient conditions for synchronization of such chaotic systems are also derived. Then the feasibility and effectiveness of the proposed method are illustrated via numerical simulations of chaotic Chen system. Finally, the proposed synchronization schemes are applied to secure communication system successfully. The experimental results demonstrate that the employed observer can manage real-time fault diagnosis and parameter identification as well as states tracing of the master system, and so the synchronization of master system and slave system is achieved.


Author(s):  
Salman Ijaz ◽  
Mirza T Hamayun ◽  
Lin Yan ◽  
Cun Shi

The research about the dissimilar redundant actuation system has indicated the potential fault-tolerant capability in modern aircraft. This paper proposed a new design methodology to achieve fault-tolerant control of an aircraft equipped with dissimilar actuators and is suffered from vertical tail damage. The proposed design is based on the concept of online control allocation to redistribute the control signals among healthy actuators and integral sliding mode controller is designed to achieve the closed-loop stability in the presence of both component and actuator faults. To cope with severe damage condition, the aircraft is equipped with dissimilar actuators (hydraulic and electrohydraulic actuators). In this paper, the performance degradation due to slower dynamics of electrohydraulic actuator is taken in account. Therefore, the feed-forward compensator is designed for electrohydraulic actuator based on fractional-order control strategy. In case of failure of hydraulic actuator subject to severe damage of vertical tail, an active switching mechanism is developed based on the information of fault estimation unit. Additionally, a severe type of actuator failure so-called actuator saturation or actuator lock in place is also taken into account in this work. The proposed strategy is compared with the existing control strategies in the literature. Simulation results indicate the dominant performance of the proposed scheme. Moreover, the proposed controller is found robust with a certain level of mismatch between the actuator effectiveness level and its estimate.


2012 ◽  
Vol 195-196 ◽  
pp. 1089-1094
Author(s):  
Yuan Yuan He ◽  
Li Liu

This paper presents an investigation into the modeling and analysis of an innovative actuation system for a wing with a seamless flexible trailing edge control surface. Research was started with the study of aerodynamic behavior and advantage of the wing in smooth variable chamber shape under control. Based on the concept and design, an experimental wing section integrated with the actuation mechanism was built and tested. The main effort was then made to the modeling of the internal actuation system for the purpose of obtaining the physical properties and accurate modeling of the whole wing structural system. To validate and update the numerical model of the system, vibration test of the actuation system including the mechanism and actuator was carried out. Some key parameters such as the stiffness of the actuation system were identified from vibration test data. The investigation demonstrated a practical approach to quantify some key parameters and update the numerical model of an actuation system.


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