scholarly journals Development of the PD/PI Extended State Observer to Detect Sensor and Actuator Faults Simultaneously

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Katherin Indriawati ◽  
Trihastuti Agustinah ◽  
Achmad Jazidie
Keyword(s):  
State Observer ◽  
Extended State Observer ◽  
Actuator Faults ◽  
Extended State

Attitude stabilization of a rigid spacecraft with actuator delay and fault

2017 ◽  
Vol 40 (7) ◽  
pp. 2340-2351 ◽  
Author(s):  
Alireza Safa ◽  
Mahdi Baradarannia ◽  
Hamed Kharrati ◽  
Sohrab Khanmohammadi
Keyword(s):  
Feedforward Control ◽  
State Observer ◽  
Extended State Observer ◽  
Actuator Faults ◽  
State Variables ◽  
Extended State ◽  
External Disturbances ◽  
Modelling Uncertainties ◽  
Rigid Spacecraft ◽  
And Control

Time delays and actuator faults are phenomena which are frequently encountered in practical control systems and are found to have significant effects on the performance of operation and control. It is shown that even a very small delay may destabilize the spacecraft system. Therefore, besides considering the effects of modelling uncertainties and external disturbances, time delay and actuator fault effects should be properly handled in the spacecraft to achieve reliable and accurate control. This paper describes a simple and effective method to attitude stabilize a spacecraft. The proposed method works by augmenting a backstepping controller with a modified extended state observer-based feedforward control law. The backstepping control is used to compensate for an unknown delay in the inputs, while the feedforward term attenuates the effects of modelling uncertainties, external disturbances and actuator faults. In particular, actuator faults, modelling uncertainties and external disturbances are viewed as unknown nonlinear functions of the measurable state variables, estimated using a modified extended state observer, and then compensated for. The effectiveness of the proposed control algorithm is analytically authenticated and verified via simulation studies.

scholarly journals Super-Twisting Extended State Observer and Sliding Mode Controller for Quadrotor UAV Attitude System in Presence of Wind Gust and Actuator Faults

Electronics ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 128 ◽  
Author(s):  
Di Shi ◽  
Zhong Wu ◽  
Wusheng Chou
Keyword(s):  
Attitude Control ◽  
Sliding Mode ◽  
Lyapunov Stability Theory ◽  
State Observer ◽  
Extended State Observer ◽  
Wind Gust ◽  
Actuator Faults ◽  
Extended State ◽  
Twisting Algorithm ◽  
The Impact

This article addresses the problem of high precision attitude control for quadrotor unmanned aerial vehicle in presence of wind gust and actuator faults. We consider the effect of those factors as lumped disturbances, and in order to realize the quickly and accurately estimation of the disturbances, we propose a control strategy based on the online disturbance uncertainty estimation and attenuation method. Firstly, an enhanced extended state observer (ESO) is constructed based on the super-twisting (ST) algorithm to estimate and attenuate the impact of wind gust and actuator faults in finite time. And the convergence analysis and parameter selection rule of STESO are given following. Secondly, in order to guarantee the asymptotic convergence of desired attitude timely, a sliding mode control law is derived based on the super-twisting algorithm. And a comprehensive stability analysis for the entire system is presented based on the Lyapunov stability theory. Finally, to demonstrate the efficiency of the proposed solution, numerical simulations and real time experiments are carried out in presences of wind disturbance and actuator faults.

scholarly journals Fault-tolerant control for a class of n-order systems based on fast terminal sliding mode and extended state observer

2021 ◽  
pp. 002029402110286
Author(s):  
Pu Yang ◽  
Peng Liu ◽  
ChenWan Wen ◽  
Huilin Geng
Keyword(s):  
Fault Tolerant ◽  
Sliding Mode ◽  
Singular Control ◽  
Fault Tolerant Control ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Terminal Sliding Mode ◽  
Fast Terminal Sliding Mode ◽  
Terminal Sliding Surface

This paper focuses on fast terminal sliding mode fault-tolerant control for a class of n-order nonlinear systems. Firstly, when the actuator fault occurs, the extended state observer (ESO) is used to estimate the lumped uncertainty and its derivative of the system, so that the fault boundary is not needed to know. The convergence of ESO is proved theoretically. Secondly, a new type of fast terminal sliding surface is designed to achieve global fast convergence, non-singular control law and chattering reduction, and the Lyapunov stability criterion is used to prove that the system states converge to the origin of the sliding mode surface in finite time, which ensures the stability of the closed-loop system. Finally, the effectiveness and superiority of the proposed algorithm are verified by two simulation experiments of different order systems.

Extended state observer–based output feedback control for spacecraft pose tracking with control input saturation

2021 ◽  
pp. 095441002110177
Author(s):  
Kejie Gong ◽  
Ying Liao ◽  
Yafei Mei
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
Finite Time ◽  
Output Feedback Control ◽  
State Observer ◽  
Extended State Observer ◽  
Control Input ◽  
Extended State ◽  
Pose Tracking ◽  
Control Scheme

This article proposed an extended state observer (ESO)–based output feedback control scheme for rigid spacecraft pose tracking without velocity feedback, which accounts for inertial uncertainties, external disturbances, and control input constraints. In this research, the 6-DOF tracking error dynamics is described by the exponential coordinates on SE(3). A novel continuous finite-time ESO is proposed to estimate the velocity information and the compound disturbance, and the estimations are utilized in the control law design. The ESO ensures a finite-time uniform ultimately bounded stability of the observation states, which is proved utilizing the homogeneity method. A non-singular finite-time terminal sliding mode controller based on super-twisting technology is proposed, which would drive spacecraft tracking the desired states. The other two observer-based controllers are also proposed for comparison. The superiorities of the proposed control scheme are demonstrated by theory analyses and numerical simulations.

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