An Extended State Observer Based on Tracking Differentiator

2006 ◽  
Author(s):  
Zhu Jianhong ◽  
Zhang Zhaojing ◽  
Yang Huizhong
Keyword(s):  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Tracking Differentiator

scholarly journals Active Disturbance Rejection Station-Keeping Control of Unstable Orbits around Collinear Libration Points

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Min Zhu ◽  
Hamid Reza Karimi ◽  
Hui Zhang ◽  
Qing Gao ◽  
Yong Wang
Keyword(s):  
Disturbance Rejection ◽  
External Disturbance ◽  
State Observer ◽  
Libration Points ◽  
Extended State Observer ◽  
Unstable Periodic Orbits ◽  
Extended State ◽  
Station Keeping ◽  
Tracking Differentiator ◽  
Active Disturbance Rejection

An active disturbance rejection station-keeping control scheme is derived and analyzed for station-keeping missions of spacecraft along a class of unstable periodic orbits near collinear libration points of the Sun-Earth system. It is an error driven, rather than model-based control law, essentially accounting for the independence of model accuracy and linearization. An extended state observer is designed to estimate the states in real time by setting an extended state, that is, the sum of unmodeled dynamic and external disturbance. This total disturbance is compensated by a nonlinear state error feedback controller based on the extended state observer. A nonlinear tracking differentiator is designed to obtain the velocity of the spacecraft since only position signals are available. In addition, the system contradiction between rapid response and overshoot can be effectively solved via arranging the transient process in tracking differentiator. Simulation results illustrate that the proposed method is adequate for station-keeping of unstable Halo orbits in the presence of system uncertainties, initial injection errors, solar radiation pressure, and perturbations of the eccentric nature of the Earth's orbit. It is also shown that the closed-loop control system performance is improved significantly using our method comparing with the general LQR method.

scholarly journals Extended state observer–based nonlinear cascade proportional–integral–derivative control of the nano quadrotor

2016 ◽  
Vol 8 (12) ◽  
pp. 168781401668079 ◽  
Author(s):  
Xiaoran Li ◽  
Mou Chen
Keyword(s):  
Control Method ◽  
Design Procedure ◽  
State Observer ◽  
Extended State Observer ◽  
Model Parameters ◽  
Proportional Integral Derivative ◽  
Extended State ◽  
Proportional Integral Derivative Controller ◽  
Proportional Integral ◽  
Tracking Differentiator

The nano quadrotor is a nonlinear multi-input and multi-output system with strong coupling, which causes difficulties in control law design. In order to achieve a favorable performance, an extended state observer–based nonlinear cascade proportional–integral–derivative controller is proposed in this article. First, the nano quadrotor platform is built, and the dynamic model is established. Second, a novel and practical measuring method is given to obtain model parameters. Then, based on the active disturbance rejection control method, the design procedure of the extended state observer–based nonlinear cascade proportional–integral–derivative controller is presented. In the developed controller, a tracking differentiator is involved to extract the signals of gyroscope, and extended state observer is used to estimate the disturbance. To obtain a better performance of tracking differentiator and extended state observer, a systematic parameter-tuning method is studied. Finally, simulation results are given to demonstrate the efficiency of the proposed controller.

Novel nonsingular fast terminal sliding mode control for a PMSM chaotic system with extended state observer and tracking differentiator

2015 ◽  
Vol 23 (15) ◽  
pp. 2478-2493 ◽  
Author(s):  
Xuejian Chang ◽  
Ling Liu ◽  
Wen Ding ◽  
Deliang Liang ◽  
Chongxin Liu ◽  
...  
Keyword(s):  
Chaotic System ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Transition Process ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Terminal Sliding Mode ◽  
Tracking Differentiator ◽  
Fast Terminal Sliding Mode

A novel nonsingular fast terminal sliding mode (NNFTSM) control strategy based on the extended state observer (ESO) and the tracking differentiator (TD) is developed for the stabilization and tracking of the uncertain perturbed permanent magnet synchronous motor (PMSM) chaotic system. The proposed NNFTSM surface not only makes the system state rapidly converge to the equilibrium point in finite time with high steady-state precision, but also avoids the singular phenomenon. Furthermore, the ESO which does not rely on the mathematical model of the system is used for estimating uncertainties and disturbances to decrease the chattering caused by the big switching gain through compensating controller. Meanwhile, the TD is introduced to arrange the transition process for the reference input signal to realize the coordinated control between the rapidity and overshoot, and to decrease the initial impulse of the manipulative variable. The simulation results demonstrate that the proposed control scheme can flexibly restrain chaos which provides good dynamic and static performances, and has strong robustness to parameter variations and external load disturbances with low chattering.

Adaptive neural impedance control with extended state observer for human–robot interactions by output feedback through tracking differentiator

2020 ◽  
Vol 234 (7) ◽  
pp. 820-833
Author(s):  
JianTao Yang ◽  
Cheng Peng
Keyword(s):  
Neural Network ◽  
Output Feedback ◽  
Impedance Control ◽  
State Observer ◽  
Lyapunov Theory ◽  
Extended State Observer ◽  
Compact Set ◽  
Extended State ◽  
Adaptive Neural Network ◽  
Tracking Differentiator

Although impedance control has huge application potential in human–robot cooperation, its engineering application is still quite limited, owing to the high nonlinearity of the human–robot dynamics and disturbances. This article presents a novel adaptive neural network controller with extended state observer for the human–robot interaction using output feedback. The adaptive neural network with extended state observer integrates the adaptive neural network and extended state observer to combine their advantages. The proposed algorithm can address the challenges encountered in human–machine systems, for example, slow convergence of neural networks, internal and external disturbances. Output feedback is realized using tracking differentiator to avoid the costly measurements of certain states. The errors of the closed-loop system are proven to converge to a small compact set containing 0 by Lyapunov theory. Simulations and experiments were conducted to verify the effectiveness of the proposed controller. Results show that the proposed strategy offers superior convergence and better tracking performance compared with the adaptive neural network. The proposed controller can be widely applied in various human–machine interactions to enhance productivity and efficiency.

scholarly journals Nonsingular Fast Terminal Sliding Mode Control with Extended State Observer and Tracking Differentiator for Uncertain Nonlinear Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Zhenxin He ◽  
Chuntong Liu ◽  
Ying Zhan ◽  
Hongcai Li ◽  
Xianxiang Huang ◽  
...  
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Tracking Differentiator ◽  
Fast Terminal Sliding Mode

A continuous nonsingular fast terminal sliding mode (NFTSM) control scheme with the extended state observer (ESO) and the tracking differentiator (TD) is proposed for second-order uncertain SISO nonlinear systems. The system’s disturbances and states can be estimated by introducing the ESO, then the disturbances are compensated effectively, and the ideal transient process of the system can be arranged based on TD to provide the target tracking signal and its high-order derivatives. The proposed controller obtains finite-time convergence property and keeps good robustness of sliding mode control (SMC) for disturbances. Moreover, compared with conventional SMC, the proposed control law is continuous and no chattering phenomenon exists. The property of system stability is guaranteed by Lyapunov stability theory. The simulation results show that the proposed method can be employed to shorten the system reaching time, improve the system tracking precision, and suppress the system chattering and the input noise. The proposed control method is finally applied for the rotating control problem of theodolite servo system.

Spatial trajectory tracking control for unmanned airships based on active disturbance rejection control

2018 ◽  
Vol 233 (6) ◽  
pp. 2231-2240 ◽  
Author(s):  
Wenjie Lou ◽  
Ming Zhu ◽  
Xiao Guo
Keyword(s):  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
State Observer ◽  
Extended State Observer ◽  
Active Disturbance Rejection Control ◽  
Extended State ◽  
Tracking Differentiator ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Spatial Trajectory

In this paper, to address the spatial trajectory tracking problem of unmanned airships, a robust controller based on active disturbance rejection control is presented. By transforming the airship model to a standardized form, a straightforward design approach is adopted for the design of the controller. Active disturbance rejection control is composed of a tracking differentiator, an extended state observer, and a nonlinear state error feedback. The proposed controller replaces the conventional tracking differentiator with a third-order differentiator. The new tracking differentiator provides higher tracking precision and smoother transient process. The external disturbances and model uncertainties are observed by the extended state observer and compensated in the controller design, subsequently. Comparisons with technologies frequently used in the trajectory tracking are made through numerical simulation. The comparisons validate that the proposed controller provides satisfying performance and robustness in the presence of model uncertainty and external disturbance.

scholarly journals Pitching axis control for a satellite camera based on a novel active disturbance rejection controller

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401668903 ◽  
Author(s):  
Bingyou Liu ◽  
Yi Jin ◽  
Changan Zhu ◽  
Changzheng Chen
Keyword(s):  
Disturbance Rejection ◽  
Nonlinear Function ◽  
State Observer ◽  
Extended State Observer ◽  
The Novel ◽  
Error Feedback ◽  
Extended State ◽  
Tracking Differentiator ◽  
Active Disturbance Rejection ◽  
Nonlinear State

The pitching axis of a satellite camera is controlled under the weightless environment. A novel active disturbance rejection controller is designed to eliminate the influences of the pitching axis. The novel active disturbance rejection controller is designed based on a new nonlinear function, and thus, this function is first established. The function exhibits better continuity and smoothness than previously available functions, hence, it can effectively improve the high-frequency flutter phenomenon. Therefore, the novel active disturbance rejection controller based on the new nonlinear function can eliminate disturbances of the pitching axis. The novel active disturbance rejection controller is composed of a tracking differentiator, a novel extended state observer, and a novel nonlinear state error feedback. The tracking differentiator is used to arrange the transient process. Nonlinear dynamics, model uncertainty, and external disturbances are extended to a new state. The novel extended state observer is utilized to observe this state. The overtime variation of the system can be predicted and compensated using the novel extended state observer. The novel nonlinear state error feedback is adopted to restrain the residual errors of the system. Finally, simulation experiments are performed, and results show that the novel active disturbance rejection controller exhibits better performance than the traditional active disturbance rejection controller.

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