scholarly journals PD-Based Optimal ADRC with Improved Linear Extended State Observer

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 888
Author(s):  
Zhen Zhang ◽  
Jian Cheng ◽  
Yinan Guo
Keyword(s):  
Disturbance Rejection ◽  
Dead Zone ◽  
State Observer ◽  
Extended State Observer ◽  
Control Law ◽  
Extended State ◽  
Pd Control ◽  
Active Disturbance Rejection ◽  
Linear Extended State Observer ◽  
The Dead

Taking dead-zone nonlinearlity and external disturbances into account, an active disturbance rejection optimal controller based on a proportional-derivative (PD) control law is proposed by connecting the proportional-integral-derivative (PID) control, the active disturbance rejection control (ADRC) and particle swarm optimization (PSO), with the purpose of providing an efficient and practical technology, and improving the dynamic and steady-state control performances. Firstly, in order to eliminate the negative effects of the dead-zone, a class of 2-order typical single-input single-out system model is established after compensating the dead-zone. Following that, PD control law is introduced to replace the state error feedback control law in ADRC to simplify the control design. By analyzing the characteristics of the traditional linear extended state observer, an improved linear extended state observer is designed, with the purpose of improving the estimation performance of disturbances. Moreover, employing PSO with a designed objective function to optimize parameters of controller to improve control performance. Finally, ten comparative experiments are carried out to verify the effectiveness and superiority of the proposed controller.

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.

Applying LESO for Disturbance Rejection of Space Station

2014 ◽  
Vol 721 ◽  
pp. 257-260
Author(s):  
Ping Liu ◽  
Wei Jie Sun
Keyword(s):  
Attitude Control ◽  
Disturbance Rejection ◽  
Space Station ◽  
State Observer ◽  
Extended State Observer ◽  
Disturbance Compensation ◽  
Extended State ◽  
Lqr Controller ◽  
Linear Extended State Observer ◽  
Simulation Results

In this paper, a combing method based on the linear extended state observer (LESO) and the LQR controller is presented. The LESO is applied to estimate the total disturbance of the space station, and an effective disturbance compensation strategy is proposed for the attitude control and moment management. The simulation results illustrate this method is effective

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