Constrained Robust Control for Spacecraft Attitude Stabilization Under Actuator Delays and Faults

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Alireza Safa ◽  
Mahdi Baradarannia ◽  
Hamed Kharrati ◽  
Sohrab Khanmohammadi
Keyword(s):  
Disturbance Observer ◽  
Sufficient Conditions ◽  
Control Input ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Attitude Stabilization ◽  
Delay Effects ◽  
Rigid Spacecraft ◽  
Backstepping Controller ◽  
And Control

This paper deals with the attitude stabilizing control problem for a rigid spacecraft in the presence of model uncertainties, external disturbances, and actuator faults when delay effects and control input constraints are taken into consideration. First, a backstepping method is introduced in the control design for compensating unknown delays in inputs. Then, a disturbance observer is investigated for estimating model uncertainties, external disturbances, and actuator fault effects. The backstepping controller is augmented with the reconstructed information provided by the disturbance observer to make the closed-loop system insensitive to disturbances and faults. Next, the proposed observer–controller structure is redesigned to deal with control constraints. Rigorous proofs show that the developed control under simple sufficient conditions can render the system globally input-to-state stable (ISS). Numerical simulations are presented to illustrate the effectiveness of the proposed controllers.

Implementation of State and Disturbance Estimation for Quadrotor Control Using Extended High-Gain Observers

2016 ◽  
Author(s):  
Connor J. Boss ◽  
Joonho Lee ◽  
Charles Carvalho de Aguiar ◽  
Jongeun Choi
Keyword(s):  
Control Algorithm ◽  
High Gain ◽  
Dynamic Inversion ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Disturbance Estimation ◽  
Sample Data ◽  
Estimation And Control ◽  
Control Forces ◽  
And Control

This paper proposes a discrete-time, multi-time-scale estimation and control design for quadrotors in the presence of external disturbances and model uncertainties. Assuming that not all state measurements are available, they will need to be estimated. The sample-data Extended High-Gain Observers are used to estimate unmeasured states, system uncertainties, and external disturbances. Discretized dynamic inversion utilizes those estimates and deals with an uncertain principal inertia matrix. In the plant dynamics, the proposed control forces the rotational dynamics to be faster than the translational dynamics. Numerical simulations and experimental results verify the proposed estimation and control algorithm. All sensing and computation is done on-board the vehicle.

scholarly journals Disturbance Observer-Based Nonsingular Terminal Sliding Mode Control for Spacecraft Electromagnetic Docking

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Jinghui Zhang ◽  
Guoqiang Zeng ◽  
Shifeng Zhang
Keyword(s):  
Sliding Mode Control ◽  
Magnetic Moment ◽  
Disturbance Observer ◽  
Field Model ◽  
Sliding Mode ◽  
Far Field ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Control Scheme ◽  
On Line

This paper presents a novel nonlinear sliding mode control scheme that combines on-line model modification, a nonlinear sliding mode controller, and a disturbance observer to solve the essential problems in spacecraft electromagnetic docking control, such as model uncertainties, unknown external disturbances, and inherent strong nonlinearity and coupling. An improved far-field model of electromagnetic force which is much more accurate than the widely used far-field model is proposed to enable the model parameters to be on-line self-adjusting. Then, the relationship between magnetic moment allocation and energy consumption is derived, and the optimal direction of the magnetic moment vector is obtained. Based on the proposed improved far-field model and the research results of magnetic moment allocation law, a fast-nonsingular terminal mode controller driven by a disturbance observer is designed in the presence of model uncertainties and external disturbances. The proposed control method is guaranteed to be chattering-free and to possess superior properties such as finite-time convergence, high-precision tracking, and strong robustness. Two simulation scenarios are conducted to illustrate the necessity of modifying the far-field model and the effectiveness of the proposed control scheme. The simulation results indicate the realization of electromagnetic soft docking and validate the merits of the proposed control scheme. In the end of this paper, some conclusions are drawn.

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 Attitude Tracking of Rigid Spacecraft with Actuator Saturation and Fault Based on a Compound Control

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Chunhua Cheng ◽  
Hang Yang ◽  
Qian Wang ◽  
Lin Li ◽  
Qiang Han ◽  
...  
Keyword(s):  
Disturbance Rejection ◽  
Control Input ◽  
Tracking Problem ◽  
External Disturbances ◽  
Attitude Stabilization ◽  
Actuator Failures ◽  
Compound Control ◽  
Active Disturbance Rejection ◽  
Attitude Tracking ◽  
Modeling Uncertainties

A compound control based on active disturbance rejection control (ADRC) scheme and slide mode control (SMC) is proposed to investigate the attitude tracking problem for a spacecraft with modeling uncertainties, external disturbances, actuator failures, and actuator saturations simultaneously. A positive term including control input is separated from the system, and then, the active disturbance rejection concept and the extended state observer (ESO) are applied to deal with the general uncertain item caused by uncertainties, external disturbances, actuator failures, and actuator saturations. The sliding mode surface is designed to transform the attitude tracking problem into attitude stabilization problem. In order to deal with the actuator saturations, a saturation degree coefficient and its corresponding adaptive law are introduced. Compared to other existing references, the proposed scheme does not need to know the structure or upper bound information of the inertial matrix uncertainties and external disturbances. Finally, the stability of the closed-loop system is analyzed by using input to state stability theory. Simulation results are given to verify the effectiveness of the proposed scheme. More importantly, the proposed technique can also be applied to the attitude stabilization of other aircraft, such as the attitude of unmanned aerial vehicle and helicopter in maritime rescue.

Disturbance observer-based attitude stabilization for rigid spacecraft with input MRCs

2020 ◽  
Vol 66 (3) ◽  
pp. 689-701 ◽  
Author(s):  
Keke Shi ◽  
Chuang Liu ◽  
Zhaowei Sun ◽  
Xiaokui Yue
Keyword(s):  
Disturbance Observer ◽  
Attitude Stabilization ◽  
Rigid Spacecraft

scholarly journals Finite-Time Synchronization and Identification between Two Nonlinear Coupled Multiweighted Markovian Switching Delayed Networks with Uncertain Models and External Disturbances

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xiaofei Chen ◽  
Haifeng Qiu ◽  
Chong Xu ◽  
Zhipeng Sun
Keyword(s):  
Finite Time ◽  
Time Synchronization ◽  
Sufficient Conditions ◽  
Network Models ◽  
Markovian Switching ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Multiple Weights ◽  
Adaptive Laws ◽  
True Values

In this paper, two different nonlinear coupled Markovian switching delayed network models with multiple weights are established, and the effects of parameter and model uncertainties and external disturbances are fully considered. Firstly, based on the finite-time theory, several sufficient conditions for the finite-time synchronization of Markovian switching networks are obtained. Secondly, under the feedback controller with adaptive laws, when the synchronization of the networks is achieved in a finite time, the uncertain parameters of the networks can also be identified as true values. Finally, a representative numerical simulation is given to further illustrate the validity and practicability of the theoretical analysis and proof of this paper.

scholarly journals Finite-Time Stabilization Control for a Rigid Spacecraft under Parameter Uncertainties

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Aihua Zhang ◽  
Jianfei Ni ◽  
Xing Huo
Keyword(s):  
Finite Time ◽  
Parameter Uncertainties ◽  
External Disturbances ◽  
Attitude Stabilization ◽  
Stabilization Control ◽  
Time Control ◽  
Control Scheme ◽  
Lyapunov Stability Analysis ◽  
Homogeneous Method ◽  
Rigid Spacecraft

A novel finite-time control scheme is investigated for a rigid spacecraft in present of parameter uncertainties and external disturbances. Firstly, the spacecraft mathematical model is transformed into a cascading system by introducing an adaptive variable. Then a novel finite-time attitude stabilization control scheme for a rigid spacecraft is proposed based on the homogeneous method. Lyapunov stability analysis shows that the resulting closed-loop attitude system is proven to be stable in finite time without parameter uncertainties and asymptotically stable with parameter uncertainties. Finally, numerical simulation examples are also presented to demonstrate that the control strategy developed is feasible and effective for spacecraft attitude stabilization mission.

Adaptive robust control of coupled attitude and orbit for spacecraft with model uncertainties

2018 ◽  
Vol 90 (1) ◽  
pp. 186-195
Author(s):  
Jun Sun ◽  
Xiande Wu ◽  
Shijie Zhang ◽  
Fengzhi Guo ◽  
Ting Song
Keyword(s):  
Design Methodology ◽  
Adaptive Robust Control ◽  
Dual Quaternion ◽  
Model Uncertainties ◽  
Robust Controller ◽  
External Disturbances ◽  
Content Type ◽  
Orbit Control ◽  
Rigid Spacecraft ◽  
Simulation Results

Purpose The purpose of this paper is to propose an adaptive robust controller for coupled attitude and orbit control of rigid spacecraft based on dual quaternion in the presence of external disturbances and model uncertainties. Design/methodology/approach First, based on dual quaternion, a theoretical model of the relative motion for rigid spacecraft is introduced. Then, an adaptive robust controller which can realize coordinated control of attitude and orbit is designed in the existence of external disturbances and model uncertainties. Findings This paper takes advantage of the Lyapunov function which can guarantee the asymptotic stabilization of the whole system in the existence of parameters uncertainties. Simulation results show that the proposed controller is feasible and effective. Originality/value This paper proposes a coupled attitude and orbit adaptive robust controller based on dual quaternion. Simulation results demonstrate that the proposed controller can achieve higher control performance in the presence of parameters uncertainties.

scholarly journals Synchronization of a Non-Equilibrium Four-Dimensional Chaotic System Using a Disturbance-Observer-Based Adaptive Terminal Sliding Mode Control Method

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 271 ◽  
Author(s):  
Shaojie Wang ◽  
Amin Yousefpour ◽  
Abdullahi Yusuf ◽  
Hadi Jahanshahi ◽  
Raúl Alcaraz ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Chaotic System ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Input Saturation ◽  
Control Input ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
And Control

In this paper, dynamical behavior and synchronization of a non-equilibrium four-dimensional chaotic system are studied. The system only includes one constant term and has hidden attractors. Some dynamical features of the governing system, such as invariance and symmetry, the existence of attractors and dissipativity, chaotic flow with a plane of equilibria, and offset boosting of the chaotic attractor, are stated and discussed and a new disturbance-observer-based adaptive terminal sliding mode control (ATSMC) method with input saturation is proposed for the control and synchronization of the chaotic system. To deal with unexpected noises, an extended Kalman filter (EKF) is implemented along with the designed controller. Through the concept of Lyapunov stability, the proposed control technique guarantees the finite time convergence of the uncertain system in the presence of disturbances and control input limits. Furthermore, to decrease the chattering phenomena, a genetic algorithm is used to optimize the controller parameters. Finally, numerical simulations are presented to demonstrate the performance of the designed control scheme in the presence of noise, disturbances, and control input saturation.

Adaptive nonlinear disturbance observer-based control for stochastic systems with multiple heterogeneous disturbances

2020 ◽  
Vol 42 (11) ◽  
pp. 2020-2030
Author(s):  
Xinqing Li ◽  
Xinjiang Wei ◽  
Huifeng Zhang ◽  
Jian Han ◽  
Xin Hu ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
Composite System ◽  
Stochastic Systems ◽  
Nonlinear Function ◽  
Control Input ◽  
System State ◽  
Nonlinear Disturbance Observer ◽  
Nonlinear Disturbance ◽  
Nonlinear Signal ◽  
And Control

The problem of anti-disturbance control is studied for a class of stochastic systems with multiple heterogeneous disturbances, which include three kinds of disturbance. One is the non-harmonic disturbance coupled with system state and control input. The other one is an unexpected nonlinear signal described as a nonlinear function. The third one is white noise. An adaptive nonlinear disturbance observer (ANDO) is constructed to estimate non-harmonic disturbance. Based on which, a new adaptive nonlinear disturbance observer-based control (ANDOBC) strategy is developed such that the composite system is asymptotically bounded in mean square. Simulation results are given to show its effectiveness of the proposed method.

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