A fixed-time output feedback control scheme for double integrator systems

et al. 2019

Self Cite

Summary The fault‐tolerant control and vibration suppression for flexible spacecraft without angular velocity measurement are investigated. External disturbances, actuator faults, unknown angular velocity, and flexible vibration are addressed simultaneously. Firstly, a model‐free adaptive supertwisting state observer and an angular velocity calculation algorithm in one step are developed by using attitude information only, which can estimate the angular velocity in finite time. Then, on the basis of angular velocity estimation, a novel continuous multivariable integral sliding mode (CMISM) is proposed for the first time, which is a combination of continuous nominal controller and a modified multivariable twisting controller to reject disturbances and faults. The CMISM can stabilize attitudes in finite time and attenuate chattering effectively. Furthermore, the input shaping technique is developed to achieve effective vibration suppression of the flexible appendages. Finally, the efficiency of the proposed method is illustrated by numerical simulations.

Section: Introductionmentioning

confidence: 99%

Continuous robust fault‐tolerant control and vibration suppression for flexible spacecraft without angular velocity

Zhang

et al. 2019

Self Cite

“…All the preceding fault‐tolerant attitude control schemes yield only asymptotic convergence for the closed‐loop system. Generally, the closed‐loop systems under finite‐time stability demonstrate the faster convergence and better disturbance rejection . It is widely known that SMC is a representative technology in the field of finite‐time convergence theory .…”

Section: Introductionmentioning

confidence: 99%

Adaptive multivariable finite‐time continuous fault‐tolerant control of rigid spacecraft

Zhao

et al. 2019

Self Cite

Summary The problem of fault‐tolerant attitude tracking control for rigid spacecraft in the presence of inertia uncertainties, actuator faults, and external disturbances is investigated in this paper. A novel adaptive finite‐time continuous fault‐tolerant control strategy is developed by combining the fast nonsingular terminal sliding mode surface and the adaptive multivariable super‐twisting algorithm, which improves the robustness while preserving high accuracy and finite‐time convergence. The main features of the control strategy are the double‐layer adaptive algorithm based on equivalent control, which ensures nonoverestimation of the control gain and the continuous controller, which maintains better property of chattering reduction. Finally, the efficiency of the proposed controller is illustrated by numerical simulations.

“…In practice, the external disturbance and model uncertainty, the rudder assignment, the intervehicle collision avoidance must be considered for UAV helicopters at the same time. Compared with the asymptotic control approach, finite‐time control is a more effective approach with better performance and robustness to uncertainty and for disturbance rejection …”

Section: Introductionmentioning

confidence: 99%

Finite‐time fully distributed formation reconfiguration control for UAV helicopters

Wang

et al. 2018

Self Cite

Summary This paper studies finite‐time fully distributed formation and reconfiguration control of multiple unmanned aerial vehicle helicopter with disturbances and uncertainty. Based on adaptive and terminal sliding‐mode control techniques, a disturbance observer‐based fully distributed control strategy is proposed, which is independent of least nonzero eigenvalue of Laplacian matrix and achieves practical finite‐time formation tracking for a moving leader without any additional condition. The proposed method is proved superior to the existing method in converging time. The finite‐time stability of the closed‐loop error is proved by the Lyapunov theory. Considering formation configuration changing as a result of a task change, a modified finite‐time fully distributed controller including potential energy function gradient terms with an adaptive law is proposed. The novelty of the reconfiguration controller is that an adaptive law is firstly integrated in the gradient items, then the asymptotical stability is extended to practical finite‐time stability. Simulation results are presented to demonstrate the efficiency of the developed algorithm.