The rapid attitude stabilization problem of flexible spacecraft with uncertain inertia and disturbances is investigated. In this article, a sliding mode-based fixed-time control approach presented new surface ensuring faster convergence rate incorporated. This has no singularity can guarantee the settling time to be independent initial states. An adaptive law then synthesized, which continuous chattering free. It rigorously proved that states system converge into small neighborhood after...

This study focuses on the adaptive finite-time tracking problem for uncertain non-linear n -order systems subjected to unmatched uncertainties. Using a novel form of fast terminal sliding mode (FTSM) control method with self-tuning algorithm, robust controller is obtained drive error origin in finite time spite Indeed, FTSM combined global SMC approach eliminate reaching phase which improves performance and robustness system. To alleviate chattering phenomenon get rid knowing exact value...

This paper investigates the difficult issue of fixed-time constrained attitude control for a flexible spacecraft under influence system uncertainties, environmental disturbance and abrupt actuator faults. The contributions proposed framework are twofold. Firstly, an observer is presented to precisely reconstruct uncertain dynamics within fixed time regardless initial estimation error while settling given as specific parameter. Secondly, using combination prescribed performance (PPC) barrier...

This work deals with the complicated problem of constrained fixed-time attitude control for flexible spacecraft in view actuator saturations and fault. The proposed controller is composed two parts. first part provides fast convergence system trajectories using a novel nonsingular terminal sliding mode control. second offers desired performance specification, such as rate convergence, overshoot, steady-state bounds attitude/rotation velocity to improve attitude-pointing accuracy pointing...

This study proposes a finite‐time integral backstepping control for class of non‐linear systems considering practical aspects including saturation constraints, actuator fault, external disturbances and system uncertainties in order to achieve strong robustness, fast response high‐precision tracking performance. An adaptive version the controller is then developed deal with total system. The main property suggested that there no need knowledge be available. Not only are all closed‐loop states...

This article investigates the prescribed performance control problem associated with attitude stabilization of a rigid body, considering angular velocity constraint, actuator faults, and input saturation. The desired specifications in transient steady-state phases including convergence speed, overshoot, value for variable are also provided. To this end, methodology is combined backstepping-based barrier Lyapunov function so as to develop controller simple structure compared existing...

This article presents an energy-efficient constrained attitude control scheme with fixed-time convergence for spacecraft. Although provides fast of the system trajectories, it requires large efforts at beginning response that may result in actuator saturation. To deal this important problem, a nonlinear first-order stable (NFOFTSS) is introduced. It analytically proved problem initial associated effort solved without deteriorating time. Using NFOFTSS, sliding-mode-based rigid spacecraft...

This paper addresses the problem of attitude control a spacecraft in presence model uncertainty, external disturbance, actuator fault and saturation. By introducing novel form integral backstepping control, finite-time tolerant is designed to obtain satisfactory performance, rapid convergence system states, reduced steady-state error high robustness. Guaranteeing trajectory significant feature proposed law that critical systems. Since upper bound uncertainty disturbance quite difficult...

This paper presents an adaptive constrained attitude control for uncertain spacecraft. Inspired by the concept of nonsingular terminal sliding mode and funnel nonlinear systems, a novel is introduced which contains time-varying gain to handle constraints imposed on spacecraft attitude. Indeed, when trajectory approaches boundary constraint set, effort as well will increase in order preclude from intersecting boundary. Then, it analytically proved that system trajectories converge arbitrary...

Summary This paper considers the problem of robust adaptive tracking control nonlinear second‐order systems subjected to matched and unmatched uncertainties. presents a law derived by new form fast terminal sliding mode that is combined with global scheme. An adaptation mechanism also employed estimate unknown parameters system. The proposed guarantees finite‐time convergence variable in presence uncertainties parameters. By elimination reaching phase, robustness system guaranteed throughout...

This paper considers the problem of fault-tolerant attitude control for a flexible spacecraft subject to input and state constraint. Particularly, new sliding mode-based with fixed-time convergent is developed in which convergence rate system improved both far from at close range origin. In contrast existing complicated prescribed performance controls (PPC), proposed PPC possesses much simpler structure due use novel constraint concept without employing error transformation. It also...

In this work, a new nonlinear guidance law with finite-time convergence considering control loop dynamics is developed to intercept highly maneuvering targets. The approach based on integral sliding mode combined state feedback control. Since terminal process occurs in short time, the line-of-sight (LOS) angular rate should converge zero finite time. proposed scheme successively guides LOS finite-time, and stability robustness of are demonstrated by means Lyapunov theorem. Three-dimensional...

This paper investigates the problem of output feedback attitude control for rigid spacecraft subject to inertia matrix uncertainty, space disturbance, and input saturation. Firstly, a model transformation is adopted convert an system with immeasurable angular velocity into new system. All states converted are measurable available feedback; however, contains mismatched uncertainty resulting from coordinate transformation. Then, adaptive nonsingular back-stepping practical predefined-time...

Based on a new fixed-time sliding mode control, finite-time control for attitude stabilization of rigid spacecraft subject to external disturbance, actuator faults, and input saturation has been presented by Jiang et al. The main objective this comment is point out mistake in critical theorem al., which resulted the ineffectiveness proposed controller.

This study deals with the problem of disturbances in observer-based attitude tracking control for spacecraft presence inertia-matrix uncertainty and arbitrary disturbance. Following backstepping control, a tan-type barrier Lyapunov function (BLF)-based method prescribed settling time performance is systematically developed. The proposed framework possesses three advantages over existing controllers. Firstly, singularity associated use fractional power fixed-time effectively resolved without...

This study investigates the challenging and complicated issue of full-state constraint attitude control for rigid bodies under actuators physical limitation. Using concept prescribed performance (PPC), a novel proportional-derivative (PD)-type is introduced by which both quaternion rotation velocity body are enforced to possess specific behaviors in transient steady state. To this end, function (PPF) with finite-time convergence first defined as predefined boundaries velocity. Subsequently,...