One of the key problems for space vehicles is how to deal with the contradiction between the control constraints and the disturbances from multiple resources. This paper focuses on the adaptive full state constrained controller design problem for the flexible air-breathing hypersonic vehicles with multisource uncertainties. In simultaneous presence of the aerodynamical uncertainties, the modeling errors, the external disturbances, and the contingent actuator failures, an adaptive fault-tolerant control scheme is put forward in the context of dynamic surface control. Then, the barrier Lyapunov functions are utilized to guarantee that the constraints on the velocity, the flight path angle, the altitude, and the pitch rate are never violated. In virtue of the bound estimation approach, the multisource disturbances are effectively dealt with. Finally, a number of illustrative examples are provided to demonstrate the effectiveness of the proposed methodology.

In this paper, an adaptive fuzzy tracking controller is developed for a class of strict-feedback Markovian jumping systems subjected to multisource uncertainties. The unpredictable actuator failures, the unknown nonlinearities, and the unmodeled dynamics are simultaneously taken into consideration, which evolve according to the Markov chain. It is noted that the elements in the transition rate matrix of the Markov chain are not fully available. In virtue of the norm estimation approach, the challenges caused by the complex multiple uncertainties and actuator failures are effectively handled. Furthermore, to compensate for the unavailable switching nonlinearities, the fuzzy logic systems are employed as online approximators. As a result, a novel adaptive fuzzy fault-tolerant tracking control structure is constructed. The sufficient condition is provided to guarantee that the studied system is stochastically stable. Finally, a number of illustrative examples are employed to demonstrate the effectiveness of the proposed methodology.

This paper presents a performance-guaranteed adaptive asymptotic tracking control scheme for a class of nonlinear systems with unknown sign-switching control direction. By introducing the periodic sliding mode technique and equivalent control-based adaptive mechanism, the proposed control approach ensures that the sliding mode surface is reached in finite time, and thus the asymptotic stability is achieved rather than only signals boundedness. Simultaneously, the tracking performance is strictly guaranteed inside the preassigned performance bounds even when the unknown control coefficients switch to the opposite direction. The effectiveness of the proposed control law is verified by numerical simulations.

In this paper, a fuzzy adaptive full-state-constrained control approach is proposed for a class of stochastic switched systems subject to quantized input signals and actuator faults. The inherent discontinuous and hybrid characteristics of the concerned systems lead to a difficult task for designing a stable controller. Several fuzzy logic systems (FLSs) are utilized to approximate the unknown nonlinearities and the bound estimation approach is employed to deal with the stochastic switched disturbances. As a result, the negative effects caused by the discontinuous multiple uncertainties can be suppressed. Furthermore, several four-order Barrier Lyapunov Functions (BLFs) are introduced to guarantee that the constraints of the system states are not violated. It is proved that all the signals in the closed-loop system is semi-globally uniformly ultimately bounded. Numerical simulation results have been provided to illustrate the satisfactory performance of the proposed control algorithm.

This paper proposes an adaptive smooth second-order sliding mode control law for a class of uncertain non-linear systems. The key point of this control law is ensuring a smooth control signal considering parametric uncertainty and disturbances with unknown bounds. The proposed control method is obtained by introducing a continuous function under the integral and using adaptive gains. The switching function and its derivative are forced to zero in finite time. This is achieved using a smooth control command and without the prior knowledge of upper bound parameters of uncertainties. The finite-time stability is proved based on a quadratic Lyapunov approach and the reaching time is estimated. This structure is used to create a homing guidance law and the efficiency is evaluated via simulations.