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An adaptive dynamic sliding mode control law is proposed in this paper for rigid body satellite attitude control using variable speed control moment gyroscopes (VSCMG) actuators to improve the robustness of the control system under disturbances. In the proposed control algorithm, the disturbance torque is estimated by using some kind of adaptive method. The differential signal of the control torque is used as the controller output rather than the actual control torque itself. Therefore, the chattering problem of the control torque caused by the high-frequency switching action would be softened through the integral operation, so that the dynamic performance of the control system could be improved. Numerical simulation shows that rapid? attitude maneuvers of rigid body satellites could be accomplished in the presence of external disturbance and the inherent chattering problem of sliding mode control could be softened. [ABSTRACT FROM AUTHOR]

In this paper, an optimal adaptive integral sliding mode control (OAISMC) strategy is proposed for the reentry vehicle with a strong coupling, nonlinearity and uncertainty. Firstly, the State Dependent Riccati Equation (SDRE) is used to design the attitude controller for the nonlinear reentry vehicle without uncertainties. Then the integral sliding mode control theory is applied to reentry vehicle with parameter variations or external disturbances. By combining the integral sliding mode control theory with SDRE, the optimal performance index is achieved and the uncertainties can be rejected. Moreover, by using an adaplively adjusted switching gain, the upper bound of the lumped uncertainty is not required to be known. A sliding mode disturbance observer is introduced to improve the control performance. Finally, simulation is made in the presence of external disturbance and as well as perturbation by aerodynamic coefficients and atmospheric density. The validity and robustness of the proposed strategies are verified by simulation results. [ABSTRACT FROM AUTHOR]

As a cruise vehicle is characterized by quickly time-varying, strongly coupled and highly nonlinear, a accurate and robust control strategy is proposed for the cruise vehicle flight control in the presence of aerodynamic parameter and inertial parameter uncertainties. A disturbance observer based exponential time-varying sliding mode control (DOETVSMC) strategy is developed the for cruise vehicle by combining the disturbance observer method and exponential time-varying sliding mode control (ETVSMC) approach, and the related stability of the overall controller is further analyzed by using Lyapunov stability principle. As a result, the proposed approach can be used to effectively reduce the steady state error caused by the boundary layer approach used to process the chattering problem in the sliding mode control (SMC). Finally, simulations are employed to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]