In this paper, the output tracking control is addressed for discrete‐time multi‐input‐multi‐output nonlinear systems subjected to external disturbance by a novel output‐based discrete‐time integral sliding mode predictive control scheme. First of all, a control law is proposed based on a new type of discrete‐time integral sliding mode surfaces. To further improve control accuracy, an integral sliding mode predictive control law is obtained in combination with the designed integral sliding mode control and model predictive control. Rigorous analysis is provided to demonstrate that the quasi‐sliding‐mode band width and ultimate bound of output tracking error under the designed discrete‐time integral sliding mode predictive control law are of higher accuracy than those under the designed integral sliding mode control law. Numerical simulations are performed to illustrate that the presented integral sliding mode predictive control law offers better performance than the proposed integral sliding mode control law.

In this paper, attitude stabilization control for flexible spacecraft subject to external disturbance without angular velocity and flexible mode variables measurement is considered. First, an adaptive law is constructed to estimate the upper bound of a lumped disturbance consisting of flexible accessories and external disturbance. Based on the proposed adaptive law, an adaptive observer is established to estimate angular velocity and the lumped disturbance. Besides, for the case where flexible modal variables cannot be measured, a flexible modal variable observer-based sliding mode control law is proposed. Simulations are performed to verify the validity of the proposed control law. The simulation results show that the proposed control law can eliminate the influence of external disturbance for flexible spacecraft under the situation that angular velocity and flexible modal variables cannot be measured.

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In this paper, the attitude stabilization of flexible spacecraft with unmeasurable states and disturbances is addressed by an observer-based fuzzy integral sliding mode control scheme. First, a Takagi–Sugeno fuzzy model of flexible spacecraft is established and an observer is proposed based on this model. The convergence conditions of the estimation errors are given by Lyapunov function and the gains of the observer are thus determined. According to the obtained estimates, a novel fuzzy sliding mode control strategy is designed to compensate the influence of disturbance. Finally, an example of flexible spacecraft is employed to verify the effectiveness of the proposed observer and control law.

The cosmological principle states that our Universe is statistically homogeneous and isotropic at large scales. However, due to the relative motion of the Solar System, an additional kinematic dipole can be detected in the distribution of galaxies, which should be consistent with the dipole observed in the cosmic microwave background (CMB) temperature. In this paper, we forecast the mock number count maps from the China Space Station Telescope photometric survey to reconstruct the kinematic dipole. Using the whole photometric mock data, we obtain a positive evidence for the dipole signal detection at 3σ confidence level, and the significance would be increased to 4σ when we only use the high-redshift samples with z = 1.8 ∼ 4. This result can provide a good consistency check between the kinematic dipoles measured in the CMB and that from the large scale structure, which can help us to verify the basic cosmological principle.