Spacecraft time-delay state feedback control based on extended state observer

This paper researches the problem of rigid body spacecraft time-delay attitude stabilization. Firstly, the spacecraft nonlinear state model based on modified rodrigues parameters (MRPs) is established, the time delay term with certain upper boundary is modeled in state feedback control law. Lyapunov-Krasovskii functional is constructed for this nonlinear time-delay system to achieve asymptotic stabilization, linear matrix inequalities are accordingly obtained and the state feedback control coefficients matrixes are thereby computed with. Concerning the three-axis coupling nonlinear terms in spacecraft, the extended state observer (ESO) method is used to design a two rank nonlinear ESO, the spacecraft system internal state vector is therefore acquired and used in the aforementioned state feedback control law. For the convenience of engineering application, the MRPs state vector is converted to Euler angles in simulation. The simulation results show the efficient of the state feedback control law with three-axis attitude asymptotic stabilization achieved.