Discrete-Time HOFA Adaptive Control for a Type of Combined Spacecraft with Unknown Parameters and State Delays

In this paper, a discrete-time high-order fully actuated (DT-HOFA) adaptive stabilization control of a combined spacecraft simulator (CSS) with unknown parameters under state delays is considered. First, a general DT-HOFA system (DT-HOFAS) with state delays and unknown parameters is introduced by generalizing the time-delay fully actuated system (FAS) model of the CSS system. Then, for the proposed control objective, a DT-HOFA adaptive stabilization controller including state feedback and parameter estimation is designed, which effectively solves the nonlinear term affected by state delays. Moreover, using discrete-time Lyapunov theory, the stability analysis of the closed-loop system is given and its eigenstructure can be configured arbitrarily. Finally, the proposed technique is successfully used to stabilize CSS system with unknown parameters and state delays, verifying its effectiveness.