A high-order fully actuated predictive control approach of spacecraft flying-around under time-variant communication constraints

A High-Order Fully Actuated (HOFA) predictive control approach is proposed for the problem of spacecraft flying-around under time-variant communication constraints in a sight coordinate system, including both time-variant communication delays and time-variant packets dropouts in the communication channels between the servicing spacecraft and the tracking and data relay satellite system. In the sight coordinate system, a nonlinear HOFA system model is introduced to describe the relative dynamics of spacecraft flying-around, such that the proposed flying-around task can be considered as a tracking control problem of nonlinear HOFA system. In this approach, the nonlinearities can be eliminated to construct a linear HOFA system because of full actuation characteristic, and then a Linear Incremental HOFA (LIHOFA) prediction model is constructed by applying a Diophantine Equation to replace a reduced-order prediction model, such that multi-step ahead predictions are developed to achieve the optimization of tracking control performance and the compensation of time-variant communication constraints, which guarantees the realization of this flying-around mission. A necessary and sufficient condition is given to analyze the stability and tracking performance of closed-loop system. Further, two simulated examples of spacecraft flying-around in circular and elliptical orbits are provided to verify the feasibility of HOFA predictive control approach.