Robust Multiplexed Piecewise Affine MPC-Based Decentralized Control of Multisatellite Formations Using Aerodynamic Forces

Aerodynamic forces are well suited to be exploited for low Earth orbit satellite formation control. However, some critical gaps still exist in control schemes suitable for multisatellite formation applications, especially when facing atmospheric environmental uncertainties. This article proposes a scalable and flexible decentralized control scheme for the multisatellite formation using only aerodynamic forces. This scheme adopts a strategy of updating the control inputs alternatively and is applicable to various formation configurations with different architectures without increasing the computational complexity and communication pressure of each satellite. Aerodynamic forces are changed by reorienting the satellite, and the linear formation control model with pointing angles as inputs is obtained by the piecewise affine (PWA) approximation method. A decentralized control scheme is proposed in which each satellite only has to communicate with its neighboring satellites and update its own inputs. This control scheme allows various generalizations of formation architectures, such as one that includes local chief satellites. To deal with model uncertainties, an improved model predictive control (MPC) algorithm named robust PWA-multiplexed MPC is developed using the constraint tightening approach, and then its feasibility and stability issues are analyzed. Hard-in-the-loop simulations are carried out for formation maintenance and reconfiguration, in which aerodynamic force uncertainties are considered.