Decentralized Collision-Free Satellite Formation Reconfiguration with Control Barrier Functions

This paper develops a Control Barrier Function (CBF)-based safety filter, extended from safety barrier certificates originally designed for simple double integrator systems, to achieve collision-free reconfiguration of multiple satellites in formation. The proposed decentralized framework integrates observer-based relative state estimation with CBF-based safety filtering, enabling each satellite to assess potential collisions with neighboring satellites based on relative position and velocity measurements. Safe control inputs are computed in real time by solving a decentralized quadratic program, which minimally modifies the nominal control to enforce safety constraints while relying solely on local sensor information. A numerical simulation of eight satellites initially placed at the vertices of a cube and reconfigured by swapping positions with their diagonal counterparts validates the effectiveness of the proposed approach.