Relative position keeping in satellite formation flying with input saturation

This paper studies a relative position keeping problem in satellite formation flying with input saturation. The relative motion dynamics is designed with polytopic-type uncertainties by considering elliptic and noncoplanar formation, and unknown angular rate and acceleration within some boundary. A composite nonlinear feedback control law is developed by using a low-and-high gain control scheme with an algebraic Riccati inequality (ARI). In the presence of input saturation and disturbances, finite-gain L∞ stability of the relative motion dynamics is ensured using the proposed control law. Additionally, the domain of attraction for the stability is evaluated by formulating an optimization problem. Through numerical simulations, the validity of the proposed scheme is illustrated.