Global output feedback tracking control of spacecraft formation flying with parametric uncertainty

Considers the problem of relative position control for multiple spacecraft formation flying (MSFF) without velocity measurements. Specifically, the nonlinear dynamics describing the relative positioning of MSFF are used to develop a nonlinear, output feedback control law that guarantees the global uniform ultimate boundedness of the position and velocity tracking errors, despite the lack of velocity feedback and the presence of unknown spacecraft masses and disturbance force parameters. Simulation results are included to illustrate the controller performance.