Nonlinear model predictive control for attitude maneuver of a barbell electric sail through voltage regulation

Abstract

The paper focuses on the attitude dynamics and control of a barbell electric sail (E-sail). The barbell E-sail is composed of two tip satellites connected via long conductive tethers to a central insulated confluence point. The two tethers are insulated from each other at the confluence point such that the voltages of the two tethers can be independently controlled. A nonsingular formulation based on the dumbbell assumption is proposed to describe the attitude dynamics of the barbell E-sail, and exploited to develop a nonlinear model predictive controller for attitude adjustment and maintenance of the barbell E-sail by regulating the tether voltages. The nonlinear model predictive control law explicitly accounts for the nonlinear attitude dynamics and mission-related constraints of the barbell E-sail. Finally, the efficiency and performance of the proposed control law are demonstrated via numerical case studies.