Switching LPV control for electromagnetic formation flying on highly elliptical orbit

The electromagnetic force generated by the interaction of electromagnetic coils can be used to replace the conventional propellant consumption mode in close relative motion control, thereby promoting the application of formation flight technology for long-term and continuous space missions. Herein, a hysteresis-switching logic-based switching linear parameter varying (LPV) controller synthesis technique with guaranteed performance for electromagnetic formation flying on a highly elliptical orbit is proposed. First, considering that the relative dynamics model of an elliptical orbit is characterized by time-varying uncertainty, the LPV model is described. By introducing switching LPV controllers among different scheduled parameter subsets, conservativeness can be reduced. Second, the system modeling error, the uncertainty caused by a simplified electromagnetic coil model, and external disturbance are considered to derive switching LPV controller synthesis conditions based on the guaranteed H_∞ performance. Derivation analysis shows that the proposed switching LPV controller not only ensures the robustness of the system against uncertainties, but also realizes the control input constraints. Finally, numerical simulations and comparative analyses are performed to demonstrate the effectiveness and advantages of the proposed control method.