Dynamics modeling and motion programming for electromagnetic formation flight

Based on the mechanism of electromagnetic spacecraft, the relative translational “tethered” dynamics model for two-craft electromagnetic formation flight (EMFF) in low earth orbit was developed by using Lagrange theory. The linearized equations for motion and stability analysis of two-craft radial and along-track formation were investigated. To stabilize the formation structure, the feedback control law was studied. The motion programming of electromagnetic formation could be transformed into a standard optimal problem, which could be perfectly solved by the Gauss pseudospectral method. In order to deal with the reconfiguration maneuver of multi-craft electromagnetic formation, the sequence control strategy was proposed. Then the multi-craft problem was transformed into a multi-phase motion planning problem. Thus, the problem of multi-phase optimal control could be solved by Gauss pseudospectral optimization software (GPOPS). The simulation result shows that the methods of dynamics modeling and motion planning proposed in this paper are valid.