Controllability of Flux-Pinned Docking Interface

The flux-pinned docking interface (FPDI) is composed of an YBCO high-temperature superconductor bulk and an electromagnet (EM). They are installed on the spherical target spacecraft module and another spherical tracking spacecraft module, respectively. This novel docking interface can enable the active control of the docking process to become an additional option rather than a necessary option. The vertical force between two flux-pinned spacecraft modules (FPSMs) can be analytically calculated based on the improved image dipole model. The controllability of the FPDI is achieved through varying current flowing through the EM. Two FPSMs can be linked or detached by changing the direction of current. The distinct equilibrium connection state of two FPSMs can be transformed by changing the current intensity. The orbital dynamic docking equation of two FPSMs is established based on Clohessy-Wiltshire's equation. The numerical calculation based on the Runge-Kutta algorithm can calculate the derived dynamic docking equation. The simulated consequence shows that proportional-derivative active feedback control applied to this docking interface can effectively suppress the vibration amplitude and significantly shorten the settling time, which suggests that this potential novel docking interface can be readily controlled.