Partial State Feedback Consensus Model Reference Adaptive Control for Non-affine Drag-Free Spacecraft Inner-Formation System

This paper proposes a consensus control approach for the inner-formation system containing the drag-free spacecraft and two cubic test masses. Considering the control problem caused by immeasurable states of the velocities in the system, a partial state feedback control scheme is investigated, and the consensus model reference adaptive control is established to adaptively actuate the inner-formation system to a stable reference model in consideration of parameter uncertainties. Concerning the non-affine electrostatic actuation and suspension of the test masses, the fuzzy logic system is used to estimate the unknown nonlinearities. By combining the fuzzy logic-based estimator and adaptive consensus controller, the partial state feedback model reference adaptive consensus control scheme is developed for the non-affine inner-formation system. Theoretical analysis proves the uniformly ultimately boundedness of each closed-loop signal in the formation system, the control performance is verified by the numerical simulations of the dragfree spacecraft inner-formation system.