Constrained adaptive fuzzy super-twisting control for space circumnavigation mission with input constraints and rough dynamics information

The 6-DOF attitude-orbit fast synchronous control problem in the space circumnavigation mission is investigated in this paper with dynamics coupling, uncertainties and disturbances, input constraints, and rough dynamical information feedbacks. The orbital-information-based desired angular acceleration information is dynamically compensated via a set of hierarchical fuzzy systems to avoid the derivation operation of orbital states amplifying measurement noise. Since the adaptive laws for updating fuzzy weights are developed based on hyperbolic tangent function, estimation results are updated slowly, even if the initial tracking errors are large. A novel nonsingular practical terminal sliding-mode (PTSM) reduced-order system is proposed for drive tracking errors fast converge with high precision. Benefiting from the absence of information coupling in the derivative of the PTSM function, an observation-based super-twisting algorithm (STA) is employed to establish the PTSM manifold with weakened chattering. Adaptive laws estimate the maximum uncertainty, and an auxiliary system compensates for the input constraints. Simulation results verify the effectiveness of the proposed control scheme.