Abstract:

To realize accurate tracking of the test mass in a drag free satellite, the relative motion between the test mass and the outer satellite is derived and the main disturbance sources in the relative dynamics are analyzed. Based on the analysis, an adaptive controller requiring only relative position measurement is designed for the displacement mode of drag free satellites with single test mass and is applicable for unknown but constant or slow varying satellite mass and spatial disturbances. Under the assumption that both satellite mass and disturbances are unknown constants, the controller can guarantee global asymptotic convergence of the tracking errors. Simulation results are given to show the efficiency of results of this paper.

Key words: Drag Free satellite, Displacement mode, Adaptive control, Parameter estimation, Disturbance compensation