为了实现无拖曳(Drag—Free)卫星中卫星本体对内部质量块的高精度跟踪,首先推导了近地环境下卫星与质量块的相对运动动力学方程,并分析了影响二者相对运动的主要干扰源。针对位移模式单质量块Drag—Free卫星只能获取质量块与卫星相对位置测量,设计了自适应控制器,适用于卫星质量和空间干扰为定常或慢变未知量的情况,且在卫星质量和外部干扰为未知常值的假设下,控制器能够保证卫星对质量块跟踪误差的全局渐近收敛。最后给出了仿真场景以说明本文方法的有效性。
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.