基于偏置角动量的欠驱动航天器姿态保持控制

摘要

对有扰情况下欠驱动航天器三轴姿态保持控制问题进行了研究，提出一种基于俯仰偏置动量轮和滚动轴推力器的姿态保持控制方法。该方法基于偏置动量航天器滚动-俯仰轴耦合的原理实现，避免了欠驱动零动量航天器平衡点附近欠驱动轴耦合弱的问题；将航天器的姿态运动分为长周期运动和短周期运动，用极点配置方法进行控制律设计，给出保证系统稳定的参数选取范围，求出了系统稳态误差。最后，通过数值仿真验证了所设计的控制器不但能快速消除初始姿态偏差，而且能抵抗外干扰将航天器姿态保持在平衡点附近。%To maintain the three-axis attitude of the underactuated nadir-pointing spacecraft,an attitude hold control method based on the pitch-axis bias momentum wheel and roll-axis thruster was proposed.The method was based on coupling between the roll and yaw axes of biased-momentum spacecraft, and could avoid the problem that zero momentum spacecraft′s underactuated axis and actuated axis were almost decoupled. Spacecraft attitude dynamics was divided into long-period dynamics and short-period dynamics, and the control laws were designed by the pole-assignment method. The scale of control parameters was confirmed, and the stable state error of the control system was obtained. The simulation results show that the designed controller can eliminate initial attitude error of the spacecraft and resist the external disturbance,and the spacecraft attitude is maintained at the equilibrium point.