基于四元数的带飞轮航天器的自适应姿态控制

由于各种环境因素的影响，航天器在运行过程中其动力学参数的准确值难以确定．姿态控制系统必须具有自适应性以适应参数的变化．文中针对飞轮控制航天器提出了一种基于四元数的自适应控制方法．与欧拉角比较，姿态运动的四元数表达的主要优点是数值计算过程中不存在奇异位置．这种控制方法在不需提供航天器参数的情况下可保证航天器跟踪期望的姿态变化以实现姿态机动．应用Lyapunov直接方法证明系统的渐近稳定性，并通过航天器姿态机动跟踪的数值仿真证实了这种控制方法的有效性．

Quaternion-Based Adaptive Control of a Spacecraft with Reaction Wheels

Considering the influence of environmental factors it is impossible to determine the accurate value of dynamical parameters of a spacecraft in orbit. Therefore the adaptive ability of attitude control system is necessary to adapt the variation of parameters. An adaptive control approach based on quaternions for the spacecraft with reaction wheels was proposed. Compared to the Euler angles the main advantage of the quaternions expression of attitude motion is the avoidance of singular position in numeration procedure. This approach can ensure the spacecraft to track the predetermined attitude motion and realize the attitude maneuver when all dynamical parameters are unknown. The asymptotic stability of the control system was proved by use of Lyapunov direct method. The efficiency of the suggested approach was confirmed by numerical simulation of a maneuver tracking motion of spacecraft.