基于飞轮的欠驱动航天器姿态控制器设计

在以飞轮作为姿态控制执行机构的航天器中,如果部分飞轮发生故障而使得航天器欠驱动时,姿态控制性能会急剧下降.本文对两个匕轮的刚性航天器,研究了姿态控制问题.在零动量的假设下,利用Backstepping方法,为欠驱动姿态控制系统设计了一个新型的姿态控制器.设计过程分两步进行:首先,根据姿态运动学模型,设计出可使航天器姿态全局渐近稳定的控制角速率;然后,根据姿态动力学模型,得到使航天器姿态全局渐近稳定的控制力矩.该控制器为非连续控制器,可使航天器姿态误差全局一致渐近收敛为零,并使系统具有良好的动态性能.计算机仿真表明,本文所设计出的控制器是可行的.

An attitude controller for under-actuated spacecraft with two flywheels

The spacecraft with flywheels becomes under-actuated and the attitude controllability goes worse when only two flywheels can work.We deal with this problem for a rigid spacecraft with two flywheels.A new controller is designed by using the Backstepping design method,under the assumption of zero momentum for the spacecraft.The design process is in two steps:First,the desired angular velocity is designed to stabilize the attitude of the spacecraft,by considering the kinematics only.Next,the dynamics is combined to give the attitude control torque.The controller is a discontinuous one. It makes the attitude of the under-actuated spacecraft globally asymptotically converge to zero,and the system has a rapid and desirable transient process.Finally,simulation results indicate the feasibility of the controller presented above.