带可控臂绳系卫星释放及姿态控制

考虑带可控机械臂绳系卫星的面内运动, 研究其释放阶段的子星位置和姿态控制问题. 系绳释放时, 通过调整机械臂转角实现子星姿态的无动量轮控制. 控制律设计分为两步: 首先, 基于非线性最优控制理论, 研究在状态和控制约束下的子星位置及其姿态控制, 通过二阶Legendre伪谱法求解开环最优控制律; 其次, 以开环解为参考, 基于轨迹跟踪思想设计反馈控制器, 其中反馈控制增益由开环最优控制算法及数值插值确定. 最后通过算例研究验证了该方法的有效性.

DEPLOYMENT AND ATTITUDE CONTROL OF A TETHERED SUBSATELLITE WITH CONTROLLABLE ARM

The paper presents an investigation on the position and attitude control problem concerning the inplane motions of a tethered sub-satellite,the attitude of which is controlled by using a controllable arm instead of momentum-wheel actuation in the phase of tether deployment.There are two main steps in the design of the controller.Firstly,a study accounting for the state-control constraints is presented on the nonlinear optimal control problems of the position and attitude of the sub-satellite,the open-loop solution of which is determined by using the Legendre pseudo-spectral algorithm in the second-order form.Secondly,a feedback control law is derived to track the reference trajectory prescribed by the open-loop control law,and the gains of online feedback control are determined by interpolating a sequence of gain data pre-computed via the algorithm of open-loop optimal control.The case studies in the paper well demonstrate the performance of the proposed strategy.