针对空间绳系机器人对目标逼近过程中的姿态协调控制问题,设计了一种基于可移动系绳点的姿态协调控制机构,利用系绳实现姿态的协调控制。针对该类型空间绳系机器人,进行动力学建模,并对其动力学特性进行了分析。为了克服利用系绳拉力进行姿态协调控制过程中,拉力波动对姿态控制的影响,采用具有较强鲁棒性的滑模变结构方法设计了姿态协调控制器。可移动系绳点的姿态协调控制机构提供空间绳系机器人两个方向的姿态控制力矩,另一个方向的控制力矩通过空间绳系机器人自身提供,从而实现逼近过程中姿态协调控制。仿真结果表明,通过可移动系绳点的姿态协调控制机构,利用系绳拉力可实现空间绳系机器人目标逼近过程中的姿态控制,并且达到节省姿态控制燃料消耗的目的。
The coordinated attitude control of the Tethered Space Robot (TSR) during target approaching phase is studied here. An attitude coordinated control mechanism with a mobile tether attachment point is designed, and orbit and attitude dynamics models of a TSR with this mechanism are established. Given the dynamics characteristics of mobile attachment point, the sliding mode control method is utilized in the design of the attitude coordinated controller, in which the attitude control mechanism and the thrusters provide three axis control torques together. The simulation result shows that the attitude of the TSR during target approaching phase can be controlled by tether tension via this attitude coordinated control mechanism and the fuel consumption is efficiently reduced.