卫星天线展开臂的随动吊挂重力补偿系统设计

Design of Tracking Suspension Gravity Compensation System for Satellite Antenna Deployable Manipulator

为了给卫星天线展开臂的展开特性测试提供真实的零重力地面仿真环境,设计了卫星天线随动吊挂重力补偿系统.首先设计了与卫星天线展开臂结构相同的3轴随动吊挂机械臂,对卫星天线展开臂进行位置跟随,并通过有限元方法分析其受载时的位置精度:然后根据导纳控制方法设计出随动机械臂的力跟随控制器,采用基于位置内环的PD(比例-微分)力控制策略设计出拉力系统对吊索拉力的控制算法;最后通过实验考核了随动吊挂机械臂各关节对在轨运行模式下的天线展开臂相应关节的位置跟随性能和重力平衡补偿.实验结果表明各轴位置跟随误差均不超过±0.03°,稳定运行时吊索张力控制偏差均小于1.2%F.S.(全量程),在天线展开机械臂的展开过程中实现了较高精度的位置跟随和重力补偿,满足天线展开测试要求.

A relatively real zero gravity ground simulation environment is created to test the deployment characteristics of the deployable manipulator of satellite antenna. A tracking suspension gravity compensation system of the satelite antenna is designed. Firstly, a three-axis tracking suspension manipulator is designed with the same structure as the antenna deployable manipulator, to track the position of deployable manipulator of satellite antenna. The under-load position accuracy is analyzed by the finite element method. Then, a force tracking controller of the manipulator is designed according to the admittance control method, and a PD(proportional-differential) force control strategy based on position inner loop is adopted to design the tension control algorithm of the tension system to the sling. Finally, the position tracking performances of the joints of the tracking suspension manipulator to the corresponding joints of the antenna deployable manipulator in orbit operation mode are verified by experiments, as well as the precision of gravity compensation. Experimental results show that the tracking error of each axis is less than ±0.03°. During the stable operation, the tension control deviation of the sling is within 1.2%F.S.(full scale). High-precision position tracking and gravity compensation are achieved during the unfolding process of the antenna deployable manipulator, which meets the requirements of antenna deployment test.