交会对接航天器推力分配算法研究

Research on a Thrust Allocation Algorithm of Spacecraft in RVD

如何将期望控制指令动态地分配到冗余配置的推力器系统成为航天器控制算法设计的关键问题之一。针对推力器冗余配置的航天器控制分配问题进行初步探索性研究,提出了一种基于控制分配技术的推力动态分配新方法。首先建立推力分配问题的数学模型,并运用伪逆与线性规划相结合的二次分步优化方法对问题进行求解,且将其应用于以推力器为执行机构的交会航天器轨道与姿态一体化控制问题研究。最后对算法进行开环仿真验证,并采用微小卫星物理仿真平台(MicroSim平台)的推力器配置方案进行交会对接最后接近段的六自由度闭环数学仿真验证。仿真结果表明:所提算法在燃料消耗上优于传统的轨道与姿态单独控制模式。

How to make the expected control directives assigned dynamically to the redundant thruster configuration system is one of the key issues during the desigmnent of spacecraft control algorithm. The paper tended to make a primary exploratory research work about this problem and presented a new method of dynamic thrust allocation algorithm based on the technology of control allocation. Mathematical model about integrated thrust allocation problem was established at first, and then we took two steps of optimization method to solve the problem, the first pseudo-inverse and the second linear programming, which was applied to solve the problem of spacecraft＇ s integrated orbit and attitude control using thrusters as actuators in Rendezvous and Docking （RVD）. At last open-loop simulation was performed to testify the validity of the algorithm, and 6-DOF closed-loop simulation about the last approximation of RVD was performed based on the thruster configuration of Microsim. Simulation results indicate that less fuel is consumed using the algorithm mentioned above compared with traditional control mode.