基于最优推力锥的级联推力分配算法  

A Cascaded Thruster Allocation Algorithm Based on Optimal Thruster Cone

作　　者：朱孟萍[1] 徐世杰[1] 

机构地区：[1]北京航空航天大学宇航学院,北京100191

出　　处：《航天控制》2012年第5期48-54,共7页Aerospace Control

基　　金：国家自然科学基金资助项目(10902003)

摘　　要：推力分配是推力系统冗余配置时航天器姿态控制系统的必备组成单元。针对传统直接搜索法以及单纯形法在分配过程中在线计算量大、工程实现较难的不足,提出了一种基于最优推力锥的级联分配方法。该算法首先进行无约束分配,搜索出实现目标控制量的准最优推力锥,然后用推力器喷气时间上限对无约束问题的最优推力组合进行饱和处理,更新推力器喷气时间上限,计算当前推力组合的控制误差,并作为下一步的目标控制量,更新推力锥,重复迭代,直至控制误差为0或当前目标量的可行锥不存在。文中以空间站核心舱为例进行了仿真,结果显示:与传统单纯形法相比,该方法能在保持计算量优势的前提下,在目标量可实现时能优化推力组合,精确实现目标量;目标量不可实现时,能在可达集内最大限度地实现目标控制量,充分利用了推力系统的控制能力。The thrust allocation is a necessary component of the attitude control system for spacecrafts with redundant thrusters. A thrust allocation algorithm for over actuated spacecraft based on cascaded optimiza- tion of feasible thruster cones is proposed to reduce the tremendous online computational load associated with the conventional direct allocation approach and the simplex method. A quasi-optimal thruster cone for the unconstrained allocation problem is firstly determined. Then the maximum thruster open time is used to han- dle the saturation as well as to update thrust upper bounds. The control error is calculated for current selec- tion and new thrusters are selected to update the optimal feasible cone. The above cycle is repeated until the control error finally comes to zero or no feasible thrusters are available. An illustrative example based on the core module of the space station is provided to verify the effectiveness and correctness of the proposed method. The situations when target control is attainable as well as not attainable are testified. The algorithm demon- strates excellent allocation performance and favorable computational requirement compared with the simplex algorithm.

关 键 词：推力分配 航天器 最优推力锥 级联分配 

分 类 号：V448.22[航空宇航科学与技术—飞行器设计]