一种基于多终端约束的最优制导方法  

An optimal guidance method based on multiple terminal constraints

作　　者：李超兵[1] 王晋麟[1] 李海[1] LI Chaobing WANG Jinlin LI Ha(Beijing Aerospace Automatic Control Institute, Beijing 100854, China)

机构地区：[1]北京航天自动控制研究所,北京100854

出　　处：《中国空间科学技术》2016年第5期9-17,共9页Chinese Space Science and Technology

摘　　要：在航天器主发动机推力大小不可调的前提下,针对5个终端约束下传统迭代制导小角度修正假设的不足,对一种基于多终端约束的最优制导方法进行了研究。在入轨点轨道坐标系下建立航天器的最优控制模型,对横截条件方程组直接进行迭代求解获得制导角度指令,在此基础上,通过对开关机点进行优化以减小未被满足的终端位置约束的影响;进一步,推导了地心惯性系下等效的5个终端约束,并通过引入权重因子来提高制导方程数值求解的精度。标准条件下的仿真结果表明,所提制导方法与传统迭代制导相比,未被满足的终端位置约束精度提高了159.535 5m,而其余5个终端约束几乎不受影响;蒙特卡罗打靶仿真结果表明,所提制导方法对航天器初始位置和速度偏差具有一定的适用性。Since the thrust amplitude of the main engine on spacecraft is unadjustable, a multiple terminal constrain based optimal guidance method was proposed, considering the deficiency of small correction angle assumption of conventional iterative guidance under five terminal constrains. An optimal control model was established in the orbit injection orbital coordinate frame. Transversality equations ware directly solved by iteration to obtain the guidance angle command. The switch on and off instants were then optimized to reduce the influence of unsatisfied terminal constraints. Besides, the five equivalent terminal constraints in the geocentric inertial coordinate frame were derived and appropriate weight factors were adjusted to improve the precision of numerical solving of guidance equations. Simulations on standard conditions demonstrate that the proposed guidance method has increased the precision of unsatisfied terminal constraints by 159.535 5 m, compared with the conventional iterative guidance. The Monte Carlo simulations show the adaptability of the proposed method to the initial bias of the spacecraft position and velocity.

关 键 词：航天器变轨 迭代制导 最优控制 坐标转换 开关机点优化 权重调整 

分 类 号：TP249[自动化与计算机技术—检测技术与自动化装置] V448.22[自动化与计算机技术—控制科学与工程]