基于Gauss伪谱法的临近空间飞行器上升段轨迹优化  

Ascent Phase Trajectory Optimization for Near Space Vehicle Based on Gauss Pseudospectral Method

作　　者：宗群[1] 田栢苓[1] 窦立谦[1] 

机构地区：[1]天津大学电气工程与自动化学院,天津300072

出　　处：《宇航学报》2010年第7期1775-1781,共7页Journal of Astronautics

基　　金：天津市科技计划项目(07FZRJGX03600);国家自然科学基金(60874073)

摘　　要：综合考虑密度变化、声速变化、发动机推力变化及地球引力等因素对飞行轨迹的影响,研究了与实际飞行环境更加相符的临近空间飞行器燃料最优爬升轨迹。针对该问题在气动数据处理和优化求解上存在的困难,提出一种基于Gauss伪谱法(Gauss Pseudospectral Method,GPM)的求解策略。首先,依据气动数据特点,设计拟合模型对气动参数进行高精度拟合;其次,为避免间接法和传统直接法的缺点,将Gauss伪谱法和序贯二次规划(Sequential Quadratic Programming,SQP)相结合,对存在边值及加速度约束的轨迹优化问题进行求解,获得最优飞行轨迹。仿真结果表明,在更为真实的飞行环境下,利用GPM和SQP相结合的方法可在5.83s获得一条精度为10-4～10-6左右的飞行轨迹。Considering the impacts of the changes,such as the density of atmospheric,the speed of sound,the thrust and the earth gravity on flight trajectory,a more realistic near space vehicle ascent minimum fuel-consumption trajectory optimization problem is studied. Aiming at the difficulties of the problem in processing of aerodynamic data as well as optimization solving,a strategy based on the Gauss pseudospectral method is proposed in the paper. Firstly,high-accuracy fitting of aerodynamic parameters is achieved by designing a fitting model according to the characteristics of aerodynamic data. Secondly,to avoid the drawback of indirect methods and traditional direct methods,the combination of Gauss pseudospectral method and the sequential quadratic programming is proposed to solve the trajectory optimization problem with boundary and acceleration constraints. Finally,simulation results illustrate that the optimal trajectory with the accuracy of 10-4～10-6 can be generated within 5.83 s in more realistic environment.

关 键 词：临近空间飞行器 上升段轨迹优化 气动数据 GAUSS伪谱法 序贯二次规划 

分 类 号：V412.44[航空宇航科学与技术—航空宇航推进理论与工程]