多级航天器在有限推力情况下的最优变轨问题探讨

与航天运载器类似,航天器也可以有单级与多级之分。一个多级航天器是由几个具有动力装置的航天器经串联而成的组合体。本文研究这类航天器的最优变轨问题。多级航天器在有限推力情况下的最优变轨问题,实质上属于多级最优控制问题。本文应用多级最优控制问题的求解原理,讨论有限推力情况下,两级航天器在两共面圆轨道之间的两类最优转移问题,给出了确定最优推力程序和最优转移轨迹的定解方程和定解条件,特别考察了级间分离时刻应满足的条件。本文给出的原理同样适用于非圆形、非共面轨道之间的最优转移问题。

DISCUSSION ON OPTIMAL ORBITAL TRANSFER OF THRUST-LIMITED MULTISTAGE SPACE VEHICLE

Similar to rocket vehicle,space vehicle can be divided intosingle and multistage ones.A multistage space vehicle consists of several spacevehicles with engines(by series-mounting).This paper deals with the opti-mal orbital transfer for this class of space vehicle.The optimal orbital transfer of a thrust-limited multistage space vehiclebelongs essentially to a multistage optimal control problem.Using the solvingprinciple of a multistage optimal control problem,this paper discusses twokinds of the problems of the optimal transfer between two circular coplanerorbits for a thrust-limited two-stage space vehicle,gives the solving equationsand conditions of determining optimum thrust programs and optimum trans-fer orbit for the two kinds of problems.Especially,the conditions to besatisfied at the stage-to-stage separation moment are examined.The concept introduced in this paper is adaptable to the problems of opti-mal transfer between non-circular and non-coplaner orbits.