载人航天器再入的制导与控制

Guidance and Control of Manned Reentry Space Transporter

通过确定阻力参考型将泛函极值转换成参数优化问题,利用过载、动压及加热约束确定参数的解域;再由航程要求和终端制导精度进一步缩小解域;最后以总加热量最小优化得到唯一解,采用比例-积分-微分制导律,给出了确定控制增益系数的途径,得到了一种易于工程实现的求解方法,以美国航天飞机数据为例进行了模拟计算.

In this paper a special design' method for optimal reentry trajectory and guidance of manned spacecraft is presented. This method has the advantage over traditional theoretical optimization. It should be emphasized that with this method the state parameters vary smoothly even during the last stage of the reentry trajectory. The reentry trajectory guided by means of Drag Reference Profile (DRP) is designed through parameter optimization. The flight corridor determined by system and operational constraints is described analytically in the plane of drag acceleration and flight velocity. The DRP must be within this corridor and is adjusted then according to the range and terminal requirements. The PID (proportional, integral and differential) guidance law is used. The optimal feedback gains are calculated through using DRP and optimization. The minimal heat input is taken as the criterion to determine the final DRP. The optimal reentry trajectory is then obtained. Finally, numerical calculations using the data of American Space Shuttle give satisfactory results.