升力式再入侧向制导的无奇异方位误差算法  

Singularity-free Azimuth/Heading Error Algorithm of Lateral Guidance for Lifting Re-entry Vehicle

作　　者：李洪波[1] 肖业伦[1] 

机构地区：[1]北京航空航天大学宇航学院,北京100083

出　　处：《宇航学报》2008年第3期901-906,共6页Journal of Astronautics

摘　　要：升力式再入侧向制导的传统方位误差算法在地球南北极点处有奇异,在极点附近呈现病态;使用该算法的侧向制导律在极点处无法产生制导信号,在极点附近制导信号错乱。根据方位误差的物理意义,结合无奇异的再入飞行器质心运动方程,利用位置和速度三元数,提出了无奇异的方位误差算法。针对某假想的在极区再入的升力式再入飞行器,在固定纵向控制参量的情况下,进行仅检测侧向制导在极区的有效性的再入过程仿真。算例显示,对于同一侧向制导律,使用无奇异算法可避免传统算法在极区存在的奇异性问题。此外,新算法的计算细节无需因地球模型和再入飞行的地域不同而进行调整,与传统算法相比有更好的普适性,适合需要满足全球到达飞行任务要求的制导律使用。The conventional azimuth/heading error algorithm, used by lifting re-entry lateral guidance, has singularities at the North and South Poles and becomes ill behaved in polar neighborhoods. Consequently, the lateral guidance logics using the conventional algorithm fail in making guidance signals at the poles and in making ＇correct＇ guidance signals in polar neighborhoods. To avoid the problems, a singularlty-free azimuth/heading error algorithm is presented by using Position and Velocity Triads, based on the original definition of azimuth/heading error and the singularlty-free re-entry translational equations. For a hypothetical re-entry vehicle operating in Polar Regions, fixing the longitudinal control parameters, re-entry trajectories were simulated only to test the validity of lateral guidance in Polar Regions. The simulation validated the singularity-free algorithm. Two examples showed, with same lateral guidance logic, the new algorithm succeeded in avoiding the singular problems, while the conventional algorithm failed. In addition, the new algorithm is independent of the zone of voyage and the Earth model, is more general than the conventional algorithm, and suits with the guidance for hypersonic global reach vehicles.

关 键 词：飞行动力学 升力式再入 侧向制导 极区 全球到达 

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]