火星大气进入段侧向预测校正制导律设计

Lateral Predictive Guidance for Mars Atmospheric Entry

火星大气进入段预测校正制导方法通常采用误差走廊来约束侧向运动,该方法只能满足侧向运动的末端约束,而无法实现对侧向运动过程约束的满足。将预测制导的方法引入侧向制导律设计中,该方法无需离线规划误差走廊,而是根据侧向运动中的相关约束,在线计算倾侧角反转时刻,从而同时满足侧向运动的末端约束与过程约束,并能够克服采用误差走廊可能导致的飞行器因频繁反转机动而使燃料过快消耗的问题。仿真结果表明:该侧向预测制导律不仅能满足开伞位置精度,同时也能实现对进入轨迹侧向运动的灵活规划。

The state-of-the-art Mars atmospheric entry predictive guidance method focuses on dealing with the longitudinal motion,while the lateral motion is always regulated by the error threshold with bank angle reversal. Such lateral logic strictly limits the lateral motion. In view of this problem,a lateral predictive guidance method for Mars atmospheric entry is put forward,in which the guidance command is generated on board according to the constraints of lateral motion without planning the error threshold. Such a method can avoid the problem of reversing frequently in the method of planning relevant threshold. Numerical simulation illustrates that the lateral predictive guidance method can satisfy the position accuracy of parachute deployment. At the same time,it can also achieve the design flexibility of entry trajectory lateral motion.