减速板故障下的RLV末端区域能量管理算法设计

Design of Terminal Area Energy Management Algorithm for RLV with Airbrake Failure

针对可重复使用运载器(RLV)在末端区域能量管理阶段可能存在减速板故障而无法精确控制速度大小,导致无法稳定到达着陆窗口的问题,提出一种考虑减速板故障下的在线RLV末端区域能量管理算法。首先给出减速板卡死故障下的飞行器运动模型,并分析其对飞行器运动产生的影响。然后,在能量走廊内设计纵向标称轨迹,结合飞行能力,设计有限时间轨迹跟踪控制器跟踪地面侧向几何轨迹。最后,分析动压剖面与飞行距离之间的关系,提出减速板卡死故障下的在线修正动压剖面算法,将传统的动压剖面四参数求解简化为单参数更新问题,避免动压剖面的迭代,简化计算流程。仿真结果表明,所设计的算法在减速板故障且存在气动不确定性时,能够顺利到达自主着陆窗口,具有鲁棒性。

Aiming at the problem that a reusable launch vehicle(RLV)may have airbrake failure during the terminal area energy management phase and cannot accurately control the speed,which may lead to a failure to reach the landing window steadily,an on-line RLV terminal area energy management algorithm considering the failure of the airbrake is proposed.Firstly,the motion model of the vehicle under the condition that the airbrake is stuck is established,and the influence on the vehicle motion is also analyzed.Secondly,the longitudinal nominal trajectory of the vehicle is designed based on the energy corridor method.In combination with the flight capability,a finite-time convergence trajectory tracking controller is designed to track the ground geometric trajectory.Then,the relationship between the dynamic pressure profile and the flight distance is deduced.The traditional four-parameter solution of the dynamic pressure profile is simplified to a single parameter update problem.An on-line modified dynamic pressure profile algorithm under the condition that the airbrake is stuck is proposed to avoid the iteration of the dynamic pressure profile.Finally,the simulation verification shows that the RLV can reach the autonomous landing window smoothly when the airbrake is faulty and with aerodynamic uncertainty,which is robust.