滑翔再入飞行器横侧向耦合姿态控制策略

针对气动舵面仅为两片体襟翼的欠驱动构型可重复使用运载器(RLV)再入过程中的强耦合现象,提出一种基于此类布局飞行器耦合特性的横侧向控制策略。在分析惯性耦合、运动耦合和稳定性耦合的产生机理与规避方式的基础上,计算标称轨迹下的急滚稳定边界并将倾侧角指令速率限制在此边界内以稳定惯性耦合;针对现有的荷兰滚模态预测式不适用于此布局飞行器的问题推导出一种新的荷兰滚运动预判方法,并根据预判结果设计控制增益。最终得到低动压下体襟翼-反作用力控制系统(RCS)复合控制策略和高动压下体襟翼单独作用的横侧向耦合控制策略。六自由度(6-DOF)仿真结果表明该控制策略能很好地跟踪制导指令并且能最大限度利用气动舵面以减少RCS燃料的消耗。

Gliding reentry vehicle lateral/directional coupling attitude control strategy

A lateral/directional coupling control strategy based on the analysis of coupling characteristics was proposed for a class of under-actuated reusable launch vehicle (RLV) with only two body flaps and strongly coupling phenomena. Several common coupling mechanisms and evasion modes were described, including the inertial coupling, the motion coupling, the Dutch coupling and the control coupling. A rapid roll stability boundary was calculated along a nominal trajectory to limit the angular rate of bank angle command, and aiming at the problem that the existing Dutch-roll forecast formula is not suitable for this aircraft, a criterion of the Dutch-roll motion stabilization was proposed in order to adjust the controller gain in different situations. Based on the analysis of the coupling characteristics, a RLV longitudinal and lateral/directional motion control strategy was designed: elevators were used to trim and control on the longitudinal channel; body flaps and reaction control system (RCS) were used to hybrid control on the lateral/direction channel at low dynamic pressure and at high dynamic pressure body flaps can work alone. The 6 degree of freedom (6-DOF) numerical simulation results have demonstrated the control strategy proposed can track the guidance command well and maximize the using of aerodynamic actuators to reduce the consumption of RCS fuel.