模糊变结构在可重复使用运载器再入轨迹跟踪上的应用

Entry Trajectory Tracking of RLV Based on Fuzzy Variable Structure Control

为了减小可重复使用运载器(RLV)轨迹跟踪对气动参数及初始状态的依赖性,克服鲁棒性差的问题,在纵向跟踪制导方面,提出一种基于模糊变结构的轨迹跟踪方法。在侧向轨迹控制方面,提出了一种快速收敛的在线规划倾侧角反向时机的方法。仿真结果表明:采用模糊变结构的纵向跟踪控制方法,在存在较大初始状态误差及气动参数摄动的情况下,能较好地实现对标准轨迹的稳定跟踪,具有较强的鲁棒性;采用所设计的侧向制导方法可以实现反向点的在线规划,有效地提高了侧向制导的精度。

To reduce the dependence of trajectory tracking of reusable launch vehicle（ RLV） on the aerodynamic parameters and initial conditions,and improve the robustness of traditional control method,a new entry trajectory tracking method based on the fuzzy variable structure is proposed from the perspective of longitudinal tracking guidance. Also,a method of on-line planning the point of the bank angle reversal is designed in the aspect of lateral trajectory control. The simulation results show that the longitudinal tracking control method which is based on the fuzzy variable structure can track the designed trajectory perfectly and stably,and has strong robustness in the condition of big initial state error and aerodynamic coefficient error. The online searching of the bank angle reversal point can be realized by using the proposed lateral guidance method,which can also improve the lateral guidance accuracy effectively.