一种高超声速飞行器的再入鲁棒输出反馈控制

A Robust Output Feedback Control Method for Reentry Hypersonic Vehicle

高超声速飞行器X-38在再入过程中存在快时变、强非线性耦合、不确定性、多干扰等特性。针对此问题,提出了一种鲁棒反馈线性化技术,对不确定再入动力学系统进行非线性解耦,建立了范数有界的不确定线性系统。对解耦后的不确定系统模型设计动态高增益观测器重构系统的不可观测状态,有效处理系统中的非线性项和不确定性;设计非光滑反馈控制器,实现系统输出的设定精度跟踪,避免通过复杂的计算估计不确定边界来设计鲁棒控制器。仿真结果表明,鲁棒反馈线性化和非光滑控制有效保证了闭环系统的稳定性,抑制了再入不确定性对控制精度的影响。

Hypersonic vehicle X- 38 has strong nonlinear time-varying coupling, uncertainty, many disturbance characteristics in re-entry phase. Aiming at this problem, a robust feedback linearization of uncertain nonlinear decoupling system was established, and the norm bounded uncertain linear system was established. The dynamic high gain observer was designed for decoupling uncertain systems,and the nonlinear term and uncertainty were dealt with effectively. The nonsmooth feedback controller was designed,and the tracking of system output with given accuracy was realized, and uncertainty estimation through the calculation of complex boundary was avoided to design robust controller. The simulation results show that the robust feedback linearization and nonsmooth control effectively guarantee the stability of the closed-loop system and inhibit the reentry uncertainty influence on control precision.