基于非线性干扰观测器的空天飞行器轨迹线性化控制

研究一种新的空天飞行器基于非线性干扰观测器的轨迹线性化飞行控制方案。轨迹线性化控制是一种新颖有效的非线性跟踪和解耦控制方法,但空天飞行器飞行过程中存在的建模误差和外界干扰等不确定因素将导致其性能下降甚至失效。为了满足空天飞行器高精度高稳定控制的要求,本文利用非线性干扰观测器对系统中存在的不确定进行估计,其输出用以设计新的补偿控制律,从而使当前轨迹线性化方法的控制性能得到改善。最后利用该方案设计出空天飞行器飞行控制系统,通过高超声速飞行条件下的仿真,验证了该方法的有效性。

Nonlinear Disturbance Observer-Enhanced Trajectory Linearization Control for Aerospace Vehicle

A novel nonlinear disturbance observer-enhanced trajectory linearization control(TLC) structure is applied to an aerospace vehicle(ASV). The flight control of ASV poses several challenges due to its large attitude maneuvers and complicated flight conditions.TLC is a promising nonlinear tracking and decoupling control method.However,the investigation shows that it may exhibit poor performance when uncertainties exist and turn large.Therefore,the requirement for high performance and strong robustness cannot be satisfied by the current TLC method.An improved trajectory linearization control structure is developed based on the nonlinear disturbance observer(NDO) technique.NDO is used to estimate the external disturbances and internal unmodeled dynamics,and then its output is integrated with TLC.The proposed method is used to design the flight control system of ASV,and simulation results show that the method has excellent performence and strong robustness.