基于干扰力矩辨识的高精度非线性姿态控制方法

弹道式航天飞行器末修闭路制导飞行段通常采用具有非线性特性的固定姿控喷管进行姿态跟踪和稳定控制,此时姿态控制精度直接影响闭路制导效果。传统斜线开关线控制方法存在系统性姿态角偏差,导致末修推力方向与待增速度方向始终存在差异,进而影响到飞行器落点精度。提出的基于干扰力矩辨识的高精度非线性姿态控制方法,通过干扰力矩在线辨识,实时设计姿控喷管开关线,将极限环调整至环绕原点,从而提高姿控精度。基于某型飞行器的仿真结果表明,与传统设计方法相比,基于干扰力矩辨识的高精度非线性姿态控制方法可将闭路制导段姿态控制精度提高约90%,减小姿态偏差对闭路制导的影响,飞行器落点精度提高约25%。

High Precision Nonlinear Attitude Control Method Based on Identification of Disturbing Torque

During the terminal correction segment of ballistic vehicle,attitude control nozzle is often used for attitude trackdng and stabilization,thus the accuracy of attitude control system directly affects the fall point accuracy.Because of the disturbing torques,systemic errors exist when using traditional diagonal on-off control method,which will influence the terminal correction of ballistic vehicle.In order to solve this problem,this article proposes a high precision nonlinear attitude control method based on the limit cycle model and disturbing torque identification model.Simulation results illustrate that when using this nonlinear attitude control method,the accuracy of attitude control can improve almost ninety percent and the fall point accuracy can improve almost twenty five percent comparing to traditional method.