QFT/μ控制器设计法及其在飞行器控制中的应用

Combined QFT/μ Controller Design Method and Its Application in Aircraft Control

针对具有大的不确定性和强非线性性的被控对象，提出了将定量反馈理论QFT与μ-综合法相结合的控制器设计算法。应用动态逆方法处理对象非线性不确定性，基于H—infinity优化方法设计初始控制器，当μ-综合对闭环权函数进行调整难以有效改进控制品质时，依据开环性能指标边界采用QFT方法对初始控制器进行调整，显示出QFT开环调整具有透明性和频段剪裁性。针对具有复杂非线性特性的F-16攻角控制问题，在空速变化50～150m／s、气动数据变化±20％的范围内，实现对攻角的大范围精确控制。与基本QFT控制器相比，仿真结果表明所设计系统具有优良的响应特性。

A combined QFT/μ controller design method for the plant with uncertainty and high nonlinearity is proposed in this paper. A dynamic inversion （DI） method is used to treat plant＇ s nonlinear uncertainty, and then a method of incorporating QFT （Quantitative feedback theory） with μ technique is developed. Based on the/μ-synthesis, an initial controller is given. When the controller quality can not be improved effectively by tuning closed-loop weighting function, QFT is used to shape an open-loop transfer function according to the performance index bounds. The shaping has transparency in Nichols Chart and tailor-characteristic on special frequencies. In the light of angle of attack （AOA） control of F-16 with complicated and nonlinear features, the designed control law demonstrates perfect performance by following AOA commands at flight speeds raging from 53 to 150m/s. Robustness is verified by ±20% variations in pitching moment derivatives. The simulation results show that the proposed method has perfect responses compared with an original controller.