基于μ分析的鲁棒特征结构配置飞行控制律设计

Robust eigenstructure assignment based on μ-analysis applied to flight control law design

针对特征结构配置应用于飞行控制律设计鲁棒性较差的问题,提出了一种新的鲁棒特征结构配置方法.该方法结合参数化特征结构配置与μ分析,把鲁棒特征结构配置问题转化为包含系统全部自由参数的带约束条件的非线性优化问题.根据飞行控制律特点,提出分步优化策略解决鲁棒特征结构配置多变量优化问题,以降低问题复杂度,同时采用等值分布曲线直观描述优化指标随设计参数变化规律.该方法利用系统全部自由度提高系统鲁棒性,并对自由参数施加约束条件以保证标称闭环系统性能.仿真表明该方法能满足一级飞行品质要求,提高系统鲁棒性,减小保守性.

A new robust eigenstructure assignment algorithm was presented to improve the robustness of control law designed by eigenstructure assignment.This algorithm combined parametric eigenstructure assignment with μ-analysis,was based on linear fractional transformation,and then transformed robust eigenstructure assignment problem into a nonlinear constrained minimization problem including all free parameters of the system.In order to reduce the problem complexity,robust eigenstructure assignment with multivariable optimization was divided into two steps with contour graph of robustness index,considering the characteristics of flight control.This algorithm ensures the performance of nominal closed-loop system with parameter constraints,and can improve the robustness with all free parameters of the system and has the advantages of μ-analysis.The simulation results show that this algorithm can satisfy level 1 flying qualities,improve the robustness and reduce the conversation.