空客A320飞机横航向控制律采用特征结构配置方法计算闭环增益,实现了期望特征值的配置及横航向关键参数之间的解耦。基于A320横航向控制律架构,提出使用线性二次型( Linear Quadratic,简称LQ)方法,对闭环增益进行重新设计。首先根据期望的特征值引入关键参数的频域整形环节,而后通过调整二次型性能指标加权矩阵实现期望特征值的逼近及关键参数之间的解耦,并求得闭环反馈增益,最后在特征结构、稳定裕度和横航向解耦效果方面与空客设计结果作了对比分析。仿真结果表明,LQ设计可获得与特征结构配置设计相近的结果,即得到接近期望值的特征值,并实现关键变量的解耦,同时保证了闭环稳定裕度。
Eigenstructure assignment ( EA) technique was utilized to design Airbus A320 lateral and directional control law, which provides advantages regarding to desired closed loop eigenvalue assignment and critical variables decoupling. Using Linear Quadratic ( LQ) technique,this paper redesigns close loop gains based on the structure of A320 control law. Firstly, specific frequency shaping functions are incorporated with critical parameters based on the desired eigenvalue. Then performance index are adjusted to approach the desired eigenvalue and decouple the critical variables, and all gains are obtained simultaneously. Finally, the resulted eigenstructure, stability margins and decoupling performance between two axes critical parameters are compared with Airbus design which is based on EA technique. Analysis results show that a similar set of gains and closed loop performance can be obtained with LQ technique, i. e. the resulted eigenvalues are close to the designed ones, critica
