飞行控制律评估与确认的μ分析方法

Method based on μ-analysis techniques for the clearance of flight control laws

针对目前应用的网格法在实际使用中的不足,将μ分析方法应用到飞行控制律的评估与确认中.以某型战斗机及为其设计的鲁棒飞行控制律为研究对象,采用相应的稳定性准则,利用线性分式变换形式,考虑各种已知的不确定参数摄动,用μ分析方法实现了对该准则的评估与确认.与传统网格法相比,基于μ分析的方法具有两个明显的优点,一是网格间的点可以得到评估,二是不存在网格法的“维数灾”问题,从而提高了评估的可靠性和效率.

The clearance of modern flight control laws to take into account the many uncertainties has become a great challenge to engineers and researchers, and traditional grid-based methods have gradually been incompetent for this task. A method based on μ-analysis techniques was used to solve this very difficult problem. The aircraft model and flight control law used in the present study is a twin-engine fighter with a robust inverse dynamics estimation（RIDE） controller. Our approach was applied to evaluate a linear stability margin criterion currently widely used by the aerospace industry. Using the linear fractional transformation based uncertainty model developed from the nonlinear aircraft model, and a fictitious multiplicative input uncertainty representation of the criterion, stability robustness analysis results were presented for the flight control law. Compared with traditional grld-based ones, the μ-analysis based method has two obvious advantages which provide more rigorous and efficient in the presence of multiple sources of parametric uncertainty. One is the points between grids can be cleared, the other is there exists no ＂disaster of dimension＂ problems.