Begin with the generalized stability margin and its correlation concepts,clearance criteria and linear fractional transformation(LFT),the μ-analysis method used to clear stability margin of the multivariable flight control system(FCS) is present.

The generalized stability margin and the linear fractional transformation(LFT) are introduced.

The paper constructs the robust flight control systems by using linear fractional transformation (LFT) based on parameters uncertainty and μsynthesis.

The missile linear fractional transformation(LFT) model was established by the graph approach,and the missile s dynamics was separated into certainty part and uncertainty part.

Due to the parameter′s uncertainty in the electro-hydraulic proportional system,a system model with uncertain parameters is built by analyzing the electro-hydraulic model,using the method of linear fractional transformation(LFT) and adopting the multiplying uncertain parameters.

Based on linear matrix inequality (LMI) and linear fractional transformation (LFT),this paper researches on robust H ∞ fault-tolerant controller design of linear uncertain continuous systems in which there are time-varying normbounded parameter uncertainty and actuator failures.

By means of the nonlinear state feedback and coordinates transformation,many uncertain nonlinear systems can be transformed as a linear fractional transformation(LFT) on the generalized plant and the uncertainty.

Generally speaking,Linear Fractional Transformation(LFT) is the most common method for description of uncertain plants.

By transfonnation group, a new integrable method is devoloped, and two conditions to the special Abelian equation is acquired by accurate linear fractional transformation.