To estimate the component performance parameters of early deteriorated areoengine

a linear parameter varying(LPV)filter was given for LPV model of a turbofan engine.Based on conceptions of affined parameter-dependent quadratic Lyapunov function and affined quadratic stability

the filter design method was converted into a normal linear matrix inequalities(LMI)constrained convex optimization by introducing the lemma of multiconvexity.Also the difficulties in solving the optimization problem with parameterized linear matrix inequalities(PLMI)constraint were avoided.Besides the convenience of filter gain scheduling

the accuracy and robustness of the filter were validated by simulation on parameter estimation for the early-deteriorated turbofan engine.