An improved method of identification for aero-engine's state variable model

The method for aeroengines' state variable model(SVM)identification was implemented by using the linear relation of the variable of the differential equations,and separating the steady process and transient process to eliminate the steady errors coupled by transient process. Without solving the differential equations or using any iterative methods, the coefficient of the SVM could be acquired simply using matrix operation, so it has a higher computational efficiency than former least square method. And this method might also be combined with other identification method to realize better effect. Finally, to illustrate the validity and accuracy of the proposed method, a small perturbation SVM of some turbo-shaft engine model had been established through it, and the simulation results from the engine's state space model and nonlinear model were compared,and we can draw a conclusion that the SVM got by this method meets the dynamic and static objectives well, though the plant has a severe nonlinearity.