Method to identify the multimode linear model of aeroengine based on nonlinear response

The dynamic process of aeroengine is nonlinear. The linear model cannot be identified from the response directly. So, the method was studied to identify the linear model in multimode based on nonlinear response. The nonlinear dynamic model of aeroengine was described as the Volterra series model. An adaptive arithmetic was carried out to identify the Volterra series model robustly. Cutting off the model's high rank, the linear pulse response model of engine would be built. Then it can be converted into other linear dynamic models. It was applied in a turbofan engine through the simulation. The linear models of some standard states were found. According to the contrast, it is evident that the model is accurate. It can be used to identify the linear model in multimode based on the actual flight data.