Global Model Identification for a Coaxial Helicopter

In this paper, the Blade Element Momentum Theory (BEMT) hast been applied to setup a nonlinear model structure for a coaxial helicopter with a maximum take-off weight (MTOW) of 600kg. The model includes unknown aerodynamic parameters, which are estimated using flight test data. An extensive flight test campaign, with a fully instrumented CoAx 600 helicopter has been carried out to generate the required flight test data for parameter estimation. In this study, we use the maneuvers performed in the vicinity of the hover flight condition for system identification. The nonlinear model can be trimmed and linearized for the analysis of the system dynamics and control design. This has been done for one trim point in the study and the corresponding pole plan has been provided.