Analysis of the Autorotation Maneuver in Small-Scale Helicopters and Application for Emergency Landing
In this chapter, we derive linear and nonlinear models of a helicopter autorotation maneuver focusing on main rotor revolutions and descent rate dynamics. The nonlinear model for descent rate dynamics is derived by combining blade element theory (BET) with an induced velocity linear approximation proposed in this chapter. The linear model is derived by implementing a neural network optimization method based on the experimental data. The derived nonlinear and linear models are verified by comparing the simulated data of the model with experimental data. We also perform a preliminary experiment on autorotation landing with a simple PI controller. Rotor revolutions and descent rates are found to be efficiently controlled by the designed controller.