Practical Nonlinear Flight Dynamic Modeling for Multirotor Aircraft

High-fidelity yet compact nonlinear flight dynamic models for multirotor aircraft are derived from blade-element and momentum theory for use in control, estimation, and efficient simulation. The aim is to obtain models that are valid over a wide range of flight conditions and identifiable from flight data. Individual rotor force and moment models, along with airframe aerodynamics and motor inertial effects, are incorporated into a quasi-steady, nonlinear model for generic multirotor aircraft. A simulation study is conducted in which the derived model is used to inform the design of statistically principled experiments that facilitate accurate model identification. The relative importance of model parameters is evaluated using a high-fidelity simulation constructed from wind tunnel data. This process informs the selection and estimation of model parameters, which are then used to quantify the contribution of model terms across common flight conditions.