Modeling and Simulation of a Quadrotor using Curve Fitting Method

This study focuses on aerodynamic modeling of a rotor for an AscTec Hummingbird quadrotor used for controls research at the METU Aerospace Engineering Department through the wind tunnel tests and to develop a high fidelity simulation model for the quadrotor. The main factors which determine the movement of a quadrotor are the aerodynamic forces and moments in three axes created by four rotors. Hence, accurate calculation of rotor forces and moments in varying flight conditions are essential to get a precise simulation of the quadrotor. Instead of using analytical models for aerodynamic forces and moments of a rotor derived using blade element and momentum theories, a second order polynomial rotor model has been developed by MATLAB Curve Fitting algorithm. The developed empirical model allows us to accurately predict aerodynamic loads on a quadrotor in various rotor speeds and flight conditions. Thanks to the new method used in this study, the parameters are integrated easiliy into the simulation of the quadrotor in different flight conditions. Besides, an accurate simulation is conducted by taking into account hub force, rolling moment, and body effect which are usually ignored.