This paper proposes a systematic modeling approach of rotor-driving dynamics for small unmanned aerial vehicles (UAVs) based on system identification and first principle-based methods. Both steady state response analyses and frequency-domain identifications are conducted for the rotor, and Comprehensive Identification from Frequency Responses (CIFER) software is mainly utilized for the frequency-domain analysis. Moreover, a novel semi-empirical model integrating the rotor and the electrical speed controller is presented and validated. The demonstrated results and model are promising in UAV dynamics and control applications.
