System Identification Modeling of a Model-Scale Helicopter

Abstract: Development of a reliable high-performance helicopter-based unmanned aerial vehicle (UAV) requires an accurate and practical model of the vehicle dynamics. This report describes the process and results of the dynamic modeling of a model-scale unmanned helicopter (Yamaha R-50 with 10 ft rotor diameter) using system identification. A complete dynamic model was derived for both hover and cruise flight conditions. In addition to standard helicopter flight characteristics, the model explicitly accounts for the stabilizer bar, which has a strong influence on the flight dynamics and is widely used in model-scale helicopters. The accuracy of the developed model is verified by the comparison between predicted and actual responses from the model and the flight experiments (in both frequency and time domains), and between key identified parameters and their theoretical values. Scaling of the main characteristics of the R-50 modelscale helicopter with respect to those of a UH-1H full-size helicopter was performed to determine how the size influences the flight dynamics of helicopters. System Identification Modeling of a Model-Scale Helicopter