System Identification of Small-Size Unmanned Helicopter Dynamics

Flight testing of a fully-instrumented model-scale unmanned helicopter (Yamaha R-50 with 10ft. diameter rotor) was conducted for the purpose of dynamic model identification. This paper describes the application of CIFER® system identification techniques, which have been developed for full size helicopters, to this aircraft. An accurate, high-bandwidth, linear state-space model was derived for the hover condition. The model structure includes the explicit representation of regressive rotor-flap dynamics, rigid-body fuselage dynamics, and the yaw damper. The R-50 configuration and identified dynamics are compared with those of a dynamically scaled UH-1H. The identified model shows excellent predictive capability and is well suited for flight control design and simulation applications.