System Identification Modeling and Flight Characteristics Analysis of Miniature Coaxial Helicopter

Abstract

This paper describes the identification modeling and analysis of a miniature coaxial helicopter. The first part of the paper focuses on the development of the parameterized model with an emphasis on the coaxial rotor configuration. The model explicitly accounts for the dynamics of the lower rotor and uses an implicit lumped parameter model for the upper rotor and stabilizer bar. The parameterized model was identified using frequency domain system identification. The flight data collection experiments were performed in an indoor flight-test facility built around a commercial vision-based tracking system. The second part of the paper focuses on the verification of the model's accuracy, the consistency of the identified parameters, and the analysis of the flight dynamics. The accuracy was verified by comparing model-predicted responses with flight experimental responses. The identified parameters and model's physical consistency were examined using experiments in which specific aspects of the dynamics were isolated. For example, we used video images from a high-speed camera to verify the rotor and stabilizer bar time constants. Finally, the identified derivatives were verified based on first principles to demonstrate that the derivatives are physically meaningful.