A nonlinear model and control of a small-scale helicopter near hovering are investigated. Aiming at the characteristics of the model helicopter, the stabilizer bar dynamics is studied, and the tail rotor with the electronic gyro is discussed in detail. In addition, the main rotor inflow dynamics is modeled basing on the three-state nonlinear Pitt/Peters model. Then, a simplified nonlinear model is proposed for system identification and controller design. It is proved that the attitude-heave subsystem can be linearized by the dynamic feedback linearization technique. So, we conclude that the full nonlinear model can also be feedback linearized.
['Baoquan Song', 'Caizhi Fan', 'Yun-Hui Liu', 'James K. Mills', 'Xuanping Cai']
Nonlinear system and control of the model-scale helicopter