Quaternion-based Navigation and Control for Small Unmanned Helicopter *

In this paper, the development of a quaternion-based navigation and autonomous control system for a small single-rotor helicopter is described. First, a quaternion-based small attitude sensor and an INS-GPS navigation system are constructed. The performance of the small attitude sensor is shown via a comparison with a commercial attitude sensor that is precise and heavy. A nonlinear attitude controller for a single-rotor helicopter is designed by using quaternion feedback, and a guidance controller is constructed with the attitude control system as an inner loop. Finally, a flight experiment is performed with a small electric helicopter, and the results indicate the effectiveness of the proposed navigation and control system.