  A rotorcraft-based unmanned aerial vehicle exhibits more complex properties
compared to its full-size counterparts due to its increased sensitivity to
control inputs and disturbances and higher bandwidth of its dynamics. As an
aerial vehicle with vertical take-off and landing capability, the helicopter
specifically poses a difficult problem of transition between forward flight and
unstable hover and vice versa. The LPV control technique explicitly takes into
account the change in performance due to the real-time parameter variations.
The technique therefore theoretically guarantees the performance and robustness
over the entire operating envelope. In this study, we investigate a new
approach implementing model identification for use in the LPV control
framework. The identification scheme employs recursive least square technique
implemented on the LPV system represented by dynamics of helicopter during a
transition. The airspeed as the scheduling of parameter trajectory is not
assumed to vary slowly. The exclusion of slow parameter change requirement
allows for the application of the algorithm for aggressive maneuvering
capability without the need of expensive computation. The technique is tested
numerically and will be validated in the autonomous flight of a small scale
helicopter.
