| dc.description.abstract | The helicopter is a Multiple-Input Multiple-Output (MIMO) system with
highly coupled characteristics, which increases the complexity of the
system dynamics.
In addition, the system dynamics of the helicopter are unstable,
referring to its tendency to deviate from an equilibrium when
disturbed.
Despite the complexity in its modelling and control, the benefit of
using a helicopter for unmanned, autonomous applications can be
tremendous.
One particular application that motivates this research is the
use of an unmanned small-scale helicopter in an autonomous
survey mission over an area struck by disaster, such as an earthquake.
The work presented in this thesis provides a framework for utilizing
a platform system for research and development of small-scale helicopter
systems.
A platform system enables testing and analysis to be performed indoor in
a controlled environment.
This can provide a more convenient mean for helicopter research since the
system is not affected by environmental elements, such as wind, rain or
snow condition.
However, the presence of the platform linkages poses challenges
for analysis and controller design as it alters the helicopter system
flight dynamics.
Through a six degree-of-freedom (6 DOF) platform model derived in this
research, the criteria for matching the trim conditions between the
platform system and a stand alone helicopter have been identified.
With the matched trim conditions, linearization is applied to perform
analysis on the effects that the platform has on the system dynamics.
The results of the analysis provide insights into both the limitations
and benefits of utilizing the platform system for helicopter research.
Finally, a Virtual Joint Control scheme is proposed as an unified control
strategy for both the platform and the stand alone helicopter systems.
Having a consistent control scheme between the two systems allows for
comparisons between simulation and experimental results for the two systems
to be made more readily.
Furthermore, the Virtual Joint Control scheme represents a novel
flight control strategy for stand alone helicopter systems. | en |
