Abstract:
This paper presents attitude control using the unit
quaternion. Specifically, the orientation of a maneuvering fixed
wing UAV is investigated through set point tracking. Two
formulations are explored; the first, through quaternion error
dynamics and the second, through quaternion logarithm. Both
methods apply appropriate Lyapunov functions for the design
and analysis of the closed stability of the control laws. The error
dynamics are deduced from composite rotations between
different frames of the UAV. Through the error dynamics, the
orientation of the UAV’s wind frame is aligned to a desired
orientation. Using this procedure, the desired equilibrium
points of the closed system are guaranteed to converge and are
asymptotically stable. The formulation and implementation of
these two methods is simple and intuitive, and through
simulations, their successful use and effectiveness is shown.
