IV. FLIGHT CONTROLLERS
A. Position Controllers
In order to develop flight controllers, we will follow the
approach detailed in [3]. A path, P ∈ NxR3 is generated by
N waypoints xdi
. Let the desired flight speeds of the vehicle
between two consecutive waypoints i and i+1 be vdi
. For
each path segment Pi, the vehicle travels along the subpath
vector that combines xdi
and xd
i+1. A unit tangent vector ti
and a unit normal vector ni along and perpendicular to the
subpath vector are defined. Let x(t) be the current position
of the vehicle measured from GPS. The cross track error ect
and its derivative, and along track error rate ˙ eat are defined
as