[Studies in Computational Intelligence 481] Artur Babiarz, Robert Bieda, Karol Jędrasiak, Aleksander Nawrat (auth.), Aleksander Nawrat, Zygmunt Kuś (eds.) - Vision Based Systemsfor UAV Applications (2013, Sprin

Object Tracking for Rapid Camera Movements in 3D Space 59
It is assumed that connection between the helicopter and camera is rigid therefore
there are not any dynamic relationships between the location and orientation of the
camera and the location and orientation of the helicopter. As a consequence, the
camera head control algorithm is based on fundamental geometrical relationships
between camera and tracked object locations. Similarly, as it was presented in [25]
the current object position is calculated only in the moment when pattern recognition
algorithms give information that the object is in the picture. It allows to direct
the camera to the tracked object immediately after distortion occurrence which
turns the camera in an incorrect direction (orientation measured by IMU [28]).
Fig.1 presents the examined 3D scene.
Fig. 1. The scheme of a camera and helicopter in 3D space
Fig.2 presents notations and the range of camera rotation angles in an (x, y)
plane view.
As it is shown in figure 2 it is assumed that an x axis direction is a reference direction
for determining the camera rotation angle in an (x, y) plane.
For the clockwise rotation direction we assume that 0 within the range 0 to
-180 degrees. For the counter-clockwise rotation direction we assume that 0
within the range 0 to 180 degrees. Conclusively, the aforementioned description of
a camera rotation angle defines the camera rotation in a horizontal plane around
the circle for the complete range of the camera rotation. Figure 3 presents notations
and the range of camera rotation angles on a projection on a vertical
plane .