[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 in a Picture during Rapid Camera Movements 83
- transfer function for distortion in axis (5)
- transfer function for distortion which results
in helicopter rotation.
(6)
Figure 6 shows camera head control system. The aim of this control system is to
compute required set value for variable. This signal allows to set camera direction
to the object regardless of the helicopter position. The first block computes
the position of the object on the basis of the distance d and camera position. The
next block is Key1 closed for 0 which means the object is in the center
of the camera picture.
Mem block remember current value of computed . Required set camera angle
is calculated on the basis of the camera and object positions. It allows to set camera
direction to the object. The block after the adder is block Key2 which is closed
for 0 which means the object is out of the center of the picture. Transfer
function denotes the dynamics of camera head. It is as follows:
·1
(7)
The first order lag denotes inert properties and integrator denotes the motor.
Fig. 6. Camera head control system
This way we obtain correct measurement of the object position. We measure it
only if the object is in the center of the picture. However, the control signal
changes the camera position only the object is out of the center of the picture.