[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 89
30 · 1
1 · 0.01
(8)
The compensator was tuned in such way that it is reducing dominant time constant
[24]. For system with lead compensator PD the responses of signals and
in a case of excitations , and , which are the same as the above-mentioned,
are presented in figure 14.
As figure 14 presents the control system works excellent in a steady state and in
transients. The change of , and , causes the change of the required angle
but current value of camera rotation is following signal very closely.
There are not overshoots.
The camera head turns continuously in order to set the camera rotation angle
to the set value . This way the camera is all time directed towards the
tracked object.
5 Summary
The paper presents camera head control algorithm for Unmanned Aerial Vehicles.
What is more, the presented solution is complementary for methods based on image
processing. Interestingly, the most important feature of the presented solution
is the use of information from IMU (Inertial Measurement Unit) [27] and GPS
(Global Positioning System). It is significant enrichment of the range of tools and
data which are used. The tracking of the objects, which are located on the ground,
was considered in the paper. It was assumed that image processing algorithms are
used and produce information about location of the object in the picture. UAV
behavior depends on the gusts and rapid changes of the wind. The tracked object
can be lost from the camera field of view in the above-mentioned case. Thus it
was necessary to seek other sources of data - sources different then image
processing system. What was also discussed herein is the case when the object
which is located on flat ground is tracked by the helicopter with the camera. The
presented solution was based on calculation of the object position in the moment
when the object is in the center of the picture. The current camera position, orientation
and the calculated object position were indispensable information for the
control algorithm.
The examples which were presented herein demonstrate a correct behavior of the
camera head control system. The similar thought process could be applied to various
different mobile robots [29] and implemented in their navigation systems [31].
References
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contrast objects. In: Proceedings of the 9th British Machine Vision Conference
(September 1998)
[2] Zhang, S., Karim, M.A.: Automatic target tracking for video annotation. Op.
Eng. 43, 1867–1873 (2004)