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[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

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220 K. Daniec et al.<br />

The construction and service for unmanned aircraft is fairly expensive and it<br />

should be added that the cameras are usually the most expensive part of the aircraft.<br />

Furthermore, prototyp<strong>in</strong>g autonomous flight algorithms and vision based<br />

algorithms is time consum<strong>in</strong>g and requires multiple tests and a priori assumptions.<br />

In prototyp<strong>in</strong>g the algorithms helpful appear to be a real-world simulators. There<strong>in</strong><br />

can be tested the control algorithms <strong>in</strong>clud<strong>in</strong>g the dynamics of fly<strong>in</strong>g object, GPS<br />

system simulation and among others earth model WGS-84. Us<strong>in</strong>g the simulator<br />

allows to run the tests without fear of destruction of the real object, and what goes<br />

with it, from possible accidents and exposure to the risk of third parties. Us<strong>in</strong>g a<br />

simulation of the real world we are mak<strong>in</strong>g a large f<strong>in</strong>ancial sav<strong>in</strong>gs result<strong>in</strong>g from<br />

no need for rebuild<strong>in</strong>g the model <strong>in</strong> the case of (undesirable) breakdown. We also<br />

save the time that we could spend much more, dur<strong>in</strong>g the design of mechanisms<br />

for autonomous flight. Us<strong>in</strong>g a simulation environment Prepar3D® Lockheed<br />

Mart<strong>in</strong>, we are able to get data from all k<strong>in</strong>ds of sensors and also to control the<br />

fly<strong>in</strong>g object model. This environment has mapped physics, not only <strong>in</strong> the air, but<br />

also on land and <strong>in</strong> the water. Importantly, the simulation allows us to change the<br />

weather, which greatly <strong>in</strong>fluences the dynamics of mov<strong>in</strong>g objects <strong>in</strong> it. The simulation<br />

<strong>in</strong>cludes, for example, build<strong>in</strong>gs and artificial traffic, which can be used to<br />

prototype the vision based algorithms. In addition, it should be mentioned, that<br />

realistic is also a terra<strong>in</strong>, as well as locations of all airports and cities.<br />

Ma<strong>in</strong> contribution of this paper are control algorithms for <strong>UAV</strong> on the set trajectory.<br />

This trajectory can overlap with the exist<strong>in</strong>g highway network, waterways<br />

and air routes. Thanks to this, it is possible to use a video stream from the onboard<br />

virtual camera for prototyp<strong>in</strong>g vision based algorithms.<br />

2 Literature Review<br />

The Control of the unmanned objects based on vision is an active area of research.<br />

In many publications we met with topics devoted just to control of fly<strong>in</strong>g objects<br />

us<strong>in</strong>g a flight simulators. One of them, worth mention<strong>in</strong>g is the work of Eric R.<br />

Mueller [1], which was based on the studies carried out with Hardware-<strong>in</strong>-the-<br />

Loop simulation. Simulation was based there on Matlab/Simul<strong>in</strong>k® mathematic<br />

model, while the control values was calculated by us<strong>in</strong>g LQR controllers [2].<br />

Another important publication is the work of Eric N. Johnson and Sumit'a Mishra<br />

[3], which uses simulation both <strong>in</strong> SIL (Software In the Loop) and HIL (Hardware<br />

In the Loop) and the simulation visualization. In the will of the explanation, the<br />

SIL-loop simulation controls a physical process model (the simulator) us<strong>in</strong>g the<br />

software, which is a model of the regulator, which was run on the same hardware<br />

platform. In the HIL-simulation process is <strong>in</strong>volved a real regulator, which communicates<br />

with the simulator through the appropriate <strong>in</strong>terfaces. In the articles [4]<br />

and [5] the <strong>auth</strong>ors use a simulation environment implemented <strong>in</strong> the "Matlab/Simul<strong>in</strong>k®<br />

6-DOF", and visualization, "FlightGear". The simulator that was<br />

used there is characterized by a greater reality, because it <strong>in</strong>cludes the basic model<br />

of atmospheric, gravity and magnetic field.

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