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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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Prototyp<strong>in</strong>g the Autonomous<br />

Flight Algorithms Us<strong>in</strong>g the Prepar3D® Simulator 223<br />

4 Fly<strong>in</strong>g Model Description<br />

Fly<strong>in</strong>g object model should receive control data and returns the sensory variables.<br />

Another example of the Prepar3D® functionalities is read<strong>in</strong>g the variables from<br />

the simulation environment. Be<strong>in</strong>g used by us data returned by the virtual sensors<br />

from the simulator are as follows:<br />

• LLA geodetic position: latitude (), longitude (), altitude above sea-level (),<br />

• object orientation: roll (rotation around the axis,α), pitch (rotation around the<br />

axis,β) and yaw (rotation around the axis,),<br />

• airspeed (.<br />

The third, and the mostly<br />

useful functionality, which is used, is controll<strong>in</strong>g the<br />

aircraft. To control an object <strong>in</strong> the Prepar3D® environment algorithm uses four<br />

variables: rudder, elevator, ailerons and throttle. The ma<strong>in</strong> airplane axes and the<br />

three ma<strong>in</strong> control elements are illustrated <strong>in</strong> the fig. 4.<br />

Fig. 4. Airplane model with axes description<br />

5 Controllers Cascade<br />

Object control and stabilization is based on PI controllers.[12] Algorithm uses the<br />

discrete PI controller, thatt is described by formula (1).<br />

<br />

( 1)<br />

2<br />

where: – controller output at the moment , – error, controller <strong>in</strong>put at the<br />

moment , – controller proportional ga<strong>in</strong>, – controller <strong>in</strong>tegrator ga<strong>in</strong>, –<br />

delay time.

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