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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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Probabilistic Approach to Plann<strong>in</strong>g Collision Free Path of <strong>UAV</strong> 197<br />

pair , of po<strong>in</strong>ts from the set (12) it is checked if for any po<strong>in</strong>t that lays on<br />

the l<strong>in</strong>e between , the height is lower than $H_0$. If yes, the po<strong>in</strong>t is attributed<br />

with the coord<strong>in</strong>ate Δ and this po<strong>in</strong>t is added to the solution. As<br />

a result of this iterative procedure the f<strong>in</strong>al solution def<strong>in</strong>ed <strong>in</strong> 3D space is determ<strong>in</strong>ed:<br />

, ,…, , (13)<br />

where each element , 1,2,… def<strong>in</strong>es a po<strong>in</strong>t <strong>in</strong> 3D space that has coord<strong>in</strong>ates<br />

( , , ).<br />

2.7 Indices of the Quality of Generated Solution<br />

Here we <strong>in</strong>troduce three <strong>in</strong>dices for rat<strong>in</strong>g founded solution. It is reasonable to<br />

assume that <strong>UAV</strong> energy consumption <strong>in</strong>creases with the <strong>in</strong>cease of trajectory. It<br />

also <strong>in</strong>creases for frequent changes of the altitude of <strong>UAV</strong> dur<strong>in</strong>g the mission. The<br />

follow<strong>in</strong>g are three proposed <strong>in</strong>dices:<br />

• - is the length of the path <strong>in</strong> 2D space.<br />

• - is the length of the path <strong>in</strong> 3D space.<br />

• - is the sum of changes of absolute values of <strong>UAV</strong> altitudes.<br />

3 Simulations<br />

In this chapter we present simulation results. The follow<strong>in</strong>g are the ma<strong>in</strong> assumptions<br />

that were followed dur<strong>in</strong>g the simulation process:<br />

• The reference altitude (priory stated height ) of <strong>UAV</strong> is set to = 1500 m,<br />

1600 m and 1700 m.<br />

• The m<strong>in</strong>imal distance between <strong>UAV</strong> and the terra<strong>in</strong> surface ('safety marg<strong>in</strong>')<br />

is set to = 50 m.<br />

• The number of randomly generated po<strong>in</strong>ts is set to = 30.<br />

Below three sets of figures are shown for different altitudes. For readers convenience<br />

<strong>in</strong> these figures the state border l<strong>in</strong>es are represented by canyons. Figures 4<br />

and 5 are for = 1500 m, figures 6 and 7 for = 1600 m, figures 8 and 9 for <br />

= 1700 m.<br />

In the follow<strong>in</strong>g tables the <strong>in</strong>dices values are presented. For each altitude 5 solutions<br />

were generated. Table 1 shows the values of <strong>in</strong>dices for = 1500 m,<br />

table 2 is for = 1600 m and f<strong>in</strong>ally, table 3 is for = 1700 m. It is observed,<br />

that the values of <strong>in</strong>dices are decreas<strong>in</strong>g with <strong>in</strong>crease of .

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