32 lines
1.5 KiB
TeX
32 lines
1.5 KiB
TeX
\subsection{Transition}
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To enhance the quality of the proposal distribution, the transition step is
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based on a \SI{20}{\centimeter}-gridded graph $G = (V,E)$
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with vertices $v_i \in V$ and undirected edges $e_{i,j} \in E$
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derived from the buildings floorplan. This ensures that only valid
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movements can be sampled from the previous state.%
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\todo{wenn platz dann bild?}
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The graph is built once and offline using the floorplan created by our editor.
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Besides realistic stairwells, additional semantic information (e.g. doors)
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can be included. Hereafter, the built graph is transmitted to the smartphone
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and is used during the online phase.
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If the pedestrian's destination is know beforehand, this information can
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be included as prior knowledge into the transition step. A shortest-path
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calculation imposes additional constraints to the transition by favouring
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movements that approach the desired destination (pedestrian sticking to the shortest path)
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over movements that depart from the destination.
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To ensure that the calculated shortest path is realistic (resembled human walking paths)
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each node within the graph contains a weight, denoting the likelyhood for being visited
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by the pedestrian. Using this approach, nodes near to walls receive a lower likelyhood.
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During the path-calculation this importance is used to artificially increase/decrease the
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weight $\delta(\mEdgeAB)$ between two nodes. This ensures that the resulting path is
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farther away from obstacles and looks much more realistic
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\todo{wenn platz dann bild?}
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