From 3cebfb8839cdb040e240de61ff19ca4b5acf50d7 Mon Sep 17 00:00:00 2001 From: toni Date: Wed, 13 Jun 2018 18:31:00 +0200 Subject: [PATCH] experimante weiter gemacht --- tex/chapters/estimation.tex | 1 + tex/chapters/eval.tex | 1 - tex/chapters/experiments.tex | 92 +++++++++++++++++++++++++++++++++++- tex/egbib.bib | 11 +++++ 4 files changed, 103 insertions(+), 2 deletions(-) diff --git a/tex/chapters/estimation.tex b/tex/chapters/estimation.tex index 4b9c950..23530ec 100644 --- a/tex/chapters/estimation.tex +++ b/tex/chapters/estimation.tex @@ -1,4 +1,5 @@ \subsection{State Estimation} +\label{sec:estimation} 1/2 bis 3/4 Seite diff --git a/tex/chapters/eval.tex b/tex/chapters/eval.tex index 9435fc6..c7d1284 100644 --- a/tex/chapters/eval.tex +++ b/tex/chapters/eval.tex @@ -1,6 +1,5 @@ \section{Evaluation} - The probability density of the state evaluation in \eqref{equ:bayesInt} is given by % \begin{equation} diff --git a/tex/chapters/experiments.tex b/tex/chapters/experiments.tex index 32e856b..e871503 100644 --- a/tex/chapters/experiments.tex +++ b/tex/chapters/experiments.tex @@ -1,6 +1,96 @@ \section{Experiments} -3 1/2 seiten sollten das schon werden. also eine ausführliche evaluation. +As explained at the very beginning of this work, we wanted to explore the limits of the here presented localization system. +By utilizing it to a 13th century historic building, we created a challenging scenario not only because of the various architectural factors, but also because of its function as a museum. +During all experiments, the museum was open to the public and had a varying number of \SI{10}{} to \SI{50}{} visitors while recording. + +The \SI{2500}{\square\meter} building consists of \SI{6}{} different levels, which are grouped into 4 floors (see fig. \ref{fig:apfingerprint}). +Thus, the ceiling height is not constant over one floor and varies between \SI{2.6}{\meter} to \SI{3.6}{\meter}. +In the middle of the building is an outdoor area, which is only accessible from one side. +While most of the exterior and ground level walls are made of massive stones, the floors above are half-timbered constructions. +Due to different objects like exhibits, cabinets or signs not all positions within the building were walkable. +For the sake of simplicity we did not incorporate such knowledge into the floorplan. +Thus, the floorplan consists only of walls, ceilings, doors, windows and stairs. +It was created using our 3D map editor software based on architectural drawings from the 1980s. + +The computation of the state estimation as well as the \docWifi{} optimization are done offline using an Intel Core i7-4702HQ CPU with a frequency of \SI{2.2}{GHz} running \SI{8}{cores} and \SI{16}{GB} main memory. +However, similar to our previous, award-winning system, the setup is able to run completely on commercial smartphones as well as it uses C++ code \cite{torres2017smartphone}. +%Sensor measurements are recorded using a simple mobile application that implements the standard Android SensorManager. + +The experiments are separated into three sections: +At first, we discuss the performance of the novel transition model and compare it to a grid-based approach. +In section \ref{sec:exp:opti} we have a look at \docWIFI{} optimization and how the real \docAPshort{} positions differ from it. +Following, we conducted several test walks throughout the building to examine the estimation accuracy (in \SI{}{\meter}) of the localisation system. +We try to resolve sample impoverishment with the here presented method and compare the different estimation methods as presented in section \ref{sec:estimation}. + + +\subsection{Transition} +To make a statement about the performance of our novel transition model presented within section \ref {}, we + +\todo{Unser liebes Treppensteigen. Vergleich altes und neues Bewegungsmodell.} + +\subsection{\docWIFI{} Optimization} +\label{sec:exp:opti} + +%wie viele ap sind es insgesamt? +The \docAPshort{} positions as well as the fingerprints used for optimization can be seen in fig. \ref{fig:apfingerprint}. +As described in section \ref{sec:wifi} we used \SI{42}{} WEMOS D1 mini to provide a \docWIFI{} infrastructure throughout the building. +The position of every installed beacon was measured using a laser scanner. +This allows a comparison with the optimized \docAPshort{} positions. +Within all Wi-Fi observations, we only consider the beacons, which are identified by their well-known MAC address. +Other transmitters like smart TVs or smartphone hotspots are ignored as they might cause estimation errors. +%wie fingerprints aufgenommen, wie viele ... + +\begin{figure}[bt] + \centering + \includegraphics[width=0.9\textwidth]{gfx/floorplanDummy.png} + \caption{Floorplan Dummy} + \label{fig:apfingerprint} +\end{figure} + + +%kurze beschreibung was wir jetzt alles testen wollen. + + +%was kommt bei der optimierung raus. vergleichen mit ground truth. auch den fehler gegenüberstellen. +%man sollte sehen das ohne optimierung gar nichts geht. + +\subsection{Location Estimation Error} + + +\begin{figure}[ht] + \centering + \includegraphics[width=0.9\textwidth]{gfx/floorplanDummy.png} + \caption{Floorplan Dummy} + \label{fig:floorplan} +\end{figure} +% +The 4 arranged walks can be seen in fig. \ref{fig:floorplan}. +They were carried out be 4 different male testers using either a Samsung Note 2, Google Pixel One or Motorola Nexus 6 for recording the measurements. +All in all, we recorded \SI{28}{} distinct measurement series, \SI{7}{} for each walk. +A walk is indicated by a set of numbered markers, fixed to the ground. +Small icons on those markers give the direction of the next marker and in some cases provide instructions to pause walking for a certain time. +The intervals for pausing vary between \SI{10}{\second} to \SI{60}{\second}. +The ground truth is then measured by recording a timestamp while passing a marker. +For this, the tester clicks a button on the smartphone application. +Between two consecutive points, a constant movement speed is assumed. +Thus, the ground truth might not be \SI{100}{\percent} accurate, but fair enough for error measurements. +The approximation error is then calculated by comparing the interpolated ground truth position with the current estimation \cite{Fetzer-16}. + +%computation und monte carlo runs +For each walk we deployed 50 runs using a varying size of particles. +Instead of an initial position and heading, all walks start with a uniform distribution (random position and heading) as prior. + + +%probleme mit impoverishment aufzeigen, wo bringt es was, was macht es kaputt etc pp + +%%estimation + +%wie in bulli paper. + +%letzer absatz nochmal gesamtergebniss des gesamten systems +%was läuft noch schief? wo macht was probleme? + \begin{itemize} \item Noch ein paar Dinge über das gebäude und das setup an sich diff --git a/tex/egbib.bib b/tex/egbib.bib index f2a54b7..796fabf 100644 --- a/tex/egbib.bib +++ b/tex/egbib.bib @@ -2951,4 +2951,15 @@ note = {\url{https://www.wemos.cc/}, Accessed: 2018-03-22}, address = {{Rothenburg, Germany}}, } +@article{torres2017smartphone, + title={The Smartphone-Based Offline Indoor Location Competition at IPIN 2016: Analysis and Future Work}, + author={Torres-Sospedra, Joaqu{\'\i}n and Jim{\'e}nez, Antonio R and Knauth, Stefan and Moreira, Adriano and Beer, Yair and Fetzer, Toni and Ta, Viet-Cuong and Montoliu, Raul and Seco, Fernando and Mendoza-Silva, Germ{\'a}n M and others}, + journal={Sensors}, + volume={17}, + number={3}, + pages={557}, + year={2017}, + publisher={Multidisciplinary Digital Publishing Institute} +} +