diff --git a/tex/bare_conf.pdf b/tex/bare_conf.pdf index 367dbb8..e12b8f2 100644 Binary files a/tex/bare_conf.pdf and b/tex/bare_conf.pdf differ diff --git a/tex/chapters/introduction.tex b/tex/chapters/introduction.tex index 6e862f8..32458b2 100644 --- a/tex/chapters/introduction.tex +++ b/tex/chapters/introduction.tex @@ -4,19 +4,29 @@ Setting up a localization solution for a building is a challenging and time-cons Such scenarios are of special interest when old or even historical buildings serve a new purpose such as museums, shopping malls or retirement homes. In terms of European architecture, the problems emanating from these buildings worsen with age. +Such buildings are often full of nooks and crannies, what makes it hard for dynamical models using any kind of pedestrian dead reckoning (PDR). Here, the error accumulates not only over time, but also with the number of turns and steps made \cite{}. +There is also a higher chance of detecting false or misplaced turns, what can cause the position estimation to lose track or get stuck within a demarcated area. +Thus, this paper presents a very robust but realistic movement model using a navigation mesh based on triangles. +\todo{into all three dimensions \\what allows for very small map sizes} -Such buildings are often full of nooks and crannies, ... infrastructure based walking, with high potentiol of sample impoverishment... -However outdated or inaccurate building plans... +In localization systems using a sample based representation, like particle filters, the above mentioned problems can further lead to more advanced problems like sample impoverishment \cite{}. +Sample impoverishment refers to a situation, in which the filter is unable to sample enough particles into proper regions of the building, caused by a high concentration of misplaced particles. +Within this work we present a simple yet efficient method that enables a particle filter to fully recover from sample impoverishment. +\todo{exact estimation fehlt hier noch} -have massive stonewalls, annexes from different historical periods with different construction materials... wifi optimization +Many historical buildings, especially bigger ones like castles, monasteries or churches, are built of massive stone walls and have annexes from different historical periods out of different construction materials. +This makes it hard for methods using received signal strengths (RSS) from Wi-Fi or Bluetooth, due to a high signal attenuation between different rooms. +Many unknown quantities like the walls definitive material or thickness, makes it expensive to determine important parameters as the signals depletion over distance. +Additionally, most wireless approaches adapt a line-of-sight assumption, the performance will be even more limited due to the irregularly shaped spatial structure of such buildings. +Our approach tries to avoid those problems. +We distributing a small number of simple and cheap Wi-Fi beacons over the whole building and instead of measuring their position inside the building, we use a optimization scheme based on some reference measurements. - have massive stonewalls, annexes from different historical periods with different construction materials and outdated or inaccurate building plans. - -\todo{hier vielleicht einfach auf die schlechten eigenschaften eingehen, wie sie die sensoren schädigen und was wir dagegen tun?} - -All this requires additional effort when setting up the system, what is then contrary to most costumers expectations of a fast to deploy and low-cost solution. +A optimization scheme also helps against inaccuracies like wrong positioned access points or fingerprints caused by outdated or inaccurate building plans. +It is obvious, that this could be solved by re-measuring the building, however this is a very time-consuming process requiring specialist hardware and in most cases a surveying engineer. +However, this is contrary to most costumers expectations of a fast to deploy and low-cost solution. In addition, this is not only a question of costs incurred, but also for buildings under monumental protection, what does not allow for larger construction measures. Thus a highly flexible, robust and scalable system is needed to deal with such conditions, especially with the claim of a universal solution in multiple different environments. +Smartphone-based solution was choosen... To tackle the challenges above, a novel indoor localization approach is presented within this paper and then deployed to a 13th century building. The first 300 years the building was constructed and used as a convent, after that it had different functions ranging from a granary to an office for Bavarian officials. @@ -36,15 +46,12 @@ Finally, the here presented work is an updated and highly refactored version of - -unser system bietet aber für alle anwendungen einen überschaubaren aufwand und soll generell unter unterschiedlichen bedingungen funktionieren. weshalb wir auch so ein worst case scenary wie ein museum ausgesucht haben. d.h. wir haben einen überschaubaren aufwand für alle gebäude. sind zwar nicht zero, aber auch nicht fingerprinting. - -besonders kleine karten (wenig speicherplatz) - - \cite{Ebner-17} +wifi line of sight modelle versagen bei dicken wänden +\todo{stark aufs wlan eingehen in den experimenten, das wir hier neue modelle brauchen, weil die line of sight annahme einfach zu schwach ist bei solchen wänden.} + max. 1 Seite