Conference on Electronics, Telecommunications and Computers - CETC 2013 Traveled Distance Estimation Algorithm for Indoor Localization

AbstractThis paper presents an ankle mounted Inertial Navigation System (INS) used to estimate the distance traveled by a pedestrian. Thisdistance is estimated by the number of steps given by the user. The proposed method is based on force sensors to enhance theresults obtained from an INS. Experimental results have shown that, depending on the step frequency, the traveled distance errorvaries between 2.7% and 5.6%.c 2014 The Authors. Published by Elsevier Ltd.Selection and peer-review under responsibility of ISEL – Instituto Superior de Engenharia de Lisboa. Keywords: Inertial Navigation System; Pedestrian Dead Reckoning; Step Frequency; Step Length Estimation. 1. IntroductionThe ability to locate an individual is an increasing need for various purposes, for instance, healthcare, tourism,safety, etc.. Current existing outdoor localization systems are relatively accurate, easy to access and are available onany recent mobile device. However, in dense environments (forests or urban canyons) and indoor environments theselocalization systems don’t work properly.Several navigation systems, for indoor environments, have been developed using very difftechnologies sucherentas, radio frequency identification [1], infrared [2], ultrasound [3], bluetooth beacons [4], bar code [5], among others[6]. The main problem of these systems is that they need a structured environment to determine user location. Thismakesthesystemscontext-dependent, impracticalandexpensivetoimplement. Thus,ifitisdesiredtoobtainlocationindoors without the need of a structured environment another solution must be found.TheInertialNavigation(IN)isalocalizationtechniqueinwhichthevaluesobtainedbyinertialsensors(accelerom-eters and gyroscopes) are used to estimate the location and orientation without requiring external references. The useof an Inertial Navigation System (INS) for estimating the successive displacements, in conjunction with the techniqueDead Reckoning (DR), allows estimation of the current location based on an initial one. The main purpose of thisworkistodescribeourproposalforasystemthatestimatesthetraveleddistanceinindoorenvironmentswithoutusingany structured environment.