Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor

All non-foot-mounted inertial localization systems have a common challenge: the need for calibrating the parameters of the step length model. The calibration of the parameters of a step length model is key for an accurate estimation of the pedestrian’s step length, and therefore, for the accuracy of...

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Main Authors: Dina Bousdar Ahmed, Estefania Munoz Diaz, Juan Jesús García Domínguez
Format: Article
Language:English
Published: MDPI AG 2020-04-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/20/7/2083
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author Dina Bousdar Ahmed
Estefania Munoz Diaz
Juan Jesús García Domínguez
author_facet Dina Bousdar Ahmed
Estefania Munoz Diaz
Juan Jesús García Domínguez
author_sort Dina Bousdar Ahmed
collection DOAJ
description All non-foot-mounted inertial localization systems have a common challenge: the need for calibrating the parameters of the step length model. The calibration of the parameters of a step length model is key for an accurate estimation of the pedestrian’s step length, and therefore, for the accuracy of the position estimation. In a previous work, we provided a proof of concept on how to calibrate step length models with a foot inertial navigation system (INS), i.e., an INS based on an inertial measurement unit (IMU) mounted on the upper front part of the foot. The reason is that the foot INS does not require calibration thanks to the implementation of the strapdown algorithm. The goal of this article is to automatically calibrate the parameters of a step length model of the pocket INS by means of the foot INS. The step length model of the pocket INS has two parameters: the slope and offset of a first-order linear regression that relates the amplitude of the thigh pitch with the user’s step length. Firstly, we show that it is necessary to estimate the two parameters of the step length model. Secondly, we propose a method to automatically estimate these parameters by means of a foot INS. Finally, we propose a practical implementation of the proposed method in the pocket INS. We evaluate the pocket INS with the proposed calibration method and we compare the results to the state of the art implementations of the pocket INS. The results show that the proposed automatic calibration method outperforms the previous work, which proves the need for calibrating all the parameters of the step length model of the pocket INS. In this work, we conclude that it is possible to use a foot INS to automatically calibrate all parameters of the step length model of the pocket INS. Since the calibration of the step length model is always needed, our proposed automatic calibration method is a key enabler for using the pocket INS.
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spelling doaj.art-06c12ddb1c3b43c583db268490f4c7932023-11-19T20:57:33ZengMDPI AGSensors1424-82202020-04-01207208310.3390/s20072083Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial SensorDina Bousdar Ahmed0Estefania Munoz Diaz1Juan Jesús García Domínguez2German Aerospace Center (DLR), Institute of Communications and Navigation, 82234 Oberpfaffenhofen, GermanyGerman Aerospace Center (DLR), Institute of Communications and Navigation, 82234 Oberpfaffenhofen, GermanyElectronics Department of the University of Alcalá, 28805 Alcalá de Henares, SpainAll non-foot-mounted inertial localization systems have a common challenge: the need for calibrating the parameters of the step length model. The calibration of the parameters of a step length model is key for an accurate estimation of the pedestrian’s step length, and therefore, for the accuracy of the position estimation. In a previous work, we provided a proof of concept on how to calibrate step length models with a foot inertial navigation system (INS), i.e., an INS based on an inertial measurement unit (IMU) mounted on the upper front part of the foot. The reason is that the foot INS does not require calibration thanks to the implementation of the strapdown algorithm. The goal of this article is to automatically calibrate the parameters of a step length model of the pocket INS by means of the foot INS. The step length model of the pocket INS has two parameters: the slope and offset of a first-order linear regression that relates the amplitude of the thigh pitch with the user’s step length. Firstly, we show that it is necessary to estimate the two parameters of the step length model. Secondly, we propose a method to automatically estimate these parameters by means of a foot INS. Finally, we propose a practical implementation of the proposed method in the pocket INS. We evaluate the pocket INS with the proposed calibration method and we compare the results to the state of the art implementations of the pocket INS. The results show that the proposed automatic calibration method outperforms the previous work, which proves the need for calibrating all the parameters of the step length model of the pocket INS. In this work, we conclude that it is possible to use a foot INS to automatically calibrate all parameters of the step length model of the pocket INS. Since the calibration of the step length model is always needed, our proposed automatic calibration method is a key enabler for using the pocket INS.https://www.mdpi.com/1424-8220/20/7/2083pedestrian localizationwearablesinertial navigationIMUstep and headingstrapdown
spellingShingle Dina Bousdar Ahmed
Estefania Munoz Diaz
Juan Jesús García Domínguez
Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor
Sensors
pedestrian localization
wearables
inertial navigation
IMU
step and heading
strapdown
title Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor
title_full Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor
title_fullStr Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor
title_full_unstemmed Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor
title_short Automatic Calibration of the Step Length Model of a Pocket INS by Means of a Foot Inertial Sensor
title_sort automatic calibration of the step length model of a pocket ins by means of a foot inertial sensor
topic pedestrian localization
wearables
inertial navigation
IMU
step and heading
strapdown
url https://www.mdpi.com/1424-8220/20/7/2083
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AT juanjesusgarciadominguez automaticcalibrationofthesteplengthmodelofapocketinsbymeansofafootinertialsensor