Using inertial measurement units to identify medio-lateral ground reaction forces due to walking and swaying

James Brownjohn, J Chen, Mateusz Bocian, Vitomir Racic, Erfan Shahabpoor Ardakani

Research output: Contribution to journalArticle

1 Citation (Scopus)
42 Downloads (Pure)

Abstract

Horizontal ground reaction forces (GRFs) due to human walking and swaying have been investigated (respectively) through direct measurements using a treadmill and a set of force plates. These GRFs have also been measured (or estimated) indirectly using acceleration data provided by inertial measurement units (IMUs). One motivation for this research has been the lack of published data on these two forms of loading that are generated by movements of the human body in the medio-lateral plane perpendicular to the direction of walking or the direction faced during swaying. The other motivation, following from successful developments in applying IMUs to in-situ vertical GRF measurements, has been to identify best practice for estimating medio-lateral GRFs outside the constraints of a laboratory. Examination of 852 treadmill measurements shows that medio-lateral GRFs at the first sub-harmonic of pacing rate can exceed 10% of body weight. Using a smaller and more recent set of measurements including motion capture, it has been shown that IMUs can be used to reconstruct these GRFs using a linear combination of body accelerations at each of the lower back and sternum positions. There are a number of potential applications for this capability yet to be explored, in particular relating to footbridge performance. A separate set of measurements using force plates has shown that harmonic components of medio-lateral dynamic load factors due to on the spot swaying can approach 50% of body weight. Such forces provide a capability to excite horizontal vibration modes of large civil structures with frequencies below 2 Hz that are problematic for mechanical excitation. As with walking, the ability to use IMUs to estimate medio-lateral swaying GRFs outside laboratory constraints has been demonstrated. As for walking a pair of IMUs is needed, but the best linear combination varies strongly between individuals, according to swaying style. In-situ application of indirect measurement has been successfully demonstrated through a very challenging application of system identification of a multi-storey building, including estimation of modal mass.

Original languageEnglish
Pages (from-to)90-110
Number of pages21
JournalJournal of Sound and Vibration
Volume426
Early online date24 Apr 2018
DOIs
Publication statusPublished - 21 Jul 2018

Keywords

  • Force plate
  • Ground reaction force
  • Inertial measurement unit
  • Swaying
  • System identification
  • Treadmill
  • Vibration testing
  • Walking

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Acoustics and Ultrasonics
  • Mechanical Engineering

Cite this

Using inertial measurement units to identify medio-lateral ground reaction forces due to walking and swaying. / Brownjohn, James; Chen, J; Bocian, Mateusz; Racic, Vitomir; Shahabpoor Ardakani, Erfan.

In: Journal of Sound and Vibration, Vol. 426, 21.07.2018, p. 90-110.

Research output: Contribution to journalArticle

@article{8855dc42e77c4950b9ad24ab4a041036,
title = "Using inertial measurement units to identify medio-lateral ground reaction forces due to walking and swaying",
abstract = "Horizontal ground reaction forces (GRFs) due to human walking and swaying have been investigated (respectively) through direct measurements using a treadmill and a set of force plates. These GRFs have also been measured (or estimated) indirectly using acceleration data provided by inertial measurement units (IMUs). One motivation for this research has been the lack of published data on these two forms of loading that are generated by movements of the human body in the medio-lateral plane perpendicular to the direction of walking or the direction faced during swaying. The other motivation, following from successful developments in applying IMUs to in-situ vertical GRF measurements, has been to identify best practice for estimating medio-lateral GRFs outside the constraints of a laboratory. Examination of 852 treadmill measurements shows that medio-lateral GRFs at the first sub-harmonic of pacing rate can exceed 10{\%} of body weight. Using a smaller and more recent set of measurements including motion capture, it has been shown that IMUs can be used to reconstruct these GRFs using a linear combination of body accelerations at each of the lower back and sternum positions. There are a number of potential applications for this capability yet to be explored, in particular relating to footbridge performance. A separate set of measurements using force plates has shown that harmonic components of medio-lateral dynamic load factors due to on the spot swaying can approach 50{\%} of body weight. Such forces provide a capability to excite horizontal vibration modes of large civil structures with frequencies below 2 Hz that are problematic for mechanical excitation. As with walking, the ability to use IMUs to estimate medio-lateral swaying GRFs outside laboratory constraints has been demonstrated. As for walking a pair of IMUs is needed, but the best linear combination varies strongly between individuals, according to swaying style. In-situ application of indirect measurement has been successfully demonstrated through a very challenging application of system identification of a multi-storey building, including estimation of modal mass.",
keywords = "Force plate, Ground reaction force, Inertial measurement unit, Swaying, System identification, Treadmill, Vibration testing, Walking",
author = "James Brownjohn and J Chen and Mateusz Bocian and Vitomir Racic and {Shahabpoor Ardakani}, Erfan",
year = "2018",
month = "7",
day = "21",
doi = "10.1016/j.jsv.2018.04.019",
language = "English",
volume = "426",
pages = "90--110",
journal = "Journal of Sound and Vibration",
issn = "0022-460X",
publisher = "Elsevier Academic Press Inc",

}

TY - JOUR

T1 - Using inertial measurement units to identify medio-lateral ground reaction forces due to walking and swaying

AU - Brownjohn, James

AU - Chen, J

AU - Bocian, Mateusz

AU - Racic, Vitomir

AU - Shahabpoor Ardakani, Erfan

PY - 2018/7/21

Y1 - 2018/7/21

N2 - Horizontal ground reaction forces (GRFs) due to human walking and swaying have been investigated (respectively) through direct measurements using a treadmill and a set of force plates. These GRFs have also been measured (or estimated) indirectly using acceleration data provided by inertial measurement units (IMUs). One motivation for this research has been the lack of published data on these two forms of loading that are generated by movements of the human body in the medio-lateral plane perpendicular to the direction of walking or the direction faced during swaying. The other motivation, following from successful developments in applying IMUs to in-situ vertical GRF measurements, has been to identify best practice for estimating medio-lateral GRFs outside the constraints of a laboratory. Examination of 852 treadmill measurements shows that medio-lateral GRFs at the first sub-harmonic of pacing rate can exceed 10% of body weight. Using a smaller and more recent set of measurements including motion capture, it has been shown that IMUs can be used to reconstruct these GRFs using a linear combination of body accelerations at each of the lower back and sternum positions. There are a number of potential applications for this capability yet to be explored, in particular relating to footbridge performance. A separate set of measurements using force plates has shown that harmonic components of medio-lateral dynamic load factors due to on the spot swaying can approach 50% of body weight. Such forces provide a capability to excite horizontal vibration modes of large civil structures with frequencies below 2 Hz that are problematic for mechanical excitation. As with walking, the ability to use IMUs to estimate medio-lateral swaying GRFs outside laboratory constraints has been demonstrated. As for walking a pair of IMUs is needed, but the best linear combination varies strongly between individuals, according to swaying style. In-situ application of indirect measurement has been successfully demonstrated through a very challenging application of system identification of a multi-storey building, including estimation of modal mass.

AB - Horizontal ground reaction forces (GRFs) due to human walking and swaying have been investigated (respectively) through direct measurements using a treadmill and a set of force plates. These GRFs have also been measured (or estimated) indirectly using acceleration data provided by inertial measurement units (IMUs). One motivation for this research has been the lack of published data on these two forms of loading that are generated by movements of the human body in the medio-lateral plane perpendicular to the direction of walking or the direction faced during swaying. The other motivation, following from successful developments in applying IMUs to in-situ vertical GRF measurements, has been to identify best practice for estimating medio-lateral GRFs outside the constraints of a laboratory. Examination of 852 treadmill measurements shows that medio-lateral GRFs at the first sub-harmonic of pacing rate can exceed 10% of body weight. Using a smaller and more recent set of measurements including motion capture, it has been shown that IMUs can be used to reconstruct these GRFs using a linear combination of body accelerations at each of the lower back and sternum positions. There are a number of potential applications for this capability yet to be explored, in particular relating to footbridge performance. A separate set of measurements using force plates has shown that harmonic components of medio-lateral dynamic load factors due to on the spot swaying can approach 50% of body weight. Such forces provide a capability to excite horizontal vibration modes of large civil structures with frequencies below 2 Hz that are problematic for mechanical excitation. As with walking, the ability to use IMUs to estimate medio-lateral swaying GRFs outside laboratory constraints has been demonstrated. As for walking a pair of IMUs is needed, but the best linear combination varies strongly between individuals, according to swaying style. In-situ application of indirect measurement has been successfully demonstrated through a very challenging application of system identification of a multi-storey building, including estimation of modal mass.

KW - Force plate

KW - Ground reaction force

KW - Inertial measurement unit

KW - Swaying

KW - System identification

KW - Treadmill

KW - Vibration testing

KW - Walking

UR - http://www.scopus.com/inward/record.url?scp=85045546718&partnerID=8YFLogxK

U2 - 10.1016/j.jsv.2018.04.019

DO - 10.1016/j.jsv.2018.04.019

M3 - Article

VL - 426

SP - 90

EP - 110

JO - Journal of Sound and Vibration

JF - Journal of Sound and Vibration

SN - 0022-460X

ER -