An effortless procedure to align the local frame of an inertial measurement unit to the local frame of another motion capture system.

Details

Serval ID
serval:BIB_CE3FF7C2B660
Type
Article: article from journal or magazin.
Collection
Publications
Title
An effortless procedure to align the local frame of an inertial measurement unit to the local frame of another motion capture system.
Journal
Journal of biomechanics
Author(s)
Chardonnens J., Favre J., Aminian K.
ISSN
1873-2380 (Electronic)
ISSN-L
0021-9290
Publication state
Published
Issued date
31/08/2012
Peer-reviewed
Oui
Volume
45
Number
13
Pages
2297-2300
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
Inertial measurement units (IMUs) offer great opportunities to analyze segmental and joints kinematics. When combined with another motion capture system (MCS), for example, to validate new IMU-based applications or to develop mixed systems, it is necessary to align the local frame of the IMU sensors to the local frame of the MCS. Currently, all alignment methods use landmarks on the IMU's casing. Therefore, they can only be used with well-documented IMUs and they are prone to error when the IMU's casing is small. This study proposes an effortless procedure to align the local frame of any IMU to the local frame of any other MCS able to measure the orientation of its local frame. The general concept of this method is to derive the gyroscopic angles for both devices during an alignment movement, and then to use an optimization algorithm to calculate the alignment matrix between both local frames. The alignment movement consists of rotations around three more or less orthogonal axes and it can easily be performed by hands. To test the alignment procedure, an IMU and a magnetic marker were attached to a plate, and 20 alignment movements were recorded. The maximum errors of alignment (accuracy±precision) were 1.02°±0.32° and simulations showed that the method was robust against noise that typically affect IMUs. In conclusion, this study describes an efficient alignment procedure that is quick and easy to perform, and that does not require any alignment device or any knowledge about the IMU casing.

Keywords
Algorithms, Animals, Biomechanical Phenomena, Humans, Image Processing, Computer-Assisted/instrumentation, Image Processing, Computer-Assisted/methods, Joints, Models, Theoretical, Movement
Pubmed
Web of science
Create date
22/11/2017 18:48
Last modification date
20/08/2019 15:48
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