Low-Latency Tracking of Multiple Permanent Magnets
© 2001-2012 IEEE. Magnetic target tracking is a low-cost, portable, and passive method for tracking materials wherein magnets are physically attached or embedded without the need for line of sight. Traditional magnet tracking techniques use optimization algorithms to determine the positions and orie...
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Institute of Electrical and Electronics Engineers (IEEE)
2021
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Online Access: | https://hdl.handle.net/1721.1/136595 |
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author | Taylor, Cameron R Abramson, Haley G Herr, Hugh M |
author2 | Massachusetts Institute of Technology. Center for Extreme Bionics |
author_facet | Massachusetts Institute of Technology. Center for Extreme Bionics Taylor, Cameron R Abramson, Haley G Herr, Hugh M |
author_sort | Taylor, Cameron R |
collection | MIT |
description | © 2001-2012 IEEE. Magnetic target tracking is a low-cost, portable, and passive method for tracking materials wherein magnets are physically attached or embedded without the need for line of sight. Traditional magnet tracking techniques use optimization algorithms to determine the positions and orientations of permanent magnets from magnetic field measurements. However, such techniques are constrained by high latencies, primarily due to the numerical calculation of the gradient. In this study, we derive the analytic gradient for multiple-magnet tracking and show a dramatic reduction in tracking latency. We design a physical system comprising an array of magnetometers and one or more spherical magnets. To validate the performance of our tracking algorithm, we compare the magnet tracking estimates with state-of-the-art motion capture measurements for each of four distinct magnet sizes. We find comparable position and orientation errors to state-of-the-art magnet tracking, but demonstrate increased maximum bandwidths of 336%, 525%, 635%, and 773% for the simultaneous tracking of 1, 2, 3, and 4 magnets, respectively. We further show that it is possible to extend the analytic gradient to account for disturbance fields, and we demonstrate the simultaneous tracking of 1 to 4 magnets with disturbance compensation. These findings extend the use of magnetic target tracking to high-speed, real-time applications requiring the tracking of one or more targets without the constraint of a fixed magnetometer array. This advancement enables applications such as low-latency augmented and virtual reality interaction, volitional or reflexive control of prostheses and exoskeletons, and simplified multi-degree-of-freedom magnetic levitation. |
first_indexed | 2024-09-23T08:15:10Z |
format | Article |
id | mit-1721.1/136595 |
institution | Massachusetts Institute of Technology |
language | English |
last_indexed | 2024-09-23T08:15:10Z |
publishDate | 2021 |
publisher | Institute of Electrical and Electronics Engineers (IEEE) |
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spelling | mit-1721.1/1365952023-02-22T21:39:15Z Low-Latency Tracking of Multiple Permanent Magnets Taylor, Cameron R Abramson, Haley G Herr, Hugh M Massachusetts Institute of Technology. Center for Extreme Bionics Massachusetts Institute of Technology. Media Laboratory © 2001-2012 IEEE. Magnetic target tracking is a low-cost, portable, and passive method for tracking materials wherein magnets are physically attached or embedded without the need for line of sight. Traditional magnet tracking techniques use optimization algorithms to determine the positions and orientations of permanent magnets from magnetic field measurements. However, such techniques are constrained by high latencies, primarily due to the numerical calculation of the gradient. In this study, we derive the analytic gradient for multiple-magnet tracking and show a dramatic reduction in tracking latency. We design a physical system comprising an array of magnetometers and one or more spherical magnets. To validate the performance of our tracking algorithm, we compare the magnet tracking estimates with state-of-the-art motion capture measurements for each of four distinct magnet sizes. We find comparable position and orientation errors to state-of-the-art magnet tracking, but demonstrate increased maximum bandwidths of 336%, 525%, 635%, and 773% for the simultaneous tracking of 1, 2, 3, and 4 magnets, respectively. We further show that it is possible to extend the analytic gradient to account for disturbance fields, and we demonstrate the simultaneous tracking of 1 to 4 magnets with disturbance compensation. These findings extend the use of magnetic target tracking to high-speed, real-time applications requiring the tracking of one or more targets without the constraint of a fixed magnetometer array. This advancement enables applications such as low-latency augmented and virtual reality interaction, volitional or reflexive control of prostheses and exoskeletons, and simplified multi-degree-of-freedom magnetic levitation. 2021-10-27T20:36:09Z 2021-10-27T20:36:09Z 2019 2021-06-24T17:15:25Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/136595 en 10.1109/JSEN.2019.2936766 IEEE Sensors Journal Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Institute of Electrical and Electronics Engineers (IEEE) MIT web domain |
spellingShingle | Taylor, Cameron R Abramson, Haley G Herr, Hugh M Low-Latency Tracking of Multiple Permanent Magnets |
title | Low-Latency Tracking of Multiple Permanent Magnets |
title_full | Low-Latency Tracking of Multiple Permanent Magnets |
title_fullStr | Low-Latency Tracking of Multiple Permanent Magnets |
title_full_unstemmed | Low-Latency Tracking of Multiple Permanent Magnets |
title_short | Low-Latency Tracking of Multiple Permanent Magnets |
title_sort | low latency tracking of multiple permanent magnets |
url | https://hdl.handle.net/1721.1/136595 |
work_keys_str_mv | AT taylorcameronr lowlatencytrackingofmultiplepermanentmagnets AT abramsonhaleyg lowlatencytrackingofmultiplepermanentmagnets AT herrhughm lowlatencytrackingofmultiplepermanentmagnets |